Index: third_party/sqlite/src/ext/fts3/fts3_write.c |
diff --git a/third_party/sqlite/src/ext/fts3/fts3_write.c b/third_party/sqlite/src/ext/fts3/fts3_write.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..1e71874384aab94f3624e2c8f4595ad4ee89fd26 |
--- /dev/null |
+++ b/third_party/sqlite/src/ext/fts3/fts3_write.c |
@@ -0,0 +1,2727 @@ |
+/* |
+** 2009 Oct 23 |
+** |
+** The author disclaims copyright to this source code. In place of |
+** a legal notice, here is a blessing: |
+** |
+** May you do good and not evil. |
+** May you find forgiveness for yourself and forgive others. |
+** May you share freely, never taking more than you give. |
+** |
+****************************************************************************** |
+** |
+** This file is part of the SQLite FTS3 extension module. Specifically, |
+** this file contains code to insert, update and delete rows from FTS3 |
+** tables. It also contains code to merge FTS3 b-tree segments. Some |
+** of the sub-routines used to merge segments are also used by the query |
+** code in fts3.c. |
+*/ |
+ |
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) |
+ |
+#include "fts3Int.h" |
+#include <string.h> |
+#include <assert.h> |
+#include <stdlib.h> |
+ |
+/* |
+** When full-text index nodes are loaded from disk, the buffer that they |
+** are loaded into has the following number of bytes of padding at the end |
+** of it. i.e. if a full-text index node is 900 bytes in size, then a buffer |
+** of 920 bytes is allocated for it. |
+** |
+** This means that if we have a pointer into a buffer containing node data, |
+** it is always safe to read up to two varints from it without risking an |
+** overread, even if the node data is corrupted. |
+*/ |
+#define FTS3_NODE_PADDING (FTS3_VARINT_MAX*2) |
+ |
+typedef struct PendingList PendingList; |
+typedef struct SegmentNode SegmentNode; |
+typedef struct SegmentWriter SegmentWriter; |
+ |
+/* |
+** Data structure used while accumulating terms in the pending-terms hash |
+** table. The hash table entry maps from term (a string) to a malloc'd |
+** instance of this structure. |
+*/ |
+struct PendingList { |
+ int nData; |
+ char *aData; |
+ int nSpace; |
+ sqlite3_int64 iLastDocid; |
+ sqlite3_int64 iLastCol; |
+ sqlite3_int64 iLastPos; |
+}; |
+ |
+ |
+/* |
+** Each cursor has a (possibly empty) linked list of the following objects. |
+*/ |
+struct Fts3DeferredToken { |
+ Fts3PhraseToken *pToken; /* Pointer to corresponding expr token */ |
+ int iCol; /* Column token must occur in */ |
+ Fts3DeferredToken *pNext; /* Next in list of deferred tokens */ |
+ PendingList *pList; /* Doclist is assembled here */ |
+}; |
+ |
+/* |
+** An instance of this structure is used to iterate through the terms on |
+** a contiguous set of segment b-tree leaf nodes. Although the details of |
+** this structure are only manipulated by code in this file, opaque handles |
+** of type Fts3SegReader* are also used by code in fts3.c to iterate through |
+** terms when querying the full-text index. See functions: |
+** |
+** sqlite3Fts3SegReaderNew() |
+** sqlite3Fts3SegReaderFree() |
+** sqlite3Fts3SegReaderCost() |
+** sqlite3Fts3SegReaderIterate() |
+** |
+** Methods used to manipulate Fts3SegReader structures: |
+** |
+** fts3SegReaderNext() |
+** fts3SegReaderFirstDocid() |
+** fts3SegReaderNextDocid() |
+*/ |
+struct Fts3SegReader { |
+ int iIdx; /* Index within level, or 0x7FFFFFFF for PT */ |
+ |
+ sqlite3_int64 iStartBlock; /* Rowid of first leaf block to traverse */ |
+ sqlite3_int64 iLeafEndBlock; /* Rowid of final leaf block to traverse */ |
+ sqlite3_int64 iEndBlock; /* Rowid of final block in segment (or 0) */ |
+ sqlite3_int64 iCurrentBlock; /* Current leaf block (or 0) */ |
+ |
+ char *aNode; /* Pointer to node data (or NULL) */ |
+ int nNode; /* Size of buffer at aNode (or 0) */ |
+ Fts3HashElem **ppNextElem; |
+ |
+ /* Variables set by fts3SegReaderNext(). These may be read directly |
+ ** by the caller. They are valid from the time SegmentReaderNew() returns |
+ ** until SegmentReaderNext() returns something other than SQLITE_OK |
+ ** (i.e. SQLITE_DONE). |
+ */ |
+ int nTerm; /* Number of bytes in current term */ |
+ char *zTerm; /* Pointer to current term */ |
+ int nTermAlloc; /* Allocated size of zTerm buffer */ |
+ char *aDoclist; /* Pointer to doclist of current entry */ |
+ int nDoclist; /* Size of doclist in current entry */ |
+ |
+ /* The following variables are used to iterate through the current doclist */ |
+ char *pOffsetList; |
+ sqlite3_int64 iDocid; |
+}; |
+ |
+#define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0) |
+#define fts3SegReaderIsRootOnly(p) ((p)->aNode==(char *)&(p)[1]) |
+ |
+/* |
+** An instance of this structure is used to create a segment b-tree in the |
+** database. The internal details of this type are only accessed by the |
+** following functions: |
+** |
+** fts3SegWriterAdd() |
+** fts3SegWriterFlush() |
+** fts3SegWriterFree() |
+*/ |
+struct SegmentWriter { |
+ SegmentNode *pTree; /* Pointer to interior tree structure */ |
+ sqlite3_int64 iFirst; /* First slot in %_segments written */ |
+ sqlite3_int64 iFree; /* Next free slot in %_segments */ |
+ char *zTerm; /* Pointer to previous term buffer */ |
+ int nTerm; /* Number of bytes in zTerm */ |
+ int nMalloc; /* Size of malloc'd buffer at zMalloc */ |
+ char *zMalloc; /* Malloc'd space (possibly) used for zTerm */ |
+ int nSize; /* Size of allocation at aData */ |
+ int nData; /* Bytes of data in aData */ |
+ char *aData; /* Pointer to block from malloc() */ |
+}; |
+ |
+/* |
+** Type SegmentNode is used by the following three functions to create |
+** the interior part of the segment b+-tree structures (everything except |
+** the leaf nodes). These functions and type are only ever used by code |
+** within the fts3SegWriterXXX() family of functions described above. |
+** |
+** fts3NodeAddTerm() |
+** fts3NodeWrite() |
+** fts3NodeFree() |
+*/ |
+struct SegmentNode { |
+ SegmentNode *pParent; /* Parent node (or NULL for root node) */ |
+ SegmentNode *pRight; /* Pointer to right-sibling */ |
+ SegmentNode *pLeftmost; /* Pointer to left-most node of this depth */ |
+ int nEntry; /* Number of terms written to node so far */ |
+ char *zTerm; /* Pointer to previous term buffer */ |
+ int nTerm; /* Number of bytes in zTerm */ |
+ int nMalloc; /* Size of malloc'd buffer at zMalloc */ |
+ char *zMalloc; /* Malloc'd space (possibly) used for zTerm */ |
+ int nData; /* Bytes of valid data so far */ |
+ char *aData; /* Node data */ |
+}; |
+ |
+/* |
+** Valid values for the second argument to fts3SqlStmt(). |
+*/ |
+#define SQL_DELETE_CONTENT 0 |
+#define SQL_IS_EMPTY 1 |
+#define SQL_DELETE_ALL_CONTENT 2 |
+#define SQL_DELETE_ALL_SEGMENTS 3 |
+#define SQL_DELETE_ALL_SEGDIR 4 |
+#define SQL_DELETE_ALL_DOCSIZE 5 |
+#define SQL_DELETE_ALL_STAT 6 |
+#define SQL_SELECT_CONTENT_BY_ROWID 7 |
+#define SQL_NEXT_SEGMENT_INDEX 8 |
+#define SQL_INSERT_SEGMENTS 9 |
+#define SQL_NEXT_SEGMENTS_ID 10 |
+#define SQL_INSERT_SEGDIR 11 |
+#define SQL_SELECT_LEVEL 12 |
+#define SQL_SELECT_ALL_LEVEL 13 |
+#define SQL_SELECT_LEVEL_COUNT 14 |
+#define SQL_SELECT_SEGDIR_COUNT_MAX 15 |
+#define SQL_DELETE_SEGDIR_BY_LEVEL 16 |
+#define SQL_DELETE_SEGMENTS_RANGE 17 |
+#define SQL_CONTENT_INSERT 18 |
+#define SQL_DELETE_DOCSIZE 19 |
+#define SQL_REPLACE_DOCSIZE 20 |
+#define SQL_SELECT_DOCSIZE 21 |
+#define SQL_SELECT_DOCTOTAL 22 |
+#define SQL_REPLACE_DOCTOTAL 23 |
+ |
+/* |
+** This function is used to obtain an SQLite prepared statement handle |
+** for the statement identified by the second argument. If successful, |
+** *pp is set to the requested statement handle and SQLITE_OK returned. |
+** Otherwise, an SQLite error code is returned and *pp is set to 0. |
+** |
+** If argument apVal is not NULL, then it must point to an array with |
+** at least as many entries as the requested statement has bound |
+** parameters. The values are bound to the statements parameters before |
+** returning. |
+*/ |
+static int fts3SqlStmt( |
+ Fts3Table *p, /* Virtual table handle */ |
+ int eStmt, /* One of the SQL_XXX constants above */ |
+ sqlite3_stmt **pp, /* OUT: Statement handle */ |
+ sqlite3_value **apVal /* Values to bind to statement */ |
+){ |
+ const char *azSql[] = { |
+/* 0 */ "DELETE FROM %Q.'%q_content' WHERE rowid = ?", |
+/* 1 */ "SELECT NOT EXISTS(SELECT docid FROM %Q.'%q_content' WHERE rowid!=?)", |
+/* 2 */ "DELETE FROM %Q.'%q_content'", |
+/* 3 */ "DELETE FROM %Q.'%q_segments'", |
+/* 4 */ "DELETE FROM %Q.'%q_segdir'", |
+/* 5 */ "DELETE FROM %Q.'%q_docsize'", |
+/* 6 */ "DELETE FROM %Q.'%q_stat'", |
+/* 7 */ "SELECT %s FROM %Q.'%q_content' AS x WHERE rowid=?", |
+/* 8 */ "SELECT (SELECT max(idx) FROM %Q.'%q_segdir' WHERE level = ?) + 1", |
+/* 9 */ "INSERT INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)", |
+/* 10 */ "SELECT coalesce((SELECT max(blockid) FROM %Q.'%q_segments') + 1, 1)", |
+/* 11 */ "INSERT INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)", |
+ |
+ /* Return segments in order from oldest to newest.*/ |
+/* 12 */ "SELECT idx, start_block, leaves_end_block, end_block, root " |
+ "FROM %Q.'%q_segdir' WHERE level = ? ORDER BY idx ASC", |
+/* 13 */ "SELECT idx, start_block, leaves_end_block, end_block, root " |
+ "FROM %Q.'%q_segdir' ORDER BY level DESC, idx ASC", |
+ |
+/* 14 */ "SELECT count(*) FROM %Q.'%q_segdir' WHERE level = ?", |
+/* 15 */ "SELECT count(*), max(level) FROM %Q.'%q_segdir'", |
+ |
+/* 16 */ "DELETE FROM %Q.'%q_segdir' WHERE level = ?", |
+/* 17 */ "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?", |
+/* 18 */ "INSERT INTO %Q.'%q_content' VALUES(%s)", |
+/* 19 */ "DELETE FROM %Q.'%q_docsize' WHERE docid = ?", |
+/* 20 */ "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)", |
+/* 21 */ "SELECT size FROM %Q.'%q_docsize' WHERE docid=?", |
+/* 22 */ "SELECT value FROM %Q.'%q_stat' WHERE id=0", |
+/* 23 */ "REPLACE INTO %Q.'%q_stat' VALUES(0,?)", |
+ }; |
+ int rc = SQLITE_OK; |
+ sqlite3_stmt *pStmt; |
+ |
+ assert( SizeofArray(azSql)==SizeofArray(p->aStmt) ); |
+ assert( eStmt<SizeofArray(azSql) && eStmt>=0 ); |
+ |
+ pStmt = p->aStmt[eStmt]; |
+ if( !pStmt ){ |
+ char *zSql; |
+ if( eStmt==SQL_CONTENT_INSERT ){ |
+ zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName, p->zWriteExprlist); |
+ }else if( eStmt==SQL_SELECT_CONTENT_BY_ROWID ){ |
+ zSql = sqlite3_mprintf(azSql[eStmt], p->zReadExprlist, p->zDb, p->zName); |
+ }else{ |
+ zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName); |
+ } |
+ if( !zSql ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, NULL); |
+ sqlite3_free(zSql); |
+ assert( rc==SQLITE_OK || pStmt==0 ); |
+ p->aStmt[eStmt] = pStmt; |
+ } |
+ } |
+ if( apVal ){ |
+ int i; |
+ int nParam = sqlite3_bind_parameter_count(pStmt); |
+ for(i=0; rc==SQLITE_OK && i<nParam; i++){ |
+ rc = sqlite3_bind_value(pStmt, i+1, apVal[i]); |
+ } |
+ } |
+ *pp = pStmt; |
+ return rc; |
+} |
+ |
+static int fts3SelectDocsize( |
+ Fts3Table *pTab, /* FTS3 table handle */ |
+ int eStmt, /* Either SQL_SELECT_DOCSIZE or DOCTOTAL */ |
+ sqlite3_int64 iDocid, /* Docid to bind for SQL_SELECT_DOCSIZE */ |
+ sqlite3_stmt **ppStmt /* OUT: Statement handle */ |
+){ |
+ sqlite3_stmt *pStmt = 0; /* Statement requested from fts3SqlStmt() */ |
+ int rc; /* Return code */ |
+ |
+ assert( eStmt==SQL_SELECT_DOCSIZE || eStmt==SQL_SELECT_DOCTOTAL ); |
