Index: third_party/sqlite/src/ext/session/sqlite3session.c |
diff --git a/third_party/sqlite/src/ext/session/sqlite3session.c b/third_party/sqlite/src/ext/session/sqlite3session.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..8dde8501a3967349821f159b1a283d431103f49d |
--- /dev/null |
+++ b/third_party/sqlite/src/ext/session/sqlite3session.c |
@@ -0,0 +1,4654 @@ |
+ |
+#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK) |
+#include "sqlite3session.h" |
+#include <assert.h> |
+#include <string.h> |
+ |
+#ifndef SQLITE_AMALGAMATION |
+# include "sqliteInt.h" |
+# include "vdbeInt.h" |
+#endif |
+ |
+typedef struct SessionTable SessionTable; |
+typedef struct SessionChange SessionChange; |
+typedef struct SessionBuffer SessionBuffer; |
+typedef struct SessionInput SessionInput; |
+ |
+/* |
+** Minimum chunk size used by streaming versions of functions. |
+*/ |
+#ifndef SESSIONS_STRM_CHUNK_SIZE |
+# ifdef SQLITE_TEST |
+# define SESSIONS_STRM_CHUNK_SIZE 64 |
+# else |
+# define SESSIONS_STRM_CHUNK_SIZE 1024 |
+# endif |
+#endif |
+ |
+typedef struct SessionHook SessionHook; |
+struct SessionHook { |
+ void *pCtx; |
+ int (*xOld)(void*,int,sqlite3_value**); |
+ int (*xNew)(void*,int,sqlite3_value**); |
+ int (*xCount)(void*); |
+ int (*xDepth)(void*); |
+}; |
+ |
+/* |
+** Session handle structure. |
+*/ |
+struct sqlite3_session { |
+ sqlite3 *db; /* Database handle session is attached to */ |
+ char *zDb; /* Name of database session is attached to */ |
+ int bEnable; /* True if currently recording */ |
+ int bIndirect; /* True if all changes are indirect */ |
+ int bAutoAttach; /* True to auto-attach tables */ |
+ int rc; /* Non-zero if an error has occurred */ |
+ void *pFilterCtx; /* First argument to pass to xTableFilter */ |
+ int (*xTableFilter)(void *pCtx, const char *zTab); |
+ sqlite3_session *pNext; /* Next session object on same db. */ |
+ SessionTable *pTable; /* List of attached tables */ |
+ SessionHook hook; /* APIs to grab new and old data with */ |
+}; |
+ |
+/* |
+** Instances of this structure are used to build strings or binary records. |
+*/ |
+struct SessionBuffer { |
+ u8 *aBuf; /* Pointer to changeset buffer */ |
+ int nBuf; /* Size of buffer aBuf */ |
+ int nAlloc; /* Size of allocation containing aBuf */ |
+}; |
+ |
+/* |
+** An object of this type is used internally as an abstraction for |
+** input data. Input data may be supplied either as a single large buffer |
+** (e.g. sqlite3changeset_start()) or using a stream function (e.g. |
+** sqlite3changeset_start_strm()). |
+*/ |
+struct SessionInput { |
+ int bNoDiscard; /* If true, discard no data */ |
+ int iCurrent; /* Offset in aData[] of current change */ |
+ int iNext; /* Offset in aData[] of next change */ |
+ u8 *aData; /* Pointer to buffer containing changeset */ |
+ int nData; /* Number of bytes in aData */ |
+ |
+ SessionBuffer buf; /* Current read buffer */ |
+ int (*xInput)(void*, void*, int*); /* Input stream call (or NULL) */ |
+ void *pIn; /* First argument to xInput */ |
+ int bEof; /* Set to true after xInput finished */ |
+}; |
+ |
+/* |
+** Structure for changeset iterators. |
+*/ |
+struct sqlite3_changeset_iter { |
+ SessionInput in; /* Input buffer or stream */ |
+ SessionBuffer tblhdr; /* Buffer to hold apValue/zTab/abPK/ */ |
+ int bPatchset; /* True if this is a patchset */ |
+ int rc; /* Iterator error code */ |
+ sqlite3_stmt *pConflict; /* Points to conflicting row, if any */ |
+ char *zTab; /* Current table */ |
+ int nCol; /* Number of columns in zTab */ |
+ int op; /* Current operation */ |
+ int bIndirect; /* True if current change was indirect */ |
+ u8 *abPK; /* Primary key array */ |
+ sqlite3_value **apValue; /* old.* and new.* values */ |
+}; |
+ |
+/* |
+** Each session object maintains a set of the following structures, one |
+** for each table the session object is monitoring. The structures are |
+** stored in a linked list starting at sqlite3_session.pTable. |
+** |
+** The keys of the SessionTable.aChange[] hash table are all rows that have |
+** been modified in any way since the session object was attached to the |
+** table. |
+** |
+** The data associated with each hash-table entry is a structure containing |
+** a subset of the initial values that the modified row contained at the |
+** start of the session. Or no initial values if the row was inserted. |
+*/ |
+struct SessionTable { |
+ SessionTable *pNext; |
+ char *zName; /* Local name of table */ |
+ int nCol; /* Number of columns in table zName */ |
+ const char **azCol; /* Column names */ |
+ u8 *abPK; /* Array of primary key flags */ |
+ int nEntry; /* Total number of entries in hash table */ |
+ int nChange; /* Size of apChange[] array */ |
+ SessionChange **apChange; /* Hash table buckets */ |
+}; |
+ |
+/* |
+** RECORD FORMAT: |
+** |
+** The following record format is similar to (but not compatible with) that |
+** used in SQLite database files. This format is used as part of the |
+** change-set binary format, and so must be architecture independent. |
+** |
+** Unlike the SQLite database record format, each field is self-contained - |
+** there is no separation of header and data. Each field begins with a |
+** single byte describing its type, as follows: |
+** |
+** 0x00: Undefined value. |
+** 0x01: Integer value. |
+** 0x02: Real value. |
+** 0x03: Text value. |
+** 0x04: Blob value. |
+** 0x05: SQL NULL value. |
+** |
+** Note that the above match the definitions of SQLITE_INTEGER, SQLITE_TEXT |
+** and so on in sqlite3.h. For undefined and NULL values, the field consists |
+** only of the single type byte. For other types of values, the type byte |
+** is followed by: |
+** |
+** Text values: |
+** A varint containing the number of bytes in the value (encoded using |
+** UTF-8). Followed by a buffer containing the UTF-8 representation |
+** of the text value. There is no nul terminator. |
+** |
+** Blob values: |
+** A varint containing the number of bytes in the value, followed by |
+** a buffer containing the value itself. |
+** |
+** Integer values: |
+** An 8-byte big-endian integer value. |
+** |
+** Real values: |
+** An 8-byte big-endian IEEE 754-2008 real value. |
+** |
+** Varint values are encoded in the same way as varints in the SQLite |
+** record format. |
+** |
+** CHANGESET FORMAT: |
+** |
+** A changeset is a collection of DELETE, UPDATE and INSERT operations on |
+** one or more tables. Operations on a single table are grouped together, |
+** but may occur in any order (i.e. deletes, updates and inserts are all |
+** mixed together). |
+** |
+** Each group of changes begins with a table header: |
+** |
+** 1 byte: Constant 0x54 (capital 'T') |
+** Varint: Number of columns in the table. |
+** nCol bytes: 0x01 for PK columns, 0x00 otherwise. |
+** N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated. |
+** |
+** Followed by one or more changes to the table. |
+** |
+** 1 byte: Either SQLITE_INSERT (0x12), UPDATE (0x17) or DELETE (0x09). |
+** 1 byte: The "indirect-change" flag. |
+** old.* record: (delete and update only) |
+** new.* record: (insert and update only) |
+** |
+** The "old.*" and "new.*" records, if present, are N field records in the |
+** format described above under "RECORD FORMAT", where N is the number of |
+** columns in the table. The i'th field of each record is associated with |
+** the i'th column of the table, counting from left to right in the order |
+** in which columns were declared in the CREATE TABLE statement. |
+** |
+** The new.* record that is part of each INSERT change contains the values |
+** that make up the new row. Similarly, the old.* record that is part of each |
+** DELETE change contains the values that made up the row that was deleted |
+** from the database. In the changeset format, the records that are part |
+** of INSERT or DELETE changes never contain any undefined (type byte 0x00) |
+** fields. |
+** |
+** Within the old.* record associated with an UPDATE change, all fields |
+** associated with table columns that are not PRIMARY KEY columns and are |
+** not modified by the UPDATE change are set to "undefined". Other fields |
+** are set to the values that made up the row before the UPDATE that the |
+** change records took place. Within the new.* record, fields associated |
+** with table columns modified by the UPDATE change contain the new |
+** values. Fields associated with table columns that are not modified |
+** are set to "undefined". |
+** |
+** PATCHSET FORMAT: |
+** |
+** A patchset is also a collection of changes. It is similar to a changeset, |
+** but leaves undefined those fields that are not useful if no conflict |
+** resolution is required when applying the changeset. |
+** |
+** Each group of changes begins with a table header: |
+** |
+** 1 byte: Constant 0x50 (capital 'P') |
+** Varint: Number of columns in the table. |
+** nCol bytes: 0x01 for PK columns, 0x00 otherwise. |
+** N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated. |
+** |
+** Followed by one or more changes to the table. |
+** |
+** 1 byte: Either SQLITE_INSERT (0x12), UPDATE (0x17) or DELETE (0x09). |
+** 1 byte: The "indirect-change" flag. |
+** single record: (PK fields for DELETE, PK and modified fields for UPDATE, |
+** full record for INSERT). |
+** |
+** As in the changeset format, each field of the single record that is part |
+** of a patchset change is associated with the correspondingly positioned |
+** table column, counting from left to right within the CREATE TABLE |
+** statement. |
+** |
+** For a DELETE change, all fields within the record except those associated |
+** with PRIMARY KEY columns are set to "undefined". The PRIMARY KEY fields |
+** contain the values identifying the row to delete. |
+** |
+** For an UPDATE change, all fields except those associated with PRIMARY KEY |
+** columns and columns that are modified by the UPDATE are set to "undefined". |
+** PRIMARY KEY fields contain the values identifying the table row to update, |
+** and fields associated with modified columns contain the new column values. |
+** |
+** The records associated with INSERT changes are in the same format as for |
+** changesets. It is not possible for a record associated with an INSERT |
+** change to contain a field set to "undefined". |
+*/ |
+ |
+/* |
+** For each row modified during a session, there exists a single instance of |
+** this structure stored in a SessionTable.aChange[] hash table. |
+*/ |
+struct SessionChange { |
+ int op; /* One of UPDATE, DELETE, INSERT */ |
+ int bIndirect; /* True if this change is "indirect" */ |
+ int nRecord; /* Number of bytes in buffer aRecord[] */ |
+ u8 *aRecord; /* Buffer containing old.* record */ |
+ SessionChange *pNext; /* For hash-table collisions */ |
+}; |
+ |
+/* |
+** Write a varint with value iVal into the buffer at aBuf. Return the |
+** number of bytes written. |
+*/ |
+static int sessionVarintPut(u8 *aBuf, int iVal){ |
+ return putVarint32(aBuf, iVal); |
+} |
+ |
+/* |
+** Return the number of bytes required to store value iVal as a varint. |
+*/ |
+static int sessionVarintLen(int iVal){ |
+ return sqlite3VarintLen(iVal); |
+} |
+ |
+/* |
+** Read a varint value from aBuf[] into *piVal. Return the number of |
+** bytes read. |
+*/ |
+static int sessionVarintGet(u8 *aBuf, int *piVal){ |
+ return getVarint32(aBuf, *piVal); |
+} |
+ |
+/* Load an unaligned and unsigned 32-bit integer */ |
+#define SESSION_UINT32(x) (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3]) |
+ |
+/* |
+** Read a 64-bit big-endian integer value from buffer aRec[]. Return |
+** the value read. |
+*/ |
+static sqlite3_int64 sessionGetI64(u8 *aRec){ |
+ u64 x = SESSION_UINT32(aRec); |
+ u32 y = SESSION_UINT32(aRec+4); |
+ x = (x<<32) + y; |
+ return (sqlite3_int64)x; |
+} |
+ |
+/* |
+** Write a 64-bit big-endian integer value to the buffer aBuf[]. |
+*/ |
+static void sessionPutI64(u8 *aBuf, sqlite3_int64 i){ |
+ aBuf[0] = (i>>56) & 0xFF; |
+ aBuf[1] = (i>>48) & 0xFF; |
+ aBuf[2] = (i>>40) & 0xFF; |
+ aBuf[3] = (i>>32) & 0xFF; |
+ aBuf[4] = (i>>24) & 0xFF; |
+ aBuf[5] = (i>>16) & 0xFF; |
+ aBuf[6] = (i>> 8) & 0xFF; |
+ aBuf[7] = (i>> 0) & 0xFF; |
+} |
+ |
+/* |
+** This function is used to serialize the contents of value pValue (see |
+** comment titled "RECORD FORMAT" above). |
+** |
+** If it is non-NULL, the serialized form of the value is written to |
+** buffer aBuf. *pnWrite is set to the number of bytes written before |
+** returning. Or, if aBuf is NULL, the only thing this function does is |
+** set *pnWrite. |
+** |
+** If no error occurs, SQLITE_OK is returned. Or, if an OOM error occurs |
+** within a call to sqlite3_value_text() (may fail if the db is utf-16)) |
+** SQLITE_NOMEM is returned. |
+*/ |
+static int sessionSerializeValue( |
+ u8 *aBuf, /* If non-NULL, write serialized value here */ |
+ sqlite3_value *pValue, /* Value to serialize */ |
+ int *pnWrite /* IN/OUT: Increment by bytes written */ |
+){ |
+ int nByte; /* Size of serialized value in bytes */ |
+ |
+ if( pValue ){ |
+ int eType; /* Value type (SQLITE_NULL, TEXT etc.) */ |
+ |
+ eType = sqlite3_value_type(pValue); |
+ if( aBuf ) aBuf[0] = eType; |
+ |
+ switch( eType ){ |
+ case SQLITE_NULL: |
+ nByte = 1; |
+ break; |
+ |
+ case SQLITE_INTEGER: |
+ case SQLITE_FLOAT: |
+ if( aBuf ){ |
+ /* TODO: SQLite does something special to deal with mixed-endian |
+ ** floating point values (e.g. ARM7). This code probably should |
+ ** too. */ |
+ u64 i; |
+ if( eType==SQLITE_INTEGER ){ |
+ i = (u64)sqlite3_value_int64(pValue); |
+ }else{ |
+ double r; |
+ assert( sizeof(double)==8 && sizeof(u64)==8 ); |
+ r = sqlite3_value_double(pValue); |
+ memcpy(&i, &r, 8); |
+ } |
+ sessionPutI64(&aBuf[1], i); |
+ } |
+ nByte = 9; |
+ break; |
+ |
+ default: { |
+ u8 *z; |
+ int n; |
+ int nVarint; |
+ |
+ assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); |
+ if( eType==SQLITE_TEXT ){ |
+ z = (u8 *)sqlite3_value_text(pValue); |
+ }else{ |
+ z = (u8 *)sqlite3_value_blob(pValue); |
+ } |
+ n = sqlite3_value_bytes(pValue); |
+ if( z==0 && (eType!=SQLITE_BLOB || n>0) ) return SQLITE_NOMEM; |
+ nVarint = sessionVarintLen(n); |
+ |
+ if( aBuf ){ |
+ sessionVarintPut(&aBuf[1], n); |
+ if( n ) memcpy(&aBuf[nVarint + 1], z, n); |
+ } |
+ |
+ nByte = 1 + nVarint + n; |
+ break; |
+ } |
+ } |
+ }else{ |
+ nByte = 1; |
+ if( aBuf ) aBuf[0] = '\0'; |
+ } |
+ |
+ if( pnWrite ) *pnWrite += nByte; |
+ return SQLITE_OK; |
+} |
+ |
+ |
+/* |
+** This macro is used to calculate hash key values for data structures. In |
+** order to use this macro, the entire data structure must be represented |
+** as a series of unsigned integers. In order to calculate a hash-key value |
+** for a data structure represented as three such integers, the macro may |
+** then be used as follows: |
+** |
+** int hash_key_value; |
+** hash_key_value = HASH_APPEND(0, <value 1>); |
+** hash_key_value = HASH_APPEND(hash_key_value, <value 2>); |
+** hash_key_value = HASH_APPEND(hash_key_value, <value 3>); |
+** |
+** In practice, the data structures this macro is used for are the primary |
+** key values of modified rows. |
+*/ |
+#define HASH_APPEND(hash, add) ((hash) << 3) ^ (hash) ^ (unsigned int)(add) |
+ |
+/* |
+** Append the hash of the 64-bit integer passed as the second argument to the |
+** hash-key value passed as the first. Return the new hash-key value. |
+*/ |
+static unsigned int sessionHashAppendI64(unsigned int h, i64 i){ |
+ h = HASH_APPEND(h, i & 0xFFFFFFFF); |
+ return HASH_APPEND(h, (i>>32)&0xFFFFFFFF); |
+} |
+ |
+/* |
+** Append the hash of the blob passed via the second and third arguments to |
+** the hash-key value passed as the first. Return the new hash-key value. |
+*/ |
+static unsigned int sessionHashAppendBlob(unsigned int h, int n, const u8 *z){ |
+ int i; |
+ for(i=0; i<n; i++) h = HASH_APPEND(h, z[i]); |
+ return h; |
+} |
+ |
+/* |
+** Append the hash of the data type passed as the second argument to the |
+** hash-key value passed as the first. Return the new hash-key value. |
+*/ |
+static unsigned int sessionHashAppendType(unsigned int h, int eType){ |
+ return HASH_APPEND(h, eType); |
+} |
+ |
+/* |
+** This function may only be called from within a pre-update callback. |
+** It calculates a hash based on the primary key values of the old.* or |
+** new.* row currently available and, assuming no error occurs, writes it to |
+** *piHash before returning. If the primary key contains one or more NULL |
+** values, *pbNullPK is set to true before returning. |
+** |
+** If an error occurs, an SQLite error code is returned and the final values |
+** of *piHash asn *pbNullPK are undefined. Otherwise, SQLITE_OK is returned |
+** and the output variables are set as described above. |
+*/ |
+static int sessionPreupdateHash( |
+ sqlite3_session *pSession, /* Session object that owns pTab */ |
+ SessionTable *pTab, /* Session table handle */ |
+ int bNew, /* True to hash the new.* PK */ |
+ int *piHash, /* OUT: Hash value */ |
+ int *pbNullPK /* OUT: True if there are NULL values in PK */ |
+){ |
+ unsigned int h = 0; /* Hash value to return */ |
+ int i; /* Used to iterate through columns */ |
+ |
+ assert( *pbNullPK==0 ); |
+ assert( pTab->nCol==pSession->hook.xCount(pSession->hook.pCtx) ); |
+ for(i=0; i<pTab->nCol; i++){ |
+ if( pTab->abPK[i] ){ |
+ int rc; |
+ int eType; |
+ sqlite3_value *pVal; |
+ |
+ if( bNew ){ |
+ rc = pSession->hook.xNew(pSession->hook.pCtx, i, &pVal); |
+ }else{ |
+ rc = pSession->hook.xOld(pSession->hook.pCtx, i, &pVal); |
+ } |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ eType = sqlite3_value_type(pVal); |
+ h = sessionHashAppendType(h, eType); |
+ if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ i64 iVal; |
+ if( eType==SQLITE_INTEGER ){ |
+ iVal = sqlite3_value_int64(pVal); |
+ }else{ |
+ double rVal = sqlite3_value_double(pVal); |
+ assert( sizeof(iVal)==8 && sizeof(rVal)==8 ); |
+ memcpy(&iVal, &rVal, 8); |
+ } |
+ h = sessionHashAppendI64(h, iVal); |
+ }else if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){ |
+ const u8 *z; |
+ int n; |
+ if( eType==SQLITE_TEXT ){ |
+ z = (const u8 *)sqlite3_value_text(pVal); |
+ }else{ |
+ z = (const u8 *)sqlite3_value_blob(pVal); |
+ } |
+ n = sqlite3_value_bytes(pVal); |
+ if( !z && (eType!=SQLITE_BLOB || n>0) ) return SQLITE_NOMEM; |
+ h = sessionHashAppendBlob(h, n, z); |
+ }else{ |
+ assert( eType==SQLITE_NULL ); |
+ *pbNullPK = 1; |
+ } |
+ } |
+ } |
+ |
+ *piHash = (h % pTab->nChange); |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** The buffer that the argument points to contains a serialized SQL value. |
+** Return the number of bytes of space occupied by the value (including |
+** the type byte). |
+*/ |
+static int sessionSerialLen(u8 *a){ |
+ int e = *a; |
+ int n; |
+ if( e==0 ) return 1; |
+ if( e==SQLITE_NULL ) return 1; |
+ if( e==SQLITE_INTEGER || e==SQLITE_FLOAT ) return 9; |
+ return sessionVarintGet(&a[1], &n) + 1 + n; |
