Import SQLite 3.10.2.

third_party/sqlite/src/src/btreeInt.h

 /*
 ** 2004 April 6
 **
 ** 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.
 **
@@ skipping 213 matching lines @@
 /* The maximum number of cells on a single page of the database.  This
 ** assumes a minimum cell size of 6 bytes  (4 bytes for the cell itself
 ** plus 2 bytes for the index to the cell in the page header).  Such
 ** small cells will be rare, but they are possible.
 */
 #define MX_CELL(pBt) ((pBt->pageSize-8)/6)
 
 /* Forward declarations */
 typedef struct MemPage MemPage;
 typedef struct BtLock BtLock;
+typedef struct CellInfo CellInfo;
 
 /*
 ** This is a magic string that appears at the beginning of every
 ** SQLite database in order to identify the file as a real database.
 **
 ** You can change this value at compile-time by specifying a
 ** -DSQLITE_FILE_HEADER="..." on the compiler command-line.  The
 ** header must be exactly 16 bytes including the zero-terminator so
 ** the string itself should be 15 characters long.  If you change
 ** the header, then your custom library will not be able to read 
@@ skipping 29 matching lines @@
 struct MemPage {
   u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
   u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
   u8 intKey;           /* True if table b-trees.  False for index b-trees */
   u8 intKeyLeaf;       /* True if the leaf of an intKey table */
   u8 noPayload;        /* True if internal intKey page (thus w/o data) */
   u8 leaf;             /* True if a leaf page */
   u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
   u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
   u8 max1bytePayload;  /* min(maxLocal,127) */
+  u8 bBusy;            /* Prevent endless loops on corrupt database files */
   u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */
   u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */
   u16 cellOffset;      /* Index in aData of first cell pointer */
   u16 nFree;           /* Number of free bytes on the page */
   u16 nCell;           /* Number of cells on this page, local and ovfl */
   u16 maskPage;        /* Mask for page offset */
   u16 aiOvfl[5];       /* Insert the i-th overflow cell before the aiOvfl-th
                        ** non-overflow cell */
   u8 *apOvfl[5];       /* Pointers to the body of overflow cells */
   BtShared *pBt;       /* Pointer to BtShared that this page is part of */
   u8 *aData;           /* Pointer to disk image of the page data */
   u8 *aDataEnd;        /* One byte past the end of usable data */
   u8 *aCellIdx;        /* The cell index area */
+  u8 *aDataOfst;       /* Same as aData for leaves.  aData+4 for interior */
   DbPage *pDbPage;     /* Pager page handle */
+  u16 (*xCellSize)(MemPage*,u8*);             /* cellSizePtr method */
+  void (*xParseCell)(MemPage*,u8*,CellInfo*); /* btreeParseCell method */
   Pgno pgno;           /* Page number for this page */
 };
 
 /*
 ** The in-memory image of a disk page has the auxiliary information appended
 ** to the end.  EXTRA_SIZE is the number of bytes of space needed to hold
 ** that extra information.
 */
 #define EXTRA_SIZE sizeof(MemPage)
 
@@ skipping 35 matching lines @@
 ** in the referenced BtShared that point back to this Btree since those
 ** cursors have to go through this Btree to find their BtShared and
 ** they often do so without holding sqlite3.mutex.
 */
 struct Btree {
   sqlite3 *db;       /* The database connection holding this btree */
   BtShared *pBt;     /* Sharable content of this btree */
   u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
   u8 sharable;       /* True if we can share pBt with another db */
   u8 locked;         /* True if db currently has pBt locked */
+  u8 hasIncrblobCur; /* True if there are one or more Incrblob cursors */
   int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */
   int nBackup;       /* Number of backup operations reading this btree */
+  u32 iDataVersion;  /* Combines with pBt->pPager->iDataVersion */
   Btree *pNext;      /* List of other sharable Btrees from the same db */
   Btree *pPrev;      /* Back pointer of the same list */
 #ifndef SQLITE_OMIT_SHARED_CACHE
   BtLock lock;       /* Object used to lock page 1 */
 #endif
 };
 
 /*
 ** Btree.inTrans may take one of the following values.
 **
@@ skipping 46 matching lines @@
   BtCursor *pCursor;    /* A list of all open cursors */
   MemPage *pPage1;      /* First page of the database */
   u8 openFlags;         /* Flags to sqlite3BtreeOpen() */
 #ifndef SQLITE_OMIT_AUTOVACUUM
   u8 autoVacuum;        /* True if auto-vacuum is enabled */
   u8 incrVacuum;        /* True if incr-vacuum is enabled */
   u8 bDoTruncate;       /* True to truncate db on commit */
 #endif
   u8 inTransaction;     /* Transaction state */
   u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */
+#ifdef SQLITE_HAS_CODEC
+  u8 optimalReserve;    /* Desired amount of reserved space per page */
+#endif
   u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */
   u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
   u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
   u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
   u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
   u32 pageSize;         /* Total number of bytes on a page */
   u32 usableSize;       /* Number of usable bytes on each page */
   int nTransaction;     /* Number of open transactions (read + write) */
   u32 nPage;            /* Number of pages in the database */
   void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
@@ skipping 18 matching lines @@
 #define BTS_INITIALLY_EMPTY  0x0008   /* Database was empty at trans start */
 #define BTS_NO_WAL           0x0010   /* Do not open write-ahead-log files */
 #define BTS_EXCLUSIVE        0x0020   /* pWriter has an exclusive lock */
 #define BTS_PENDING          0x0040   /* Waiting for read-locks to clear */
 