+ |
+ rc = fts3SqlStmt(pTab, eStmt, &pStmt, 0); |
+ if( rc==SQLITE_OK ){ |
+ if( eStmt==SQL_SELECT_DOCSIZE ){ |
+ sqlite3_bind_int64(pStmt, 1, iDocid); |
+ } |
+ rc = sqlite3_step(pStmt); |
+ if( rc!=SQLITE_ROW || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){ |
+ rc = sqlite3_reset(pStmt); |
+ if( rc==SQLITE_OK ) rc = SQLITE_CORRUPT; |
+ pStmt = 0; |
+ }else{ |
+ rc = SQLITE_OK; |
+ } |
+ } |
+ |
+ *ppStmt = pStmt; |
+ return rc; |
+} |
+ |
+int sqlite3Fts3SelectDoctotal( |
+ Fts3Table *pTab, /* Fts3 table handle */ |
+ sqlite3_stmt **ppStmt /* OUT: Statement handle */ |
+){ |
+ return fts3SelectDocsize(pTab, SQL_SELECT_DOCTOTAL, 0, ppStmt); |
+} |
+ |
+int sqlite3Fts3SelectDocsize( |
+ Fts3Table *pTab, /* Fts3 table handle */ |
+ sqlite3_int64 iDocid, /* Docid to read size data for */ |
+ sqlite3_stmt **ppStmt /* OUT: Statement handle */ |
+){ |
+ return fts3SelectDocsize(pTab, SQL_SELECT_DOCSIZE, iDocid, ppStmt); |
+} |
+ |
+/* |
+** Similar to fts3SqlStmt(). Except, after binding the parameters in |
+** array apVal[] to the SQL statement identified by eStmt, the statement |
+** is executed. |
+** |
+** Returns SQLITE_OK if the statement is successfully executed, or an |
+** SQLite error code otherwise. |
+*/ |
+static void fts3SqlExec( |
+ int *pRC, /* Result code */ |
+ Fts3Table *p, /* The FTS3 table */ |
+ int eStmt, /* Index of statement to evaluate */ |
+ sqlite3_value **apVal /* Parameters to bind */ |
+){ |
+ sqlite3_stmt *pStmt; |
+ int rc; |
+ if( *pRC ) return; |
+ rc = fts3SqlStmt(p, eStmt, &pStmt, apVal); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_step(pStmt); |
+ rc = sqlite3_reset(pStmt); |
+ } |
+ *pRC = rc; |
+} |
+ |
+ |
+/* |
+** This function ensures that the caller has obtained a shared-cache |
+** table-lock on the %_content table. This is required before reading |
+** data from the fts3 table. If this lock is not acquired first, then |
+** the caller may end up holding read-locks on the %_segments and %_segdir |
+** tables, but no read-lock on the %_content table. If this happens |
+** a second connection will be able to write to the fts3 table, but |
+** attempting to commit those writes might return SQLITE_LOCKED or |
+** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain |
+** write-locks on the %_segments and %_segdir ** tables). |
+** |
+** We try to avoid this because if FTS3 returns any error when committing |
+** a transaction, the whole transaction will be rolled back. And this is |
+** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can |
+** still happen if the user reads data directly from the %_segments or |
+** %_segdir tables instead of going through FTS3 though. |
+*/ |
+int sqlite3Fts3ReadLock(Fts3Table *p){ |
+ int rc; /* Return code */ |
+ sqlite3_stmt *pStmt; /* Statement used to obtain lock */ |
+ |
+ rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_bind_null(pStmt, 1); |
+ sqlite3_step(pStmt); |
+ rc = sqlite3_reset(pStmt); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** Set *ppStmt to a statement handle that may be used to iterate through |
+** all rows in the %_segdir table, from oldest to newest. If successful, |
+** return SQLITE_OK. If an error occurs while preparing the statement, |
+** return an SQLite error code. |
+** |
+** There is only ever one instance of this SQL statement compiled for |
+** each FTS3 table. |
+** |
+** The statement returns the following columns from the %_segdir table: |
+** |
+** 0: idx |
+** 1: start_block |
+** 2: leaves_end_block |
+** 3: end_block |
+** 4: root |
+*/ |
+int sqlite3Fts3AllSegdirs(Fts3Table *p, int iLevel, sqlite3_stmt **ppStmt){ |
+ int rc; |
+ sqlite3_stmt *pStmt = 0; |
+ if( iLevel<0 ){ |
+ rc = fts3SqlStmt(p, SQL_SELECT_ALL_LEVEL, &pStmt, 0); |
+ }else{ |
+ rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0); |
+ if( rc==SQLITE_OK ) sqlite3_bind_int(pStmt, 1, iLevel); |
+ } |
+ *ppStmt = pStmt; |
+ return rc; |
+} |
+ |
+ |
+/* |
+** Append a single varint to a PendingList buffer. SQLITE_OK is returned |
+** if successful, or an SQLite error code otherwise. |
+** |
+** This function also serves to allocate the PendingList structure itself. |
+** For example, to create a new PendingList structure containing two |
+** varints: |
+** |
+** PendingList *p = 0; |
+** fts3PendingListAppendVarint(&p, 1); |
+** fts3PendingListAppendVarint(&p, 2); |
+*/ |
+static int fts3PendingListAppendVarint( |
+ PendingList **pp, /* IN/OUT: Pointer to PendingList struct */ |
+ sqlite3_int64 i /* Value to append to data */ |
+){ |
+ PendingList *p = *pp; |
+ |
+ /* Allocate or grow the PendingList as required. */ |
+ if( !p ){ |
+ p = sqlite3_malloc(sizeof(*p) + 100); |
+ if( !p ){ |
+ return SQLITE_NOMEM; |
+ } |
+ p->nSpace = 100; |
+ p->aData = (char *)&p[1]; |
+ p->nData = 0; |
+ } |
+ else if( p->nData+FTS3_VARINT_MAX+1>p->nSpace ){ |
+ int nNew = p->nSpace * 2; |
+ p = sqlite3_realloc(p, sizeof(*p) + nNew); |
+ if( !p ){ |
+ sqlite3_free(*pp); |
+ *pp = 0; |
+ return SQLITE_NOMEM; |
+ } |
+ p->nSpace = nNew; |
+ p->aData = (char *)&p[1]; |
+ } |
+ |
+ /* Append the new serialized varint to the end of the list. */ |
+ p->nData += sqlite3Fts3PutVarint(&p->aData[p->nData], i); |
+ p->aData[p->nData] = '\0'; |
+ *pp = p; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Add a docid/column/position entry to a PendingList structure. Non-zero |
+** is returned if the structure is sqlite3_realloced as part of adding |
+** the entry. Otherwise, zero. |
+** |
+** If an OOM error occurs, *pRc is set to SQLITE_NOMEM before returning. |
+** Zero is always returned in this case. Otherwise, if no OOM error occurs, |
+** it is set to SQLITE_OK. |
+*/ |
+static int fts3PendingListAppend( |
+ PendingList **pp, /* IN/OUT: PendingList structure */ |
+ sqlite3_int64 iDocid, /* Docid for entry to add */ |
+ sqlite3_int64 iCol, /* Column for entry to add */ |
+ sqlite3_int64 iPos, /* Position of term for entry to add */ |
+ int *pRc /* OUT: Return code */ |
+){ |
+ PendingList *p = *pp; |
+ int rc = SQLITE_OK; |
+ |
+ assert( !p || p->iLastDocid<=iDocid ); |
+ |
+ if( !p || p->iLastDocid!=iDocid ){ |
+ sqlite3_int64 iDelta = iDocid - (p ? p->iLastDocid : 0); |
+ if( p ){ |
+ assert( p->nData<p->nSpace ); |
+ assert( p->aData[p->nData]==0 ); |
+ p->nData++; |
+ } |
+ if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iDelta)) ){ |
+ goto pendinglistappend_out; |
+ } |
+ p->iLastCol = -1; |
+ p->iLastPos = 0; |
+ p->iLastDocid = iDocid; |
+ } |
+ if( iCol>0 && p->iLastCol!=iCol ){ |
+ if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, 1)) |
+ || SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iCol)) |
+ ){ |
+ goto pendinglistappend_out; |
+ } |
+ p->iLastCol = iCol; |
+ p->iLastPos = 0; |
+ } |
+ if( iCol>=0 ){ |
+ assert( iPos>p->iLastPos || (iPos==0 && p->iLastPos==0) ); |
+ rc = fts3PendingListAppendVarint(&p, 2+iPos-p->iLastPos); |
+ if( rc==SQLITE_OK ){ |
+ p->iLastPos = iPos; |
+ } |
+ } |
+ |
+ pendinglistappend_out: |
+ *pRc = rc; |
+ if( p!=*pp ){ |
+ *pp = p; |
+ return 1; |
+ } |
+ return 0; |
+} |
+ |
+/* |
+** Tokenize the nul-terminated string zText and add all tokens to the |
+** pending-terms hash-table. The docid used is that currently stored in |
+** p->iPrevDocid, and the column is specified by argument iCol. |
+** |
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code. |
+*/ |
+static int fts3PendingTermsAdd( |
+ Fts3Table *p, /* Table into which text will be inserted */ |
+ const char *zText, /* Text of document to be inserted */ |
+ int iCol, /* Column into which text is being inserted */ |
+ u32 *pnWord /* OUT: Number of tokens inserted */ |
+){ |
+ int rc; |
+ int iStart; |
+ int iEnd; |
+ int iPos; |
+ int nWord = 0; |
+ |
+ char const *zToken; |
+ int nToken; |
+ |
+ sqlite3_tokenizer *pTokenizer = p->pTokenizer; |
+ sqlite3_tokenizer_module const *pModule = pTokenizer->pModule; |
+ sqlite3_tokenizer_cursor *pCsr; |
+ int (*xNext)(sqlite3_tokenizer_cursor *pCursor, |
+ const char**,int*,int*,int*,int*); |
+ |
+ assert( pTokenizer && pModule ); |
+ |
+ rc = pModule->xOpen(pTokenizer, zText, -1, &pCsr); |
+ if( rc!=SQLITE_OK ){ |
+ return rc; |
+ } |
+ pCsr->pTokenizer = pTokenizer; |
+ |
+ xNext = pModule->xNext; |
+ while( SQLITE_OK==rc |
+ && SQLITE_OK==(rc = xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos)) |
+ ){ |
+ PendingList *pList; |
+ |
+ if( iPos>=nWord ) nWord = iPos+1; |
+ |
+ /* Positions cannot be negative; we use -1 as a terminator internally. |
+ ** Tokens must have a non-zero length. |
+ */ |
+ if( iPos<0 || !zToken || nToken<=0 ){ |
+ rc = SQLITE_ERROR; |
+ break; |
+ } |
+ |
+ pList = (PendingList *)fts3HashFind(&p->pendingTerms, zToken, nToken); |
+ if( pList ){ |
+ p->nPendingData -= (pList->nData + nToken + sizeof(Fts3HashElem)); |
+ } |
+ if( fts3PendingListAppend(&pList, p->iPrevDocid, iCol, iPos, &rc) ){ |
+ if( pList==fts3HashInsert(&p->pendingTerms, zToken, nToken, pList) ){ |
+ /* Malloc failed while inserting the new entry. This can only |
+ ** happen if there was no previous entry for this token. |
+ */ |
+ assert( 0==fts3HashFind(&p->pendingTerms, zToken, nToken) ); |
+ sqlite3_free(pList); |
+ rc = SQLITE_NOMEM; |
+ } |
+ } |
+ if( rc==SQLITE_OK ){ |
+ p->nPendingData += (pList->nData + nToken + sizeof(Fts3HashElem)); |
+ } |
+ } |
+ |
+ pModule->xClose(pCsr); |
+ *pnWord = nWord; |
+ return (rc==SQLITE_DONE ? SQLITE_OK : rc); |
+} |
+ |
+/* |
+** Calling this function indicates that subsequent calls to |
+** fts3PendingTermsAdd() are to add term/position-list pairs for the |
+** contents of the document with docid iDocid. |
+*/ |
+static int fts3PendingTermsDocid(Fts3Table *p, sqlite_int64 iDocid){ |
+ /* TODO(shess) Explore whether partially flushing the buffer on |
+ ** forced-flush would provide better performance. I suspect that if |
+ ** we ordered the doclists by size and flushed the largest until the |
+ ** buffer was half empty, that would let the less frequent terms |
+ ** generate longer doclists. |
+ */ |
+ if( iDocid<=p->iPrevDocid || p->nPendingData>p->nMaxPendingData ){ |
+ int rc = sqlite3Fts3PendingTermsFlush(p); |
+ if( rc!=SQLITE_OK ) return rc; |
+ } |
+ p->iPrevDocid = iDocid; |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Discard the contents of the pending-terms hash table. |
+*/ |
+void sqlite3Fts3PendingTermsClear(Fts3Table *p){ |
+ Fts3HashElem *pElem; |
+ for(pElem=fts3HashFirst(&p->pendingTerms); pElem; pElem=fts3HashNext(pElem)){ |
+ sqlite3_free(fts3HashData(pElem)); |
+ } |
+ fts3HashClear(&p->pendingTerms); |
+ p->nPendingData = 0; |
+} |
+ |
+/* |
+** This function is called by the xUpdate() method as part of an INSERT |
+** operation. It adds entries for each term in the new record to the |
+** pendingTerms hash table. |
+** |
+** Argument apVal is the same as the similarly named argument passed to |
+** fts3InsertData(). Parameter iDocid is the docid of the new row. |
+*/ |
+static int fts3InsertTerms(Fts3Table *p, sqlite3_value **apVal, u32 *aSz){ |
+ int i; /* Iterator variable */ |
+ for(i=2; i<p->nColumn+2; i++){ |
+ const char *zText = (const char *)sqlite3_value_text(apVal[i]); |
+ if( zText ){ |
+ int rc = fts3PendingTermsAdd(p, zText, i-2, &aSz[i-2]); |
+ if( rc!=SQLITE_OK ){ |
+ return rc; |
+ } |
+ } |
+ aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]); |