+} |
+ |
+/* |
+** Based on the primary key values stored in change aRecord, calculate a |
+** hash key. Assume the has table has nBucket buckets. The hash keys |
+** calculated by this function are compatible with those calculated by |
+** sessionPreupdateHash(). |
+** |
+** The bPkOnly argument is non-zero if the record at aRecord[] is from |
+** a patchset DELETE. In this case the non-PK fields are omitted entirely. |
+*/ |
+static unsigned int sessionChangeHash( |
+ SessionTable *pTab, /* Table handle */ |
+ int bPkOnly, /* Record consists of PK fields only */ |
+ u8 *aRecord, /* Change record */ |
+ int nBucket /* Assume this many buckets in hash table */ |
+){ |
+ unsigned int h = 0; /* Value to return */ |
+ int i; /* Used to iterate through columns */ |
+ u8 *a = aRecord; /* Used to iterate through change record */ |
+ |
+ for(i=0; i<pTab->nCol; i++){ |
+ int eType = *a; |
+ int isPK = pTab->abPK[i]; |
+ if( bPkOnly && isPK==0 ) continue; |
+ |
+ /* It is not possible for eType to be SQLITE_NULL here. The session |
+ ** module does not record changes for rows with NULL values stored in |
+ ** primary key columns. */ |
+ assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT |
+ || eType==SQLITE_TEXT || eType==SQLITE_BLOB |
+ || eType==SQLITE_NULL || eType==0 |
+ ); |
+ assert( !isPK || (eType!=0 && eType!=SQLITE_NULL) ); |
+ |
+ if( isPK ){ |
+ a++; |
+ h = sessionHashAppendType(h, eType); |
+ if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ h = sessionHashAppendI64(h, sessionGetI64(a)); |
+ a += 8; |
+ }else{ |
+ int n; |
+ a += sessionVarintGet(a, &n); |
+ h = sessionHashAppendBlob(h, n, a); |
+ a += n; |
+ } |
+ }else{ |
+ a += sessionSerialLen(a); |
+ } |
+ } |
+ return (h % nBucket); |
+} |
+ |
+/* |
+** Arguments aLeft and aRight are pointers to change records for table pTab. |
+** This function returns true if the two records apply to the same row (i.e. |
+** have the same values stored in the primary key columns), or false |
+** otherwise. |
+*/ |
+static int sessionChangeEqual( |
+ SessionTable *pTab, /* Table used for PK definition */ |
+ int bLeftPkOnly, /* True if aLeft[] contains PK fields only */ |
+ u8 *aLeft, /* Change record */ |
+ int bRightPkOnly, /* True if aRight[] contains PK fields only */ |
+ u8 *aRight /* Change record */ |
+){ |
+ u8 *a1 = aLeft; /* Cursor to iterate through aLeft */ |
+ u8 *a2 = aRight; /* Cursor to iterate through aRight */ |
+ int iCol; /* Used to iterate through table columns */ |
+ |
+ for(iCol=0; iCol<pTab->nCol; iCol++){ |
+ if( pTab->abPK[iCol] ){ |
+ int n1 = sessionSerialLen(a1); |
+ int n2 = sessionSerialLen(a2); |
+ |
+ if( pTab->abPK[iCol] && (n1!=n2 || memcmp(a1, a2, n1)) ){ |
+ return 0; |
+ } |
+ a1 += n1; |
+ a2 += n2; |
+ }else{ |
+ if( bLeftPkOnly==0 ) a1 += sessionSerialLen(a1); |
+ if( bRightPkOnly==0 ) a2 += sessionSerialLen(a2); |
+ } |
+ } |
+ |
+ return 1; |
+} |
+ |
+/* |
+** Arguments aLeft and aRight both point to buffers containing change |
+** records with nCol columns. This function "merges" the two records into |
+** a single records which is written to the buffer at *paOut. *paOut is |
+** then set to point to one byte after the last byte written before |
+** returning. |
+** |
+** The merging of records is done as follows: For each column, if the |
+** aRight record contains a value for the column, copy the value from |
+** their. Otherwise, if aLeft contains a value, copy it. If neither |
+** record contains a value for a given column, then neither does the |
+** output record. |
+*/ |
+static void sessionMergeRecord( |
+ u8 **paOut, |
+ int nCol, |
+ u8 *aLeft, |
+ u8 *aRight |
+){ |
+ u8 *a1 = aLeft; /* Cursor used to iterate through aLeft */ |
+ u8 *a2 = aRight; /* Cursor used to iterate through aRight */ |
+ u8 *aOut = *paOut; /* Output cursor */ |
+ int iCol; /* Used to iterate from 0 to nCol */ |
+ |
+ for(iCol=0; iCol<nCol; iCol++){ |
+ int n1 = sessionSerialLen(a1); |
+ int n2 = sessionSerialLen(a2); |
+ if( *a2 ){ |
+ memcpy(aOut, a2, n2); |
+ aOut += n2; |
+ }else{ |
+ memcpy(aOut, a1, n1); |
+ aOut += n1; |
+ } |
+ a1 += n1; |
+ a2 += n2; |
+ } |
+ |
+ *paOut = aOut; |
+} |
+ |
+/* |
+** This is a helper function used by sessionMergeUpdate(). |
+** |
+** When this function is called, both *paOne and *paTwo point to a value |
+** within a change record. Before it returns, both have been advanced so |
+** as to point to the next value in the record. |
+** |
+** If, when this function is called, *paTwo points to a valid value (i.e. |
+** *paTwo[0] is not 0x00 - the "no value" placeholder), a copy of the *paTwo |
+** pointer is returned and *pnVal is set to the number of bytes in the |
+** serialized value. Otherwise, a copy of *paOne is returned and *pnVal |
+** set to the number of bytes in the value at *paOne. If *paOne points |
+** to the "no value" placeholder, *pnVal is set to 1. In other words: |
+** |
+** if( *paTwo is valid ) return *paTwo; |
+** return *paOne; |
+** |
+*/ |
+static u8 *sessionMergeValue( |
+ u8 **paOne, /* IN/OUT: Left-hand buffer pointer */ |
+ u8 **paTwo, /* IN/OUT: Right-hand buffer pointer */ |
+ int *pnVal /* OUT: Bytes in returned value */ |
+){ |
+ u8 *a1 = *paOne; |
+ u8 *a2 = *paTwo; |
+ u8 *pRet = 0; |
+ int n1; |
+ |
+ assert( a1 ); |
+ if( a2 ){ |
+ int n2 = sessionSerialLen(a2); |
+ if( *a2 ){ |
+ *pnVal = n2; |
+ pRet = a2; |
+ } |
+ *paTwo = &a2[n2]; |
+ } |
+ |
+ n1 = sessionSerialLen(a1); |
+ if( pRet==0 ){ |
+ *pnVal = n1; |
+ pRet = a1; |
+ } |
+ *paOne = &a1[n1]; |
+ |
+ return pRet; |
+} |
+ |
+/* |
+** This function is used by changeset_concat() to merge two UPDATE changes |
+** on the same row. |
+*/ |
+static int sessionMergeUpdate( |
+ u8 **paOut, /* IN/OUT: Pointer to output buffer */ |
+ SessionTable *pTab, /* Table change pertains to */ |
+ int bPatchset, /* True if records are patchset records */ |
+ u8 *aOldRecord1, /* old.* record for first change */ |
+ u8 *aOldRecord2, /* old.* record for second change */ |
+ u8 *aNewRecord1, /* new.* record for first change */ |
+ u8 *aNewRecord2 /* new.* record for second change */ |
+){ |
+ u8 *aOld1 = aOldRecord1; |
+ u8 *aOld2 = aOldRecord2; |
+ u8 *aNew1 = aNewRecord1; |
+ u8 *aNew2 = aNewRecord2; |
+ |
+ u8 *aOut = *paOut; |
+ int i; |
+ |
+ if( bPatchset==0 ){ |
+ int bRequired = 0; |
+ |
+ assert( aOldRecord1 && aNewRecord1 ); |
+ |
+ /* Write the old.* vector first. */ |
+ for(i=0; i<pTab->nCol; i++){ |
+ int nOld; |
+ u8 *aOld; |
+ int nNew; |
+ u8 *aNew; |
+ |
+ aOld = sessionMergeValue(&aOld1, &aOld2, &nOld); |
+ aNew = sessionMergeValue(&aNew1, &aNew2, &nNew); |
+ if( pTab->abPK[i] || nOld!=nNew || memcmp(aOld, aNew, nNew) ){ |
+ if( pTab->abPK[i]==0 ) bRequired = 1; |
+ memcpy(aOut, aOld, nOld); |
+ aOut += nOld; |
+ }else{ |
+ *(aOut++) = '\0'; |
+ } |
+ } |
+ |
+ if( !bRequired ) return 0; |
+ } |
+ |
+ /* Write the new.* vector */ |
+ aOld1 = aOldRecord1; |
+ aOld2 = aOldRecord2; |
+ aNew1 = aNewRecord1; |
+ aNew2 = aNewRecord2; |
+ for(i=0; i<pTab->nCol; i++){ |
+ int nOld; |
+ u8 *aOld; |
+ int nNew; |
+ u8 *aNew; |
+ |
+ aOld = sessionMergeValue(&aOld1, &aOld2, &nOld); |
+ aNew = sessionMergeValue(&aNew1, &aNew2, &nNew); |
+ if( bPatchset==0 |
+ && (pTab->abPK[i] || (nOld==nNew && 0==memcmp(aOld, aNew, nNew))) |
+ ){ |
+ *(aOut++) = '\0'; |
+ }else{ |
+ memcpy(aOut, aNew, nNew); |
+ aOut += nNew; |
+ } |
+ } |
+ |
+ *paOut = aOut; |
+ return 1; |
+} |
+ |
+/* |
+** This function is only called from within a pre-update-hook callback. |
+** It determines if the current pre-update-hook change affects the same row |
+** as the change stored in argument pChange. If so, it returns true. Otherwise |
+** if the pre-update-hook does not affect the same row as pChange, it returns |
+** false. |
+*/ |
+static int sessionPreupdateEqual( |
+ sqlite3_session *pSession, /* Session object that owns SessionTable */ |
+ SessionTable *pTab, /* Table associated with change */ |
+ SessionChange *pChange, /* Change to compare to */ |
+ int op /* Current pre-update operation */ |
+){ |
+ int iCol; /* Used to iterate through columns */ |
+ u8 *a = pChange->aRecord; /* Cursor used to scan change record */ |
+ |
+ assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE ); |
+ for(iCol=0; iCol<pTab->nCol; iCol++){ |
+ if( !pTab->abPK[iCol] ){ |
+ a += sessionSerialLen(a); |
+ }else{ |
+ sqlite3_value *pVal; /* Value returned by preupdate_new/old */ |
+ int rc; /* Error code from preupdate_new/old */ |
+ int eType = *a++; /* Type of value from change record */ |
+ |
+ /* The following calls to preupdate_new() and preupdate_old() can not |
+ ** fail. This is because they cache their return values, and by the |
+ ** time control flows to here they have already been called once from |
+ ** within sessionPreupdateHash(). The first two asserts below verify |
+ ** this (that the method has already been called). */ |
+ if( op==SQLITE_INSERT ){ |
+ /* assert( db->pPreUpdate->pNewUnpacked || db->pPreUpdate->aNew ); */ |
+ rc = pSession->hook.xNew(pSession->hook.pCtx, iCol, &pVal); |
+ }else{ |
+ /* assert( db->pPreUpdate->pUnpacked ); */ |
+ rc = pSession->hook.xOld(pSession->hook.pCtx, iCol, &pVal); |
+ } |
+ assert( rc==SQLITE_OK ); |
+ if( sqlite3_value_type(pVal)!=eType ) return 0; |
+ |
+ /* A SessionChange object never has a NULL value in a PK column */ |
+ assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT |
+ || eType==SQLITE_BLOB || eType==SQLITE_TEXT |
+ ); |
+ |
+ if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ i64 iVal = sessionGetI64(a); |
+ a += 8; |
+ if( eType==SQLITE_INTEGER ){ |
+ if( sqlite3_value_int64(pVal)!=iVal ) return 0; |
+ }else{ |
+ double rVal; |
+ assert( sizeof(iVal)==8 && sizeof(rVal)==8 ); |
+ memcpy(&rVal, &iVal, 8); |
+ if( sqlite3_value_double(pVal)!=rVal ) return 0; |
+ } |
+ }else{ |
+ int n; |
+ const u8 *z; |
+ a += sessionVarintGet(a, &n); |
+ if( sqlite3_value_bytes(pVal)!=n ) return 0; |
+ if( eType==SQLITE_TEXT ){ |
+ z = sqlite3_value_text(pVal); |
+ }else{ |
+ z = sqlite3_value_blob(pVal); |
+ } |
+ if( memcmp(a, z, n) ) return 0; |
+ a += n; |
+ break; |
+ } |
+ } |
+ } |
+ |
+ return 1; |
+} |
+ |
+/* |
+** If required, grow the hash table used to store changes on table pTab |
+** (part of the session pSession). If a fatal OOM error occurs, set the |
+** session object to failed and return SQLITE_ERROR. Otherwise, return |
+** SQLITE_OK. |
+** |
+** It is possible that a non-fatal OOM error occurs in this function. In |
+** that case the hash-table does not grow, but SQLITE_OK is returned anyway. |
+** Growing the hash table in this case is a performance optimization only, |
+** it is not required for correct operation. |
+*/ |
+static int sessionGrowHash(int bPatchset, SessionTable *pTab){ |
+ if( pTab->nChange==0 || pTab->nEntry>=(pTab->nChange/2) ){ |
+ int i; |
+ SessionChange **apNew; |
+ int nNew = (pTab->nChange ? pTab->nChange : 128) * 2; |
+ |
+ apNew = (SessionChange **)sqlite3_malloc(sizeof(SessionChange *) * nNew); |
+ if( apNew==0 ){ |
+ if( pTab->nChange==0 ){ |
+ return SQLITE_ERROR; |
+ } |
+ return SQLITE_OK; |
+ } |
+ memset(apNew, 0, sizeof(SessionChange *) * nNew); |
+ |
+ for(i=0; i<pTab->nChange; i++){ |
+ SessionChange *p; |
+ SessionChange *pNext; |
+ for(p=pTab->apChange[i]; p; p=pNext){ |
+ int bPkOnly = (p->op==SQLITE_DELETE && bPatchset); |
+ int iHash = sessionChangeHash(pTab, bPkOnly, p->aRecord, nNew); |
+ pNext = p->pNext; |
+ p->pNext = apNew[iHash]; |
+ apNew[iHash] = p; |
+ } |
+ } |
+ |
+ sqlite3_free(pTab->apChange); |
+ pTab->nChange = nNew; |
+ pTab->apChange = apNew; |
+ } |
+ |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** This function queries the database for the names of the columns of table |
+** zThis, in schema zDb. It is expected that the table has nCol columns. If |
+** not, SQLITE_SCHEMA is returned and none of the output variables are |
+** populated. |
+** |
+** Otherwise, if they are not NULL, variable *pnCol is set to the number |
+** of columns in the database table and variable *pzTab is set to point to a |
+** nul-terminated copy of the table name. *pazCol (if not NULL) is set to |
+** point to an array of pointers to column names. And *pabPK (again, if not |
+** NULL) is set to point to an array of booleans - true if the corresponding |
+** column is part of the primary key. |
+** |
+** For example, if the table is declared as: |
+** |
+** CREATE TABLE tbl1(w, x, y, z, PRIMARY KEY(w, z)); |
+** |
+** Then the four output variables are populated as follows: |
+** |
+** *pnCol = 4 |
+** *pzTab = "tbl1" |
+** *pazCol = {"w", "x", "y", "z"} |
+** *pabPK = {1, 0, 0, 1} |
+** |
+** All returned buffers are part of the same single allocation, which must |
+** be freed using sqlite3_free() by the caller. If pazCol was not NULL, then |
+** pointer *pazCol should be freed to release all memory. Otherwise, pointer |
+** *pabPK. It is illegal for both pazCol and pabPK to be NULL. |
+*/ |
+static int sessionTableInfo( |
+ sqlite3 *db, /* Database connection */ |
+ const char *zDb, /* Name of attached database (e.g. "main") */ |
+ const char *zThis, /* Table name */ |
+ int *pnCol, /* OUT: number of columns */ |
+ const char **pzTab, /* OUT: Copy of zThis */ |
+ const char ***pazCol, /* OUT: Array of column names for table */ |
+ u8 **pabPK /* OUT: Array of booleans - true for PK col */ |
+){ |
+ char *zPragma; |
+ sqlite3_stmt *pStmt; |
+ int rc; |
+ int nByte; |
+ int nDbCol = 0; |
+ int nThis; |
+ int i; |
+ u8 *pAlloc = 0; |
+ char **azCol = 0; |
+ u8 *abPK = 0; |
+ |
+ assert( pazCol && pabPK ); |
+ |
+ nThis = sqlite3Strlen30(zThis); |
+ zPragma = sqlite3_mprintf("PRAGMA '%q'.table_info('%q')", zDb, zThis); |
+ if( !zPragma ) return SQLITE_NOMEM; |
+ |
+ rc = sqlite3_prepare_v2(db, zPragma, -1, &pStmt, 0); |
+ sqlite3_free(zPragma); |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ nByte = nThis + 1; |
+ while( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ nByte += sqlite3_column_bytes(pStmt, 1); |
+ nDbCol++; |
+ } |
+ rc = sqlite3_reset(pStmt); |
+ |
+ if( rc==SQLITE_OK ){ |
+ nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1); |
+ pAlloc = sqlite3_malloc(nByte); |
+ if( pAlloc==0 ){ |
+ rc = SQLITE_NOMEM; |
+ } |
+ } |
+ if( rc==SQLITE_OK ){ |
+ azCol = (char **)pAlloc; |
+ pAlloc = (u8 *)&azCol[nDbCol]; |
+ abPK = (u8 *)pAlloc; |
+ pAlloc = &abPK[nDbCol]; |
+ if( pzTab ){ |
+ memcpy(pAlloc, zThis, nThis+1); |
+ *pzTab = (char *)pAlloc; |
+ pAlloc += nThis+1; |
+ } |
+ |
+ i = 0; |
+ while( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ int nName = sqlite3_column_bytes(pStmt, 1); |
+ const unsigned char *zName = sqlite3_column_text(pStmt, 1); |
+ if( zName==0 ) break; |
+ memcpy(pAlloc, zName, nName+1); |
+ azCol[i] = (char *)pAlloc; |
+ pAlloc += nName+1; |
+ abPK[i] = sqlite3_column_int(pStmt, 5); |
+ i++; |
+ } |
+ rc = sqlite3_reset(pStmt); |
+ |
+ } |
+ |
+ /* If successful, populate the output variables. Otherwise, zero them and |
+ ** free any allocation made. An error code will be returned in this case. |
+ */ |
+ if( rc==SQLITE_OK ){ |
+ *pazCol = (const char **)azCol; |
+ *pabPK = abPK; |
+ *pnCol = nDbCol; |
+ }else{ |
+ *pazCol = 0; |
+ *pabPK = 0; |
+ *pnCol = 0; |
+ if( pzTab ) *pzTab = 0; |
+ sqlite3_free(azCol); |
+ } |
+ sqlite3_finalize(pStmt); |
+ return rc; |
+} |
+ |
+/* |
+** This function is only called from within a pre-update handler for a |
+** write to table pTab, part of session pSession. If this is the first |
+** write to this table, initalize the SessionTable.nCol, azCol[] and |
+** abPK[] arrays accordingly. |
+** |
+** If an error occurs, an error code is stored in sqlite3_session.rc and |
+** non-zero returned. Or, if no error occurs but the table has no primary |
+** key, sqlite3_session.rc is left set to SQLITE_OK and non-zero returned to |
+** indicate that updates on this table should be ignored. SessionTable.abPK |
+** is set to NULL in this case. |
+*/ |
+static int sessionInitTable(sqlite3_session *pSession, SessionTable *pTab){ |
+ if( pTab->nCol==0 ){ |
+ u8 *abPK; |
+ assert( pTab->azCol==0 || pTab->abPK==0 ); |
+ pSession->rc = sessionTableInfo(pSession->db, pSession->zDb, |
+ pTab->zName, &pTab->nCol, 0, &pTab->azCol, &abPK |
+ ); |
+ if( pSession->rc==SQLITE_OK ){ |
+ int i; |
+ for(i=0; i<pTab->nCol; i++){ |
+ if( abPK[i] ){ |
+ pTab->abPK = abPK; |
+ break; |
+ } |
+ } |
+ } |
+ } |
+ return (pSession->rc || pTab->abPK==0); |
+} |
+ |
+/* |
+** This function is only called from with a pre-update-hook reporting a |
+** change on table pTab (attached to session pSession). The type of change |
+** (UPDATE, INSERT, DELETE) is specified by the first argument. |
+** |
+** Unless one is already present or an error occurs, an entry is added |
+** to the changed-rows hash table associated with table pTab. |
+*/ |
+static void sessionPreupdateOneChange( |
+ int op, /* One of SQLITE_UPDATE, INSERT, DELETE */ |
+ sqlite3_session *pSession, /* Session object pTab is attached to */ |
+ SessionTable *pTab /* Table that change applies to */ |
+){ |
+ int iHash; |
+ int bNull = 0; |
+ int rc = SQLITE_OK; |
+ |
+ if( pSession->rc ) return; |
+ |
+ /* Load table details if required */ |
+ if( sessionInitTable(pSession, pTab) ) return; |
+ |
+ /* Check the number of columns in this xPreUpdate call matches the |
+ ** number of columns in the table. */ |
+ if( pTab->nCol!=pSession->hook.xCount(pSession->hook.pCtx) ){ |
+ pSession->rc = SQLITE_SCHEMA; |
+ return; |
+ } |
+ |
+ /* Grow the hash table if required */ |
+ if( sessionGrowHash(0, pTab) ){ |
+ pSession->rc = SQLITE_NOMEM; |
+ return; |
+ } |
+ |
+ /* Calculate the hash-key for this change. If the primary key of the row |
+ ** includes a NULL value, exit early. Such changes are ignored by the |
+ ** session module. */ |
+ rc = sessionPreupdateHash(pSession, pTab, op==SQLITE_INSERT, &iHash, &bNull); |
+ if( rc!=SQLITE_OK ) goto error_out; |
+ |
+ if( bNull==0 ){ |
+ /* Search the hash table for an existing record for this row. */ |
+ SessionChange *pC; |
+ for(pC=pTab->apChange[iHash]; pC; pC=pC->pNext){ |
+ if( sessionPreupdateEqual(pSession, pTab, pC, op) ) break; |
+ } |
+ |
+ if( pC==0 ){ |
+ /* Create a new change object containing all the old values (if |
+ ** this is an SQLITE_UPDATE or SQLITE_DELETE), or just the PK |
+ ** values (if this is an INSERT). */ |
+ SessionChange *pChange; /* New change object */ |
+ int nByte; /* Number of bytes to allocate */ |
+ int i; /* Used to iterate through columns */ |
+ |
+ assert( rc==SQLITE_OK ); |
+ pTab->nEntry++; |
+ |
+ /* Figure out how large an allocation is required */ |
+ nByte = sizeof(SessionChange); |
+ for(i=0; i<pTab->nCol; i++){ |
+ sqlite3_value *p = 0; |
+ if( op!=SQLITE_INSERT ){ |
+ TESTONLY(int trc = ) pSession->hook.xOld(pSession->hook.pCtx, i, &p); |
+ assert( trc==SQLITE_OK ); |
+ }else if( pTab->abPK[i] ){ |
+ TESTONLY(int trc = ) pSession->hook.xNew(pSession->hook.pCtx, i, &p); |
+ assert( trc==SQLITE_OK ); |
+ } |
+ |
+ /* This may fail if SQLite value p contains a utf-16 string that must |
+ ** be converted to utf-8 and an OOM error occurs while doing so. */ |
+ rc = sessionSerializeValue(0, p, &nByte); |
+ if( rc!=SQLITE_OK ) goto error_out; |
+ } |
+ |
+ /* Allocate the change object */ |
+ pChange = (SessionChange *)sqlite3_malloc(nByte); |
+ if( !pChange ){ |
+ rc = SQLITE_NOMEM; |
+ goto error_out; |
+ }else{ |
+ memset(pChange, 0, sizeof(SessionChange)); |
+ pChange->aRecord = (u8 *)&pChange[1]; |
+ } |
+ |
+ /* Populate the change object. None of the preupdate_old(), |
+ ** preupdate_new() or SerializeValue() calls below may fail as all |
+ ** required values and encodings have already been cached in memory. |
+ ** It is not possible for an OOM to occur in this block. */ |
+ nByte = 0; |
+ for(i=0; i<pTab->nCol; i++){ |
+ sqlite3_value *p = 0; |
+ if( op!=SQLITE_INSERT ){ |
+ pSession->hook.xOld(pSession->hook.pCtx, i, &p); |
+ }else if( pTab->abPK[i] ){ |
+ pSession->hook.xNew(pSession->hook.pCtx, i, &p); |
+ } |
+ sessionSerializeValue(&pChange->aRecord[nByte], p, &nByte); |
+ } |
+ |
+ /* Add the change to the hash-table */ |
+ if( pSession->bIndirect || pSession->hook.xDepth(pSession->hook.pCtx) ){ |
+ pChange->bIndirect = 1; |
+ } |
+ pChange->nRecord = nByte; |
+ pChange->op = op; |
+ pChange->pNext = pTab->apChange[iHash]; |
+ pTab->apChange[iHash] = pChange; |
+ |
+ }else if( pC->bIndirect ){ |
+ /* If the existing change is considered "indirect", but this current |
+ ** change is "direct", mark the change object as direct. */ |
+ if( pSession->hook.xDepth(pSession->hook.pCtx)==0 |
+ && pSession->bIndirect==0 |
+ ){ |
+ pC->bIndirect = 0; |
+ } |
+ } |
+ } |
+ |
+ /* If an error has occurred, mark the session object as failed. */ |
+ error_out: |
+ if( rc!=SQLITE_OK ){ |
+ pSession->rc = rc; |
+ } |
+} |
+ |
+static int sessionFindTable( |
+ sqlite3_session *pSession, |
+ const char *zName, |
+ SessionTable **ppTab |
+){ |
+ int rc = SQLITE_OK; |
+ int nName = sqlite3Strlen30(zName); |
+ SessionTable *pRet; |
+ |
+ /* Search for an existing table */ |
+ for(pRet=pSession->pTable; pRet; pRet=pRet->pNext){ |
+ if( 0==sqlite3_strnicmp(pRet->zName, zName, nName+1) ) break; |
+ } |
+ |
+ if( pRet==0 && pSession->bAutoAttach ){ |
+ /* If there is a table-filter configured, invoke it. If it returns 0, |
+ ** do not automatically add the new table. */ |
+ if( pSession->xTableFilter==0 |
+ || pSession->xTableFilter(pSession->pFilterCtx, zName) |
+ ){ |
+ rc = sqlite3session_attach(pSession, zName); |
+ if( rc==SQLITE_OK ){ |
+ for(pRet=pSession->pTable; pRet->pNext; pRet=pRet->pNext); |
+ assert( 0==sqlite3_strnicmp(pRet->zName, zName, nName+1) ); |
+ } |
+ } |
+ } |
+ |
+ assert( rc==SQLITE_OK || pRet==0 ); |
+ *ppTab = pRet; |
+ return rc; |
+} |
+ |
+/* |
+** The 'pre-update' hook registered by this module with SQLite databases. |
+*/ |
+static void xPreUpdate( |
+ void *pCtx, /* Copy of third arg to preupdate_hook() */ |
+ sqlite3 *db, /* Database handle */ |
+ int op, /* SQLITE_UPDATE, DELETE or INSERT */ |
+ char const *zDb, /* Database name */ |
+ char const *zName, /* Table name */ |
+ sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ |
+ sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ |
+){ |
+ sqlite3_session *pSession; |
+ int nDb = sqlite3Strlen30(zDb); |
+ |
+ assert( sqlite3_mutex_held(db->mutex) ); |
+ |
+ for(pSession=(sqlite3_session *)pCtx; pSession; pSession=pSession->pNext){ |
+ SessionTable *pTab; |
+ |
+ /* If this session is attached to a different database ("main", "temp" |
+ ** etc.), or if it is not currently enabled, there is nothing to do. Skip |
+ ** to the next session object attached to this database. */ |
+ if( pSession->bEnable==0 ) continue; |
+ if( pSession->rc ) continue; |
+ if( sqlite3_strnicmp(zDb, pSession->zDb, nDb+1) ) continue; |
+ |
+ pSession->rc = sessionFindTable(pSession, zName, &pTab); |
+ if( pTab ){ |
+ assert( pSession->rc==SQLITE_OK ); |
+ sessionPreupdateOneChange(op, pSession, pTab); |
+ if( op==SQLITE_UPDATE ){ |
+ sessionPreupdateOneChange(SQLITE_INSERT, pSession, pTab); |
+ } |
+ } |
+ } |
+} |
+ |
+/* |
+** The pre-update hook implementations. |
+*/ |
+static int sessionPreupdateOld(void *pCtx, int iVal, sqlite3_value **ppVal){ |
+ return sqlite3_preupdate_old((sqlite3*)pCtx, iVal, ppVal); |
+} |
+static int sessionPreupdateNew(void *pCtx, int iVal, sqlite3_value **ppVal){ |
+ return sqlite3_preupdate_new((sqlite3*)pCtx, iVal, ppVal); |
+} |
+static int sessionPreupdateCount(void *pCtx){ |
+ return sqlite3_preupdate_count((sqlite3*)pCtx); |
+} |
+static int sessionPreupdateDepth(void *pCtx){ |
+ return sqlite3_preupdate_depth((sqlite3*)pCtx); |
+} |
+ |
+/* |
+** Install the pre-update hooks on the session object passed as the only |
+** argument. |
+*/ |
+static void sessionPreupdateHooks( |
+ sqlite3_session *pSession |
+){ |
+ pSession->hook.pCtx = (void*)pSession->db; |
+ pSession->hook.xOld = sessionPreupdateOld; |
+ pSession->hook.xNew = sessionPreupdateNew; |
+ pSession->hook.xCount = sessionPreupdateCount; |
+ pSession->hook.xDepth = sessionPreupdateDepth; |
+} |
+ |
+typedef struct SessionDiffCtx SessionDiffCtx; |
+struct SessionDiffCtx { |
+ sqlite3_stmt *pStmt; |
+ int nOldOff; |
+}; |
+ |
+/* |
+** The diff hook implementations. |
+*/ |
+static int sessionDiffOld(void *pCtx, int iVal, sqlite3_value **ppVal){ |
+ SessionDiffCtx *p = (SessionDiffCtx*)pCtx; |
+ *ppVal = sqlite3_column_value(p->pStmt, iVal+p->nOldOff); |
+ return SQLITE_OK; |
+} |
+static int sessionDiffNew(void *pCtx, int iVal, sqlite3_value **ppVal){ |
+ SessionDiffCtx *p = (SessionDiffCtx*)pCtx; |
+ *ppVal = sqlite3_column_value(p->pStmt, iVal); |
+ return SQLITE_OK; |
+} |
+static int sessionDiffCount(void *pCtx){ |
+ SessionDiffCtx *p = (SessionDiffCtx*)pCtx; |
+ return p->nOldOff ? p->nOldOff : sqlite3_column_count(p->pStmt); |
+} |
+static int sessionDiffDepth(void *pCtx){ |
+ return 0; |
+} |
+ |
+/* |
+** Install the diff hooks on the session object passed as the only |
+** argument. |
+*/ |
+static void sessionDiffHooks( |
+ sqlite3_session *pSession, |
+ SessionDiffCtx *pDiffCtx |
+){ |
+ pSession->hook.pCtx = (void*)pDiffCtx; |
+ pSession->hook.xOld = sessionDiffOld; |
+ pSession->hook.xNew = sessionDiffNew; |
+ pSession->hook.xCount = sessionDiffCount; |
+ pSession->hook.xDepth = sessionDiffDepth; |
+} |
+ |
+static char *sessionExprComparePK( |
+ int nCol, |
+ const char *zDb1, const char *zDb2, |
+ const char *zTab, |
+ const char **azCol, u8 *abPK |
+){ |
+ int i; |
+ const char *zSep = ""; |
+ char *zRet = 0; |
+ |
+ for(i=0; i<nCol; i++){ |
+ if( abPK[i] ){ |
+ zRet = sqlite3_mprintf("%z%s\"%w\".\"%w\".\"%w\"=\"%w\".\"%w\".\"%w\"", |
+ zRet, zSep, zDb1, zTab, azCol[i], zDb2, zTab, azCol[i] |
+ ); |
+ zSep = " AND "; |
+ if( zRet==0 ) break; |
+ } |
+ } |
+ |
+ return zRet; |
+} |
+ |
+static char *sessionExprCompareOther( |
+ int nCol, |
+ const char *zDb1, const char *zDb2, |
+ const char *zTab, |
+ const char **azCol, u8 *abPK |
+){ |
+ int i; |
+ const char *zSep = ""; |
+ char *zRet = 0; |
+ int bHave = 0; |
+ |
+ for(i=0; i<nCol; i++){ |
+ if( abPK[i]==0 ){ |
+ bHave = 1; |
+ zRet = sqlite3_mprintf( |
+ "%z%s\"%w\".\"%w\".\"%w\" IS NOT \"%w\".\"%w\".\"%w\"", |
+ zRet, zSep, zDb1, zTab, azCol[i], zDb2, zTab, azCol[i] |
+ ); |
+ zSep = " OR "; |
+ if( zRet==0 ) break; |
+ } |
+ } |
+ |
+ if( bHave==0 ){ |
+ assert( zRet==0 ); |
+ zRet = sqlite3_mprintf("0"); |
+ } |
+ |
+ return zRet; |
+} |
+ |
+static char *sessionSelectFindNew( |
+ int nCol, |
+ const char *zDb1, /* Pick rows in this db only */ |
+ const char *zDb2, /* But not in this one */ |
+ const char *zTbl, /* Table name */ |
+ const char *zExpr |
+){ |
+ char *zRet = sqlite3_mprintf( |
+ "SELECT * FROM \"%w\".\"%w\" WHERE NOT EXISTS (" |
+ " SELECT 1 FROM \"%w\".\"%w\" WHERE %s" |
+ ")", |
+ zDb1, zTbl, zDb2, zTbl, zExpr |
+ ); |
+ return zRet; |
+} |
+ |
+static int sessionDiffFindNew( |
+ int op, |
+ sqlite3_session *pSession, |
+ SessionTable *pTab, |
+ const char *zDb1, |
+ const char *zDb2, |
+ char *zExpr |
+){ |
+ int rc = SQLITE_OK; |
+ char *zStmt = sessionSelectFindNew(pTab->nCol, zDb1, zDb2, pTab->zName,zExpr); |
+ |
+ if( zStmt==0 ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ sqlite3_stmt *pStmt; |
+ rc = sqlite3_prepare(pSession->db, zStmt, -1, &pStmt, 0); |
+ if( rc==SQLITE_OK ){ |
+ SessionDiffCtx *pDiffCtx = (SessionDiffCtx*)pSession->hook.pCtx; |
+ pDiffCtx->pStmt = pStmt; |
+ pDiffCtx->nOldOff = 0; |
+ while( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ sessionPreupdateOneChange(op, pSession, pTab); |
+ } |
+ rc = sqlite3_finalize(pStmt); |
+ } |
+ sqlite3_free(zStmt); |
+ } |
+ |
+ return rc; |
+} |
+ |
+static int sessionDiffFindModified( |
+ sqlite3_session *pSession, |
+ SessionTable *pTab, |
+ const char *zFrom, |
+ const char *zExpr |
+){ |
+ int rc = SQLITE_OK; |
+ |
+ char *zExpr2 = sessionExprCompareOther(pTab->nCol, |
+ pSession->zDb, zFrom, pTab->zName, pTab->azCol, pTab->abPK |
+ ); |
+ if( zExpr2==0 ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ char *zStmt = sqlite3_mprintf( |
+ "SELECT * FROM \"%w\".\"%w\", \"%w\".\"%w\" WHERE %s AND (%z)", |
+ pSession->zDb, pTab->zName, zFrom, pTab->zName, zExpr, zExpr2 |
+ ); |
+ if( zStmt==0 ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ sqlite3_stmt *pStmt; |
+ rc = sqlite3_prepare(pSession->db, zStmt, -1, &pStmt, 0); |
+ |
+ if( rc==SQLITE_OK ){ |
+ SessionDiffCtx *pDiffCtx = (SessionDiffCtx*)pSession->hook.pCtx; |
+ pDiffCtx->pStmt = pStmt; |
+ pDiffCtx->nOldOff = pTab->nCol; |
+ while( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ sessionPreupdateOneChange(SQLITE_UPDATE, pSession, pTab); |
+ } |
+ rc = sqlite3_finalize(pStmt); |
+ } |
+ sqlite3_free(zStmt); |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+int sqlite3session_diff( |
+ sqlite3_session *pSession, |
+ const char *zFrom, |
+ const char *zTbl, |
+ char **pzErrMsg |
+){ |
+ const char *zDb = pSession->zDb; |
+ int rc = pSession->rc; |
+ SessionDiffCtx d; |
+ |
+ memset(&d, 0, sizeof(d)); |
+ sessionDiffHooks(pSession, &d); |
+ |
+ sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db)); |
+ if( pzErrMsg ) *pzErrMsg = 0; |
+ if( rc==SQLITE_OK ){ |
+ char *zExpr = 0; |
+ sqlite3 *db = pSession->db; |
+ SessionTable *pTo; /* Table zTbl */ |
+ |
+ /* Locate and if necessary initialize the target table object */ |
+ rc = sessionFindTable(pSession, zTbl, &pTo); |
+ if( pTo==0 ) goto diff_out; |
+ if( sessionInitTable(pSession, pTo) ){ |
+ rc = pSession->rc; |
+ goto diff_out; |
+ } |
+ |
+ /* Check the table schemas match */ |
+ if( rc==SQLITE_OK ){ |
+ int bHasPk = 0; |
+ int bMismatch = 0; |
+ int nCol; /* Columns in zFrom.zTbl */ |
+ u8 *abPK; |
+ const char **azCol = 0; |
+ rc = sessionTableInfo(db, zFrom, zTbl, &nCol, 0, &azCol, &abPK); |
+ if( rc==SQLITE_OK ){ |
+ if( pTo->nCol!=nCol ){ |
+ bMismatch = 1; |
+ }else{ |
+ int i; |
+ for(i=0; i<nCol; i++){ |
+ if( pTo->abPK[i]!=abPK[i] ) bMismatch = 1; |
+ if( sqlite3_stricmp(azCol[i], pTo->azCol[i]) ) bMismatch = 1; |
+ if( abPK[i] ) bHasPk = 1; |
+ } |
+ } |
+ |
+ } |
+ sqlite3_free((char*)azCol); |
+ if( bMismatch ){ |
+ *pzErrMsg = sqlite3_mprintf("table schemas do not match"); |
+ rc = SQLITE_SCHEMA; |
+ } |
+ if( bHasPk==0 ){ |
+ /* Ignore tables with no primary keys */ |
+ goto diff_out; |
+ } |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ zExpr = sessionExprComparePK(pTo->nCol, |
+ zDb, zFrom, pTo->zName, pTo->azCol, pTo->abPK |
+ ); |
+ } |
+ |
+ /* Find new rows */ |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionDiffFindNew(SQLITE_INSERT, pSession, pTo, zDb, zFrom, zExpr); |
+ } |
+ |
+ /* Find old rows */ |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionDiffFindNew(SQLITE_DELETE, pSession, pTo, zFrom, zDb, zExpr); |
+ } |
+ |
+ /* Find modified rows */ |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionDiffFindModified(pSession, pTo, zFrom, zExpr); |
+ } |
+ |
+ sqlite3_free(zExpr); |
+ } |
+ |
+ diff_out: |
+ sessionPreupdateHooks(pSession); |
+ sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db)); |
+ return rc; |
+} |
+ |
+/* |
+** Create a session object. This session object will record changes to |
+** database zDb attached to connection db. |
+*/ |
+int sqlite3session_create( |
+ sqlite3 *db, /* Database handle */ |
+ const char *zDb, /* Name of db (e.g. "main") */ |
+ sqlite3_session **ppSession /* OUT: New session object */ |
+){ |
+ sqlite3_session *pNew; /* Newly allocated session object */ |
+ sqlite3_session *pOld; /* Session object already attached to db */ |
+ int nDb = sqlite3Strlen30(zDb); /* Length of zDb in bytes */ |
+ |
+ /* Zero the output value in case an error occurs. */ |
+ *ppSession = 0; |
+ |
+ /* Allocate and populate the new session object. */ |
+ pNew = (sqlite3_session *)sqlite3_malloc(sizeof(sqlite3_session) + nDb + 1); |
+ if( !pNew ) return SQLITE_NOMEM; |
+ memset(pNew, 0, sizeof(sqlite3_session)); |
+ pNew->db = db; |
+ pNew->zDb = (char *)&pNew[1]; |
+ pNew->bEnable = 1; |
+ memcpy(pNew->zDb, zDb, nDb+1); |
+ sessionPreupdateHooks(pNew); |
+ |
+ /* Add the new session object to the linked list of session objects |
+ ** attached to database handle $db. Do this under the cover of the db |
+ ** handle mutex. */ |
+ sqlite3_mutex_enter(sqlite3_db_mutex(db)); |
+ pOld = (sqlite3_session*)sqlite3_preupdate_hook(db, xPreUpdate, (void*)pNew); |
+ pNew->pNext = pOld; |
+ sqlite3_mutex_leave(sqlite3_db_mutex(db)); |
+ |
+ *ppSession = pNew; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Free the list of table objects passed as the first argument. The contents |
+** of the changed-rows hash tables are also deleted. |
+*/ |
+static void sessionDeleteTable(SessionTable *pList){ |
+ SessionTable *pNext; |
+ SessionTable *pTab; |
+ |
+ for(pTab=pList; pTab; pTab=pNext){ |
+ int i; |
+ pNext = pTab->pNext; |
+ for(i=0; i<pTab->nChange; i++){ |
+ SessionChange *p; |
+ SessionChange *pNextChange; |
+ for(p=pTab->apChange[i]; p; p=pNextChange){ |
+ pNextChange = p->pNext; |
+ sqlite3_free(p); |
+ } |
+ } |
+ sqlite3_free((char*)pTab->azCol); /* cast works around VC++ bug */ |
+ sqlite3_free(pTab->apChange); |
+ sqlite3_free(pTab); |
+ } |
+} |
+ |
+/* |
+** Delete a session object previously allocated using sqlite3session_create(). |
+*/ |
+void sqlite3session_delete(sqlite3_session *pSession){ |
+ sqlite3 *db = pSession->db; |
+ sqlite3_session *pHead; |
+ sqlite3_session **pp; |
+ |
+ /* Unlink the session from the linked list of sessions attached to the |
+ ** database handle. Hold the db mutex while doing so. */ |
+ sqlite3_mutex_enter(sqlite3_db_mutex(db)); |
+ pHead = (sqlite3_session*)sqlite3_preupdate_hook(db, 0, 0); |
+ for(pp=&pHead; ALWAYS((*pp)!=0); pp=&((*pp)->pNext)){ |
+ if( (*pp)==pSession ){ |
+ *pp = (*pp)->pNext; |
+ if( pHead ) sqlite3_preupdate_hook(db, xPreUpdate, (void*)pHead); |
+ break; |
+ } |
+ } |
+ sqlite3_mutex_leave(sqlite3_db_mutex(db)); |
+ |
+ /* Delete all attached table objects. And the contents of their |
+ ** associated hash-tables. */ |
+ sessionDeleteTable(pSession->pTable); |
+ |
+ /* Free the session object itself. */ |
+ sqlite3_free(pSession); |
+} |
+ |
+/* |
+** Set a table filter on a Session Object. |
+*/ |
+void sqlite3session_table_filter( |
+ sqlite3_session *pSession, |
+ int(*xFilter)(void*, const char*), |
+ void *pCtx /* First argument passed to xFilter */ |
+){ |
+ pSession->bAutoAttach = 1; |
+ pSession->pFilterCtx = pCtx; |
+ pSession->xTableFilter = xFilter; |
+} |
+ |
+/* |
+** Attach a table to a session. All subsequent changes made to the table |
+** while the session object is enabled will be recorded. |
+** |
+** Only tables that have a PRIMARY KEY defined may be attached. It does |
+** not matter if the PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) |
+** or not. |
+*/ |
+int sqlite3session_attach( |
+ sqlite3_session *pSession, /* Session object */ |
+ const char *zName /* Table name */ |
+){ |
+ int rc = SQLITE_OK; |
+ sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db)); |
+ |
+ if( !zName ){ |
+ pSession->bAutoAttach = 1; |
+ }else{ |
+ SessionTable *pTab; /* New table object (if required) */ |
+ int nName; /* Number of bytes in string zName */ |
+ |
+ /* First search for an existing entry. If one is found, this call is |
+ ** a no-op. Return early. */ |
+ nName = sqlite3Strlen30(zName); |
+ for(pTab=pSession->pTable; pTab; pTab=pTab->pNext){ |
+ if( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) ) break; |
+ } |
+ |
+ if( !pTab ){ |
+ /* Allocate new SessionTable object. */ |
+ pTab = (SessionTable *)sqlite3_malloc(sizeof(SessionTable) + nName + 1); |
+ if( !pTab ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ /* Populate the new SessionTable object and link it into the list. |
+ ** The new object must be linked onto the end of the list, not |
+ ** simply added to the start of it in order to ensure that tables |
+ ** appear in the correct order when a changeset or patchset is |
+ ** eventually generated. */ |
+ SessionTable **ppTab; |
+ memset(pTab, 0, sizeof(SessionTable)); |
+ pTab->zName = (char *)&pTab[1]; |
+ memcpy(pTab->zName, zName, nName+1); |
+ for(ppTab=&pSession->pTable; *ppTab; ppTab=&(*ppTab)->pNext); |
+ *ppTab = pTab; |
+ } |
+ } |
+ } |
+ |
+ sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db)); |
+ return rc; |
+} |
+ |
+/* |
+** Ensure that there is room in the buffer to append nByte bytes of data. |
+** If not, use sqlite3_realloc() to grow the buffer so that there is. |
+** |
+** If successful, return zero. Otherwise, if an OOM condition is encountered, |
+** set *pRc to SQLITE_NOMEM and return non-zero. |
+*/ |
+static int sessionBufferGrow(SessionBuffer *p, int nByte, int *pRc){ |
+ if( *pRc==SQLITE_OK && p->nAlloc-p->nBuf<nByte ){ |
+ u8 *aNew; |
+ int nNew = p->nAlloc ? p->nAlloc : 128; |
+ do { |
+ nNew = nNew*2; |
+ }while( nNew<(p->nBuf+nByte) ); |
+ |
+ aNew = (u8 *)sqlite3_realloc(p->aBuf, nNew); |
+ if( 0==aNew ){ |
+ *pRc = SQLITE_NOMEM; |
+ }else{ |
+ p->aBuf = aNew; |
+ p->nAlloc = nNew; |
+ } |
+ } |
+ return (*pRc!=SQLITE_OK); |
+} |
+ |
+/* |
+** Append the value passed as the second argument to the buffer passed |
+** as the first. |
+** |
+** This function is a no-op if *pRc is non-zero when it is called. |
+** Otherwise, if an error occurs, *pRc is set to an SQLite error code |
+** before returning. |
+*/ |
+static void sessionAppendValue(SessionBuffer *p, sqlite3_value *pVal, int *pRc){ |
+ int rc = *pRc; |
+ if( rc==SQLITE_OK ){ |
+ int nByte = 0; |
+ rc = sessionSerializeValue(0, pVal, &nByte); |
+ sessionBufferGrow(p, nByte, &rc); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionSerializeValue(&p->aBuf[p->nBuf], pVal, 0); |
+ p->nBuf += nByte; |
+ }else{ |
+ *pRc = rc; |
+ } |
+ } |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwise, append a single byte to the buffer. |
+** |