+ } |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** This function is called by the xUpdate() method for an INSERT operation. |
+** The apVal parameter is passed a copy of the apVal argument passed by |
+** SQLite to the xUpdate() method. i.e: |
+** |
+** apVal[0] Not used for INSERT. |
+** apVal[1] rowid |
+** apVal[2] Left-most user-defined column |
+** ... |
+** apVal[p->nColumn+1] Right-most user-defined column |
+** apVal[p->nColumn+2] Hidden column with same name as table |
+** apVal[p->nColumn+3] Hidden "docid" column (alias for rowid) |
+*/ |
+static int fts3InsertData( |
+ Fts3Table *p, /* Full-text table */ |
+ sqlite3_value **apVal, /* Array of values to insert */ |
+ sqlite3_int64 *piDocid /* OUT: Docid for row just inserted */ |
+){ |
+ int rc; /* Return code */ |
+ sqlite3_stmt *pContentInsert; /* INSERT INTO %_content VALUES(...) */ |
+ |
+ /* Locate the statement handle used to insert data into the %_content |
+ ** table. The SQL for this statement is: |
+ ** |
+ ** INSERT INTO %_content VALUES(?, ?, ?, ...) |
+ ** |
+ ** The statement features N '?' variables, where N is the number of user |
+ ** defined columns in the FTS3 table, plus one for the docid field. |
+ */ |
+ rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]); |
+ if( rc!=SQLITE_OK ){ |
+ return rc; |
+ } |
+ |
+ /* There is a quirk here. The users INSERT statement may have specified |
+ ** a value for the "rowid" field, for the "docid" field, or for both. |
+ ** Which is a problem, since "rowid" and "docid" are aliases for the |
+ ** same value. For example: |
+ ** |
+ ** INSERT INTO fts3tbl(rowid, docid) VALUES(1, 2); |
+ ** |
+ ** In FTS3, this is an error. It is an error to specify non-NULL values |
+ ** for both docid and some other rowid alias. |
+ */ |
+ if( SQLITE_NULL!=sqlite3_value_type(apVal[3+p->nColumn]) ){ |
+ if( SQLITE_NULL==sqlite3_value_type(apVal[0]) |
+ && SQLITE_NULL!=sqlite3_value_type(apVal[1]) |
+ ){ |
+ /* A rowid/docid conflict. */ |
+ return SQLITE_ERROR; |
+ } |
+ rc = sqlite3_bind_value(pContentInsert, 1, apVal[3+p->nColumn]); |
+ if( rc!=SQLITE_OK ) return rc; |
+ } |
+ |
+ /* Execute the statement to insert the record. Set *piDocid to the |
+ ** new docid value. |
+ */ |
+ sqlite3_step(pContentInsert); |
+ rc = sqlite3_reset(pContentInsert); |
+ |
+ *piDocid = sqlite3_last_insert_rowid(p->db); |
+ return rc; |
+} |
+ |
+ |
+ |
+/* |
+** Remove all data from the FTS3 table. Clear the hash table containing |
+** pending terms. |
+*/ |
+static int fts3DeleteAll(Fts3Table *p){ |
+ int rc = SQLITE_OK; /* Return code */ |
+ |
+ /* Discard the contents of the pending-terms hash table. */ |
+ sqlite3Fts3PendingTermsClear(p); |
+ |
+ /* Delete everything from the %_content, %_segments and %_segdir tables. */ |
+ fts3SqlExec(&rc, p, SQL_DELETE_ALL_CONTENT, 0); |
+ fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGMENTS, 0); |
+ fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0); |
+ if( p->bHasDocsize ){ |
+ fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0); |
+ } |
+ if( p->bHasStat ){ |
+ fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** The first element in the apVal[] array is assumed to contain the docid |
+** (an integer) of a row about to be deleted. Remove all terms from the |
+** full-text index. |
+*/ |
+static void fts3DeleteTerms( |
+ int *pRC, /* Result code */ |
+ Fts3Table *p, /* The FTS table to delete from */ |
+ sqlite3_value **apVal, /* apVal[] contains the docid to be deleted */ |
+ u32 *aSz /* Sizes of deleted document written here */ |
+){ |
+ int rc; |
+ sqlite3_stmt *pSelect; |
+ |
+ if( *pRC ) return; |
+ rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, apVal); |
+ if( rc==SQLITE_OK ){ |
+ if( SQLITE_ROW==sqlite3_step(pSelect) ){ |
+ int i; |
+ for(i=1; i<=p->nColumn; i++){ |
+ const char *zText = (const char *)sqlite3_column_text(pSelect, i); |
+ rc = fts3PendingTermsAdd(p, zText, -1, &aSz[i-1]); |
+ if( rc!=SQLITE_OK ){ |
+ sqlite3_reset(pSelect); |
+ *pRC = rc; |
+ return; |
+ } |
+ aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i); |
+ } |
+ } |
+ rc = sqlite3_reset(pSelect); |
+ }else{ |
+ sqlite3_reset(pSelect); |
+ } |
+ *pRC = rc; |
+} |
+ |
+/* |
+** Forward declaration to account for the circular dependency between |
+** functions fts3SegmentMerge() and fts3AllocateSegdirIdx(). |
+*/ |
+static int fts3SegmentMerge(Fts3Table *, int); |
+ |
+/* |
+** This function allocates a new level iLevel index in the segdir table. |
+** Usually, indexes are allocated within a level sequentially starting |
+** with 0, so the allocated index is one greater than the value returned |
+** by: |
+** |
+** SELECT max(idx) FROM %_segdir WHERE level = :iLevel |
+** |
+** However, if there are already FTS3_MERGE_COUNT indexes at the requested |
+** level, they are merged into a single level (iLevel+1) segment and the |
+** allocated index is 0. |
+** |
+** If successful, *piIdx is set to the allocated index slot and SQLITE_OK |
+** returned. Otherwise, an SQLite error code is returned. |
+*/ |
+static int fts3AllocateSegdirIdx(Fts3Table *p, int iLevel, int *piIdx){ |
+ int rc; /* Return Code */ |
+ sqlite3_stmt *pNextIdx; /* Query for next idx at level iLevel */ |
+ int iNext = 0; /* Result of query pNextIdx */ |
+ |
+ /* Set variable iNext to the next available segdir index at level iLevel. */ |
+ rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_bind_int(pNextIdx, 1, iLevel); |
+ if( SQLITE_ROW==sqlite3_step(pNextIdx) ){ |
+ iNext = sqlite3_column_int(pNextIdx, 0); |
+ } |
+ rc = sqlite3_reset(pNextIdx); |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already |
+ ** full, merge all segments in level iLevel into a single iLevel+1 |
+ ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise, |
+ ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext. |
+ */ |
+ if( iNext>=FTS3_MERGE_COUNT ){ |
+ rc = fts3SegmentMerge(p, iLevel); |
+ *piIdx = 0; |
+ }else{ |
+ *piIdx = iNext; |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** The %_segments table is declared as follows: |
+** |
+** CREATE TABLE %_segments(blockid INTEGER PRIMARY KEY, block BLOB) |
+** |
+** This function reads data from a single row of the %_segments table. The |
+** specific row is identified by the iBlockid parameter. If paBlob is not |
+** NULL, then a buffer is allocated using sqlite3_malloc() and populated |
+** with the contents of the blob stored in the "block" column of the |
+** identified table row is. Whether or not paBlob is NULL, *pnBlob is set |
+** to the size of the blob in bytes before returning. |
+** |
+** If an error occurs, or the table does not contain the specified row, |
+** an SQLite error code is returned. Otherwise, SQLITE_OK is returned. If |
+** paBlob is non-NULL, then it is the responsibility of the caller to |
+** eventually free the returned buffer. |
+** |
+** This function may leave an open sqlite3_blob* handle in the |
+** Fts3Table.pSegments variable. This handle is reused by subsequent calls |
+** to this function. The handle may be closed by calling the |
+** sqlite3Fts3SegmentsClose() function. Reusing a blob handle is a handy |
+** performance improvement, but the blob handle should always be closed |
+** before control is returned to the user (to prevent a lock being held |
+** on the database file for longer than necessary). Thus, any virtual table |
+** method (xFilter etc.) that may directly or indirectly call this function |
+** must call sqlite3Fts3SegmentsClose() before returning. |
+*/ |
+int sqlite3Fts3ReadBlock( |
+ Fts3Table *p, /* FTS3 table handle */ |
+ sqlite3_int64 iBlockid, /* Access the row with blockid=$iBlockid */ |
+ char **paBlob, /* OUT: Blob data in malloc'd buffer */ |
+ int *pnBlob /* OUT: Size of blob data */ |
+){ |
+ int rc; /* Return code */ |
+ |
+ /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */ |
+ assert( pnBlob); |
+ |
+ if( p->pSegments ){ |
+ rc = sqlite3_blob_reopen(p->pSegments, iBlockid); |
+ }else{ |
+ if( 0==p->zSegmentsTbl ){ |
+ p->zSegmentsTbl = sqlite3_mprintf("%s_segments", p->zName); |
+ if( 0==p->zSegmentsTbl ) return SQLITE_NOMEM; |
+ } |
+ rc = sqlite3_blob_open( |
+ p->db, p->zDb, p->zSegmentsTbl, "block", iBlockid, 0, &p->pSegments |
+ ); |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ int nByte = sqlite3_blob_bytes(p->pSegments); |
+ if( paBlob ){ |
+ char *aByte = sqlite3_malloc(nByte + FTS3_NODE_PADDING); |
+ if( !aByte ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ rc = sqlite3_blob_read(p->pSegments, aByte, nByte, 0); |
+ memset(&aByte[nByte], 0, FTS3_NODE_PADDING); |
+ if( rc!=SQLITE_OK ){ |
+ sqlite3_free(aByte); |
+ aByte = 0; |
+ } |
+ } |
+ *paBlob = aByte; |
+ } |
+ *pnBlob = nByte; |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Close the blob handle at p->pSegments, if it is open. See comments above |
+** the sqlite3Fts3ReadBlock() function for details. |
+*/ |
+void sqlite3Fts3SegmentsClose(Fts3Table *p){ |
+ sqlite3_blob_close(p->pSegments); |
+ p->pSegments = 0; |
+} |
+ |
+/* |
+** Move the iterator passed as the first argument to the next term in the |
+** segment. If successful, SQLITE_OK is returned. If there is no next term, |
+** SQLITE_DONE. Otherwise, an SQLite error code. |
+*/ |
+static int fts3SegReaderNext(Fts3Table *p, Fts3SegReader *pReader){ |
+ char *pNext; /* Cursor variable */ |
+ int nPrefix; /* Number of bytes in term prefix */ |
+ int nSuffix; /* Number of bytes in term suffix */ |
+ |
+ if( !pReader->aDoclist ){ |
+ pNext = pReader->aNode; |
+ }else{ |
+ pNext = &pReader->aDoclist[pReader->nDoclist]; |
+ } |
+ |
+ if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){ |
+ int rc; /* Return code from Fts3ReadBlock() */ |
+ |
+ if( fts3SegReaderIsPending(pReader) ){ |
+ Fts3HashElem *pElem = *(pReader->ppNextElem); |
+ if( pElem==0 ){ |
+ pReader->aNode = 0; |
+ }else{ |
+ PendingList *pList = (PendingList *)fts3HashData(pElem); |
+ pReader->zTerm = (char *)fts3HashKey(pElem); |
+ pReader->nTerm = fts3HashKeysize(pElem); |
+ pReader->nNode = pReader->nDoclist = pList->nData + 1; |
+ pReader->aNode = pReader->aDoclist = pList->aData; |
+ pReader->ppNextElem++; |
+ assert( pReader->aNode ); |
+ } |
+ return SQLITE_OK; |
+ } |
+ |
+ if( !fts3SegReaderIsRootOnly(pReader) ){ |
+ sqlite3_free(pReader->aNode); |
+ } |
+ pReader->aNode = 0; |
+ |
+ /* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf |
+ ** blocks have already been traversed. */ |
+ assert( pReader->iCurrentBlock<=pReader->iLeafEndBlock ); |
+ if( pReader->iCurrentBlock>=pReader->iLeafEndBlock ){ |
+ return SQLITE_OK; |
+ } |
+ |
+ rc = sqlite3Fts3ReadBlock( |
+ p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode |
+ ); |
+ if( rc!=SQLITE_OK ) return rc; |
+ pNext = pReader->aNode; |
+ } |
+ |
+ /* Because of the FTS3_NODE_PADDING bytes of padding, the following is |
+ ** safe (no risk of overread) even if the node data is corrupted. |
+ */ |
+ pNext += sqlite3Fts3GetVarint32(pNext, &nPrefix); |
+ pNext += sqlite3Fts3GetVarint32(pNext, &nSuffix); |
+ if( nPrefix<0 || nSuffix<=0 |
+ || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] |
+ ){ |
+ return SQLITE_CORRUPT; |
+ } |
+ |
+ if( nPrefix+nSuffix>pReader->nTermAlloc ){ |
+ int nNew = (nPrefix+nSuffix)*2; |
+ char *zNew = sqlite3_realloc(pReader->zTerm, nNew); |
+ if( !zNew ){ |
+ return SQLITE_NOMEM; |
+ } |
+ pReader->zTerm = zNew; |
+ pReader->nTermAlloc = nNew; |
+ } |
+ memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix); |
+ pReader->nTerm = nPrefix+nSuffix; |
+ pNext += nSuffix; |
+ pNext += sqlite3Fts3GetVarint32(pNext, &pReader->nDoclist); |
+ pReader->aDoclist = pNext; |
+ pReader->pOffsetList = 0; |
+ |
+ /* Check that the doclist does not appear to extend past the end of the |
+ ** b-tree node. And that the final byte of the doclist is 0x00. If either |
+ ** of these statements is untrue, then the data structure is corrupt. |
+ */ |
+ if( &pReader->aDoclist[pReader->nDoclist]>&pReader->aNode[pReader->nNode] |
+ || pReader->aDoclist[pReader->nDoclist-1] |
+ ){ |
+ return SQLITE_CORRUPT; |
+ } |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Set the SegReader to point to the first docid in the doclist associated |
+** with the current term. |
+*/ |
+static void fts3SegReaderFirstDocid(Fts3SegReader *pReader){ |
+ int n; |
+ assert( pReader->aDoclist ); |
+ assert( !pReader->pOffsetList ); |
+ n = sqlite3Fts3GetVarint(pReader->aDoclist, &pReader->iDocid); |
+ pReader->pOffsetList = &pReader->aDoclist[n]; |
+} |
+ |
+/* |
+** Advance the SegReader to point to the next docid in the doclist |
+** associated with the current term. |
+** |
+** If arguments ppOffsetList and pnOffsetList are not NULL, then |
+** *ppOffsetList is set to point to the first column-offset list |
+** in the doclist entry (i.e. immediately past the docid varint). |
+** *pnOffsetList is set to the length of the set of column-offset |
+** lists, not including the nul-terminator byte. For example: |
+*/ |
+static void fts3SegReaderNextDocid( |
+ Fts3SegReader *pReader, |
+ char **ppOffsetList, |
+ int *pnOffsetList |
+){ |
+ char *p = pReader->pOffsetList; |
+ char c = 0; |
+ |
+ /* Pointer p currently points at the first byte of an offset list. The |
+ ** following two lines advance it to point one byte past the end of |
+ ** the same offset list. |
+ */ |
+ while( *p | c ) c = *p++ & 0x80; |
+ p++; |
+ |
+ /* If required, populate the output variables with a pointer to and the |
+ ** size of the previous offset-list. |
+ */ |
+ if( ppOffsetList ){ |
+ *ppOffsetList = pReader->pOffsetList; |
+ *pnOffsetList = (int)(p - pReader->pOffsetList - 1); |
+ } |
+ |
+ /* If there are no more entries in the doclist, set pOffsetList to |
+ ** NULL. Otherwise, set Fts3SegReader.iDocid to the next docid and |
+ ** Fts3SegReader.pOffsetList to point to the next offset list before |
+ ** returning. |
+ */ |
+ if( p>=&pReader->aDoclist[pReader->nDoclist] ){ |
+ pReader->pOffsetList = 0; |
+ }else{ |
+ sqlite3_int64 iDelta; |
+ pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta); |
+ pReader->iDocid += iDelta; |
+ } |
+} |
+ |
+/* |
+** This function is called to estimate the amount of data that will be |
+** loaded from the disk If SegReaderIterate() is called on this seg-reader, |
+** in units of average document size. |
+** |
+** This can be used as follows: If the caller has a small doclist that |
+** contains references to N documents, and is considering merging it with |
+** a large doclist (size X "average documents"), it may opt not to load |
+** the large doclist if X>N. |
+*/ |
+int sqlite3Fts3SegReaderCost( |
+ Fts3Cursor *pCsr, /* FTS3 cursor handle */ |
+ Fts3SegReader *pReader, /* Segment-reader handle */ |
+ int *pnCost /* IN/OUT: Number of bytes read */ |
+){ |
+ Fts3Table *p = (Fts3Table*)pCsr->base.pVtab; |
+ int rc = SQLITE_OK; /* Return code */ |
+ int nCost = 0; /* Cost in bytes to return */ |
+ int pgsz = p->nPgsz; /* Database page size */ |
+ |
+ /* If this seg-reader is reading the pending-terms table, or if all data |
+ ** for the segment is stored on the root page of the b-tree, then the cost |
+ ** is zero. In this case all required data is already in main memory. |
+ */ |
+ if( p->bHasStat |
+ && !fts3SegReaderIsPending(pReader) |
+ && !fts3SegReaderIsRootOnly(pReader) |
+ ){ |
+ int nBlob = 0; |
+ sqlite3_int64 iBlock; |
+ |
+ if( pCsr->nRowAvg==0 ){ |
+ /* The average document size, which is required to calculate the cost |
+ ** of each doclist, has not yet been determined. Read the required |
+ ** data from the %_stat table to calculate it. |
+ ** |
+ ** Entry 0 of the %_stat table is a blob containing (nCol+1) FTS3 |
+ ** varints, where nCol is the number of columns in the FTS3 table. |
+ ** The first varint is the number of documents currently stored in |
+ ** the table. The following nCol varints contain the total amount of |
+ ** data stored in all rows of each column of the table, from left |
+ ** to right. |
+ */ |
+ sqlite3_stmt *pStmt; |
+ sqlite3_int64 nDoc = 0; |
+ sqlite3_int64 nByte = 0; |
+ const char *pEnd; |
+ const char *a; |
+ |
+ rc = sqlite3Fts3SelectDoctotal(p, &pStmt); |
+ if( rc!=SQLITE_OK ) return rc; |
+ a = sqlite3_column_blob(pStmt, 0); |
+ assert( a ); |
+ |
+ pEnd = &a[sqlite3_column_bytes(pStmt, 0)]; |
+ a += sqlite3Fts3GetVarint(a, &nDoc); |
+ while( a<pEnd ){ |
+ a += sqlite3Fts3GetVarint(a, &nByte); |
+ } |
+ if( nDoc==0 || nByte==0 ){ |
+ sqlite3_reset(pStmt); |
+ return SQLITE_CORRUPT; |
+ } |
+ |
+ pCsr->nRowAvg = (int)(((nByte / nDoc) + pgsz) / pgsz); |
+ assert( pCsr->nRowAvg>0 ); |
+ rc = sqlite3_reset(pStmt); |
+ if( rc!=SQLITE_OK ) return rc; |
+ } |
+ |
+ /* Assume that a blob flows over onto overflow pages if it is larger |
+ ** than (pgsz-35) bytes in size (the file-format documentation |
+ ** confirms this). |
+ */ |
+ for(iBlock=pReader->iStartBlock; iBlock<=pReader->iLeafEndBlock; iBlock++){ |
+ rc = sqlite3Fts3ReadBlock(p, iBlock, 0, &nBlob); |
+ if( rc!=SQLITE_OK ) break; |
+ if( (nBlob+35)>pgsz ){ |
+ int nOvfl = (nBlob + 34)/pgsz; |
+ nCost += ((nOvfl + pCsr->nRowAvg - 1)/pCsr->nRowAvg); |
+ } |
+ } |
+ } |
+ |
+ *pnCost += nCost; |
+ return rc; |
+} |
+ |
+/* |
+** Free all allocations associated with the iterator passed as the |
+** second argument. |
+*/ |
+void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){ |
+ if( pReader && !fts3SegReaderIsPending(pReader) ){ |
+ sqlite3_free(pReader->zTerm); |
+ if( !fts3SegReaderIsRootOnly(pReader) ){ |
+ sqlite3_free(pReader->aNode); |
+ } |
+ } |
+ sqlite3_free(pReader); |
+} |
+ |
+/* |
+** Allocate a new SegReader object. |
+*/ |
+int sqlite3Fts3SegReaderNew( |
+ int iAge, /* Segment "age". */ |
+ sqlite3_int64 iStartLeaf, /* First leaf to traverse */ |
+ sqlite3_int64 iEndLeaf, /* Final leaf to traverse */ |
+ sqlite3_int64 iEndBlock, /* Final block of segment */ |
+ const char *zRoot, /* Buffer containing root node */ |
+ int nRoot, /* Size of buffer containing root node */ |
+ Fts3SegReader **ppReader /* OUT: Allocated Fts3SegReader */ |
+){ |
+ int rc = SQLITE_OK; /* Return code */ |
+ Fts3SegReader *pReader; /* Newly allocated SegReader object */ |
+ int nExtra = 0; /* Bytes to allocate segment root node */ |
+ |
+ assert( iStartLeaf<=iEndLeaf ); |
+ if( iStartLeaf==0 ){ |
+ nExtra = nRoot + FTS3_NODE_PADDING; |
+ } |
+ |
+ pReader = (Fts3SegReader *)sqlite3_malloc(sizeof(Fts3SegReader) + nExtra); |
+ if( !pReader ){ |
+ return SQLITE_NOMEM; |
+ } |
+ memset(pReader, 0, sizeof(Fts3SegReader)); |
+ pReader->iIdx = iAge; |
+ pReader->iStartBlock = iStartLeaf; |
+ pReader->iLeafEndBlock = iEndLeaf; |
+ pReader->iEndBlock = iEndBlock; |
+ |
+ if( nExtra ){ |
+ /* The entire segment is stored in the root node. */ |
+ pReader->aNode = (char *)&pReader[1]; |
+ pReader->nNode = nRoot; |
+ memcpy(pReader->aNode, zRoot, nRoot); |
+ memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING); |
+ }else{ |
+ pReader->iCurrentBlock = iStartLeaf-1; |
+ } |
+ |
+ if( rc==SQLITE_OK ){ |
+ *ppReader = pReader; |
+ }else{ |
+ sqlite3Fts3SegReaderFree(pReader); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** This is a comparison function used as a qsort() callback when sorting |
+** an array of pending terms by term. This occurs as part of flushing |
+** the contents of the pending-terms hash table to the database. |
+*/ |
+static int fts3CompareElemByTerm(const void *lhs, const void *rhs){ |
+ char *z1 = fts3HashKey(*(Fts3HashElem **)lhs); |
+ char *z2 = fts3HashKey(*(Fts3HashElem **)rhs); |
+ int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs); |
+ int n2 = fts3HashKeysize(*(Fts3HashElem **)rhs); |
+ |
+ int n = (n1<n2 ? n1 : n2); |
+ int c = memcmp(z1, z2, n); |
+ if( c==0 ){ |
+ c = n1 - n2; |
+ } |
+ return c; |
+} |
+ |
+/* |
+** This function is used to allocate an Fts3SegReader that iterates through |
+** a subset of the terms stored in the Fts3Table.pendingTerms array. |
+*/ |
+int sqlite3Fts3SegReaderPending( |
+ Fts3Table *p, /* Virtual table handle */ |
+ const char *zTerm, /* Term to search for */ |
+ int nTerm, /* Size of buffer zTerm */ |
+ int isPrefix, /* True for a term-prefix query */ |
+ Fts3SegReader **ppReader /* OUT: SegReader for pending-terms */ |
+){ |
+ Fts3SegReader *pReader = 0; /* Fts3SegReader object to return */ |
+ Fts3HashElem **aElem = 0; /* Array of term hash entries to scan */ |
+ int nElem = 0; /* Size of array at aElem */ |
+ int rc = SQLITE_OK; /* Return Code */ |
+ |
+ if( isPrefix ){ |
+ int nAlloc = 0; /* Size of allocated array at aElem */ |
+ Fts3HashElem *pE = 0; /* Iterator variable */ |
+ |
+ for(pE=fts3HashFirst(&p->pendingTerms); pE; pE=fts3HashNext(pE)){ |
+ char *zKey = (char *)fts3HashKey(pE); |
+ int nKey = fts3HashKeysize(pE); |
+ if( nTerm==0 || (nKey>=nTerm && 0==memcmp(zKey, zTerm, nTerm)) ){ |
+ if( nElem==nAlloc ){ |
+ Fts3HashElem **aElem2; |
+ nAlloc += 16; |
+ aElem2 = (Fts3HashElem **)sqlite3_realloc( |
+ aElem, nAlloc*sizeof(Fts3HashElem *) |
+ ); |
+ if( !aElem2 ){ |
+ rc = SQLITE_NOMEM; |
+ nElem = 0; |
+ break; |
+ } |
+ aElem = aElem2; |
+ } |
+ aElem[nElem++] = pE; |
+ } |
+ } |
+ |
+ /* If more than one term matches the prefix, sort the Fts3HashElem |
+ ** objects in term order using qsort(). This uses the same comparison |
+ ** callback as is used when flushing terms to disk. |
+ */ |
+ if( nElem>1 ){ |
+ qsort(aElem, nElem, sizeof(Fts3HashElem *), fts3CompareElemByTerm); |
+ } |
+ |
+ }else{ |
+ Fts3HashElem *pE = fts3HashFindElem(&p->pendingTerms, zTerm, nTerm); |
+ if( pE ){ |
+ aElem = &pE; |
+ nElem = 1; |
+ } |
+ } |
+ |
+ if( nElem>0 ){ |
+ int nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *); |
+ pReader = (Fts3SegReader *)sqlite3_malloc(nByte); |
+ if( !pReader ){ |
+ rc = SQLITE_NOMEM; |
+ }else{ |
+ memset(pReader, 0, nByte); |
+ pReader->iIdx = 0x7FFFFFFF; |
+ pReader->ppNextElem = (Fts3HashElem **)&pReader[1]; |
+ memcpy(pReader->ppNextElem, aElem, nElem*sizeof(Fts3HashElem *)); |
+ } |
+ } |
+ |
+ if( isPrefix ){ |
+ sqlite3_free(aElem); |
+ } |
+ *ppReader = pReader; |
+ return rc; |
+} |
+ |
+/* |
+** Compare the entries pointed to by two Fts3SegReader structures. |
+** Comparison is as follows: |
+** |
+** 1) EOF is greater than not EOF. |
+** |
+** 2) The current terms (if any) are compared using memcmp(). If one |
+** term is a prefix of another, the longer term is considered the |
+** larger. |
+** |
+** 3) By segment age. An older segment is considered larger. |
+*/ |
+static int fts3SegReaderCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){ |
+ int rc; |
+ if( pLhs->aNode && pRhs->aNode ){ |
+ int rc2 = pLhs->nTerm - pRhs->nTerm; |
+ if( rc2<0 ){ |
+ rc = memcmp(pLhs->zTerm, pRhs->zTerm, pLhs->nTerm); |
+ }else{ |
+ rc = memcmp(pLhs->zTerm, pRhs->zTerm, pRhs->nTerm); |
+ } |
+ if( rc==0 ){ |
+ rc = rc2; |
+ } |
+ }else{ |