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before |
+** returning. |
+*/ |
+static void sessionAppendByte(SessionBuffer *p, u8 v, int *pRc){ |
+ if( 0==sessionBufferGrow(p, 1, pRc) ){ |
+ p->aBuf[p->nBuf++] = v; |
+ } |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwise, append a single varint to the buffer. |
+** |
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before |
+** returning. |
+*/ |
+static void sessionAppendVarint(SessionBuffer *p, int v, int *pRc){ |
+ if( 0==sessionBufferGrow(p, 9, pRc) ){ |
+ p->nBuf += sessionVarintPut(&p->aBuf[p->nBuf], v); |
+ } |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwise, append a blob of data to the buffer. |
+** |
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before |
+** returning. |
+*/ |
+static void sessionAppendBlob( |
+ SessionBuffer *p, |
+ const u8 *aBlob, |
+ int nBlob, |
+ int *pRc |
+){ |
+ if( nBlob>0 && 0==sessionBufferGrow(p, nBlob, pRc) ){ |
+ memcpy(&p->aBuf[p->nBuf], aBlob, nBlob); |
+ p->nBuf += nBlob; |
+ } |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwise, append a string to the buffer. All bytes in the string |
+** up to (but not including) the nul-terminator are written to the buffer. |
+** |
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before |
+** returning. |
+*/ |
+static void sessionAppendStr( |
+ SessionBuffer *p, |
+ const char *zStr, |
+ int *pRc |
+){ |
+ int nStr = sqlite3Strlen30(zStr); |
+ if( 0==sessionBufferGrow(p, nStr, pRc) ){ |
+ memcpy(&p->aBuf[p->nBuf], zStr, nStr); |
+ p->nBuf += nStr; |
+ } |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwise, append the string representation of integer iVal |
+** to the buffer. No nul-terminator is written. |
+** |
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before |
+** returning. |
+*/ |
+static void sessionAppendInteger( |
+ SessionBuffer *p, /* Buffer to append to */ |
+ int iVal, /* Value to write the string rep. of */ |
+ int *pRc /* IN/OUT: Error code */ |
+){ |
+ char aBuf[24]; |
+ sqlite3_snprintf(sizeof(aBuf)-1, aBuf, "%d", iVal); |
+ sessionAppendStr(p, aBuf, pRc); |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwise, append the string zStr enclosed in quotes (") and |
+** with any embedded quote characters escaped to the buffer. No |
+** nul-terminator byte is written. |
+** |
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before |
+** returning. |
+*/ |
+static void sessionAppendIdent( |
+ SessionBuffer *p, /* Buffer to a append to */ |
+ const char *zStr, /* String to quote, escape and append */ |
+ int *pRc /* IN/OUT: Error code */ |
+){ |
+ int nStr = sqlite3Strlen30(zStr)*2 + 2 + 1; |
+ if( 0==sessionBufferGrow(p, nStr, pRc) ){ |
+ char *zOut = (char *)&p->aBuf[p->nBuf]; |
+ const char *zIn = zStr; |
+ *zOut++ = '"'; |
+ while( *zIn ){ |
+ if( *zIn=='"' ) *zOut++ = '"'; |
+ *zOut++ = *(zIn++); |
+ } |
+ *zOut++ = '"'; |
+ p->nBuf = (int)((u8 *)zOut - p->aBuf); |
+ } |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is other than SQLITE_OK when it is |
+** called. Otherwse, it appends the serialized version of the value stored |
+** in column iCol of the row that SQL statement pStmt currently points |
+** to to the buffer. |
+*/ |
+static void sessionAppendCol( |
+ SessionBuffer *p, /* Buffer to append to */ |
+ sqlite3_stmt *pStmt, /* Handle pointing to row containing value */ |
+ int iCol, /* Column to read value from */ |
+ int *pRc /* IN/OUT: Error code */ |
+){ |
+ if( *pRc==SQLITE_OK ){ |
+ int eType = sqlite3_column_type(pStmt, iCol); |
+ sessionAppendByte(p, (u8)eType, pRc); |
+ if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ sqlite3_int64 i; |
+ u8 aBuf[8]; |
+ if( eType==SQLITE_INTEGER ){ |
+ i = sqlite3_column_int64(pStmt, iCol); |
+ }else{ |
+ double r = sqlite3_column_double(pStmt, iCol); |
+ memcpy(&i, &r, 8); |
+ } |
+ sessionPutI64(aBuf, i); |
+ sessionAppendBlob(p, aBuf, 8, pRc); |
+ } |
+ if( eType==SQLITE_BLOB || eType==SQLITE_TEXT ){ |
+ u8 *z; |
+ int nByte; |
+ if( eType==SQLITE_BLOB ){ |
+ z = (u8 *)sqlite3_column_blob(pStmt, iCol); |
+ }else{ |
+ z = (u8 *)sqlite3_column_text(pStmt, iCol); |
+ } |
+ nByte = sqlite3_column_bytes(pStmt, iCol); |
+ if( z || (eType==SQLITE_BLOB && nByte==0) ){ |
+ sessionAppendVarint(p, nByte, pRc); |
+ sessionAppendBlob(p, z, nByte, pRc); |
+ }else{ |
+ *pRc = SQLITE_NOMEM; |
+ } |
+ } |
+ } |
+} |
+ |
+/* |
+** |
+** This function appends an update change to the buffer (see the comments |
+** under "CHANGESET FORMAT" at the top of the file). An update change |
+** consists of: |
+** |
+** 1 byte: SQLITE_UPDATE (0x17) |
+** n bytes: old.* record (see RECORD FORMAT) |
+** m bytes: new.* record (see RECORD FORMAT) |
+** |
+** The SessionChange object passed as the third argument contains the |
+** values that were stored in the row when the session began (the old.* |
+** values). The statement handle passed as the second argument points |
+** at the current version of the row (the new.* values). |
+** |
+** If all of the old.* values are equal to their corresponding new.* value |
+** (i.e. nothing has changed), then no data at all is appended to the buffer. |
+** |
+** Otherwise, the old.* record contains all primary key values and the |
+** original values of any fields that have been modified. The new.* record |
+** contains the new values of only those fields that have been modified. |
+*/ |
+static int sessionAppendUpdate( |
+ SessionBuffer *pBuf, /* Buffer to append to */ |
+ int bPatchset, /* True for "patchset", 0 for "changeset" */ |
+ sqlite3_stmt *pStmt, /* Statement handle pointing at new row */ |
+ SessionChange *p, /* Object containing old values */ |
+ u8 *abPK /* Boolean array - true for PK columns */ |
+){ |
+ int rc = SQLITE_OK; |
+ SessionBuffer buf2 = {0,0,0}; /* Buffer to accumulate new.* record in */ |
+ int bNoop = 1; /* Set to zero if any values are modified */ |
+ int nRewind = pBuf->nBuf; /* Set to zero if any values are modified */ |
+ int i; /* Used to iterate through columns */ |
+ u8 *pCsr = p->aRecord; /* Used to iterate through old.* values */ |
+ |
+ sessionAppendByte(pBuf, SQLITE_UPDATE, &rc); |
+ sessionAppendByte(pBuf, p->bIndirect, &rc); |
+ for(i=0; i<sqlite3_column_count(pStmt); i++){ |
+ int bChanged = 0; |
+ int nAdvance; |
+ int eType = *pCsr; |
+ switch( eType ){ |
+ case SQLITE_NULL: |
+ nAdvance = 1; |
+ if( sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){ |
+ bChanged = 1; |
+ } |
+ break; |
+ |
+ case SQLITE_FLOAT: |
+ case SQLITE_INTEGER: { |
+ nAdvance = 9; |
+ if( eType==sqlite3_column_type(pStmt, i) ){ |
+ sqlite3_int64 iVal = sessionGetI64(&pCsr[1]); |
+ if( eType==SQLITE_INTEGER ){ |
+ if( iVal==sqlite3_column_int64(pStmt, i) ) break; |
+ }else{ |
+ double dVal; |
+ memcpy(&dVal, &iVal, 8); |
+ if( dVal==sqlite3_column_double(pStmt, i) ) break; |
+ } |
+ } |
+ bChanged = 1; |
+ break; |
+ } |
+ |
+ default: { |
+ int n; |
+ int nHdr = 1 + sessionVarintGet(&pCsr[1], &n); |
+ assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); |
+ nAdvance = nHdr + n; |
+ if( eType==sqlite3_column_type(pStmt, i) |
+ && n==sqlite3_column_bytes(pStmt, i) |
+ && (n==0 || 0==memcmp(&pCsr[nHdr], sqlite3_column_blob(pStmt, i), n)) |
+ ){ |
+ break; |
+ } |
+ bChanged = 1; |
+ } |
+ } |
+ |
+ /* If at least one field has been modified, this is not a no-op. */ |
+ if( bChanged ) bNoop = 0; |
+ |
+ /* Add a field to the old.* record. This is omitted if this modules is |
+ ** currently generating a patchset. */ |
+ if( bPatchset==0 ){ |
+ if( bChanged || abPK[i] ){ |
+ sessionAppendBlob(pBuf, pCsr, nAdvance, &rc); |
+ }else{ |
+ sessionAppendByte(pBuf, 0, &rc); |
+ } |
+ } |
+ |
+ /* Add a field to the new.* record. Or the only record if currently |
+ ** generating a patchset. */ |
+ if( bChanged || (bPatchset && abPK[i]) ){ |
+ sessionAppendCol(&buf2, pStmt, i, &rc); |
+ }else{ |
+ sessionAppendByte(&buf2, 0, &rc); |
+ } |
+ |
+ pCsr += nAdvance; |
+ } |
+ |
+ if( bNoop ){ |
+ pBuf->nBuf = nRewind; |
+ }else{ |
+ sessionAppendBlob(pBuf, buf2.aBuf, buf2.nBuf, &rc); |
+ } |
+ sqlite3_free(buf2.aBuf); |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Append a DELETE change to the buffer passed as the first argument. Use |
+** the changeset format if argument bPatchset is zero, or the patchset |
+** format otherwise. |
+*/ |
+static int sessionAppendDelete( |
+ SessionBuffer *pBuf, /* Buffer to append to */ |
+ int bPatchset, /* True for "patchset", 0 for "changeset" */ |
+ SessionChange *p, /* Object containing old values */ |
+ int nCol, /* Number of columns in table */ |
+ u8 *abPK /* Boolean array - true for PK columns */ |
+){ |
+ int rc = SQLITE_OK; |
+ |
+ sessionAppendByte(pBuf, SQLITE_DELETE, &rc); |
+ sessionAppendByte(pBuf, p->bIndirect, &rc); |
+ |
+ if( bPatchset==0 ){ |
+ sessionAppendBlob(pBuf, p->aRecord, p->nRecord, &rc); |
+ }else{ |
+ int i; |
+ u8 *a = p->aRecord; |
+ for(i=0; i<nCol; i++){ |
+ u8 *pStart = a; |
+ int eType = *a++; |
+ |
+ switch( eType ){ |
+ case 0: |
+ case SQLITE_NULL: |
+ assert( abPK[i]==0 ); |
+ break; |
+ |
+ case SQLITE_FLOAT: |
+ case SQLITE_INTEGER: |
+ a += 8; |
+ break; |
+ |
+ default: { |
+ int n; |
+ a += sessionVarintGet(a, &n); |
+ a += n; |
+ break; |
+ } |
+ } |
+ if( abPK[i] ){ |
+ sessionAppendBlob(pBuf, pStart, (int)(a-pStart), &rc); |
+ } |
+ } |
+ assert( (a - p->aRecord)==p->nRecord ); |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Formulate and prepare a SELECT statement to retrieve a row from table |
+** zTab in database zDb based on its primary key. i.e. |
+** |
+** SELECT * FROM zDb.zTab WHERE pk1 = ? AND pk2 = ? AND ... |
+*/ |
+static int sessionSelectStmt( |
+ sqlite3 *db, /* Database handle */ |
+ const char *zDb, /* Database name */ |
+ const char *zTab, /* Table name */ |
+ int nCol, /* Number of columns in table */ |
+ const char **azCol, /* Names of table columns */ |
+ u8 *abPK, /* PRIMARY KEY array */ |
+ sqlite3_stmt **ppStmt /* OUT: Prepared SELECT statement */ |
+){ |
+ int rc = SQLITE_OK; |
+ int i; |
+ const char *zSep = ""; |
+ SessionBuffer buf = {0, 0, 0}; |
+ |
+ sessionAppendStr(&buf, "SELECT * FROM ", &rc); |
+ sessionAppendIdent(&buf, zDb, &rc); |
+ sessionAppendStr(&buf, ".", &rc); |
+ sessionAppendIdent(&buf, zTab, &rc); |
+ sessionAppendStr(&buf, " WHERE ", &rc); |
+ for(i=0; i<nCol; i++){ |
+ if( abPK[i] ){ |
+ sessionAppendStr(&buf, zSep, &rc); |
+ sessionAppendIdent(&buf, azCol[i], &rc); |
+ sessionAppendStr(&buf, " = ?", &rc); |
+ sessionAppendInteger(&buf, i+1, &rc); |
+ zSep = " AND "; |
+ } |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, ppStmt, 0); |
+ } |
+ sqlite3_free(buf.aBuf); |
+ return rc; |
+} |
+ |
+/* |
+** Bind the PRIMARY KEY values from the change passed in argument pChange |
+** to the SELECT statement passed as the first argument. The SELECT statement |
+** is as prepared by function sessionSelectStmt(). |
+** |
+** Return SQLITE_OK if all PK values are successfully bound, or an SQLite |
+** error code (e.g. SQLITE_NOMEM) otherwise. |
+*/ |
+static int sessionSelectBind( |
+ sqlite3_stmt *pSelect, /* SELECT from sessionSelectStmt() */ |
+ int nCol, /* Number of columns in table */ |
+ u8 *abPK, /* PRIMARY KEY array */ |
+ SessionChange *pChange /* Change structure */ |
+){ |
+ int i; |
+ int rc = SQLITE_OK; |
+ u8 *a = pChange->aRecord; |
+ |
+ for(i=0; i<nCol && rc==SQLITE_OK; i++){ |
+ int eType = *a++; |
+ |
+ switch( eType ){ |
+ case 0: |
+ case SQLITE_NULL: |
+ assert( abPK[i]==0 ); |
+ break; |
+ |
+ case SQLITE_INTEGER: { |
+ if( abPK[i] ){ |
+ i64 iVal = sessionGetI64(a); |
+ rc = sqlite3_bind_int64(pSelect, i+1, iVal); |
+ } |
+ a += 8; |
+ break; |
+ } |
+ |
+ case SQLITE_FLOAT: { |
+ if( abPK[i] ){ |
+ double rVal; |
+ i64 iVal = sessionGetI64(a); |
+ memcpy(&rVal, &iVal, 8); |
+ rc = sqlite3_bind_double(pSelect, i+1, rVal); |
+ } |
+ a += 8; |
+ break; |
+ } |
+ |
+ case SQLITE_TEXT: { |
+ int n; |
+ a += sessionVarintGet(a, &n); |
+ if( abPK[i] ){ |
+ rc = sqlite3_bind_text(pSelect, i+1, (char *)a, n, SQLITE_TRANSIENT); |
+ } |
+ a += n; |
+ break; |
+ } |
+ |
+ default: { |
+ int n; |
+ assert( eType==SQLITE_BLOB ); |
+ a += sessionVarintGet(a, &n); |
+ if( abPK[i] ){ |
+ rc = sqlite3_bind_blob(pSelect, i+1, a, n, SQLITE_TRANSIENT); |
+ } |
+ a += n; |
+ break; |
+ } |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** This function is a no-op if *pRc is set to other than SQLITE_OK when it |
+** is called. Otherwise, append a serialized table header (part of the binary |
+** changeset format) to buffer *pBuf. If an error occurs, set *pRc to an |
+** SQLite error code before returning. |
+*/ |
+static void sessionAppendTableHdr( |
+ SessionBuffer *pBuf, /* Append header to this buffer */ |
+ int bPatchset, /* Use the patchset format if true */ |
+ SessionTable *pTab, /* Table object to append header for */ |
+ int *pRc /* IN/OUT: Error code */ |
+){ |
+ /* Write a table header */ |
+ sessionAppendByte(pBuf, (bPatchset ? 'P' : 'T'), pRc); |
+ sessionAppendVarint(pBuf, pTab->nCol, pRc); |
+ sessionAppendBlob(pBuf, pTab->abPK, pTab->nCol, pRc); |
+ sessionAppendBlob(pBuf, (u8 *)pTab->zName, (int)strlen(pTab->zName)+1, pRc); |
+} |
+ |
+/* |
+** Generate either a changeset (if argument bPatchset is zero) or a patchset |
+** (if it is non-zero) based on the current contents of the session object |
+** passed as the first argument. |
+** |
+** If no error occurs, SQLITE_OK is returned and the new changeset/patchset |
+** stored in output variables *pnChangeset and *ppChangeset. Or, if an error |
+** occurs, an SQLite error code is returned and both output variables set |
+** to 0. |
+*/ |
+static int sessionGenerateChangeset( |
+ sqlite3_session *pSession, /* Session object */ |
+ int bPatchset, /* True for patchset, false for changeset */ |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut, /* First argument for xOutput */ |
+ int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ |
+ void **ppChangeset /* OUT: Buffer containing changeset */ |
+){ |
+ sqlite3 *db = pSession->db; /* Source database handle */ |
+ SessionTable *pTab; /* Used to iterate through attached tables */ |
+ SessionBuffer buf = {0,0,0}; /* Buffer in which to accumlate changeset */ |
+ int rc; /* Return code */ |
+ |
+ assert( xOutput==0 || (pnChangeset==0 && ppChangeset==0 ) ); |
+ |
+ /* Zero the output variables in case an error occurs. If this session |
+ ** object is already in the error state (sqlite3_session.rc != SQLITE_OK), |
+ ** this call will be a no-op. */ |
+ if( xOutput==0 ){ |
+ *pnChangeset = 0; |
+ *ppChangeset = 0; |
+ } |
+ |
+ if( pSession->rc ) return pSession->rc; |
+ rc = sqlite3_exec(pSession->db, "SAVEPOINT changeset", 0, 0, 0); |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ sqlite3_mutex_enter(sqlite3_db_mutex(db)); |
+ |
+ for(pTab=pSession->pTable; rc==SQLITE_OK && pTab; pTab=pTab->pNext){ |
+ if( pTab->nEntry ){ |
+ const char *zName = pTab->zName; |
+ int nCol; /* Number of columns in table */ |
+ u8 *abPK; /* Primary key array */ |
+ const char **azCol = 0; /* Table columns */ |
+ int i; /* Used to iterate through hash buckets */ |
+ sqlite3_stmt *pSel = 0; /* SELECT statement to query table pTab */ |
+ int nRewind = buf.nBuf; /* Initial size of write buffer */ |
+ int nNoop; /* Size of buffer after writing tbl header */ |
+ |
+ /* Check the table schema is still Ok. */ |
+ rc = sessionTableInfo(db, pSession->zDb, zName, &nCol, 0, &azCol, &abPK); |
+ if( !rc && (pTab->nCol!=nCol || memcmp(abPK, pTab->abPK, nCol)) ){ |
+ rc = SQLITE_SCHEMA; |
+ } |
+ |
+ /* Write a table header */ |
+ sessionAppendTableHdr(&buf, bPatchset, pTab, &rc); |
+ |
+ /* Build and compile a statement to execute: */ |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionSelectStmt( |
+ db, pSession->zDb, zName, nCol, azCol, abPK, &pSel); |
+ } |
+ |
+ nNoop = buf.nBuf; |
+ for(i=0; i<pTab->nChange && rc==SQLITE_OK; i++){ |
+ SessionChange *p; /* Used to iterate through changes */ |
+ |
+ for(p=pTab->apChange[i]; rc==SQLITE_OK && p; p=p->pNext){ |
+ rc = sessionSelectBind(pSel, nCol, abPK, p); |
+ if( rc!=SQLITE_OK ) continue; |
+ if( sqlite3_step(pSel)==SQLITE_ROW ){ |
+ if( p->op==SQLITE_INSERT ){ |
+ int iCol; |
+ sessionAppendByte(&buf, SQLITE_INSERT, &rc); |
+ sessionAppendByte(&buf, p->bIndirect, &rc); |
+ for(iCol=0; iCol<nCol; iCol++){ |
+ sessionAppendCol(&buf, pSel, iCol, &rc); |
+ } |
+ }else{ |
+ rc = sessionAppendUpdate(&buf, bPatchset, pSel, p, abPK); |
+ } |
+ }else if( p->op!=SQLITE_INSERT ){ |
+ rc = sessionAppendDelete(&buf, bPatchset, p, nCol, abPK); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_reset(pSel); |
+ } |
+ |
+ /* If the buffer is now larger than SESSIONS_STRM_CHUNK_SIZE, pass |
+ ** its contents to the xOutput() callback. */ |
+ if( xOutput |
+ && rc==SQLITE_OK |
+ && buf.nBuf>nNoop |
+ && buf.nBuf>SESSIONS_STRM_CHUNK_SIZE |
+ ){ |
+ rc = xOutput(pOut, (void*)buf.aBuf, buf.nBuf); |
+ nNoop = -1; |
+ buf.nBuf = 0; |
+ } |
+ |
+ } |
+ } |
+ |
+ sqlite3_finalize(pSel); |
+ if( buf.nBuf==nNoop ){ |
+ buf.nBuf = nRewind; |
+ } |
+ sqlite3_free((char*)azCol); /* cast works around VC++ bug */ |
+ } |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ if( xOutput==0 ){ |
+ *pnChangeset = buf.nBuf; |
+ *ppChangeset = buf.aBuf; |
+ buf.aBuf = 0; |
+ }else if( buf.nBuf>0 ){ |
+ rc = xOutput(pOut, (void*)buf.aBuf, buf.nBuf); |
+ } |
+ } |
+ |
+ sqlite3_free(buf.aBuf); |
+ sqlite3_exec(db, "RELEASE changeset", 0, 0, 0); |
+ sqlite3_mutex_leave(sqlite3_db_mutex(db)); |
+ return rc; |
+} |
+ |
+/* |
+** Obtain a changeset object containing all changes recorded by the |
+** session object passed as the first argument. |
+** |
+** It is the responsibility of the caller to eventually free the buffer |
+** using sqlite3_free(). |
+*/ |
+int sqlite3session_changeset( |
+ sqlite3_session *pSession, /* Session object */ |
+ int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ |
+ void **ppChangeset /* OUT: Buffer containing changeset */ |
+){ |
+ return sessionGenerateChangeset(pSession, 0, 0, 0, pnChangeset, ppChangeset); |
+} |
+ |
+/* |
+** Streaming version of sqlite3session_changeset(). |
+*/ |
+int sqlite3session_changeset_strm( |
+ sqlite3_session *pSession, |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut |
+){ |
+ return sessionGenerateChangeset(pSession, 0, xOutput, pOut, 0, 0); |
+} |
+ |
+/* |
+** Streaming version of sqlite3session_patchset(). |
+*/ |
+int sqlite3session_patchset_strm( |
+ sqlite3_session *pSession, |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut |
+){ |
+ return sessionGenerateChangeset(pSession, 1, xOutput, pOut, 0, 0); |
+} |
+ |
+/* |
+** Obtain a patchset object containing all changes recorded by the |
+** session object passed as the first argument. |
+** |
+** It is the responsibility of the caller to eventually free the buffer |
+** using sqlite3_free(). |
+*/ |
+int sqlite3session_patchset( |
+ sqlite3_session *pSession, /* Session object */ |
+ int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ |
+ void **ppPatchset /* OUT: Buffer containing changeset */ |
+){ |
+ return sessionGenerateChangeset(pSession, 1, 0, 0, pnPatchset, ppPatchset); |
+} |
+ |
+/* |
+** Enable or disable the session object passed as the first argument. |
+*/ |
+int sqlite3session_enable(sqlite3_session *pSession, int bEnable){ |
+ int ret; |
+ sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db)); |
+ if( bEnable>=0 ){ |
+ pSession->bEnable = bEnable; |
+ } |
+ ret = pSession->bEnable; |
+ sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db)); |
+ return ret; |
+} |
+ |
+/* |
+** Enable or disable the session object passed as the first argument. |
+*/ |
+int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect){ |
+ int ret; |
+ sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db)); |
+ if( bIndirect>=0 ){ |
+ pSession->bIndirect = bIndirect; |
+ } |
+ ret = pSession->bIndirect; |
+ sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db)); |
+ return ret; |
+} |
+ |
+/* |
+** Return true if there have been no changes to monitored tables recorded |
+** by the session object passed as the only argument. |
+*/ |
+int sqlite3session_isempty(sqlite3_session *pSession){ |
+ int ret = 0; |
+ SessionTable *pTab; |
+ |
+ sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db)); |
+ for(pTab=pSession->pTable; pTab && ret==0; pTab=pTab->pNext){ |
+ ret = (pTab->nEntry>0); |
+ } |
+ sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db)); |
+ |
+ return (ret==0); |
+} |
+ |
+/* |
+** Do the work for either sqlite3changeset_start() or start_strm(). |
+*/ |
+static int sessionChangesetStart( |
+ sqlite3_changeset_iter **pp, /* OUT: Changeset iterator handle */ |
+ int (*xInput)(void *pIn, void *pData, int *pnData), |
+ void *pIn, |
+ int nChangeset, /* Size of buffer pChangeset in bytes */ |
+ void *pChangeset /* Pointer to buffer containing changeset */ |
+){ |
+ sqlite3_changeset_iter *pRet; /* Iterator to return */ |
+ int nByte; /* Number of bytes to allocate for iterator */ |
+ |
+ assert( xInput==0 || (pChangeset==0 && nChangeset==0) ); |
+ |
+ /* Zero the output variable in case an error occurs. */ |
+ *pp = 0; |
+ |
+ /* Allocate and initialize the iterator structure. */ |
+ nByte = sizeof(sqlite3_changeset_iter); |
+ pRet = (sqlite3_changeset_iter *)sqlite3_malloc(nByte); |
+ if( !pRet ) return SQLITE_NOMEM; |
+ memset(pRet, 0, sizeof(sqlite3_changeset_iter)); |
+ pRet->in.aData = (u8 *)pChangeset; |
+ pRet->in.nData = nChangeset; |
+ pRet->in.xInput = xInput; |
+ pRet->in.pIn = pIn; |
+ pRet->in.bEof = (xInput ? 0 : 1); |
+ |
+ /* Populate the output variable and return success. */ |
+ *pp = pRet; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Create an iterator used to iterate through the contents of a changeset. |
+*/ |
+int sqlite3changeset_start( |
+ sqlite3_changeset_iter **pp, /* OUT: Changeset iterator handle */ |
+ int nChangeset, /* Size of buffer pChangeset in bytes */ |
+ void *pChangeset /* Pointer to buffer containing changeset */ |
+){ |
+ return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset); |
+} |
+ |
+/* |
+** Streaming version of sqlite3changeset_start(). |
+*/ |
+int sqlite3changeset_start_strm( |
+ sqlite3_changeset_iter **pp, /* OUT: Changeset iterator handle */ |
+ int (*xInput)(void *pIn, void *pData, int *pnData), |
+ void *pIn |
+){ |
+ return sessionChangesetStart(pp, xInput, pIn, 0, 0); |
+} |
+ |
+/* |
+** If the SessionInput object passed as the only argument is a streaming |
+** object and the buffer is full, discard some data to free up space. |
+*/ |
+static void sessionDiscardData(SessionInput *pIn){ |
+ if( pIn->bEof && pIn->xInput && pIn->iNext>=SESSIONS_STRM_CHUNK_SIZE ){ |
+ int nMove = pIn->buf.nBuf - pIn->iNext; |
+ assert( nMove>=0 ); |
+ if( nMove>0 ){ |
+ memmove(pIn->buf.aBuf, &pIn->buf.aBuf[pIn->iNext], nMove); |
+ } |
+ pIn->buf.nBuf -= pIn->iNext; |
+ pIn->iNext = 0; |
+ pIn->nData = pIn->buf.nBuf; |
+ } |
+} |
+ |
+/* |
+** Ensure that there are at least nByte bytes available in the buffer. Or, |
+** if there are not nByte bytes remaining in the input, that all available |
+** data is in the buffer. |
+** |
+** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise. |
+*/ |
+static int sessionInputBuffer(SessionInput *pIn, int nByte){ |
+ int rc = SQLITE_OK; |
+ if( pIn->xInput ){ |
+ while( !pIn->bEof && (pIn->iNext+nByte)>=pIn->nData && rc==SQLITE_OK ){ |
+ int nNew = SESSIONS_STRM_CHUNK_SIZE; |
+ |
+ if( pIn->bNoDiscard==0 ) sessionDiscardData(pIn); |
+ if( SQLITE_OK==sessionBufferGrow(&pIn->buf, nNew, &rc) ){ |
+ rc = pIn->xInput(pIn->pIn, &pIn->buf.aBuf[pIn->buf.nBuf], &nNew); |
+ if( nNew==0 ){ |
+ pIn->bEof = 1; |
+ }else{ |
+ pIn->buf.nBuf += nNew; |
+ } |
+ } |
+ |
+ pIn->aData = pIn->buf.aBuf; |
+ pIn->nData = pIn->buf.nBuf; |
+ } |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** When this function is called, *ppRec points to the start of a record |
+** that contains nCol values. This function advances the pointer *ppRec |
+** until it points to the byte immediately following that record. |
+*/ |
+static void sessionSkipRecord( |
+ u8 **ppRec, /* IN/OUT: Record pointer */ |
+ int nCol /* Number of values in record */ |
+){ |
+ u8 *aRec = *ppRec; |
+ int i; |
+ for(i=0; i<nCol; i++){ |
+ int eType = *aRec++; |
+ if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){ |
+ int nByte; |
+ aRec += sessionVarintGet((u8*)aRec, &nByte); |
+ aRec += nByte; |
+ }else if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ aRec += 8; |
+ } |
+ } |
+ |
+ *ppRec = aRec; |
+} |
+ |
+/* |
+** This function sets the value of the sqlite3_value object passed as the |
+** first argument to a copy of the string or blob held in the aData[] |
+** buffer. SQLITE_OK is returned if successful, or SQLITE_NOMEM if an OOM |
+** error occurs. |
+*/ |
+static int sessionValueSetStr( |
+ sqlite3_value *pVal, /* Set the value of this object */ |
+ u8 *aData, /* Buffer containing string or blob data */ |
+ int nData, /* Size of buffer aData[] in bytes */ |
+ u8 enc /* String encoding (0 for blobs) */ |
+){ |
+ /* In theory this code could just pass SQLITE_TRANSIENT as the final |
+ ** argument to sqlite3ValueSetStr() and have the copy created |
+ ** automatically. But doing so makes it difficult to detect any OOM |
+ ** error. Hence the code to create the copy externally. */ |
+ u8 *aCopy = sqlite3_malloc(nData+1); |
+ if( aCopy==0 ) return SQLITE_NOMEM; |
+ memcpy(aCopy, aData, nData); |
+ sqlite3ValueSetStr(pVal, nData, (char*)aCopy, enc, sqlite3_free); |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Deserialize a single record from a buffer in memory. See "RECORD FORMAT" |
+** for details. |
+** |
+** When this function is called, *paChange points to the start of the record |
+** to deserialize. Assuming no error occurs, *paChange is set to point to |
+** one byte after the end of the same record before this function returns. |
+** If the argument abPK is NULL, then the record contains nCol values. Or, |
+** if abPK is other than NULL, then the record contains only the PK fields |
+** (in other words, it is a patchset DELETE record). |
+** |
+** If successful, each element of the apOut[] array (allocated by the caller) |
+** is set to point to an sqlite3_value object containing the value read |
+** from the corresponding position in the record. If that value is not |
+** included in the record (i.e. because the record is part of an UPDATE change |
+** and the field was not modified), the corresponding element of apOut[] is |
+** set to NULL. |
+** |
+** It is the responsibility of the caller to free all sqlite_value structures |
+** using sqlite3_free(). |
+** |
+** If an error occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. |
+** The apOut[] array may have been partially populated in this case. |
+*/ |
+static int sessionReadRecord( |
+ SessionInput *pIn, /* Input data */ |
+ int nCol, /* Number of values in record */ |
+ u8 *abPK, /* Array of primary key flags, or NULL */ |
+ sqlite3_value **apOut /* Write values to this array */ |
+){ |
+ int i; /* Used to iterate through columns */ |
+ int rc = SQLITE_OK; |
+ |
+ for(i=0; i<nCol && rc==SQLITE_OK; i++){ |
+ int eType = 0; /* Type of value (SQLITE_NULL, TEXT etc.) */ |
+ if( abPK && abPK[i]==0 ) continue; |
+ rc = sessionInputBuffer(pIn, 9); |
+ if( rc==SQLITE_OK ){ |
+ eType = pIn->aData[pIn->iNext++]; |
+ } |
+ |
+ assert( apOut[i]==0 ); |
+ if( eType ){ |
+ apOut[i] = sqlite3ValueNew(0); |
+ if( !apOut[i] ) rc = SQLITE_NOMEM; |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ u8 *aVal = &pIn->aData[pIn->iNext]; |
+ if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){ |
+ int nByte; |
+ pIn->iNext += sessionVarintGet(aVal, &nByte); |
+ rc = sessionInputBuffer(pIn, nByte); |
+ if( rc==SQLITE_OK ){ |
+ u8 enc = (eType==SQLITE_TEXT ? SQLITE_UTF8 : 0); |
+ rc = sessionValueSetStr(apOut[i],&pIn->aData[pIn->iNext],nByte,enc); |
+ } |
+ pIn->iNext += nByte; |
+ } |
+ if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ sqlite3_int64 v = sessionGetI64(aVal); |
+ if( eType==SQLITE_INTEGER ){ |
+ sqlite3VdbeMemSetInt64(apOut[i], v); |
+ }else{ |
+ double d; |
+ memcpy(&d, &v, 8); |
+ sqlite3VdbeMemSetDouble(apOut[i], d); |
+ } |
+ pIn->iNext += 8; |
+ } |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** The input pointer currently points to the second byte of a table-header. |
+** Specifically, to the following: |
+** |
+** + number of columns in table (varint) |
+** + array of PK flags (1 byte per column), |
+** + table name (nul terminated). |
+** |
+** This function ensures that all of the above is present in the input |
+** buffer (i.e. that it can be accessed without any calls to xInput()). |
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code. |
+** The input pointer is not moved. |
+*/ |
+static int sessionChangesetBufferTblhdr(SessionInput *pIn, int *pnByte){ |
+ int rc = SQLITE_OK; |
+ int nCol = 0; |
+ int nRead = 0; |
+ |
+ rc = sessionInputBuffer(pIn, 9); |
+ if( rc==SQLITE_OK ){ |
+ nRead += sessionVarintGet(&pIn->aData[pIn->iNext + nRead], &nCol); |
+ rc = sessionInputBuffer(pIn, nRead+nCol+100); |
+ nRead += nCol; |
+ } |
+ |
+ while( rc==SQLITE_OK ){ |
+ while( (pIn->iNext + nRead)<pIn->nData && pIn->aData[pIn->iNext + nRead] ){ |
+ nRead++; |
+ } |
+ if( (pIn->iNext + nRead)<pIn->nData ) break; |
+ rc = sessionInputBuffer(pIn, nRead + 100); |
+ } |
+ *pnByte = nRead+1; |
+ return rc; |
+} |
+ |
+/* |
+** The input pointer currently points to the first byte of the first field |
+** of a record consisting of nCol columns. This function ensures the entire |
+** record is buffered. It does not move the input pointer. |
+** |
+** If successful, SQLITE_OK is returned and *pnByte is set to the size of |
+** the record in bytes. Otherwise, an SQLite error code is returned. The |
+** final value of *pnByte is undefined in this case. |
+*/ |
+static int sessionChangesetBufferRecord( |
+ SessionInput *pIn, /* Input data */ |
+ int nCol, /* Number of columns in record */ |
+ int *pnByte /* OUT: Size of record in bytes */ |
+){ |
+ int rc = SQLITE_OK; |
+ int nByte = 0; |
+ int i; |
+ for(i=0; rc==SQLITE_OK && i<nCol; i++){ |
+ int eType; |
+ rc = sessionInputBuffer(pIn, nByte + 10); |
+ if( rc==SQLITE_OK ){ |
+ eType = pIn->aData[pIn->iNext + nByte++]; |
+ if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){ |
+ int n; |
+ nByte += sessionVarintGet(&pIn->aData[pIn->iNext+nByte], &n); |
+ nByte += n; |
+ rc = sessionInputBuffer(pIn, nByte); |
+ }else if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ |
+ nByte += 8; |
+ } |
+ } |
+ } |
+ *pnByte = nByte; |
+ return rc; |
+} |
+ |
+/* |
+** The input pointer currently points to the second byte of a table-header. |
+** Specifically, to the following: |
+** |
+** + number of columns in table (varint) |
+** + array of PK flags (1 byte per column), |
+** + table name (nul terminated). |
+** |
+** This function decodes the table-header and populates the p->nCol, |
+** p->zTab and p->abPK[] variables accordingly. The p->apValue[] array is |
+** also allocated or resized according to the new value of p->nCol. The |
+** input pointer is left pointing to the byte following the table header. |
+** |
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code |
+** is returned and the final values of the various fields enumerated above |
+** are undefined. |
+*/ |
+static int sessionChangesetReadTblhdr(sqlite3_changeset_iter *p){ |
+ int rc; |
+ int nCopy; |
+ assert( p->rc==SQLITE_OK ); |
+ |
+ rc = sessionChangesetBufferTblhdr(&p->in, &nCopy); |
+ if( rc==SQLITE_OK ){ |
+ int nByte; |
+ int nVarint; |
+ nVarint = sessionVarintGet(&p->in.aData[p->in.iNext], &p->nCol); |
+ nCopy -= nVarint; |
+ p->in.iNext += nVarint; |
+ nByte = p->nCol * sizeof(sqlite3_value*) * 2 + nCopy; |
+ p->tblhdr.nBuf = 0; |
+ sessionBufferGrow(&p->tblhdr, nByte, &rc); |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ int iPK = sizeof(sqlite3_value*)*p->nCol*2; |
+ memset(p->tblhdr.aBuf, 0, iPK); |
+ memcpy(&p->tblhdr.aBuf[iPK], &p->in.aData[p->in.iNext], nCopy); |
+ p->in.iNext += nCopy; |
+ } |
+ |
+ p->apValue = (sqlite3_value**)p->tblhdr.aBuf; |
+ p->abPK = (u8*)&p->apValue[p->nCol*2]; |
+ p->zTab = (char*)&p->abPK[p->nCol]; |
+ return (p->rc = rc); |
+} |
+ |
+/* |
+** Advance the changeset iterator to the next change. |
+** |
+** If both paRec and pnRec are NULL, then this function works like the public |
+** API sqlite3changeset_next(). If SQLITE_ROW is returned, then the |
+** sqlite3changeset_new() and old() APIs may be used to query for values. |
+** |
+** Otherwise, if paRec and pnRec are not NULL, then a pointer to the change |
+** record is written to *paRec before returning and the number of bytes in |
+** the record to *pnRec. |
+** |
+** Either way, this function returns SQLITE_ROW if the iterator is |
+** successfully advanced to the next change in the changeset, an SQLite |
+** error code if an error occurs, or SQLITE_DONE if there are no further |
+** changes in the changeset. |
+*/ |
+static int sessionChangesetNext( |
+ sqlite3_changeset_iter *p, /* Changeset iterator */ |
+ u8 **paRec, /* If non-NULL, store record pointer here */ |
+ int *pnRec /* If non-NULL, store size of record here */ |
+){ |
+ int i; |
+ u8 op; |
+ |
+ assert( (paRec==0 && pnRec==0) || (paRec && pnRec) ); |
+ |
+ /* If the iterator is in the error-state, return immediately. */ |
+ if( p->rc!=SQLITE_OK ) return p->rc; |
+ |
+ /* Free the current contents of p->apValue[], if any. */ |
+ if( p->apValue ){ |
+ for(i=0; i<p->nCol*2; i++){ |
+ sqlite3ValueFree(p->apValue[i]); |
+ } |
+ memset(p->apValue, 0, sizeof(sqlite3_value*)*p->nCol*2); |
+ } |
+ |
+ /* Make sure the buffer contains at least 10 bytes of input data, or all |
+ ** remaining data if there are less than 10 bytes available. This is |
+ ** sufficient either for the 'T' or 'P' byte and the varint that follows |
+ ** it, or for the two single byte values otherwise. */ |
+ p->rc = sessionInputBuffer(&p->in, 2); |
+ if( p->rc!=SQLITE_OK ) return p->rc; |
+ |
+ /* If the iterator is already at the end of the changeset, return DONE. */ |
+ if( p->in.iNext>=p->in.nData ){ |
+ return SQLITE_DONE; |
+ } |
+ |
+ sessionDiscardData(&p->in); |
+ p->in.iCurrent = p->in.iNext; |
+ |
+ op = p->in.aData[p->in.iNext++]; |
+ if( op=='T' || op=='P' ){ |
+ p->bPatchset = (op=='P'); |
+ if( sessionChangesetReadTblhdr(p) ) return p->rc; |
+ if( (p->rc = sessionInputBuffer(&p->in, 2)) ) return p->rc; |
+ p->in.iCurrent = p->in.iNext; |
+ op = p->in.aData[p->in.iNext++]; |
+ } |
+ |
+ p->op = op; |
+ p->bIndirect = p->in.aData[p->in.iNext++]; |
+ if( p->op!=SQLITE_UPDATE && p->op!=SQLITE_DELETE && p->op!=SQLITE_INSERT ){ |
+ return (p->rc = SQLITE_CORRUPT_BKPT); |
+ } |
+ |
+ if( paRec ){ |
+ int nVal; /* Number of values to buffer */ |
+ if( p->bPatchset==0 && op==SQLITE_UPDATE ){ |
+ nVal = p->nCol * 2; |
+ }else if( p->bPatchset && op==SQLITE_DELETE ){ |
+ nVal = 0; |
+ for(i=0; i<p->nCol; i++) if( p->abPK[i] ) nVal++; |
+ }else{ |
+ nVal = p->nCol; |
+ } |
+ p->rc = sessionChangesetBufferRecord(&p->in, nVal, pnRec); |
+ if( p->rc!=SQLITE_OK ) return p->rc; |
+ *paRec = &p->in.aData[p->in.iNext]; |
+ p->in.iNext += *pnRec; |
+ }else{ |
+ |
+ /* If this is an UPDATE or DELETE, read the old.* record. */ |
+ if( p->op!=SQLITE_INSERT && (p->bPatchset==0 || p->op==SQLITE_DELETE) ){ |
+ u8 *abPK = p->bPatchset ? p->abPK : 0; |
+ p->rc = sessionReadRecord(&p->in, p->nCol, abPK, p->apValue); |
+ if( p->rc!=SQLITE_OK ) return p->rc; |
+ } |
+ |
+ /* If this is an INSERT or UPDATE, read the new.* record. */ |
+ if( p->op!=SQLITE_DELETE ){ |
+ p->rc = sessionReadRecord(&p->in, p->nCol, 0, &p->apValue[p->nCol]); |
+ if( p->rc!=SQLITE_OK ) return p->rc; |
+ } |
+ |
+ if( p->bPatchset && p->op==SQLITE_UPDATE ){ |
+ /* If this is an UPDATE that is part of a patchset, then all PK and |
+ ** modified fields are present in the new.* record. The old.* record |
+ ** is currently completely empty. This block shifts the PK fields from |
+ ** new.* to old.*, to accommodate the code that reads these arrays. */ |
+ for(i=0; i<p->nCol; i++){ |
+ assert( p->apValue[i]==0 ); |
+ assert( p->abPK[i]==0 || p->apValue[i+p->nCol] ); |
+ if( p->abPK[i] ){ |
+ p->apValue[i] = p->apValue[i+p->nCol]; |
+ p->apValue[i+p->nCol] = 0; |
+ } |
+ } |
+ } |
+ } |
+ |
+ return SQLITE_ROW; |
+} |
+ |
+/* |
+** Advance an iterator created by sqlite3changeset_start() to the next |
+** change in the changeset. This function may return SQLITE_ROW, SQLITE_DONE |
+** or SQLITE_CORRUPT. |
+** |
+** This function may not be called on iterators passed to a conflict handler |
+** callback by changeset_apply(). |
+*/ |
+int sqlite3changeset_next(sqlite3_changeset_iter *p){ |
+ return sessionChangesetNext(p, 0, 0); |
+} |
+ |
+/* |
+** The following function extracts information on the current change |
+** from a changeset iterator. It may only be called after changeset_next() |
+** has returned SQLITE_ROW. |
+*/ |
+int sqlite3changeset_op( |
+ sqlite3_changeset_iter *pIter, /* Iterator handle */ |
+ const char **pzTab, /* OUT: Pointer to table name */ |
+ int *pnCol, /* OUT: Number of columns in table */ |
+ int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ |
+ int *pbIndirect /* OUT: True if change is indirect */ |
+){ |
+ *pOp = pIter->op; |
+ *pnCol = pIter->nCol; |
+ *pzTab = pIter->zTab; |
+ if( pbIndirect ) *pbIndirect = pIter->bIndirect; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Return information regarding the PRIMARY KEY and number of columns in |
+** the database table affected by the change that pIter currently points |
+** to. This function may only be called after changeset_next() returns |
+** SQLITE_ROW. |
+*/ |
+int sqlite3changeset_pk( |
+ sqlite3_changeset_iter *pIter, /* Iterator object */ |
+ unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ |
+ int *pnCol /* OUT: Number of entries in output array */ |
+){ |
+ *pabPK = pIter->abPK; |
+ if( pnCol ) *pnCol = pIter->nCol; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** This function may only be called while the iterator is pointing to an |
+** SQLITE_UPDATE or SQLITE_DELETE change (see sqlite3changeset_op()). |
+** Otherwise, SQLITE_MISUSE is returned. |
+** |
+** It sets *ppValue to point to an sqlite3_value structure containing the |
+** iVal'th value in the old.* record. Or, if that particular value is not |
+** included in the record (because the change is an UPDATE and the field |
+** was not modified and is not a PK column), set *ppValue to NULL. |
+** |
+** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is |
+** not modified. Otherwise, SQLITE_OK. |
+*/ |
+int sqlite3changeset_old( |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ int iVal, /* Index of old.* value to retrieve */ |
+ sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ |
+){ |
+ if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_DELETE ){ |
+ return SQLITE_MISUSE; |
+ } |
+ if( iVal<0 || iVal>=pIter->nCol ){ |
+ return SQLITE_RANGE; |
+ } |
+ *ppValue = pIter->apValue[iVal]; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** This function may only be called while the iterator is pointing to an |
+** SQLITE_UPDATE or SQLITE_INSERT change (see sqlite3changeset_op()). |
+** Otherwise, SQLITE_MISUSE is returned. |
+** |
+** It sets *ppValue to point to an sqlite3_value structure containing the |
+** iVal'th value in the new.* record. Or, if that particular value is not |
+** included in the record (because the change is an UPDATE and the field |
+** was not modified), set *ppValue to NULL. |
+** |
+** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is |
+** not modified. Otherwise, SQLITE_OK. |
+*/ |
+int sqlite3changeset_new( |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ int iVal, /* Index of new.* value to retrieve */ |
+ sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ |
+){ |
+ if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_INSERT ){ |
+ return SQLITE_MISUSE; |
+ } |
+ if( iVal<0 || iVal>=pIter->nCol ){ |
+ return SQLITE_RANGE; |
+ } |
+ *ppValue = pIter->apValue[pIter->nCol+iVal]; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** The following two macros are used internally. They are similar to the |
+** sqlite3changeset_new() and sqlite3changeset_old() functions, except that |
+** they omit all error checking and return a pointer to the requested value. |
+*/ |
+#define sessionChangesetNew(pIter, iVal) (pIter)->apValue[(pIter)->nCol+(iVal)] |
+#define sessionChangesetOld(pIter, iVal) (pIter)->apValue[(iVal)] |
+ |
+/* |
+** This function may only be called with a changeset iterator that has been |
+** passed to an SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT |
+** conflict-handler function. Otherwise, SQLITE_MISUSE is returned. |
+** |
+** If successful, *ppValue is set to point to an sqlite3_value structure |
+** containing the iVal'th value of the conflicting record. |
+** |
+** If value iVal is out-of-range or some other error occurs, an SQLite error |
+** code is returned. Otherwise, SQLITE_OK. |
+*/ |
+int sqlite3changeset_conflict( |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ int iVal, /* Index of conflict record value to fetch */ |
+ sqlite3_value **ppValue /* OUT: Value from conflicting row */ |
+){ |
+ if( !pIter->pConflict ){ |
+ return SQLITE_MISUSE; |
+ } |
+ if( iVal<0 || iVal>=pIter->nCol ){ |
+ return SQLITE_RANGE; |
+ } |
+ *ppValue = sqlite3_column_value(pIter->pConflict, iVal); |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** This function may only be called with an iterator passed to an |
+** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case |
+** it sets the output variable to the total number of known foreign key |
+** violations in the destination database and returns SQLITE_OK. |
+** |
+** In all other cases this function returns SQLITE_MISUSE. |
+*/ |
+int sqlite3changeset_fk_conflicts( |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ int *pnOut /* OUT: Number of FK violations */ |
+){ |
+ if( pIter->pConflict || pIter->apValue ){ |
+ return SQLITE_MISUSE; |
+ } |
+ *pnOut = pIter->nCol; |
+ return SQLITE_OK; |
+} |
+ |
+ |
+/* |
+** Finalize an iterator allocated with sqlite3changeset_start(). |
+** |
+** This function may not be called on iterators passed to a conflict handler |
+** callback by changeset_apply(). |
+*/ |
+int sqlite3changeset_finalize(sqlite3_changeset_iter *p){ |
+ int rc = SQLITE_OK; |
+ if( p ){ |
+ int i; /* Used to iterate through p->apValue[] */ |
+ rc = p->rc; |
+ if( p->apValue ){ |
+ for(i=0; i<p->nCol*2; i++) sqlite3ValueFree(p->apValue[i]); |
+ } |
+ sqlite3_free(p->tblhdr.aBuf); |
+ sqlite3_free(p->in.buf.aBuf); |
+ sqlite3_free(p); |
+ } |
+ return rc; |
+} |
+ |
+static int sessionChangesetInvert( |
+ SessionInput *pInput, /* Input changeset */ |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut, |
+ int *pnInverted, /* OUT: Number of bytes in output changeset */ |
+ void **ppInverted /* OUT: Inverse of pChangeset */ |
+){ |
+ int rc = SQLITE_OK; /* Return value */ |
+ SessionBuffer sOut; /* Output buffer */ |
+ int nCol = 0; /* Number of cols in current table */ |
+ u8 *abPK = 0; /* PK array for current table */ |
+ sqlite3_value **apVal = 0; /* Space for values for UPDATE inversion */ |
+ SessionBuffer sPK = {0, 0, 0}; /* PK array for current table */ |
+ |
+ /* Initialize the output buffer */ |
+ memset(&sOut, 0, sizeof(SessionBuffer)); |
+ |
+ /* Zero the output variables in case an error occurs. */ |
+ if( ppInverted ){ |
+ *ppInverted = 0; |
+ *pnInverted = 0; |
+ } |
+ |
+ while( 1 ){ |
+ u8 eType; |
+ |
+ /* Test for EOF. */ |
+ if( (rc = sessionInputBuffer(pInput, 2)) ) goto finished_invert; |
+ if( pInput->iNext>=pInput->nData ) break; |
+ eType = pInput->aData[pInput->iNext]; |
+ |
+ switch( eType ){ |
+ case 'T': { |
+ /* A 'table' record consists of: |
+ ** |
+ ** * A constant 'T' character, |
+ ** * Number of columns in said table (a varint), |
+ ** * An array of nCol bytes (sPK), |
+ ** * A nul-terminated table name. |
+ */ |
+ int nByte; |
+ int nVar; |
+ pInput->iNext++; |
+ if( (rc = sessionChangesetBufferTblhdr(pInput, &nByte)) ){ |
+ goto finished_invert; |
+ } |
+ nVar = sessionVarintGet(&pInput->aData[pInput->iNext], &nCol); |
+ sPK.nBuf = 0; |
+ sessionAppendBlob(&sPK, &pInput->aData[pInput->iNext+nVar], nCol, &rc); |
+ sessionAppendByte(&sOut, eType, &rc); |
+ sessionAppendBlob(&sOut, &pInput->aData[pInput->iNext], nByte, &rc); |
+ if( rc ) goto finished_invert; |
+ |
+ pInput->iNext += nByte; |
+ sqlite3_free(apVal); |
+ apVal = 0; |
+ abPK = sPK.aBuf; |
+ break; |
+ } |
+ |
+ case SQLITE_INSERT: |
+ case SQLITE_DELETE: { |
+ int nByte; |
+ int bIndirect = pInput->aData[pInput->iNext+1]; |
+ int eType2 = (eType==SQLITE_DELETE ? SQLITE_INSERT : SQLITE_DELETE); |
+ pInput->iNext += 2; |
+ assert( rc==SQLITE_OK ); |
+ rc = sessionChangesetBufferRecord(pInput, nCol, &nByte); |
+ sessionAppendByte(&sOut, eType2, &rc); |
+ sessionAppendByte(&sOut, bIndirect, &rc); |
+ sessionAppendBlob(&sOut, &pInput->aData[pInput->iNext], nByte, &rc); |
+ pInput->iNext += nByte; |
+ if( rc ) goto finished_invert; |
+ break; |
+ } |
+ |
+ case SQLITE_UPDATE: { |
+ int iCol; |
+ |
+ if( 0==apVal ){ |
+ apVal = (sqlite3_value **)sqlite3_malloc(sizeof(apVal[0])*nCol*2); |
+ if( 0==apVal ){ |
+ rc = SQLITE_NOMEM; |
+ goto finished_invert; |
+ } |
+ memset(apVal, 0, sizeof(apVal[0])*nCol*2); |
+ } |
+ |
+ /* Write the header for the new UPDATE change. Same as the original. */ |
+ sessionAppendByte(&sOut, eType, &rc); |
+ sessionAppendByte(&sOut, pInput->aData[pInput->iNext+1], &rc); |
+ |
+ /* Read the old.* and new.* records for the update change. */ |
+ pInput->iNext += 2; |
+ rc = sessionReadRecord(pInput, nCol, 0, &apVal[0]); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionReadRecord(pInput, nCol, 0, &apVal[nCol]); |
+ } |
+ |
+ /* Write the new old.* record. Consists of the PK columns from the |
+ ** original old.* record, and the other values from the original |
+ ** new.* record. */ |
+ for(iCol=0; iCol<nCol; iCol++){ |
+ sqlite3_value *pVal = apVal[iCol + (abPK[iCol] ? 0 : nCol)]; |
+ sessionAppendValue(&sOut, pVal, &rc); |
+ } |
+ |
+ /* Write the new new.* record. Consists of a copy of all values |
+ ** from the original old.* record, except for the PK columns, which |
+ ** are set to "undefined". */ |
+ for(iCol=0; iCol<nCol; iCol++){ |
+ sqlite3_value *pVal = (abPK[iCol] ? 0 : apVal[iCol]); |
+ sessionAppendValue(&sOut, pVal, &rc); |
+ } |
+ |
+ for(iCol=0; iCol<nCol*2; iCol++){ |
+ sqlite3ValueFree(apVal[iCol]); |
+ } |
+ memset(apVal, 0, sizeof(apVal[0])*nCol*2); |
+ if( rc!=SQLITE_OK ){ |
+ goto finished_invert; |
+ } |
+ |
+ break; |
+ } |
+ |
+ default: |
+ rc = SQLITE_CORRUPT_BKPT; |
+ goto finished_invert; |
+ } |
+ |
+ assert( rc==SQLITE_OK ); |
+ if( xOutput && sOut.nBuf>=SESSIONS_STRM_CHUNK_SIZE ){ |
+ rc = xOutput(pOut, sOut.aBuf, sOut.nBuf); |
+ sOut.nBuf = 0; |
+ if( rc!=SQLITE_OK ) goto finished_invert; |
+ } |
+ } |
+ |
+ assert( rc==SQLITE_OK ); |
+ if( pnInverted ){ |
+ *pnInverted = sOut.nBuf; |
+ *ppInverted = sOut.aBuf; |
+ sOut.aBuf = 0; |
+ }else if( sOut.nBuf>0 ){ |
+ rc = xOutput(pOut, sOut.aBuf, sOut.nBuf); |
+ } |
+ |
+ finished_invert: |
+ sqlite3_free(sOut.aBuf); |
+ sqlite3_free(apVal); |
+ sqlite3_free(sPK.aBuf); |
+ return rc; |
+} |
+ |
+ |
+/* |
+** Invert a changeset object. |
+*/ |
+int sqlite3changeset_invert( |
+ int nChangeset, /* Number of bytes in input */ |
+ const void *pChangeset, /* Input changeset */ |
+ int *pnInverted, /* OUT: Number of bytes in output changeset */ |
+ void **ppInverted /* OUT: Inverse of pChangeset */ |
+){ |
+ SessionInput sInput; |
+ |
+ /* Set up the input stream */ |
+ memset(&sInput, 0, sizeof(SessionInput)); |
+ sInput.nData = nChangeset; |
+ sInput.aData = (u8*)pChangeset; |
+ |
+ return sessionChangesetInvert(&sInput, 0, 0, pnInverted, ppInverted); |
+} |
+ |
+/* |
+** Streaming version of sqlite3changeset_invert(). |
+*/ |
+int sqlite3changeset_invert_strm( |
+ int (*xInput)(void *pIn, void *pData, int *pnData), |
+ void *pIn, |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut |
+){ |
+ SessionInput sInput; |
+ int rc; |
+ |
+ /* Set up the input stream */ |
+ memset(&sInput, 0, sizeof(SessionInput)); |
+ sInput.xInput = xInput; |
+ sInput.pIn = pIn; |
+ |
+ rc = sessionChangesetInvert(&sInput, xOutput, pOut, 0, 0); |
+ sqlite3_free(sInput.buf.aBuf); |
+ return rc; |
+} |
+ |
+typedef struct SessionApplyCtx SessionApplyCtx; |
+struct SessionApplyCtx { |
+ sqlite3 *db; |
+ sqlite3_stmt *pDelete; /* DELETE statement */ |
+ sqlite3_stmt *pUpdate; /* UPDATE statement */ |
+ sqlite3_stmt *pInsert; /* INSERT statement */ |
+ sqlite3_stmt *pSelect; /* SELECT statement */ |
+ int nCol; /* Size of azCol[] and abPK[] arrays */ |
+ const char **azCol; /* Array of column names */ |
+ u8 *abPK; /* Boolean array - true if column is in PK */ |
+ |
+ int bDeferConstraints; /* True to defer constraints */ |
+ SessionBuffer constraints; /* Deferred constraints are stored here */ |
+}; |
+ |
+/* |
+** Formulate a statement to DELETE a row from database db. Assuming a table |
+** structure like this: |
+** |
+** CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c)); |
+** |
+** The DELETE statement looks like this: |
+** |
+** DELETE FROM x WHERE a = :1 AND c = :3 AND (:5 OR b IS :2 AND d IS :4) |
+** |
+** Variable :5 (nCol+1) is a boolean. It should be set to 0 if we require |
+** matching b and d values, or 1 otherwise. The second case comes up if the |
+** conflict handler is invoked with NOTFOUND and returns CHANGESET_REPLACE. |
+** |
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pDelete is left |
+** pointing to the prepared version of the SQL statement. |
+*/ |
+static int sessionDeleteRow( |
+ sqlite3 *db, /* Database handle */ |
+ const char *zTab, /* Table name */ |
+ SessionApplyCtx *p /* Session changeset-apply context */ |
+){ |
+ int i; |
+ const char *zSep = ""; |
+ int rc = SQLITE_OK; |
+ SessionBuffer buf = {0, 0, 0}; |
+ int nPk = 0; |
+ |
+ sessionAppendStr(&buf, "DELETE FROM ", &rc); |
+ sessionAppendIdent(&buf, zTab, &rc); |
+ sessionAppendStr(&buf, " WHERE ", &rc); |
+ |
+ for(i=0; i<p->nCol; i++){ |
+ if( p->abPK[i] ){ |
+ nPk++; |
+ sessionAppendStr(&buf, zSep, &rc); |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ sessionAppendStr(&buf, " = ?", &rc); |
+ sessionAppendInteger(&buf, i+1, &rc); |
+ zSep = " AND "; |
+ } |
+ } |
+ |
+ if( nPk<p->nCol ){ |
+ sessionAppendStr(&buf, " AND (?", &rc); |
+ sessionAppendInteger(&buf, p->nCol+1, &rc); |
+ sessionAppendStr(&buf, " OR ", &rc); |
+ |
+ zSep = ""; |
+ for(i=0; i<p->nCol; i++){ |
+ if( !p->abPK[i] ){ |
+ sessionAppendStr(&buf, zSep, &rc); |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ sessionAppendStr(&buf, " IS ?", &rc); |
+ sessionAppendInteger(&buf, i+1, &rc); |
+ zSep = "AND "; |
+ } |
+ } |
+ sessionAppendStr(&buf, ")", &rc); |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pDelete, 0); |
+ } |
+ sqlite3_free(buf.aBuf); |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Formulate and prepare a statement to UPDATE a row from database db. |
+** Assuming a table structure like this: |
+** |
+** CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c)); |
+** |
+** The UPDATE statement looks like this: |
+** |
+** UPDATE x SET |
+** a = CASE WHEN ?2 THEN ?3 ELSE a END, |
+** b = CASE WHEN ?5 THEN ?6 ELSE b END, |
+** c = CASE WHEN ?8 THEN ?9 ELSE c END, |
+** d = CASE WHEN ?11 THEN ?12 ELSE d END |
+** WHERE a = ?1 AND c = ?7 AND (?13 OR |
+** (?5==0 OR b IS ?4) AND (?11==0 OR d IS ?10) AND |
+** ) |
+** |
+** For each column in the table, there are three variables to bind: |
+** |
+** ?(i*3+1) The old.* value of the column, if any. |
+** ?(i*3+2) A boolean flag indicating that the value is being modified. |
+** ?(i*3+3) The new.* value of the column, if any. |
+** |
+** Also, a boolean flag that, if set to true, causes the statement to update |
+** a row even if the non-PK values do not match. This is required if the |
+** conflict-handler is invoked with CHANGESET_DATA and returns |
+** CHANGESET_REPLACE. This is variable "?(nCol*3+1)". |
+** |
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pUpdate is left |
+** pointing to the prepared version of the SQL statement. |
+*/ |
+static int sessionUpdateRow( |
+ sqlite3 *db, /* Database handle */ |
+ const char *zTab, /* Table name */ |
+ SessionApplyCtx *p /* Session changeset-apply context */ |
+){ |
+ int rc = SQLITE_OK; |
+ int i; |
+ const char *zSep = ""; |
+ SessionBuffer buf = {0, 0, 0}; |
+ |
+ /* Append "UPDATE tbl SET " */ |
+ sessionAppendStr(&buf, "UPDATE ", &rc); |
+ sessionAppendIdent(&buf, zTab, &rc); |
+ sessionAppendStr(&buf, " SET ", &rc); |
+ |
+ /* Append the assignments */ |
+ for(i=0; i<p->nCol; i++){ |
+ sessionAppendStr(&buf, zSep, &rc); |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ sessionAppendStr(&buf, " = CASE WHEN ?", &rc); |
+ sessionAppendInteger(&buf, i*3+2, &rc); |
+ sessionAppendStr(&buf, " THEN ?", &rc); |
+ sessionAppendInteger(&buf, i*3+3, &rc); |
+ sessionAppendStr(&buf, " ELSE ", &rc); |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ sessionAppendStr(&buf, " END", &rc); |
+ zSep = ", "; |
+ } |
+ |
+ /* Append the PK part of the WHERE clause */ |
+ sessionAppendStr(&buf, " WHERE ", &rc); |
+ for(i=0; i<p->nCol; i++){ |
+ if( p->abPK[i] ){ |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ sessionAppendStr(&buf, " = ?", &rc); |
+ sessionAppendInteger(&buf, i*3+1, &rc); |
+ sessionAppendStr(&buf, " AND ", &rc); |
+ } |
+ } |
+ |
+ /* Append the non-PK part of the WHERE clause */ |
+ sessionAppendStr(&buf, " (?", &rc); |
+ sessionAppendInteger(&buf, p->nCol*3+1, &rc); |
+ sessionAppendStr(&buf, " OR 1", &rc); |
+ for(i=0; i<p->nCol; i++){ |
+ if( !p->abPK[i] ){ |
+ sessionAppendStr(&buf, " AND (?", &rc); |
+ sessionAppendInteger(&buf, i*3+2, &rc); |
+ sessionAppendStr(&buf, "=0 OR ", &rc); |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ sessionAppendStr(&buf, " IS ?", &rc); |
+ sessionAppendInteger(&buf, i*3+1, &rc); |
+ sessionAppendStr(&buf, ")", &rc); |
+ } |
+ } |
+ sessionAppendStr(&buf, ")", &rc); |
+ |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pUpdate, 0); |
+ } |
+ sqlite3_free(buf.aBuf); |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Formulate and prepare an SQL statement to query table zTab by primary |
+** key. Assuming the following table structure: |
+** |
+** CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c)); |
+** |
+** The SELECT statement looks like this: |
+** |
+** SELECT * FROM x WHERE a = ?1 AND c = ?3 |
+** |
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pSelect is left |
+** pointing to the prepared version of the SQL statement. |
+*/ |
+static int sessionSelectRow( |
+ sqlite3 *db, /* Database handle */ |
+ const char *zTab, /* Table name */ |
+ SessionApplyCtx *p /* Session changeset-apply context */ |
+){ |
+ return sessionSelectStmt( |
+ db, "main", zTab, p->nCol, p->azCol, p->abPK, &p->pSelect); |
+} |
+ |
+/* |
+** Formulate and prepare an INSERT statement to add a record to table zTab. |
+** For example: |
+** |
+** INSERT INTO main."zTab" VALUES(?1, ?2, ?3 ...); |
+** |
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pInsert is left |
+** pointing to the prepared version of the SQL statement. |
+*/ |
+static int sessionInsertRow( |
+ sqlite3 *db, /* Database handle */ |
+ const char *zTab, /* Table name */ |
+ SessionApplyCtx *p /* Session changeset-apply context */ |
+){ |
+ int rc = SQLITE_OK; |
+ int i; |
+ SessionBuffer buf = {0, 0, 0}; |
+ |
+ sessionAppendStr(&buf, "INSERT INTO main.", &rc); |
+ sessionAppendIdent(&buf, zTab, &rc); |
+ sessionAppendStr(&buf, "(", &rc); |
+ for(i=0; i<p->nCol; i++){ |
+ if( i!=0 ) sessionAppendStr(&buf, ", ", &rc); |
+ sessionAppendIdent(&buf, p->azCol[i], &rc); |
+ } |
+ |
+ sessionAppendStr(&buf, ") VALUES(?", &rc); |
+ for(i=1; i<p->nCol; i++){ |
+ sessionAppendStr(&buf, ", ?", &rc); |
+ } |
+ sessionAppendStr(&buf, ")", &rc); |
+ |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pInsert, 0); |
+ } |
+ sqlite3_free(buf.aBuf); |
+ return rc; |
+} |
+ |
+/* |
+** A wrapper around sqlite3_bind_value() that detects an extra problem. |
+** See comments in the body of this function for details. |
+*/ |
+static int sessionBindValue( |
+ sqlite3_stmt *pStmt, /* Statement to bind value to */ |
+ int i, /* Parameter number to bind to */ |
+ sqlite3_value *pVal /* Value to bind */ |
+){ |
+ int eType = sqlite3_value_type(pVal); |
+ /* COVERAGE: The (pVal->z==0) branch is never true using current versions |
+ ** of SQLite. If a malloc fails in an sqlite3_value_xxx() function, either |
+ ** the (pVal->z) variable remains as it was or the type of the value is |
+ ** set to SQLITE_NULL. */ |