+ rc = (pLhs->aNode==0) - (pRhs->aNode==0); |
+ } |
+ if( rc==0 ){ |
+ rc = pRhs->iIdx - pLhs->iIdx; |
+ } |
+ assert( rc!=0 ); |
+ return rc; |
+} |
+ |
+/* |
+** A different comparison function for SegReader structures. In this |
+** version, it is assumed that each SegReader points to an entry in |
+** a doclist for identical terms. Comparison is made as follows: |
+** |
+** 1) EOF (end of doclist in this case) is greater than not EOF. |
+** |
+** 2) By current docid. |
+** |
+** 3) By segment age. An older segment is considered larger. |
+*/ |
+static int fts3SegReaderDoclistCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){ |
+ int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0); |
+ if( rc==0 ){ |
+ if( pLhs->iDocid==pRhs->iDocid ){ |
+ rc = pRhs->iIdx - pLhs->iIdx; |
+ }else{ |
+ rc = (pLhs->iDocid > pRhs->iDocid) ? 1 : -1; |
+ } |
+ } |
+ assert( pLhs->aNode && pRhs->aNode ); |
+ return rc; |
+} |
+ |
+/* |
+** Compare the term that the Fts3SegReader object passed as the first argument |
+** points to with the term specified by arguments zTerm and nTerm. |
+** |
+** If the pSeg iterator is already at EOF, return 0. Otherwise, return |
+** -ve if the pSeg term is less than zTerm/nTerm, 0 if the two terms are |
+** equal, or +ve if the pSeg term is greater than zTerm/nTerm. |
+*/ |
+static int fts3SegReaderTermCmp( |
+ Fts3SegReader *pSeg, /* Segment reader object */ |
+ const char *zTerm, /* Term to compare to */ |
+ int nTerm /* Size of term zTerm in bytes */ |
+){ |
+ int res = 0; |
+ if( pSeg->aNode ){ |
+ if( pSeg->nTerm>nTerm ){ |
+ res = memcmp(pSeg->zTerm, zTerm, nTerm); |
+ }else{ |
+ res = memcmp(pSeg->zTerm, zTerm, pSeg->nTerm); |
+ } |
+ if( res==0 ){ |
+ res = pSeg->nTerm-nTerm; |
+ } |
+ } |
+ return res; |
+} |
+ |
+/* |
+** Argument apSegment is an array of nSegment elements. It is known that |
+** the final (nSegment-nSuspect) members are already in sorted order |
+** (according to the comparison function provided). This function shuffles |
+** the array around until all entries are in sorted order. |
+*/ |
+static void fts3SegReaderSort( |
+ Fts3SegReader **apSegment, /* Array to sort entries of */ |
+ int nSegment, /* Size of apSegment array */ |
+ int nSuspect, /* Unsorted entry count */ |
+ int (*xCmp)(Fts3SegReader *, Fts3SegReader *) /* Comparison function */ |
+){ |
+ int i; /* Iterator variable */ |
+ |
+ assert( nSuspect<=nSegment ); |
+ |
+ if( nSuspect==nSegment ) nSuspect--; |
+ for(i=nSuspect-1; i>=0; i--){ |
+ int j; |
+ for(j=i; j<(nSegment-1); j++){ |
+ Fts3SegReader *pTmp; |
+ if( xCmp(apSegment[j], apSegment[j+1])<0 ) break; |
+ pTmp = apSegment[j+1]; |
+ apSegment[j+1] = apSegment[j]; |
+ apSegment[j] = pTmp; |
+ } |
+ } |
+ |
+#ifndef NDEBUG |
+ /* Check that the list really is sorted now. */ |
+ for(i=0; i<(nSuspect-1); i++){ |
+ assert( xCmp(apSegment[i], apSegment[i+1])<0 ); |
+ } |
+#endif |
+} |
+ |
+/* |
+** Insert a record into the %_segments table. |
+*/ |
+static int fts3WriteSegment( |
+ Fts3Table *p, /* Virtual table handle */ |
+ sqlite3_int64 iBlock, /* Block id for new block */ |
+ char *z, /* Pointer to buffer containing block data */ |
+ int n /* Size of buffer z in bytes */ |
+){ |
+ sqlite3_stmt *pStmt; |
+ int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_bind_int64(pStmt, 1, iBlock); |
+ sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC); |
+ sqlite3_step(pStmt); |
+ rc = sqlite3_reset(pStmt); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** Insert a record into the %_segdir table. |
+*/ |
+static int fts3WriteSegdir( |
+ Fts3Table *p, /* Virtual table handle */ |
+ int iLevel, /* Value for "level" field */ |
+ int iIdx, /* Value for "idx" field */ |
+ sqlite3_int64 iStartBlock, /* Value for "start_block" field */ |
+ sqlite3_int64 iLeafEndBlock, /* Value for "leaves_end_block" field */ |
+ sqlite3_int64 iEndBlock, /* Value for "end_block" field */ |
+ char *zRoot, /* Blob value for "root" field */ |
+ int nRoot /* Number of bytes in buffer zRoot */ |
+){ |
+ sqlite3_stmt *pStmt; |
+ int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_bind_int(pStmt, 1, iLevel); |
+ sqlite3_bind_int(pStmt, 2, iIdx); |
+ sqlite3_bind_int64(pStmt, 3, iStartBlock); |
+ sqlite3_bind_int64(pStmt, 4, iLeafEndBlock); |
+ sqlite3_bind_int64(pStmt, 5, iEndBlock); |
+ sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC); |
+ sqlite3_step(pStmt); |
+ rc = sqlite3_reset(pStmt); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** Return the size of the common prefix (if any) shared by zPrev and |
+** zNext, in bytes. For example, |
+** |
+** fts3PrefixCompress("abc", 3, "abcdef", 6) // returns 3 |
+** fts3PrefixCompress("abX", 3, "abcdef", 6) // returns 2 |
+** fts3PrefixCompress("abX", 3, "Xbcdef", 6) // returns 0 |
+*/ |
+static int fts3PrefixCompress( |
+ const char *zPrev, /* Buffer containing previous term */ |
+ int nPrev, /* Size of buffer zPrev in bytes */ |
+ const char *zNext, /* Buffer containing next term */ |
+ int nNext /* Size of buffer zNext in bytes */ |
+){ |
+ int n; |
+ UNUSED_PARAMETER(nNext); |
+ for(n=0; n<nPrev && zPrev[n]==zNext[n]; n++); |
+ return n; |
+} |
+ |
+/* |
+** Add term zTerm to the SegmentNode. It is guaranteed that zTerm is larger |
+** (according to memcmp) than the previous term. |
+*/ |
+static int fts3NodeAddTerm( |
+ Fts3Table *p, /* Virtual table handle */ |
+ SegmentNode **ppTree, /* IN/OUT: SegmentNode handle */ |
+ int isCopyTerm, /* True if zTerm/nTerm is transient */ |
+ const char *zTerm, /* Pointer to buffer containing term */ |
+ int nTerm /* Size of term in bytes */ |
+){ |
+ SegmentNode *pTree = *ppTree; |
+ int rc; |
+ SegmentNode *pNew; |
+ |
+ /* First try to append the term to the current node. Return early if |
+ ** this is possible. |
+ */ |
+ if( pTree ){ |
+ int nData = pTree->nData; /* Current size of node in bytes */ |
+ int nReq = nData; /* Required space after adding zTerm */ |
+ int nPrefix; /* Number of bytes of prefix compression */ |
+ int nSuffix; /* Suffix length */ |
+ |
+ nPrefix = fts3PrefixCompress(pTree->zTerm, pTree->nTerm, zTerm, nTerm); |
+ nSuffix = nTerm-nPrefix; |
+ |
+ nReq += sqlite3Fts3VarintLen(nPrefix)+sqlite3Fts3VarintLen(nSuffix)+nSuffix; |
+ if( nReq<=p->nNodeSize || !pTree->zTerm ){ |
+ |
+ if( nReq>p->nNodeSize ){ |
+ /* An unusual case: this is the first term to be added to the node |
+ ** and the static node buffer (p->nNodeSize bytes) is not large |
+ ** enough. Use a separately malloced buffer instead This wastes |
+ ** p->nNodeSize bytes, but since this scenario only comes about when |
+ ** the database contain two terms that share a prefix of almost 2KB, |
+ ** this is not expected to be a serious problem. |
+ */ |
+ assert( pTree->aData==(char *)&pTree[1] ); |
+ pTree->aData = (char *)sqlite3_malloc(nReq); |
+ if( !pTree->aData ){ |
+ return SQLITE_NOMEM; |
+ } |
+ } |
+ |
+ if( pTree->zTerm ){ |
+ /* There is no prefix-length field for first term in a node */ |
+ nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nPrefix); |
+ } |
+ |
+ nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nSuffix); |
+ memcpy(&pTree->aData[nData], &zTerm[nPrefix], nSuffix); |
+ pTree->nData = nData + nSuffix; |
+ pTree->nEntry++; |
+ |
+ if( isCopyTerm ){ |
+ if( pTree->nMalloc<nTerm ){ |
+ char *zNew = sqlite3_realloc(pTree->zMalloc, nTerm*2); |
+ if( !zNew ){ |
+ return SQLITE_NOMEM; |
+ } |
+ pTree->nMalloc = nTerm*2; |
+ pTree->zMalloc = zNew; |
+ } |
+ pTree->zTerm = pTree->zMalloc; |
+ memcpy(pTree->zTerm, zTerm, nTerm); |
+ pTree->nTerm = nTerm; |
+ }else{ |
+ pTree->zTerm = (char *)zTerm; |
+ pTree->nTerm = nTerm; |
+ } |
+ return SQLITE_OK; |
+ } |
+ } |
+ |
+ /* If control flows to here, it was not possible to append zTerm to the |
+ ** current node. Create a new node (a right-sibling of the current node). |
+ ** If this is the first node in the tree, the term is added to it. |
+ ** |
+ ** Otherwise, the term is not added to the new node, it is left empty for |
+ ** now. Instead, the term is inserted into the parent of pTree. If pTree |
+ ** has no parent, one is created here. |
+ */ |
+ pNew = (SegmentNode *)sqlite3_malloc(sizeof(SegmentNode) + p->nNodeSize); |
+ if( !pNew ){ |
+ return SQLITE_NOMEM; |
+ } |
+ memset(pNew, 0, sizeof(SegmentNode)); |
+ pNew->nData = 1 + FTS3_VARINT_MAX; |
+ pNew->aData = (char *)&pNew[1]; |
+ |
+ if( pTree ){ |
+ SegmentNode *pParent = pTree->pParent; |
+ rc = fts3NodeAddTerm(p, &pParent, isCopyTerm, zTerm, nTerm); |
+ if( pTree->pParent==0 ){ |
+ pTree->pParent = pParent; |
+ } |
+ pTree->pRight = pNew; |
+ pNew->pLeftmost = pTree->pLeftmost; |
+ pNew->pParent = pParent; |
+ pNew->zMalloc = pTree->zMalloc; |
+ pNew->nMalloc = pTree->nMalloc; |
+ pTree->zMalloc = 0; |
+ }else{ |
+ pNew->pLeftmost = pNew; |
+ rc = fts3NodeAddTerm(p, &pNew, isCopyTerm, zTerm, nTerm); |
+ } |
+ |
+ *ppTree = pNew; |
+ return rc; |
+} |
+ |
+/* |
+** Helper function for fts3NodeWrite(). |
+*/ |
+static int fts3TreeFinishNode( |
+ SegmentNode *pTree, |
+ int iHeight, |
+ sqlite3_int64 iLeftChild |
+){ |
+ int nStart; |
+ assert( iHeight>=1 && iHeight<128 ); |
+ nStart = FTS3_VARINT_MAX - sqlite3Fts3VarintLen(iLeftChild); |
+ pTree->aData[nStart] = (char)iHeight; |
+ sqlite3Fts3PutVarint(&pTree->aData[nStart+1], iLeftChild); |
+ return nStart; |
+} |
+ |
+/* |
+** Write the buffer for the segment node pTree and all of its peers to the |
+** database. Then call this function recursively to write the parent of |
+** pTree and its peers to the database. |
+** |
+** Except, if pTree is a root node, do not write it to the database. Instead, |
+** set output variables *paRoot and *pnRoot to contain the root node. |
+** |
+** If successful, SQLITE_OK is returned and output variable *piLast is |
+** set to the largest blockid written to the database (or zero if no |
+** blocks were written to the db). Otherwise, an SQLite error code is |
+** returned. |
+*/ |
+static int fts3NodeWrite( |
+ Fts3Table *p, /* Virtual table handle */ |
+ SegmentNode *pTree, /* SegmentNode handle */ |
+ int iHeight, /* Height of this node in tree */ |
+ sqlite3_int64 iLeaf, /* Block id of first leaf node */ |
+ sqlite3_int64 iFree, /* Block id of next free slot in %_segments */ |
+ sqlite3_int64 *piLast, /* OUT: Block id of last entry written */ |
+ char **paRoot, /* OUT: Data for root node */ |
+ int *pnRoot /* OUT: Size of root node in bytes */ |
+){ |
+ int rc = SQLITE_OK; |
+ |
+ if( !pTree->pParent ){ |
+ /* Root node of the tree. */ |
+ int nStart = fts3TreeFinishNode(pTree, iHeight, iLeaf); |
+ *piLast = iFree-1; |
+ *pnRoot = pTree->nData - nStart; |
+ *paRoot = &pTree->aData[nStart]; |
+ }else{ |
+ SegmentNode *pIter; |
+ sqlite3_int64 iNextFree = iFree; |
+ sqlite3_int64 iNextLeaf = iLeaf; |
+ for(pIter=pTree->pLeftmost; pIter && rc==SQLITE_OK; pIter=pIter->pRight){ |
+ int nStart = fts3TreeFinishNode(pIter, iHeight, iNextLeaf); |
+ int nWrite = pIter->nData - nStart; |
+ |
+ rc = fts3WriteSegment(p, iNextFree, &pIter->aData[nStart], nWrite); |
+ iNextFree++; |
+ iNextLeaf += (pIter->nEntry+1); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ assert( iNextLeaf==iFree ); |
+ rc = fts3NodeWrite( |
+ p, pTree->pParent, iHeight+1, iFree, iNextFree, piLast, paRoot, pnRoot |
+ ); |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Free all memory allocations associated with the tree pTree. |
+*/ |