+ if( (eType==SQLITE_TEXT || eType==SQLITE_BLOB) && pVal->z==0 ){ |
+ /* This condition occurs when an earlier OOM in a call to |
+ ** sqlite3_value_text() or sqlite3_value_blob() (perhaps from within |
+ ** a conflict-handler) has zeroed the pVal->z pointer. Return NOMEM. */ |
+ return SQLITE_NOMEM; |
+ } |
+ return sqlite3_bind_value(pStmt, i, pVal); |
+} |
+ |
+/* |
+** Iterator pIter must point to an SQLITE_INSERT entry. This function |
+** transfers new.* values from the current iterator entry to statement |
+** pStmt. The table being inserted into has nCol columns. |
+** |
+** New.* value $i from the iterator is bound to variable ($i+1) of |
+** statement pStmt. If parameter abPK is NULL, all values from 0 to (nCol-1) |
+** are transfered to the statement. Otherwise, if abPK is not NULL, it points |
+** to an array nCol elements in size. In this case only those values for |
+** which abPK[$i] is true are read from the iterator and bound to the |
+** statement. |
+** |
+** An SQLite error code is returned if an error occurs. Otherwise, SQLITE_OK. |
+*/ |
+static int sessionBindRow( |
+ sqlite3_changeset_iter *pIter, /* Iterator to read values from */ |
+ int(*xValue)(sqlite3_changeset_iter *, int, sqlite3_value **), |
+ int nCol, /* Number of columns */ |
+ u8 *abPK, /* If not NULL, bind only if true */ |
+ sqlite3_stmt *pStmt /* Bind values to this statement */ |
+){ |
+ int i; |
+ int rc = SQLITE_OK; |
+ |
+ /* Neither sqlite3changeset_old or sqlite3changeset_new can fail if the |
+ ** argument iterator points to a suitable entry. Make sure that xValue |
+ ** is one of these to guarantee that it is safe to ignore the return |
+ ** in the code below. */ |
+ assert( xValue==sqlite3changeset_old || xValue==sqlite3changeset_new ); |
+ |
+ for(i=0; rc==SQLITE_OK && i<nCol; i++){ |
+ if( !abPK || abPK[i] ){ |
+ sqlite3_value *pVal; |
+ (void)xValue(pIter, i, &pVal); |
+ rc = sessionBindValue(pStmt, i+1, pVal); |
+ } |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** SQL statement pSelect is as generated by the sessionSelectRow() function. |
+** This function binds the primary key values from the change that changeset |
+** iterator pIter points to to the SELECT and attempts to seek to the table |
+** entry. If a row is found, the SELECT statement left pointing at the row |
+** and SQLITE_ROW is returned. Otherwise, if no row is found and no error |
+** has occured, the statement is reset and SQLITE_OK is returned. If an |
+** error occurs, the statement is reset and an SQLite error code is returned. |
+** |
+** If this function returns SQLITE_ROW, the caller must eventually reset() |
+** statement pSelect. If any other value is returned, the statement does |
+** not require a reset(). |
+** |
+** If the iterator currently points to an INSERT record, bind values from the |
+** new.* record to the SELECT statement. Or, if it points to a DELETE or |
+** UPDATE, bind values from the old.* record. |
+*/ |
+static int sessionSeekToRow( |
+ sqlite3 *db, /* Database handle */ |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ u8 *abPK, /* Primary key flags array */ |
+ sqlite3_stmt *pSelect /* SELECT statement from sessionSelectRow() */ |
+){ |
+ int rc; /* Return code */ |
+ int nCol; /* Number of columns in table */ |
+ int op; /* Changset operation (SQLITE_UPDATE etc.) */ |
+ const char *zDummy; /* Unused */ |
+ |
+ sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0); |
+ rc = sessionBindRow(pIter, |
+ op==SQLITE_INSERT ? sqlite3changeset_new : sqlite3changeset_old, |
+ nCol, abPK, pSelect |
+ ); |
+ |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_step(pSelect); |
+ if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect); |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Invoke the conflict handler for the change that the changeset iterator |
+** currently points to. |
+** |
+** Argument eType must be either CHANGESET_DATA or CHANGESET_CONFLICT. |
+** If argument pbReplace is NULL, then the type of conflict handler invoked |
+** depends solely on eType, as follows: |
+** |
+** eType value Value passed to xConflict |
+** ------------------------------------------------- |
+** CHANGESET_DATA CHANGESET_NOTFOUND |
+** CHANGESET_CONFLICT CHANGESET_CONSTRAINT |
+** |
+** Or, if pbReplace is not NULL, then an attempt is made to find an existing |
+** record with the same primary key as the record about to be deleted, updated |
+** or inserted. If such a record can be found, it is available to the conflict |
+** handler as the "conflicting" record. In this case the type of conflict |
+** handler invoked is as follows: |
+** |
+** eType value PK Record found? Value passed to xConflict |
+** ---------------------------------------------------------------- |
+** CHANGESET_DATA Yes CHANGESET_DATA |
+** CHANGESET_DATA No CHANGESET_NOTFOUND |
+** CHANGESET_CONFLICT Yes CHANGESET_CONFLICT |
+** CHANGESET_CONFLICT No CHANGESET_CONSTRAINT |
+** |
+** If pbReplace is not NULL, and a record with a matching PK is found, and |
+** the conflict handler function returns SQLITE_CHANGESET_REPLACE, *pbReplace |
+** is set to non-zero before returning SQLITE_OK. |
+** |
+** If the conflict handler returns SQLITE_CHANGESET_ABORT, SQLITE_ABORT is |
+** returned. Or, if the conflict handler returns an invalid value, |
+** SQLITE_MISUSE. If the conflict handler returns SQLITE_CHANGESET_OMIT, |
+** this function returns SQLITE_OK. |
+*/ |
+static int sessionConflictHandler( |
+ int eType, /* Either CHANGESET_DATA or CONFLICT */ |
+ SessionApplyCtx *p, /* changeset_apply() context */ |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ int(*xConflict)(void *, int, sqlite3_changeset_iter*), |
+ void *pCtx, /* First argument for conflict handler */ |
+ int *pbReplace /* OUT: Set to true if PK row is found */ |
+){ |
+ int res = 0; /* Value returned by conflict handler */ |
+ int rc; |
+ int nCol; |
+ int op; |
+ const char *zDummy; |
+ |
+ sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0); |
+ |
+ assert( eType==SQLITE_CHANGESET_CONFLICT || eType==SQLITE_CHANGESET_DATA ); |
+ assert( SQLITE_CHANGESET_CONFLICT+1==SQLITE_CHANGESET_CONSTRAINT ); |
+ assert( SQLITE_CHANGESET_DATA+1==SQLITE_CHANGESET_NOTFOUND ); |
+ |
+ /* Bind the new.* PRIMARY KEY values to the SELECT statement. */ |
+ if( pbReplace ){ |
+ rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect); |
+ }else{ |
+ rc = SQLITE_OK; |
+ } |
+ |
+ if( rc==SQLITE_ROW ){ |
+ /* There exists another row with the new.* primary key. */ |
+ pIter->pConflict = p->pSelect; |
+ res = xConflict(pCtx, eType, pIter); |
+ pIter->pConflict = 0; |
+ rc = sqlite3_reset(p->pSelect); |
+ }else if( rc==SQLITE_OK ){ |
+ if( p->bDeferConstraints && eType==SQLITE_CHANGESET_CONFLICT ){ |
+ /* Instead of invoking the conflict handler, append the change blob |
+ ** to the SessionApplyCtx.constraints buffer. */ |
+ u8 *aBlob = &pIter->in.aData[pIter->in.iCurrent]; |
+ int nBlob = pIter->in.iNext - pIter->in.iCurrent; |
+ sessionAppendBlob(&p->constraints, aBlob, nBlob, &rc); |
+ res = SQLITE_CHANGESET_OMIT; |
+ }else{ |
+ /* No other row with the new.* primary key. */ |
+ res = xConflict(pCtx, eType+1, pIter); |
+ if( res==SQLITE_CHANGESET_REPLACE ) rc = SQLITE_MISUSE; |
+ } |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ switch( res ){ |
+ case SQLITE_CHANGESET_REPLACE: |
+ assert( pbReplace ); |
+ *pbReplace = 1; |
+ break; |
+ |
+ case SQLITE_CHANGESET_OMIT: |
+ break; |
+ |
+ case SQLITE_CHANGESET_ABORT: |
+ rc = SQLITE_ABORT; |
+ break; |
+ |
+ default: |
+ rc = SQLITE_MISUSE; |
+ break; |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Attempt to apply the change that the iterator passed as the first argument |
+** currently points to to the database. If a conflict is encountered, invoke |
+** the conflict handler callback. |
+** |
+** If argument pbRetry is NULL, then ignore any CHANGESET_DATA conflict. If |
+** one is encountered, update or delete the row with the matching primary key |
+** instead. Or, if pbRetry is not NULL and a CHANGESET_DATA conflict occurs, |
+** invoke the conflict handler. If it returns CHANGESET_REPLACE, set *pbRetry |
+** to true before returning. In this case the caller will invoke this function |
+** again, this time with pbRetry set to NULL. |
+** |
+** If argument pbReplace is NULL and a CHANGESET_CONFLICT conflict is |
+** encountered invoke the conflict handler with CHANGESET_CONSTRAINT instead. |
+** Or, if pbReplace is not NULL, invoke it with CHANGESET_CONFLICT. If such |
+** an invocation returns SQLITE_CHANGESET_REPLACE, set *pbReplace to true |
+** before retrying. In this case the caller attempts to remove the conflicting |
+** row before invoking this function again, this time with pbReplace set |
+** to NULL. |
+** |
+** If any conflict handler returns SQLITE_CHANGESET_ABORT, this function |
+** returns SQLITE_ABORT. Otherwise, if no error occurs, SQLITE_OK is |
+** returned. |
+*/ |
+static int sessionApplyOneOp( |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator */ |
+ SessionApplyCtx *p, /* changeset_apply() context */ |
+ int(*xConflict)(void *, int, sqlite3_changeset_iter *), |
+ void *pCtx, /* First argument for the conflict handler */ |
+ int *pbReplace, /* OUT: True to remove PK row and retry */ |
+ int *pbRetry /* OUT: True to retry. */ |
+){ |
+ const char *zDummy; |
+ int op; |
+ int nCol; |
+ int rc = SQLITE_OK; |
+ |
+ assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect ); |
+ assert( p->azCol && p->abPK ); |
+ assert( !pbReplace || *pbReplace==0 ); |
+ |
+ sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0); |
+ |
+ if( op==SQLITE_DELETE ){ |
+ |
+ /* Bind values to the DELETE statement. If conflict handling is required, |
+ ** bind values for all columns and set bound variable (nCol+1) to true. |
+ ** Or, if conflict handling is not required, bind just the PK column |
+ ** values and, if it exists, set (nCol+1) to false. Conflict handling |
+ ** is not required if: |
+ ** |
+ ** * this is a patchset, or |
+ ** * (pbRetry==0), or |
+ ** * all columns of the table are PK columns (in this case there is |
+ ** no (nCol+1) variable to bind to). |
+ */ |
+ u8 *abPK = (pIter->bPatchset ? p->abPK : 0); |
+ rc = sessionBindRow(pIter, sqlite3changeset_old, nCol, abPK, p->pDelete); |
+ if( rc==SQLITE_OK && sqlite3_bind_parameter_count(p->pDelete)>nCol ){ |
+ rc = sqlite3_bind_int(p->pDelete, nCol+1, (pbRetry==0 || abPK)); |
+ } |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ sqlite3_step(p->pDelete); |
+ rc = sqlite3_reset(p->pDelete); |
+ if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){ |
+ rc = sessionConflictHandler( |
+ SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry |
+ ); |
+ }else if( (rc&0xff)==SQLITE_CONSTRAINT ){ |
+ rc = sessionConflictHandler( |
+ SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0 |
+ ); |
+ } |
+ |
+ }else if( op==SQLITE_UPDATE ){ |
+ int i; |
+ |
+ /* Bind values to the UPDATE statement. */ |
+ for(i=0; rc==SQLITE_OK && i<nCol; i++){ |
+ sqlite3_value *pOld = sessionChangesetOld(pIter, i); |
+ sqlite3_value *pNew = sessionChangesetNew(pIter, i); |
+ |
+ sqlite3_bind_int(p->pUpdate, i*3+2, !!pNew); |
+ if( pOld ){ |
+ rc = sessionBindValue(p->pUpdate, i*3+1, pOld); |
+ } |
+ if( rc==SQLITE_OK && pNew ){ |
+ rc = sessionBindValue(p->pUpdate, i*3+3, pNew); |
+ } |
+ } |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_bind_int(p->pUpdate, nCol*3+1, pbRetry==0 || pIter->bPatchset); |
+ } |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ /* Attempt the UPDATE. In the case of a NOTFOUND or DATA conflict, |
+ ** the result will be SQLITE_OK with 0 rows modified. */ |
+ sqlite3_step(p->pUpdate); |
+ rc = sqlite3_reset(p->pUpdate); |
+ |
+ if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){ |
+ /* A NOTFOUND or DATA error. Search the table to see if it contains |
+ ** a row with a matching primary key. If so, this is a DATA conflict. |
+ ** Otherwise, if there is no primary key match, it is a NOTFOUND. */ |
+ |
+ rc = sessionConflictHandler( |
+ SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry |
+ ); |
+ |
+ }else if( (rc&0xff)==SQLITE_CONSTRAINT ){ |
+ /* This is always a CONSTRAINT conflict. */ |
+ rc = sessionConflictHandler( |
+ SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0 |
+ ); |
+ } |
+ |
+ }else{ |
+ assert( op==SQLITE_INSERT ); |
+ rc = sessionBindRow(pIter, sqlite3changeset_new, nCol, 0, p->pInsert); |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ sqlite3_step(p->pInsert); |
+ rc = sqlite3_reset(p->pInsert); |
+ if( (rc&0xff)==SQLITE_CONSTRAINT ){ |
+ rc = sessionConflictHandler( |
+ SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, pbReplace |
+ ); |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Attempt to apply the change that the iterator passed as the first argument |
+** currently points to to the database. If a conflict is encountered, invoke |
+** the conflict handler callback. |
+** |
+** The difference between this function and sessionApplyOne() is that this |
+** function handles the case where the conflict-handler is invoked and |
+** returns SQLITE_CHANGESET_REPLACE - indicating that the change should be |
+** retried in some manner. |
+*/ |
+static int sessionApplyOneWithRetry( |
+ sqlite3 *db, /* Apply change to "main" db of this handle */ |
+ sqlite3_changeset_iter *pIter, /* Changeset iterator to read change from */ |
+ SessionApplyCtx *pApply, /* Apply context */ |
+ int(*xConflict)(void*, int, sqlite3_changeset_iter*), |
+ void *pCtx /* First argument passed to xConflict */ |
+){ |
+ int bReplace = 0; |
+ int bRetry = 0; |
+ int rc; |
+ |
+ rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, &bReplace, &bRetry); |
+ assert( rc==SQLITE_OK || (bRetry==0 && bReplace==0) ); |
+ |
+ /* If the bRetry flag is set, the change has not been applied due to an |
+ ** SQLITE_CHANGESET_DATA problem (i.e. this is an UPDATE or DELETE and |
+ ** a row with the correct PK is present in the db, but one or more other |
+ ** fields do not contain the expected values) and the conflict handler |
+ ** returned SQLITE_CHANGESET_REPLACE. In this case retry the operation, |
+ ** but pass NULL as the final argument so that sessionApplyOneOp() ignores |
+ ** the SQLITE_CHANGESET_DATA problem. */ |
+ if( bRetry ){ |
+ assert( pIter->op==SQLITE_UPDATE || pIter->op==SQLITE_DELETE ); |
+ rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, 0, 0); |
+ } |
+ |
+ /* If the bReplace flag is set, the change is an INSERT that has not |
+ ** been performed because the database already contains a row with the |
+ ** specified primary key and the conflict handler returned |
+ ** SQLITE_CHANGESET_REPLACE. In this case remove the conflicting row |
+ ** before reattempting the INSERT. */ |
+ else if( bReplace ){ |
+ assert( pIter->op==SQLITE_INSERT ); |
+ rc = sqlite3_exec(db, "SAVEPOINT replace_op", 0, 0, 0); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionBindRow(pIter, |
+ sqlite3changeset_new, pApply->nCol, pApply->abPK, pApply->pDelete); |
+ sqlite3_bind_int(pApply->pDelete, pApply->nCol+1, 1); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_step(pApply->pDelete); |
+ rc = sqlite3_reset(pApply->pDelete); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, 0, 0); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_exec(db, "RELEASE replace_op", 0, 0, 0); |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Retry the changes accumulated in the pApply->constraints buffer. |
+*/ |
+static int sessionRetryConstraints( |
+ sqlite3 *db, |
+ int bPatchset, |
+ const char *zTab, |
+ SessionApplyCtx *pApply, |
+ int(*xConflict)(void*, int, sqlite3_changeset_iter*), |
+ void *pCtx /* First argument passed to xConflict */ |
+){ |
+ int rc = SQLITE_OK; |
+ |
+ while( pApply->constraints.nBuf ){ |
+ sqlite3_changeset_iter *pIter2 = 0; |
+ SessionBuffer cons = pApply->constraints; |
+ memset(&pApply->constraints, 0, sizeof(SessionBuffer)); |
+ |
+ rc = sessionChangesetStart(&pIter2, 0, 0, cons.nBuf, cons.aBuf); |
+ if( rc==SQLITE_OK ){ |
+ int nByte = 2*pApply->nCol*sizeof(sqlite3_value*); |
+ int rc2; |
+ pIter2->bPatchset = bPatchset; |
+ pIter2->zTab = (char*)zTab; |
+ pIter2->nCol = pApply->nCol; |
+ pIter2->abPK = pApply->abPK; |
+ sessionBufferGrow(&pIter2->tblhdr, nByte, &rc); |
+ pIter2->apValue = (sqlite3_value**)pIter2->tblhdr.aBuf; |
+ if( rc==SQLITE_OK ) memset(pIter2->apValue, 0, nByte); |
+ |
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter2) ){ |
+ rc = sessionApplyOneWithRetry(db, pIter2, pApply, xConflict, pCtx); |
+ } |
+ |
+ rc2 = sqlite3changeset_finalize(pIter2); |
+ if( rc==SQLITE_OK ) rc = rc2; |
+ } |
+ assert( pApply->bDeferConstraints || pApply->constraints.nBuf==0 ); |
+ |
+ sqlite3_free(cons.aBuf); |
+ if( rc!=SQLITE_OK ) break; |
+ if( pApply->constraints.nBuf>=cons.nBuf ){ |
+ /* No progress was made on the last round. */ |
+ pApply->bDeferConstraints = 0; |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Argument pIter is a changeset iterator that has been initialized, but |
+** not yet passed to sqlite3changeset_next(). This function applies the |
+** changeset to the main database attached to handle "db". The supplied |
+** conflict handler callback is invoked to resolve any conflicts encountered |
+** while applying the change. |
+*/ |
+static int sessionChangesetApply( |
+ sqlite3 *db, /* Apply change to "main" db of this handle */ |
+ sqlite3_changeset_iter *pIter, /* Changeset to apply */ |
+ int(*xFilter)( |
+ void *pCtx, /* Copy of sixth arg to _apply() */ |
+ const char *zTab /* Table name */ |
+ ), |
+ int(*xConflict)( |
+ void *pCtx, /* Copy of fifth arg to _apply() */ |
+ int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ |
+ sqlite3_changeset_iter *p /* Handle describing change and conflict */ |
+ ), |
+ void *pCtx /* First argument passed to xConflict */ |
+){ |
+ int schemaMismatch = 0; |
+ int rc; /* Return code */ |
+ const char *zTab = 0; /* Name of current table */ |
+ int nTab = 0; /* Result of sqlite3Strlen30(zTab) */ |
+ SessionApplyCtx sApply; /* changeset_apply() context object */ |
+ int bPatchset; |
+ |
+ assert( xConflict!=0 ); |
+ |
+ pIter->in.bNoDiscard = 1; |
+ memset(&sApply, 0, sizeof(sApply)); |
+ sqlite3_mutex_enter(sqlite3_db_mutex(db)); |
+ rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0); |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_exec(db, "PRAGMA defer_foreign_keys = 1", 0, 0, 0); |
+ } |
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter) ){ |
+ int nCol; |
+ int op; |
+ const char *zNew; |
+ |
+ sqlite3changeset_op(pIter, &zNew, &nCol, &op, 0); |
+ |
+ if( zTab==0 || sqlite3_strnicmp(zNew, zTab, nTab+1) ){ |
+ u8 *abPK; |
+ |
+ rc = sessionRetryConstraints( |
+ db, pIter->bPatchset, zTab, &sApply, xConflict, pCtx |
+ ); |
+ if( rc!=SQLITE_OK ) break; |
+ |
+ sqlite3_free((char*)sApply.azCol); /* cast works around VC++ bug */ |
+ sqlite3_finalize(sApply.pDelete); |
+ sqlite3_finalize(sApply.pUpdate); |
+ sqlite3_finalize(sApply.pInsert); |
+ sqlite3_finalize(sApply.pSelect); |
+ memset(&sApply, 0, sizeof(sApply)); |
+ sApply.db = db; |
+ sApply.bDeferConstraints = 1; |
+ |
+ /* If an xFilter() callback was specified, invoke it now. If the |
+ ** xFilter callback returns zero, skip this table. If it returns |
+ ** non-zero, proceed. */ |
+ schemaMismatch = (xFilter && (0==xFilter(pCtx, zNew))); |
+ if( schemaMismatch ){ |
+ zTab = sqlite3_mprintf("%s", zNew); |
+ if( zTab==0 ){ |
+ rc = SQLITE_NOMEM; |
+ break; |
+ } |
+ nTab = (int)strlen(zTab); |
+ sApply.azCol = (const char **)zTab; |
+ }else{ |
+ int nMinCol = 0; |
+ int i; |
+ |
+ sqlite3changeset_pk(pIter, &abPK, 0); |
+ rc = sessionTableInfo( |
+ db, "main", zNew, &sApply.nCol, &zTab, &sApply.azCol, &sApply.abPK |
+ ); |
+ if( rc!=SQLITE_OK ) break; |
+ for(i=0; i<sApply.nCol; i++){ |
+ if( sApply.abPK[i] ) nMinCol = i+1; |
+ } |
+ |
+ if( sApply.nCol==0 ){ |
+ schemaMismatch = 1; |
+ sqlite3_log(SQLITE_SCHEMA, |
+ "sqlite3changeset_apply(): no such table: %s", zTab |
+ ); |
+ } |
+ else if( sApply.nCol<nCol ){ |
+ schemaMismatch = 1; |
+ sqlite3_log(SQLITE_SCHEMA, |
+ "sqlite3changeset_apply(): table %s has %d columns, " |
+ "expected %d or more", |
+ zTab, sApply.nCol, nCol |
+ ); |
+ } |
+ else if( nCol<nMinCol || memcmp(sApply.abPK, abPK, nCol)!=0 ){ |
+ schemaMismatch = 1; |
+ sqlite3_log(SQLITE_SCHEMA, "sqlite3changeset_apply(): " |
+ "primary key mismatch for table %s", zTab |
+ ); |
+ } |
+ else{ |
+ sApply.nCol = nCol; |
+ if((rc = sessionSelectRow(db, zTab, &sApply)) |
+ || (rc = sessionUpdateRow(db, zTab, &sApply)) |
+ || (rc = sessionDeleteRow(db, zTab, &sApply)) |
+ || (rc = sessionInsertRow(db, zTab, &sApply)) |
+ ){ |
+ break; |
+ } |
+ } |
+ nTab = sqlite3Strlen30(zTab); |
+ } |
+ } |
+ |
+ /* If there is a schema mismatch on the current table, proceed to the |
+ ** next change. A log message has already been issued. */ |
+ if( schemaMismatch ) continue; |
+ |
+ rc = sessionApplyOneWithRetry(db, pIter, &sApply, xConflict, pCtx); |
+ } |
+ |
+ bPatchset = pIter->bPatchset; |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changeset_finalize(pIter); |
+ }else{ |
+ sqlite3changeset_finalize(pIter); |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionRetryConstraints(db, bPatchset, zTab, &sApply, xConflict, pCtx); |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ int nFk, notUsed; |
+ sqlite3_db_status(db, SQLITE_DBSTATUS_DEFERRED_FKS, &nFk, ¬Used, 0); |
+ if( nFk!=0 ){ |
+ int res = SQLITE_CHANGESET_ABORT; |
+ sqlite3_changeset_iter sIter; |
+ memset(&sIter, 0, sizeof(sIter)); |
+ sIter.nCol = nFk; |
+ res = xConflict(pCtx, SQLITE_CHANGESET_FOREIGN_KEY, &sIter); |
+ if( res!=SQLITE_CHANGESET_OMIT ){ |
+ rc = SQLITE_CONSTRAINT; |
+ } |
+ } |
+ } |
+ sqlite3_exec(db, "PRAGMA defer_foreign_keys = 0", 0, 0, 0); |
+ |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0); |
+ }else{ |
+ sqlite3_exec(db, "ROLLBACK TO changeset_apply", 0, 0, 0); |
+ sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0); |
+ } |
+ |
+ sqlite3_finalize(sApply.pInsert); |
+ sqlite3_finalize(sApply.pDelete); |
+ sqlite3_finalize(sApply.pUpdate); |
+ sqlite3_finalize(sApply.pSelect); |
+ sqlite3_free((char*)sApply.azCol); /* cast works around VC++ bug */ |
+ sqlite3_free((char*)sApply.constraints.aBuf); |
+ sqlite3_mutex_leave(sqlite3_db_mutex(db)); |
+ return rc; |
+} |
+ |
+/* |
+** Apply the changeset passed via pChangeset/nChangeset to the main database |
+** attached to handle "db". Invoke the supplied conflict handler callback |
+** to resolve any conflicts encountered while applying the change. |
+*/ |
+int sqlite3changeset_apply( |
+ sqlite3 *db, /* Apply change to "main" db of this handle */ |
+ int nChangeset, /* Size of changeset in bytes */ |
+ void *pChangeset, /* Changeset blob */ |
+ int(*xFilter)( |
+ void *pCtx, /* Copy of sixth arg to _apply() */ |
+ const char *zTab /* Table name */ |
+ ), |
+ int(*xConflict)( |
+ void *pCtx, /* Copy of fifth arg to _apply() */ |
+ int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ |
+ sqlite3_changeset_iter *p /* Handle describing change and conflict */ |
+ ), |
+ void *pCtx /* First argument passed to xConflict */ |
+){ |
+ sqlite3_changeset_iter *pIter; /* Iterator to skip through changeset */ |
+ int rc = sqlite3changeset_start(&pIter, nChangeset, pChangeset); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionChangesetApply(db, pIter, xFilter, xConflict, pCtx); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** Apply the changeset passed via xInput/pIn to the main database |
+** attached to handle "db". Invoke the supplied conflict handler callback |
+** to resolve any conflicts encountered while applying the change. |
+*/ |
+int sqlite3changeset_apply_strm( |
+ sqlite3 *db, /* Apply change to "main" db of this handle */ |
+ int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ |
+ void *pIn, /* First arg for xInput */ |
+ int(*xFilter)( |
+ void *pCtx, /* Copy of sixth arg to _apply() */ |
+ const char *zTab /* Table name */ |
+ ), |
+ int(*xConflict)( |
+ void *pCtx, /* Copy of sixth arg to _apply() */ |
+ int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ |
+ sqlite3_changeset_iter *p /* Handle describing change and conflict */ |
+ ), |
+ void *pCtx /* First argument passed to xConflict */ |
+){ |
+ sqlite3_changeset_iter *pIter; /* Iterator to skip through changeset */ |
+ int rc = sqlite3changeset_start_strm(&pIter, xInput, pIn); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionChangesetApply(db, pIter, xFilter, xConflict, pCtx); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** sqlite3_changegroup handle. |
+*/ |
+struct sqlite3_changegroup { |
+ int rc; /* Error code */ |
+ int bPatch; /* True to accumulate patchsets */ |
+ SessionTable *pList; /* List of tables in current patch */ |
+}; |
+ |
+/* |
+** This function is called to merge two changes to the same row together as |
+** part of an sqlite3changeset_concat() operation. A new change object is |
+** allocated and a pointer to it stored in *ppNew. |
+*/ |
+static int sessionChangeMerge( |
+ SessionTable *pTab, /* Table structure */ |
+ int bPatchset, /* True for patchsets */ |
+ SessionChange *pExist, /* Existing change */ |
+ int op2, /* Second change operation */ |
+ int bIndirect, /* True if second change is indirect */ |
+ u8 *aRec, /* Second change record */ |
+ int nRec, /* Number of bytes in aRec */ |
+ SessionChange **ppNew /* OUT: Merged change */ |
+){ |
+ SessionChange *pNew = 0; |
+ |
+ if( !pExist ){ |
+ pNew = (SessionChange *)sqlite3_malloc(sizeof(SessionChange) + nRec); |
+ if( !pNew ){ |
+ return SQLITE_NOMEM; |
+ } |
+ memset(pNew, 0, sizeof(SessionChange)); |
+ pNew->op = op2; |
+ pNew->bIndirect = bIndirect; |
+ pNew->nRecord = nRec; |
+ pNew->aRecord = (u8*)&pNew[1]; |
+ memcpy(pNew->aRecord, aRec, nRec); |
+ }else{ |
+ int op1 = pExist->op; |
+ |
+ /* |
+ ** op1=INSERT, op2=INSERT -> Unsupported. Discard op2. |
+ ** op1=INSERT, op2=UPDATE -> INSERT. |
+ ** op1=INSERT, op2=DELETE -> (none) |
+ ** |
+ ** op1=UPDATE, op2=INSERT -> Unsupported. Discard op2. |
+ ** op1=UPDATE, op2=UPDATE -> UPDATE. |
+ ** op1=UPDATE, op2=DELETE -> DELETE. |
+ ** |
+ ** op1=DELETE, op2=INSERT -> UPDATE. |
+ ** op1=DELETE, op2=UPDATE -> Unsupported. Discard op2. |
+ ** op1=DELETE, op2=DELETE -> Unsupported. Discard op2. |
+ */ |
+ if( (op1==SQLITE_INSERT && op2==SQLITE_INSERT) |
+ || (op1==SQLITE_UPDATE && op2==SQLITE_INSERT) |
+ || (op1==SQLITE_DELETE && op2==SQLITE_UPDATE) |
+ || (op1==SQLITE_DELETE && op2==SQLITE_DELETE) |
+ ){ |
+ pNew = pExist; |
+ }else if( op1==SQLITE_INSERT && op2==SQLITE_DELETE ){ |
+ sqlite3_free(pExist); |
+ assert( pNew==0 ); |
+ }else{ |
+ u8 *aExist = pExist->aRecord; |
+ int nByte; |
+ u8 *aCsr; |
+ |
+ /* Allocate a new SessionChange object. Ensure that the aRecord[] |
+ ** buffer of the new object is large enough to hold any record that |
+ ** may be generated by combining the input records. */ |
+ nByte = sizeof(SessionChange) + pExist->nRecord + nRec; |
+ pNew = (SessionChange *)sqlite3_malloc(nByte); |
+ if( !pNew ){ |
+ sqlite3_free(pExist); |
+ return SQLITE_NOMEM; |
+ } |
+ memset(pNew, 0, sizeof(SessionChange)); |
+ pNew->bIndirect = (bIndirect && pExist->bIndirect); |
+ aCsr = pNew->aRecord = (u8 *)&pNew[1]; |
+ |
+ if( op1==SQLITE_INSERT ){ /* INSERT + UPDATE */ |
+ u8 *a1 = aRec; |
+ assert( op2==SQLITE_UPDATE ); |
+ pNew->op = SQLITE_INSERT; |
+ if( bPatchset==0 ) sessionSkipRecord(&a1, pTab->nCol); |
+ sessionMergeRecord(&aCsr, pTab->nCol, aExist, a1); |
+ }else if( op1==SQLITE_DELETE ){ /* DELETE + INSERT */ |
+ assert( op2==SQLITE_INSERT ); |
+ pNew->op = SQLITE_UPDATE; |
+ if( bPatchset ){ |
+ memcpy(aCsr, aRec, nRec); |
+ aCsr += nRec; |
+ }else{ |
+ if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aExist, 0,aRec,0) ){ |
+ sqlite3_free(pNew); |
+ pNew = 0; |
+ } |
+ } |
+ }else if( op2==SQLITE_UPDATE ){ /* UPDATE + UPDATE */ |
+ u8 *a1 = aExist; |
+ u8 *a2 = aRec; |
+ assert( op1==SQLITE_UPDATE ); |
+ if( bPatchset==0 ){ |
+ sessionSkipRecord(&a1, pTab->nCol); |
+ sessionSkipRecord(&a2, pTab->nCol); |
+ } |
+ pNew->op = SQLITE_UPDATE; |
+ if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aRec, aExist,a1,a2) ){ |
+ sqlite3_free(pNew); |
+ pNew = 0; |
+ } |
+ }else{ /* UPDATE + DELETE */ |
+ assert( op1==SQLITE_UPDATE && op2==SQLITE_DELETE ); |
+ pNew->op = SQLITE_DELETE; |
+ if( bPatchset ){ |
+ memcpy(aCsr, aRec, nRec); |
+ aCsr += nRec; |
+ }else{ |
+ sessionMergeRecord(&aCsr, pTab->nCol, aRec, aExist); |
+ } |
+ } |
+ |
+ if( pNew ){ |
+ pNew->nRecord = (int)(aCsr - pNew->aRecord); |
+ } |
+ sqlite3_free(pExist); |
+ } |
+ } |
+ |
+ *ppNew = pNew; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Add all changes in the changeset traversed by the iterator passed as |
+** the first argument to the changegroup hash tables. |
+*/ |
+static int sessionChangesetToHash( |
+ sqlite3_changeset_iter *pIter, /* Iterator to read from */ |
+ sqlite3_changegroup *pGrp /* Changegroup object to add changeset to */ |
+){ |
+ u8 *aRec; |
+ int nRec; |
+ int rc = SQLITE_OK; |
+ SessionTable *pTab = 0; |
+ |
+ |
+ while( SQLITE_ROW==sessionChangesetNext(pIter, &aRec, &nRec) ){ |
+ const char *zNew; |
+ int nCol; |
+ int op; |
+ int iHash; |
+ int bIndirect; |
+ SessionChange *pChange; |
+ SessionChange *pExist = 0; |
+ SessionChange **pp; |
+ |
+ if( pGrp->pList==0 ){ |
+ pGrp->bPatch = pIter->bPatchset; |
+ }else if( pIter->bPatchset!=pGrp->bPatch ){ |
+ rc = SQLITE_ERROR; |
+ break; |
+ } |
+ |
+ sqlite3changeset_op(pIter, &zNew, &nCol, &op, &bIndirect); |
+ if( !pTab || sqlite3_stricmp(zNew, pTab->zName) ){ |
+ /* Search the list for a matching table */ |
+ int nNew = (int)strlen(zNew); |
+ u8 *abPK; |
+ |
+ sqlite3changeset_pk(pIter, &abPK, 0); |
+ for(pTab = pGrp->pList; pTab; pTab=pTab->pNext){ |
+ if( 0==sqlite3_strnicmp(pTab->zName, zNew, nNew+1) ) break; |
+ } |
+ if( !pTab ){ |
+ SessionTable **ppTab; |
+ |
+ pTab = sqlite3_malloc(sizeof(SessionTable) + nCol + nNew+1); |
+ if( !pTab ){ |
+ rc = SQLITE_NOMEM; |
+ break; |
+ } |
+ memset(pTab, 0, sizeof(SessionTable)); |
+ pTab->nCol = nCol; |
+ pTab->abPK = (u8*)&pTab[1]; |
+ memcpy(pTab->abPK, abPK, nCol); |
+ pTab->zName = (char*)&pTab->abPK[nCol]; |
+ memcpy(pTab->zName, zNew, nNew+1); |
+ |
+ /* The new object must be linked on to the end of the list, not |
+ ** simply added to the start of it. This is to ensure that the |
+ ** tables within the output of sqlite3changegroup_output() are in |
+ ** the right order. */ |
+ for(ppTab=&pGrp->pList; *ppTab; ppTab=&(*ppTab)->pNext); |
+ *ppTab = pTab; |
+ }else if( pTab->nCol!=nCol || memcmp(pTab->abPK, abPK, nCol) ){ |
+ rc = SQLITE_SCHEMA; |
+ break; |
+ } |
+ } |
+ |
+ if( sessionGrowHash(pIter->bPatchset, pTab) ){ |
+ rc = SQLITE_NOMEM; |
+ break; |
+ } |
+ iHash = sessionChangeHash( |
+ pTab, (pIter->bPatchset && op==SQLITE_DELETE), aRec, pTab->nChange |
+ ); |
+ |
+ /* Search for existing entry. If found, remove it from the hash table. |
+ ** Code below may link it back in. |
+ */ |
+ for(pp=&pTab->apChange[iHash]; *pp; pp=&(*pp)->pNext){ |
+ int bPkOnly1 = 0; |
+ int bPkOnly2 = 0; |
+ if( pIter->bPatchset ){ |
+ bPkOnly1 = (*pp)->op==SQLITE_DELETE; |
+ bPkOnly2 = op==SQLITE_DELETE; |
+ } |
+ if( sessionChangeEqual(pTab, bPkOnly1, (*pp)->aRecord, bPkOnly2, aRec) ){ |
+ pExist = *pp; |
+ *pp = (*pp)->pNext; |
+ pTab->nEntry--; |
+ break; |
+ } |
+ } |
+ |
+ rc = sessionChangeMerge(pTab, |
+ pIter->bPatchset, pExist, op, bIndirect, aRec, nRec, &pChange |
+ ); |
+ if( rc ) break; |
+ if( pChange ){ |
+ pChange->pNext = pTab->apChange[iHash]; |
+ pTab->apChange[iHash] = pChange; |
+ pTab->nEntry++; |
+ } |
+ } |
+ |
+ if( rc==SQLITE_OK ) rc = pIter->rc; |
+ return rc; |
+} |
+ |
+/* |
+** Serialize a changeset (or patchset) based on all changesets (or patchsets) |
+** added to the changegroup object passed as the first argument. |
+** |
+** If xOutput is not NULL, then the changeset/patchset is returned to the |
+** user via one or more calls to xOutput, as with the other streaming |
+** interfaces. |
+** |
+** Or, if xOutput is NULL, then (*ppOut) is populated with a pointer to a |
+** buffer containing the output changeset before this function returns. In |
+** this case (*pnOut) is set to the size of the output buffer in bytes. It |
+** is the responsibility of the caller to free the output buffer using |
+** sqlite3_free() when it is no longer required. |
+** |
+** If successful, SQLITE_OK is returned. Or, if an error occurs, an SQLite |
+** error code. If an error occurs and xOutput is NULL, (*ppOut) and (*pnOut) |
+** are both set to 0 before returning. |
+*/ |
+static int sessionChangegroupOutput( |
+ sqlite3_changegroup *pGrp, |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut, |
+ int *pnOut, |
+ void **ppOut |
+){ |
+ int rc = SQLITE_OK; |
+ SessionBuffer buf = {0, 0, 0}; |
+ SessionTable *pTab; |
+ assert( xOutput==0 || (ppOut==0 && pnOut==0) ); |
+ |
+ /* Create the serialized output changeset based on the contents of the |
+ ** hash tables attached to the SessionTable objects in list p->pList. |
+ */ |
+ for(pTab=pGrp->pList; rc==SQLITE_OK && pTab; pTab=pTab->pNext){ |
+ int i; |
+ if( pTab->nEntry==0 ) continue; |
+ |
+ sessionAppendTableHdr(&buf, pGrp->bPatch, pTab, &rc); |
+ for(i=0; i<pTab->nChange; i++){ |
+ SessionChange *p; |
+ for(p=pTab->apChange[i]; p; p=p->pNext){ |
+ sessionAppendByte(&buf, p->op, &rc); |
+ sessionAppendByte(&buf, p->bIndirect, &rc); |
+ sessionAppendBlob(&buf, p->aRecord, p->nRecord, &rc); |
+ } |
+ } |
+ |
+ if( rc==SQLITE_OK && xOutput && buf.nBuf>=SESSIONS_STRM_CHUNK_SIZE ){ |
+ rc = xOutput(pOut, buf.aBuf, buf.nBuf); |
+ buf.nBuf = 0; |
+ } |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ if( xOutput ){ |
+ if( buf.nBuf>0 ) rc = xOutput(pOut, buf.aBuf, buf.nBuf); |
+ }else{ |
+ *ppOut = buf.aBuf; |
+ *pnOut = buf.nBuf; |
+ buf.aBuf = 0; |
+ } |
+ } |
+ sqlite3_free(buf.aBuf); |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Allocate a new, empty, sqlite3_changegroup. |
+*/ |
+int sqlite3changegroup_new(sqlite3_changegroup **pp){ |
+ int rc = SQLITE_OK; /* Return code */ |
+ sqlite3_changegroup *p; /* New object */ |
+ p = (sqlite3_changegroup*)sqlite3_malloc(sizeof(sqlite3_changegroup)); |
+ if( p==0 ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ memset(p, 0, sizeof(sqlite3_changegroup)); |
+ } |
+ *pp = p; |
+ return rc; |
+} |
+ |
+/* |
+** Add the changeset currently stored in buffer pData, size nData bytes, |
+** to changeset-group p. |
+*/ |
+int sqlite3changegroup_add(sqlite3_changegroup *pGrp, int nData, void *pData){ |
+ sqlite3_changeset_iter *pIter; /* Iterator opened on pData/nData */ |
+ int rc; /* Return code */ |
+ |
+ rc = sqlite3changeset_start(&pIter, nData, pData); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionChangesetToHash(pIter, pGrp); |
+ } |
+ sqlite3changeset_finalize(pIter); |
+ return rc; |
+} |
+ |
+/* |
+** Obtain a buffer containing a changeset representing the concatenation |
+** of all changesets added to the group so far. |
+*/ |
+int sqlite3changegroup_output( |
+ sqlite3_changegroup *pGrp, |
+ int *pnData, |
+ void **ppData |
+){ |
+ return sessionChangegroupOutput(pGrp, 0, 0, pnData, ppData); |
+} |
+ |
+/* |
+** Streaming versions of changegroup_add(). |
+*/ |
+int sqlite3changegroup_add_strm( |
+ sqlite3_changegroup *pGrp, |
+ int (*xInput)(void *pIn, void *pData, int *pnData), |
+ void *pIn |
+){ |
+ sqlite3_changeset_iter *pIter; /* Iterator opened on pData/nData */ |
+ int rc; /* Return code */ |
+ |
+ rc = sqlite3changeset_start_strm(&pIter, xInput, pIn); |
+ if( rc==SQLITE_OK ){ |
+ rc = sessionChangesetToHash(pIter, pGrp); |
+ } |
+ sqlite3changeset_finalize(pIter); |
+ return rc; |
+} |
+ |
+/* |
+** Streaming versions of changegroup_output(). |
+*/ |
+int sqlite3changegroup_output_strm( |
+ sqlite3_changegroup *pGrp, |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut |
+){ |
+ return sessionChangegroupOutput(pGrp, xOutput, pOut, 0, 0); |
+} |
+ |
+/* |
+** Delete a changegroup object. |
+*/ |
+void sqlite3changegroup_delete(sqlite3_changegroup *pGrp){ |
+ if( pGrp ){ |
+ sessionDeleteTable(pGrp->pList); |
+ sqlite3_free(pGrp); |
+ } |
+} |
+ |
+/* |
+** Combine two changesets together. |
+*/ |
+int sqlite3changeset_concat( |
+ int nLeft, /* Number of bytes in lhs input */ |
+ void *pLeft, /* Lhs input changeset */ |
+ int nRight /* Number of bytes in rhs input */, |
+ void *pRight, /* Rhs input changeset */ |
+ int *pnOut, /* OUT: Number of bytes in output changeset */ |
+ void **ppOut /* OUT: changeset (left <concat> right) */ |
+){ |
+ sqlite3_changegroup *pGrp; |
+ int rc; |
+ |
+ rc = sqlite3changegroup_new(&pGrp); |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changegroup_add(pGrp, nLeft, pLeft); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changegroup_add(pGrp, nRight, pRight); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); |
+ } |
+ sqlite3changegroup_delete(pGrp); |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Streaming version of sqlite3changeset_concat(). |
+*/ |
+int sqlite3changeset_concat_strm( |
+ int (*xInputA)(void *pIn, void *pData, int *pnData), |
+ void *pInA, |
+ int (*xInputB)(void *pIn, void *pData, int *pnData), |
+ void *pInB, |
+ int (*xOutput)(void *pOut, const void *pData, int nData), |
+ void *pOut |
+){ |
+ sqlite3_changegroup *pGrp; |
+ int rc; |
+ |
+ rc = sqlite3changegroup_new(&pGrp); |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changegroup_add_strm(pGrp, xInputA, pInA); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changegroup_add_strm(pGrp, xInputB, pInB); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3changegroup_output_strm(pGrp, xOutput, pOut); |
+ } |
+ sqlite3changegroup_delete(pGrp); |
+ |
+ return rc; |
+} |
+ |
+#endif /* SQLITE_ENABLE_SESSION && SQLITE_ENABLE_PREUPDATE_HOOK */ |