+static void fts3NodeFree(SegmentNode *pTree){ |
+ if( pTree ){ |
+ SegmentNode *p = pTree->pLeftmost; |
+ fts3NodeFree(p->pParent); |
+ while( p ){ |
+ SegmentNode *pRight = p->pRight; |
+ if( p->aData!=(char *)&p[1] ){ |
+ sqlite3_free(p->aData); |
+ } |
+ assert( pRight==0 || p->zMalloc==0 ); |
+ sqlite3_free(p->zMalloc); |
+ sqlite3_free(p); |
+ p = pRight; |
+ } |
+ } |
+} |
+ |
+/* |
+** Add a term to the segment being constructed by the SegmentWriter object |
+** *ppWriter. When adding the first term to a segment, *ppWriter should |
+** be passed NULL. This function will allocate a new SegmentWriter object |
+** and return it via the input/output variable *ppWriter in this case. |
+** |
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code. |
+*/ |
+static int fts3SegWriterAdd( |
+ Fts3Table *p, /* Virtual table handle */ |
+ SegmentWriter **ppWriter, /* IN/OUT: SegmentWriter handle */ |
+ int isCopyTerm, /* True if buffer zTerm must be copied */ |
+ const char *zTerm, /* Pointer to buffer containing term */ |
+ int nTerm, /* Size of term in bytes */ |
+ const char *aDoclist, /* Pointer to buffer containing doclist */ |
+ int nDoclist /* Size of doclist in bytes */ |
+){ |
+ int nPrefix; /* Size of term prefix in bytes */ |
+ int nSuffix; /* Size of term suffix in bytes */ |
+ int nReq; /* Number of bytes required on leaf page */ |
+ int nData; |
+ SegmentWriter *pWriter = *ppWriter; |
+ |
+ if( !pWriter ){ |
+ int rc; |
+ sqlite3_stmt *pStmt; |
+ |
+ /* Allocate the SegmentWriter structure */ |
+ pWriter = (SegmentWriter *)sqlite3_malloc(sizeof(SegmentWriter)); |
+ if( !pWriter ) return SQLITE_NOMEM; |
+ memset(pWriter, 0, sizeof(SegmentWriter)); |
+ *ppWriter = pWriter; |
+ |
+ /* Allocate a buffer in which to accumulate data */ |
+ pWriter->aData = (char *)sqlite3_malloc(p->nNodeSize); |
+ if( !pWriter->aData ) return SQLITE_NOMEM; |
+ pWriter->nSize = p->nNodeSize; |
+ |
+ /* Find the next free blockid in the %_segments table */ |
+ rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pStmt, 0); |
+ if( rc!=SQLITE_OK ) return rc; |
+ if( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ pWriter->iFree = sqlite3_column_int64(pStmt, 0); |
+ pWriter->iFirst = pWriter->iFree; |
+ } |
+ rc = sqlite3_reset(pStmt); |
+ if( rc!=SQLITE_OK ) return rc; |
+ } |
+ nData = pWriter->nData; |
+ |
+ nPrefix = fts3PrefixCompress(pWriter->zTerm, pWriter->nTerm, zTerm, nTerm); |
+ nSuffix = nTerm-nPrefix; |
+ |
+ /* Figure out how many bytes are required by this new entry */ |
+ nReq = sqlite3Fts3VarintLen(nPrefix) + /* varint containing prefix size */ |
+ sqlite3Fts3VarintLen(nSuffix) + /* varint containing suffix size */ |
+ nSuffix + /* Term suffix */ |
+ sqlite3Fts3VarintLen(nDoclist) + /* Size of doclist */ |
+ nDoclist; /* Doclist data */ |
+ |
+ if( nData>0 && nData+nReq>p->nNodeSize ){ |
+ int rc; |
+ |
+ /* The current leaf node is full. Write it out to the database. */ |
+ rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData); |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ /* Add the current term to the interior node tree. The term added to |
+ ** the interior tree must: |
+ ** |
+ ** a) be greater than the largest term on the leaf node just written |
+ ** to the database (still available in pWriter->zTerm), and |
+ ** |
+ ** b) be less than or equal to the term about to be added to the new |
+ ** leaf node (zTerm/nTerm). |
+ ** |
+ ** In other words, it must be the prefix of zTerm 1 byte longer than |
+ ** the common prefix (if any) of zTerm and pWriter->zTerm. |
+ */ |
+ assert( nPrefix<nTerm ); |
+ rc = fts3NodeAddTerm(p, &pWriter->pTree, isCopyTerm, zTerm, nPrefix+1); |
+ if( rc!=SQLITE_OK ) return rc; |
+ |
+ nData = 0; |
+ pWriter->nTerm = 0; |
+ |
+ nPrefix = 0; |
+ nSuffix = nTerm; |
+ nReq = 1 + /* varint containing prefix size */ |
+ sqlite3Fts3VarintLen(nTerm) + /* varint containing suffix size */ |
+ nTerm + /* Term suffix */ |
+ sqlite3Fts3VarintLen(nDoclist) + /* Size of doclist */ |
+ nDoclist; /* Doclist data */ |
+ } |
+ |
+ /* If the buffer currently allocated is too small for this entry, realloc |
+ ** the buffer to make it large enough. |
+ */ |
+ if( nReq>pWriter->nSize ){ |
+ char *aNew = sqlite3_realloc(pWriter->aData, nReq); |
+ if( !aNew ) return SQLITE_NOMEM; |
+ pWriter->aData = aNew; |
+ pWriter->nSize = nReq; |
+ } |
+ assert( nData+nReq<=pWriter->nSize ); |
+ |
+ /* Append the prefix-compressed term and doclist to the buffer. */ |
+ nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nPrefix); |
+ nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nSuffix); |
+ memcpy(&pWriter->aData[nData], &zTerm[nPrefix], nSuffix); |
+ nData += nSuffix; |
+ nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nDoclist); |
+ memcpy(&pWriter->aData[nData], aDoclist, nDoclist); |
+ pWriter->nData = nData + nDoclist; |
+ |
+ /* Save the current term so that it can be used to prefix-compress the next. |
+ ** If the isCopyTerm parameter is true, then the buffer pointed to by |
+ ** zTerm is transient, so take a copy of the term data. Otherwise, just |
+ ** store a copy of the pointer. |
+ */ |
+ if( isCopyTerm ){ |
+ if( nTerm>pWriter->nMalloc ){ |
+ char *zNew = sqlite3_realloc(pWriter->zMalloc, nTerm*2); |
+ if( !zNew ){ |
+ return SQLITE_NOMEM; |
+ } |
+ pWriter->nMalloc = nTerm*2; |
+ pWriter->zMalloc = zNew; |
+ pWriter->zTerm = zNew; |
+ } |
+ assert( pWriter->zTerm==pWriter->zMalloc ); |
+ memcpy(pWriter->zTerm, zTerm, nTerm); |
+ }else{ |
+ pWriter->zTerm = (char *)zTerm; |
+ } |
+ pWriter->nTerm = nTerm; |
+ |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Flush all data associated with the SegmentWriter object pWriter to the |
+** database. This function must be called after all terms have been added |
+** to the segment using fts3SegWriterAdd(). If successful, SQLITE_OK is |
+** returned. Otherwise, an SQLite error code. |
+*/ |
+static int fts3SegWriterFlush( |
+ Fts3Table *p, /* Virtual table handle */ |
+ SegmentWriter *pWriter, /* SegmentWriter to flush to the db */ |
+ int iLevel, /* Value for 'level' column of %_segdir */ |
+ int iIdx /* Value for 'idx' column of %_segdir */ |
+){ |
+ int rc; /* Return code */ |
+ if( pWriter->pTree ){ |
+ sqlite3_int64 iLast = 0; /* Largest block id written to database */ |
+ sqlite3_int64 iLastLeaf; /* Largest leaf block id written to db */ |
+ char *zRoot = NULL; /* Pointer to buffer containing root node */ |
+ int nRoot = 0; /* Size of buffer zRoot */ |
+ |
+ iLastLeaf = pWriter->iFree; |
+ rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, pWriter->nData); |
+ if( rc==SQLITE_OK ){ |
+ rc = fts3NodeWrite(p, pWriter->pTree, 1, |
+ pWriter->iFirst, pWriter->iFree, &iLast, &zRoot, &nRoot); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = fts3WriteSegdir( |
+ p, iLevel, iIdx, pWriter->iFirst, iLastLeaf, iLast, zRoot, nRoot); |
+ } |
+ }else{ |
+ /* The entire tree fits on the root node. Write it to the segdir table. */ |
+ rc = fts3WriteSegdir( |
+ p, iLevel, iIdx, 0, 0, 0, pWriter->aData, pWriter->nData); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** Release all memory held by the SegmentWriter object passed as the |
+** first argument. |
+*/ |
+static void fts3SegWriterFree(SegmentWriter *pWriter){ |
+ if( pWriter ){ |
+ sqlite3_free(pWriter->aData); |
+ sqlite3_free(pWriter->zMalloc); |
+ fts3NodeFree(pWriter->pTree); |
+ sqlite3_free(pWriter); |
+ } |
+} |
+ |
+/* |
+** The first value in the apVal[] array is assumed to contain an integer. |
+** This function tests if there exist any documents with docid values that |
+** are different from that integer. i.e. if deleting the document with docid |
+** apVal[0] would mean the FTS3 table were empty. |
+** |
+** If successful, *pisEmpty is set to true if the table is empty except for |
+** document apVal[0], or false otherwise, and SQLITE_OK is returned. If an |
+** error occurs, an SQLite error code is returned. |
+*/ |
+static int fts3IsEmpty(Fts3Table *p, sqlite3_value **apVal, int *pisEmpty){ |
+ sqlite3_stmt *pStmt; |
+ int rc; |
+ rc = fts3SqlStmt(p, SQL_IS_EMPTY, &pStmt, apVal); |
+ if( rc==SQLITE_OK ){ |
+ if( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ *pisEmpty = sqlite3_column_int(pStmt, 0); |
+ } |
+ rc = sqlite3_reset(pStmt); |
+ } |
+ return rc; |
+} |
+ |
+/* |
+** Set *pnSegment to the total number of segments in the database. Set |
+** *pnMax to the largest segment level in the database (segment levels |
+** are stored in the 'level' column of the %_segdir table). |
+** |
+** Return SQLITE_OK if successful, or an SQLite error code if not. |
+*/ |
+static int fts3SegmentCountMax(Fts3Table *p, int *pnSegment, int *pnMax){ |
+ sqlite3_stmt *pStmt; |
+ int rc; |
+ |
+ rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_COUNT_MAX, &pStmt, 0); |
+ if( rc!=SQLITE_OK ) return rc; |
+ if( SQLITE_ROW==sqlite3_step(pStmt) ){ |
+ *pnSegment = sqlite3_column_int(pStmt, 0); |
+ *pnMax = sqlite3_column_int(pStmt, 1); |
+ } |
+ return sqlite3_reset(pStmt); |
+} |
+ |
+/* |
+** This function is used after merging multiple segments into a single large |
+** segment to delete the old, now redundant, segment b-trees. Specifically, |
+** it: |
+** |
+** 1) Deletes all %_segments entries for the segments associated with |
+** each of the SegReader objects in the array passed as the third |
+** argument, and |
+** |
+** 2) deletes all %_segdir entries with level iLevel, or all %_segdir |
+** entries regardless of level if (iLevel<0). |
+** |
+** SQLITE_OK is returned if successful, otherwise an SQLite error code. |
+*/ |
+static int fts3DeleteSegdir( |
+ Fts3Table *p, /* Virtual table handle */ |
+ int iLevel, /* Level of %_segdir entries to delete */ |
+ Fts3SegReader **apSegment, /* Array of SegReader objects */ |
+ int nReader /* Size of array apSegment */ |
+){ |
+ int rc; /* Return Code */ |
+ int i; /* Iterator variable */ |
+ sqlite3_stmt *pDelete; /* SQL statement to delete rows */ |
+ |
+ rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDelete, 0); |
+ for(i=0; rc==SQLITE_OK && i<nReader; i++){ |
+ Fts3SegReader *pSegment = apSegment[i]; |
+ if( pSegment->iStartBlock ){ |
+ sqlite3_bind_int64(pDelete, 1, pSegment->iStartBlock); |
+ sqlite3_bind_int64(pDelete, 2, pSegment->iEndBlock); |
+ sqlite3_step(pDelete); |
+ rc = sqlite3_reset(pDelete); |
+ } |
+ } |
+ if( rc!=SQLITE_OK ){ |
+ return rc; |
+ } |
+ |
+ if( iLevel==FTS3_SEGCURSOR_ALL ){ |
+ fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0); |
+ }else if( iLevel==FTS3_SEGCURSOR_PENDING ){ |
+ sqlite3Fts3PendingTermsClear(p); |
+ }else{ |
+ assert( iLevel>=0 ); |
+ rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_BY_LEVEL, &pDelete, 0); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3_bind_int(pDelete, 1, iLevel); |
+ sqlite3_step(pDelete); |
+ rc = sqlite3_reset(pDelete); |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** When this function is called, buffer *ppList (size *pnList bytes) contains |
+** a position list that may (or may not) feature multiple columns. This |
+** function adjusts the pointer *ppList and the length *pnList so that they |
+** identify the subset of the position list that corresponds to column iCol. |
+** |
+** If there are no entries in the input position list for column iCol, then |
+** *pnList is set to zero before returning. |
+*/ |
+static void fts3ColumnFilter( |
+ int iCol, /* Column to filter on */ |
+ char **ppList, /* IN/OUT: Pointer to position list */ |
+ int *pnList /* IN/OUT: Size of buffer *ppList in bytes */ |
+){ |
+ char *pList = *ppList; |
+ int nList = *pnList; |
+ char *pEnd = &pList[nList]; |
+ int iCurrent = 0; |
+ char *p = pList; |
+ |
+ assert( iCol>=0 ); |
+ while( 1 ){ |
+ char c = 0; |
+ while( p<pEnd && (c | *p)&0xFE ) c = *p++ & 0x80; |
+ |
+ if( iCol==iCurrent ){ |
+ nList = (int)(p - pList); |
+ break; |
+ } |
+ |
+ nList -= (int)(p - pList); |
+ pList = p; |
+ if( nList==0 ){ |
+ break; |
+ } |
+ p = &pList[1]; |
+ p += sqlite3Fts3GetVarint32(p, &iCurrent); |
+ } |
+ |
+ *ppList = pList; |
+ *pnList = nList; |
+} |
+ |
+int sqlite3Fts3SegReaderStart( |
+ Fts3Table *p, /* Virtual table handle */ |
+ Fts3SegReaderCursor *pCsr, /* Cursor object */ |
+ Fts3SegFilter *pFilter /* Restrictions on range of iteration */ |
+){ |
+ int i; |
+ |
+ /* Initialize the cursor object */ |
+ pCsr->pFilter = pFilter; |
+ |
+ /* If the Fts3SegFilter defines a specific term (or term prefix) to search |
+ ** for, then advance each segment iterator until it points to a term of |
+ ** equal or greater value than the specified term. This prevents many |
+ ** unnecessary merge/sort operations for the case where single segment |
+ ** b-tree leaf nodes contain more than one term. |
+ */ |
+ for(i=0; i<pCsr->nSegment; i++){ |
+ int nTerm = pFilter->nTerm; |
+ const char *zTerm = pFilter->zTerm; |
+ Fts3SegReader *pSeg = pCsr->apSegment[i]; |
+ do { |
+ int rc = fts3SegReaderNext(p, pSeg); |
+ if( rc!=SQLITE_OK ) return rc; |
+ }while( zTerm && fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 ); |
+ } |
+ fts3SegReaderSort( |
+ pCsr->apSegment, pCsr->nSegment, pCsr->nSegment, fts3SegReaderCmp); |
+ |
+ return SQLITE_OK; |
+} |
+ |
+int sqlite3Fts3SegReaderStep( |
+ Fts3Table *p, /* Virtual table handle */ |
+ Fts3SegReaderCursor *pCsr /* Cursor object */ |
+){ |
+ int rc = SQLITE_OK; |
+ |
+ int isIgnoreEmpty = (pCsr->pFilter->flags & FTS3_SEGMENT_IGNORE_EMPTY); |
+ int isRequirePos = (pCsr->pFilter->flags & FTS3_SEGMENT_REQUIRE_POS); |
+ int isColFilter = (pCsr->pFilter->flags & FTS3_SEGMENT_COLUMN_FILTER); |
+ int isPrefix = (pCsr->pFilter->flags & FTS3_SEGMENT_PREFIX); |
+ int isScan = (pCsr->pFilter->flags & FTS3_SEGMENT_SCAN); |
+ |
+ Fts3SegReader **apSegment = pCsr->apSegment; |
+ int nSegment = pCsr->nSegment; |
+ Fts3SegFilter *pFilter = pCsr->pFilter; |
+ |
+ if( pCsr->nSegment==0 ) return SQLITE_OK; |
+ |
+ do { |
+ int nMerge; |
+ int i; |
+ |
+ /* Advance the first pCsr->nAdvance entries in the apSegment[] array |
+ ** forward. Then sort the list in order of current term again. |
+ */ |
+ for(i=0; i<pCsr->nAdvance; i++){ |
+ rc = fts3SegReaderNext(p, apSegment[i]); |
+ if( rc!=SQLITE_OK ) return rc; |
+ } |
+ fts3SegReaderSort(apSegment, nSegment, pCsr->nAdvance, fts3SegReaderCmp); |
+ pCsr->nAdvance = 0; |
+ |
+ /* If all the seg-readers are at EOF, we're finished. return SQLITE_OK. */ |
+ assert( rc==SQLITE_OK ); |
+ if( apSegment[0]->aNode==0 ) break; |
+ |
+ pCsr->nTerm = apSegment[0]->nTerm; |
+ pCsr->zTerm = apSegment[0]->zTerm; |
+ |
+ /* If this is a prefix-search, and if the term that apSegment[0] points |
+ ** to does not share a suffix with pFilter->zTerm/nTerm, then all |
+ ** required callbacks have been made. In this case exit early. |
+ ** |
+ ** Similarly, if this is a search for an exact match, and the first term |
+ ** of segment apSegment[0] is not a match, exit early. |
+ */ |
+ if( pFilter->zTerm && !isScan ){ |
+ if( pCsr->nTerm<pFilter->nTerm |
+ || (!isPrefix && pCsr->nTerm>pFilter->nTerm) |
+ || memcmp(pCsr->zTerm, pFilter->zTerm, pFilter->nTerm) |
+ ){ |
+ break; |
+ } |
+ } |
+ |
+ nMerge = 1; |
+ while( nMerge<nSegment |
+ && apSegment[nMerge]->aNode |
+ && apSegment[nMerge]->nTerm==pCsr->nTerm |
+ && 0==memcmp(pCsr->zTerm, apSegment[nMerge]->zTerm, pCsr->nTerm) |
+ ){ |
+ nMerge++; |
+ } |
+ |
+ assert( isIgnoreEmpty || (isRequirePos && !isColFilter) ); |
+ if( nMerge==1 && !isIgnoreEmpty ){ |
+ pCsr->aDoclist = apSegment[0]->aDoclist; |
+ pCsr->nDoclist = apSegment[0]->nDoclist; |
+ rc = SQLITE_ROW; |
+ }else{ |
+ int nDoclist = 0; /* Size of doclist */ |
+ sqlite3_int64 iPrev = 0; /* Previous docid stored in doclist */ |
+ |
+ /* The current term of the first nMerge entries in the array |
+ ** of Fts3SegReader objects is the same. The doclists must be merged |
+ ** and a single term returned with the merged doclist. |
+ */ |
+ for(i=0; i<nMerge; i++){ |
+ fts3SegReaderFirstDocid(apSegment[i]); |
+ } |
+ fts3SegReaderSort(apSegment, nMerge, nMerge, fts3SegReaderDoclistCmp); |
+ while( apSegment[0]->pOffsetList ){ |
+ int j; /* Number of segments that share a docid */ |
+ char *pList; |
+ int nList; |
+ int nByte; |
+ sqlite3_int64 iDocid = apSegment[0]->iDocid; |
+ fts3SegReaderNextDocid(apSegment[0], &pList, &nList); |
+ j = 1; |
+ while( j<nMerge |
+ && apSegment[j]->pOffsetList |
+ && apSegment[j]->iDocid==iDocid |
+ ){ |
+ fts3SegReaderNextDocid(apSegment[j], 0, 0); |
+ j++; |
+ } |
+ |
+ if( isColFilter ){ |
+ fts3ColumnFilter(pFilter->iCol, &pList, &nList); |
+ } |
+ |
+ if( !isIgnoreEmpty || nList>0 ){ |
+ nByte = sqlite3Fts3VarintLen(iDocid-iPrev) + (isRequirePos?nList+1:0); |
+ if( nDoclist+nByte>pCsr->nBuffer ){ |
+ char *aNew; |
+ pCsr->nBuffer = (nDoclist+nByte)*2; |
+ aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer); |
+ if( !aNew ){ |
+ return SQLITE_NOMEM; |
+ } |
+ pCsr->aBuffer = aNew; |
+ } |
+ nDoclist += sqlite3Fts3PutVarint( |
+ &pCsr->aBuffer[nDoclist], iDocid-iPrev |
+ ); |
+ iPrev = iDocid; |
+ if( isRequirePos ){ |
+ memcpy(&pCsr->aBuffer[nDoclist], pList, nList); |
+ nDoclist += nList; |
+ pCsr->aBuffer[nDoclist++] = '\0'; |
+ } |
+ } |
+ |
+ fts3SegReaderSort(apSegment, nMerge, j, fts3SegReaderDoclistCmp); |
+ } |
+ if( nDoclist>0 ){ |
+ pCsr->aDoclist = pCsr->aBuffer; |
+ pCsr->nDoclist = nDoclist; |
+ rc = SQLITE_ROW; |
+ } |
+ } |
+ pCsr->nAdvance = nMerge; |
+ }while( rc==SQLITE_OK ); |
+ |
+ return rc; |
+} |
+ |
+void sqlite3Fts3SegReaderFinish( |
+ Fts3SegReaderCursor *pCsr /* Cursor object */ |
+){ |
+ if( pCsr ){ |
+ int i; |
+ for(i=0; i<pCsr->nSegment; i++){ |
+ sqlite3Fts3SegReaderFree(pCsr->apSegment[i]); |
+ } |
+ sqlite3_free(pCsr->apSegment); |
+ sqlite3_free(pCsr->aBuffer); |
+ |
+ pCsr->nSegment = 0; |
+ pCsr->apSegment = 0; |
+ pCsr->aBuffer = 0; |
+ } |
+} |
+ |
+/* |
+** Merge all level iLevel segments in the database into a single |
+** iLevel+1 segment. Or, if iLevel<0, merge all segments into a |
+** single segment with a level equal to the numerically largest level |
+** currently present in the database. |
+** |
+** If this function is called with iLevel<0, but there is only one |
+** segment in the database, SQLITE_DONE is returned immediately. |
+** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, |
+** an SQLite error code is returned. |
+*/ |
+static int fts3SegmentMerge(Fts3Table *p, int iLevel){ |
+ int rc; /* Return code */ |
+ int iIdx = 0; /* Index of new segment */ |
+ int iNewLevel = 0; /* Level to create new segment at */ |
+ SegmentWriter *pWriter = 0; /* Used to write the new, merged, segment */ |
+ Fts3SegFilter filter; /* Segment term filter condition */ |
+ Fts3SegReaderCursor csr; /* Cursor to iterate through level(s) */ |
+ |
+ rc = sqlite3Fts3SegReaderCursor(p, iLevel, 0, 0, 1, 0, &csr); |
+ if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished; |
+ |
+ if( iLevel==FTS3_SEGCURSOR_ALL ){ |
+ /* This call is to merge all segments in the database to a single |
+ ** segment. The level of the new segment is equal to the the numerically |
+ ** greatest segment level currently present in the database. The index |
+ ** of the new segment is always 0. */ |
+ int nDummy; /* TODO: Remove this */ |
+ if( csr.nSegment==1 ){ |
+ rc = SQLITE_DONE; |
+ goto finished; |
+ } |
+ rc = fts3SegmentCountMax(p, &nDummy, &iNewLevel); |
+ }else{ |
+ /* This call is to merge all segments at level iLevel. Find the next |
+ ** available segment index at level iLevel+1. The call to |
+ ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to |
+ ** a single iLevel+2 segment if necessary. */ |
+ iNewLevel = iLevel+1; |
+ rc = fts3AllocateSegdirIdx(p, iNewLevel, &iIdx); |
+ } |
+ if( rc!=SQLITE_OK ) goto finished; |
+ assert( csr.nSegment>0 ); |
+ assert( iNewLevel>=0 ); |
+ |
+ memset(&filter, 0, sizeof(Fts3SegFilter)); |
+ filter.flags = FTS3_SEGMENT_REQUIRE_POS; |
+ filter.flags |= (iLevel==FTS3_SEGCURSOR_ALL ? FTS3_SEGMENT_IGNORE_EMPTY : 0); |
+ |
+ rc = sqlite3Fts3SegReaderStart(p, &csr, &filter); |
+ while( SQLITE_OK==rc ){ |
+ rc = sqlite3Fts3SegReaderStep(p, &csr); |
+ if( rc!=SQLITE_ROW ) break; |
+ rc = fts3SegWriterAdd(p, &pWriter, 1, |
+ csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist); |
+ } |
+ if( rc!=SQLITE_OK ) goto finished; |
+ assert( pWriter ); |
+ |
+ rc = fts3DeleteSegdir(p, iLevel, csr.apSegment, csr.nSegment); |
+ if( rc!=SQLITE_OK ) goto finished; |
+ rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx); |
+ |
+ finished: |
+ fts3SegWriterFree(pWriter); |
+ sqlite3Fts3SegReaderFinish(&csr); |
+ return rc; |
+} |
+ |
+ |
+/* |
+** Flush the contents of pendingTerms to a level 0 segment. |
+*/ |
+int sqlite3Fts3PendingTermsFlush(Fts3Table *p){ |
+ return fts3SegmentMerge(p, FTS3_SEGCURSOR_PENDING); |
+} |
+ |
+/* |
+** Encode N integers as varints into a blob. |
+*/ |
+static void fts3EncodeIntArray( |
+ int N, /* The number of integers to encode */ |
+ u32 *a, /* The integer values */ |
+ char *zBuf, /* Write the BLOB here */ |
+ int *pNBuf /* Write number of bytes if zBuf[] used here */ |
+){ |
+ int i, j; |
+ for(i=j=0; i<N; i++){ |
+ j += sqlite3Fts3PutVarint(&zBuf[j], (sqlite3_int64)a[i]); |
+ } |
+ *pNBuf = j; |
+} |
+ |
+/* |
+** Decode a blob of varints into N integers |
+*/ |
+static void fts3DecodeIntArray( |
+ int N, /* The number of integers to decode */ |
+ u32 *a, /* Write the integer values */ |
+ const char *zBuf, /* The BLOB containing the varints */ |
+ int nBuf /* size of the BLOB */ |
+){ |
+ int i, j; |
+ UNUSED_PARAMETER(nBuf); |
+ for(i=j=0; i<N; i++){ |
+ sqlite3_int64 x; |
+ j += sqlite3Fts3GetVarint(&zBuf[j], &x); |
+ assert(j<=nBuf); |
+ a[i] = (u32)(x & 0xffffffff); |
+ } |
+} |
+ |
+/* |
+** Insert the sizes (in tokens) for each column of the document |
+** with docid equal to p->iPrevDocid. The sizes are encoded as |
+** a blob of varints. |
+*/ |
+static void fts3InsertDocsize( |
+ int *pRC, /* Result code */ |
+ Fts3Table *p, /* Table into which to insert */ |
+ u32 *aSz /* Sizes of each column */ |
+){ |
+ char *pBlob; /* The BLOB encoding of the document size */ |
+ int nBlob; /* Number of bytes in the BLOB */ |
+ sqlite3_stmt *pStmt; /* Statement used to insert the encoding */ |
+ int rc; /* Result code from subfunctions */ |
+ |
+ if( *pRC ) return; |
+ pBlob = sqlite3_malloc( 10*p->nColumn ); |
+ if( pBlob==0 ){ |
+ *pRC = SQLITE_NOMEM; |
+ return; |
+ } |
+ fts3EncodeIntArray(p->nColumn, aSz, pBlob, &nBlob); |
+ rc = fts3SqlStmt(p, SQL_REPLACE_DOCSIZE, &pStmt, 0); |
+ if( rc ){ |
+ sqlite3_free(pBlob); |
+ *pRC = rc; |
+ return; |
+ } |
+ sqlite3_bind_int64(pStmt, 1, p->iPrevDocid); |
+ sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, sqlite3_free); |
+ sqlite3_step(pStmt); |
+ *pRC = sqlite3_reset(pStmt); |
+} |
+ |
+/* |
+** Record 0 of the %_stat table contains a blob consisting of N varints, |
+** where N is the number of user defined columns in the fts3 table plus |
+** two. If nCol is the number of user defined columns, then values of the |
+** varints are set as follows: |
+** |
+** Varint 0: Total number of rows in the table. |
+** |
+** Varint 1..nCol: For each column, the total number of tokens stored in |
+** the column for all rows of the table. |
+** |
+** Varint 1+nCol: The total size, in bytes, of all text values in all |
+** columns of all rows of the table. |
+** |
+*/ |
+static void fts3UpdateDocTotals( |
+ int *pRC, /* The result code */ |
+ Fts3Table *p, /* Table being updated */ |
+ u32 *aSzIns, /* Size increases */ |
+ u32 *aSzDel, /* Size decreases */ |
+ int nChng /* Change in the number of documents */ |
+){ |
+ char *pBlob; /* Storage for BLOB written into %_stat */ |
+ int nBlob; /* Size of BLOB written into %_stat */ |
+ u32 *a; /* Array of integers that becomes the BLOB */ |
+ sqlite3_stmt *pStmt; /* Statement for reading and writing */ |
+ int i; /* Loop counter */ |
+ int rc; /* Result code from subfunctions */ |
+ |
+ const int nStat = p->nColumn+2; |
+ |
+ if( *pRC ) return; |
+ a = sqlite3_malloc( (sizeof(u32)+10)*nStat ); |
+ if( a==0 ){ |
+ *pRC = SQLITE_NOMEM; |
+ return; |
+ } |
+ pBlob = (char*)&a[nStat]; |
+ rc = fts3SqlStmt(p, SQL_SELECT_DOCTOTAL, &pStmt, 0); |
+ if( rc ){ |
+ sqlite3_free(a); |
+ *pRC = rc; |
+ return; |
+ } |
+ if( sqlite3_step(pStmt)==SQLITE_ROW ){ |
+ fts3DecodeIntArray(nStat, a, |
+ sqlite3_column_blob(pStmt, 0), |
+ sqlite3_column_bytes(pStmt, 0)); |
+ }else{ |
+ memset(a, 0, sizeof(u32)*(nStat) ); |
+ } |
+ sqlite3_reset(pStmt); |
+ if( nChng<0 && a[0]<(u32)(-nChng) ){ |
+ a[0] = 0; |
+ }else{ |
+ a[0] += nChng; |
+ } |
+ for(i=0; i<p->nColumn+1; i++){ |
+ u32 x = a[i+1]; |
+ if( x+aSzIns[i] < aSzDel[i] ){ |
+ x = 0; |
+ }else{ |
+ x = x + aSzIns[i] - aSzDel[i]; |
+ } |
+ a[i+1] = x; |
+ } |
+ fts3EncodeIntArray(nStat, a, pBlob, &nBlob); |
+ rc = fts3SqlStmt(p, SQL_REPLACE_DOCTOTAL, &pStmt, 0); |
+ if( rc ){ |
+ sqlite3_free(a); |
+ *pRC = rc; |
+ return; |
+ } |
+ sqlite3_bind_blob(pStmt, 1, pBlob, nBlob, SQLITE_STATIC); |
+ sqlite3_step(pStmt); |
+ *pRC = sqlite3_reset(pStmt); |
+ sqlite3_free(a); |
+} |
+ |
+/* |
+** Handle a 'special' INSERT of the form: |
+** |
+** "INSERT INTO tbl(tbl) VALUES(<expr>)" |
+** |
+** Argument pVal contains the result of <expr>. Currently the only |
+** meaningful value to insert is the text 'optimize'. |
+*/ |
+static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){ |
+ int rc; /* Return Code */ |
+ const char *zVal = (const char *)sqlite3_value_text(pVal); |
+ int nVal = sqlite3_value_bytes(pVal); |
+ |
+ if( !zVal ){ |
+ return SQLITE_NOMEM; |
+ }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){ |
+ rc = fts3SegmentMerge(p, FTS3_SEGCURSOR_ALL); |
+ if( rc==SQLITE_DONE ){ |
+ rc = SQLITE_OK; |
+ }else{ |
+ sqlite3Fts3PendingTermsClear(p); |
+ } |
+#ifdef SQLITE_TEST |
+ }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){ |
+ p->nNodeSize = atoi(&zVal[9]); |
+ rc = SQLITE_OK; |
+ }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){ |
+ p->nMaxPendingData = atoi(&zVal[11]); |
+ rc = SQLITE_OK; |
+#endif |
+ }else{ |
+ rc = SQLITE_ERROR; |
+ } |
+ |
+ sqlite3Fts3SegmentsClose(p); |
+ return rc; |
+} |
+ |
+/* |
+** Return the deferred doclist associated with deferred token pDeferred. |
+** This function assumes that sqlite3Fts3CacheDeferredDoclists() has already |
+** been called to allocate and populate the doclist. |
+*/ |
+char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *pDeferred, int *pnByte){ |
+ if( pDeferred->pList ){ |
+ *pnByte = pDeferred->pList->nData; |
+ return pDeferred->pList->aData; |
+ } |
+ *pnByte = 0; |
+ return 0; |
+} |
+ |
+/* |
+** Helper fucntion for FreeDeferredDoclists(). This function removes all |
+** references to deferred doclists from within the tree of Fts3Expr |
+** structures headed by |
+*/ |
+static void fts3DeferredDoclistClear(Fts3Expr *pExpr){ |
+ if( pExpr ){ |
+ fts3DeferredDoclistClear(pExpr->pLeft); |
+ fts3DeferredDoclistClear(pExpr->pRight); |
+ if( pExpr->isLoaded ){ |
+ sqlite3_free(pExpr->aDoclist); |
+ pExpr->isLoaded = 0; |
+ pExpr->aDoclist = 0; |
+ pExpr->nDoclist = 0; |
+ pExpr->pCurrent = 0; |
+ pExpr->iCurrent = 0; |
+ } |
+ } |
+} |
+ |
+/* |
+** Delete all cached deferred doclists. Deferred doclists are cached |
+** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function. |
+*/ |
+void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *pCsr){ |
+ Fts3DeferredToken *pDef; |
+ for(pDef=pCsr->pDeferred; pDef; pDef=pDef->pNext){ |
+ sqlite3_free(pDef->pList); |
+ pDef->pList = 0; |
+ } |
+ if( pCsr->pDeferred ){ |
+ fts3DeferredDoclistClear(pCsr->pExpr); |
+ } |
+} |
+ |
+/* |
+** Free all entries in the pCsr->pDeffered list. Entries are added to |
+** this list using sqlite3Fts3DeferToken(). |
+*/ |
+void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *pCsr){ |
+ Fts3DeferredToken *pDef; |
+ Fts3DeferredToken *pNext; |
+ for(pDef=pCsr->pDeferred; pDef; pDef=pNext){ |
+ pNext = pDef->pNext; |
+ sqlite3_free(pDef->pList); |
+ sqlite3_free(pDef); |
+ } |
+ pCsr->pDeferred = 0; |
+} |
+ |
+/* |
+** Generate deferred-doclists for all tokens in the pCsr->pDeferred list |
+** based on the row that pCsr currently points to. |
+** |
+** A deferred-doclist is like any other doclist with position information |
+** included, except that it only contains entries for a single row of the |
+** table, not for all rows. |
+*/ |
+int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){ |
+ int rc = SQLITE_OK; /* Return code */ |
+ if( pCsr->pDeferred ){ |
+ int i; /* Used to iterate through table columns */ |
+ sqlite3_int64 iDocid; /* Docid of the row pCsr points to */ |
+ Fts3DeferredToken *pDef; /* Used to iterate through deferred tokens */ |
+ |
+ Fts3Table *p = (Fts3Table *)pCsr->base.pVtab; |
+ sqlite3_tokenizer *pT = p->pTokenizer; |
+ sqlite3_tokenizer_module const *pModule = pT->pModule; |
+ |
+ assert( pCsr->isRequireSeek==0 ); |
+ iDocid = sqlite3_column_int64(pCsr->pStmt, 0); |
+ |
+ for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){ |
+ const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1); |
+ sqlite3_tokenizer_cursor *pTC = 0; |
+ |
+ rc = pModule->xOpen(pT, zText, -1, &pTC); |
+ while( rc==SQLITE_OK ){ |
+ char const *zToken; /* Buffer containing token */ |
+ int nToken; /* Number of bytes in token */ |
+ int iDum1, iDum2; /* Dummy variables */ |
+ int iPos; /* Position of token in zText */ |
+ |
+ pTC->pTokenizer = pT; |
+ rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos); |
+ for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){ |
+ Fts3PhraseToken *pPT = pDef->pToken; |
+ if( (pDef->iCol>=p->nColumn || pDef->iCol==i) |
+ && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken)) |
+ && (0==memcmp(zToken, pPT->z, pPT->n)) |
+ ){ |
+ fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc); |
+ } |
+ } |
+ } |
+ if( pTC ) pModule->xClose(pTC); |
+ if( rc==SQLITE_DONE ) rc = SQLITE_OK; |
+ } |
+ |
+ for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){ |
+ if( pDef->pList ){ |
+ rc = fts3PendingListAppendVarint(&pDef->pList, 0); |
+ } |
+ } |
+ } |
+ |
+ return rc; |
+} |
+ |
+/* |
+** Add an entry for token pToken to the pCsr->pDeferred list. |
+*/ |
+int sqlite3Fts3DeferToken( |
+ Fts3Cursor *pCsr, /* Fts3 table cursor */ |
+ Fts3PhraseToken *pToken, /* Token to defer */ |
+ int iCol /* Column that token must appear in (or -1) */ |
+){ |
+ Fts3DeferredToken *pDeferred; |
+ pDeferred = sqlite3_malloc(sizeof(*pDeferred)); |
+ if( !pDeferred ){ |
+ return SQLITE_NOMEM; |
+ } |
+ memset(pDeferred, 0, sizeof(*pDeferred)); |
+ pDeferred->pToken = pToken; |
+ pDeferred->pNext = pCsr->pDeferred; |
+ pDeferred->iCol = iCol; |
+ pCsr->pDeferred = pDeferred; |
+ |
+ assert( pToken->pDeferred==0 ); |
+ pToken->pDeferred = pDeferred; |
+ |
+ return SQLITE_OK; |
+} |
+ |
+ |
+/* |
+** This function does the work for the xUpdate method of FTS3 virtual |
+** tables. |
+*/ |
+int sqlite3Fts3UpdateMethod( |
+ sqlite3_vtab *pVtab, /* FTS3 vtab object */ |
+ int nArg, /* Size of argument array */ |
+ sqlite3_value **apVal, /* Array of arguments */ |
+ sqlite_int64 *pRowid /* OUT: The affected (or effected) rowid */ |
+){ |
+ Fts3Table *p = (Fts3Table *)pVtab; |
+ int rc = SQLITE_OK; /* Return Code */ |
+ int isRemove = 0; /* True for an UPDATE or DELETE */ |
+ sqlite3_int64 iRemove = 0; /* Rowid removed by UPDATE or DELETE */ |
+ u32 *aSzIns; /* Sizes of inserted documents */ |
+ u32 *aSzDel; /* Sizes of deleted documents */ |
+ int nChng = 0; /* Net change in number of documents */ |
+ |
+ assert( p->pSegments==0 ); |
+ |
+ /* Allocate space to hold the change in document sizes */ |
+ aSzIns = sqlite3_malloc( sizeof(aSzIns[0])*(p->nColumn+1)*2 ); |
+ if( aSzIns==0 ) return SQLITE_NOMEM; |
+ aSzDel = &aSzIns[p->nColumn+1]; |
+ memset(aSzIns, 0, sizeof(aSzIns[0])*(p->nColumn+1)*2); |
+ |
+ /* If this is a DELETE or UPDATE operation, remove the old record. */ |
+ if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){ |
+ int isEmpty = 0; |
+ rc = fts3IsEmpty(p, apVal, &isEmpty); |
+ if( rc==SQLITE_OK ){ |
+ if( isEmpty ){ |
+ /* Deleting this row means the whole table is empty. In this case |
+ ** delete the contents of all three tables and throw away any |
+ ** data in the pendingTerms hash table. |
+ */ |
+ rc = fts3DeleteAll(p); |
+ }else{ |
+ isRemove = 1; |
+ iRemove = sqlite3_value_int64(apVal[0]); |
+ rc = fts3PendingTermsDocid(p, iRemove); |
+ fts3DeleteTerms(&rc, p, apVal, aSzDel); |
+ fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, apVal); |
+ if( p->bHasDocsize ){ |
+ fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, apVal); |
+ } |
+ nChng--; |
+ } |
+ } |
+ }else if( sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL ){ |
+ sqlite3_free(aSzIns); |
+ return fts3SpecialInsert(p, apVal[p->nColumn+2]); |
+ } |
+ |
+ /* If this is an INSERT or UPDATE operation, insert the new record. */ |
+ if( nArg>1 && rc==SQLITE_OK ){ |
+ rc = fts3InsertData(p, apVal, pRowid); |
+ if( rc==SQLITE_OK && (!isRemove || *pRowid!=iRemove) ){ |
+ rc = fts3PendingTermsDocid(p, *pRowid); |
+ } |
+ if( rc==SQLITE_OK ){ |
+ rc = fts3InsertTerms(p, apVal, aSzIns); |
+ } |
+ if( p->bHasDocsize ){ |
+ fts3InsertDocsize(&rc, p, aSzIns); |
+ } |
+ nChng++; |
+ } |
+ |
+ if( p->bHasStat ){ |
+ fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nChng); |
+ } |
+ |
+ sqlite3_free(aSzIns); |
+ sqlite3Fts3SegmentsClose(p); |
+ return rc; |
+} |
+ |
+/* |
+** Flush any data in the pending-terms hash table to disk. If successful, |
+** merge all segments in the database (including the new segment, if |
+** there was any data to flush) into a single segment. |
+*/ |
+int sqlite3Fts3Optimize(Fts3Table *p){ |
+ int rc; |
+ rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0); |
+ if( rc==SQLITE_OK ){ |
+ rc = fts3SegmentMerge(p, FTS3_SEGCURSOR_ALL); |
+ if( rc==SQLITE_OK ){ |
+ rc = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0); |
+ if( rc==SQLITE_OK ){ |
+ sqlite3Fts3PendingTermsClear(p); |
+ } |
+ }else{ |
+ sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0); |
+ sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0); |
+ } |
+ } |
+ sqlite3Fts3SegmentsClose(p); |
+ return rc; |
+} |
+ |
+#endif |