 /*
 ** An instance of the following structure is used to hold information
 ** about a cell.  The parseCellPtr() function fills in this structure
 ** based on information extract from the raw disk page.
 */
-typedef struct CellInfo CellInfo;
 struct CellInfo {
   i64 nKey;      /* The key for INTKEY tables, or nPayload otherwise */
   u8 *pPayload;  /* Pointer to the start of payload */
   u32 nPayload;  /* Bytes of payload */
   u16 nLocal;    /* Amount of payload held locally, not on overflow */
-  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
   u16 nSize;     /* Size of the cell content on the main b-tree page */
 };
 
 /*
 ** Maximum depth of an SQLite B-Tree structure. Any B-Tree deeper than
 ** this will be declared corrupt. This value is calculated based on a
 ** maximum database size of 2^31 pages a minimum fanout of 2 for a
 ** root-node and 3 for all other internal nodes.
 **
 ** If a tree that appears to be taller than this is encountered, it is
@@ skipping 16 matching lines @@
 ** found at self->pBt->mutex. 
 **
 ** skipNext meaning:
 **    eState==SKIPNEXT && skipNext>0:  Next sqlite3BtreeNext() is no-op.
 **    eState==SKIPNEXT && skipNext<0:  Next sqlite3BtreePrevious() is no-op.
 **    eState==FAULT:                   Cursor fault with skipNext as error code.
 */
 struct BtCursor {
   Btree *pBtree;            /* The Btree to which this cursor belongs */
   BtShared *pBt;            /* The BtShared this cursor points to */
-  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
-  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
+  BtCursor *pNext;          /* Forms a linked list of all cursors */
   Pgno *aOverflow;          /* Cache of overflow page locations */
   CellInfo info;            /* A parse of the cell we are pointing at */
   i64 nKey;                 /* Size of pKey, or last integer key */
   void *pKey;               /* Saved key that was cursor last known position */
   Pgno pgnoRoot;            /* The root page of this tree */
   int nOvflAlloc;           /* Allocated size of aOverflow[] array */
   int skipNext;    /* Prev() is noop if negative. Next() is noop if positive.
                    ** Error code if eState==CURSOR_FAULT */
   u8 curFlags;              /* zero or more BTCF_* flags defined below */
+  u8 curPagerFlags;         /* Flags to send to sqlite3PagerGet() */
   u8 eState;                /* One of the CURSOR_XXX constants (see below) */
-  u8 hints;                             /* As configured by CursorSetHints() */
-  i16 iPage;                            /* Index of current page in apPage */
+  u8 hints;                 /* As configured by CursorSetHints() */
+  /* All fields above are zeroed when the cursor is allocated.  See
+  ** sqlite3BtreeCursorZero().  Fields that follow must be manually
+  ** initialized. */
+  i8 iPage;                 /* Index of current page in apPage */
+  u8 curIntKey;             /* Value of apPage[0]->intKey */
+  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
+  void *padding1;           /* Make object size a multiple of 16 */
   u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
   MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
 };
 
 /*
 ** Legal values for BtCursor.curFlags
 */
 #define BTCF_WriteFlag    0x01   /* True if a write cursor */
 #define BTCF_ValidNKey    0x02   /* True if info.nKey is valid */
 #define BTCF_ValidOvfl    0x04   /* True if aOverflow is valid */
 #define BTCF_AtLast       0x08   /* Cursor is pointing ot the last entry */
 #define BTCF_Incrblob     0x10   /* True if an incremental I/O handle */
+#define BTCF_Multiple     0x20   /* Maybe another cursor on the same btree */
 
 /*
 ** Potential values for BtCursor.eState.
 **
 ** CURSOR_INVALID:
 **   Cursor does not point to a valid entry. This can happen (for example) 
 **   because the table is empty or because BtreeCursorFirst() has not been
 **   called.
 **
 ** CURSOR_VALID:
@@ skipping 122 matching lines @@
   BtShared *pBt;    /* The tree being checked out */
   Pager *pPager;    /* The associated pager.  Also accessible by pBt->pPager */
   u8 *aPgRef;       /* 1 bit per page in the db (see above) */
   Pgno nPage;       /* Number of pages in the database */
   int mxErr;        /* Stop accumulating errors when this reaches zero */
   int nErr;         /* Number of messages written to zErrMsg so far */
   int mallocFailed; /* A memory allocation error has occurred */
   const char *zPfx; /* Error message prefix */
   int v1, v2;       /* Values for up to two %d fields in zPfx */
   StrAccum errMsg;  /* Accumulate the error message text here */
+  u32 *heap;        /* Min-heap used for analyzing cell coverage */
 };
 
 /*
 ** Routines to read or write a two- and four-byte big-endian integer values.
 */
 #define get2byte(x)   ((x)[0]<<8 | (x)[1])
 #define put2byte(p,v) ((p)[0] = (u8)((v)>>8), (p)[1] = (u8)(v))
 #define get4byte sqlite3Get4byte
 #define put4byte sqlite3Put4byte
+
+/*
+** get2byteAligned(), unlike get2byte(), requires that its argument point to a
+** two-byte aligned address.  get2bytea() is only used for accessing the
+** cell addresses in a btree header.
+*/
+#if SQLITE_BYTEORDER==4321
+# define get2byteAligned(x)  (*(u16*)(x))
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && GCC_VERSION>=4008000
+# define get2byteAligned(x)  __builtin_bswap16(*(u16*)(x))
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(_MSC_VER) && _MSC_VER>=1300
+# define get2byteAligned(x)  _byteswap_ushort(*(u16*)(x))
+#else
+# define get2byteAligned(x)  ((x)[0]<<8 | (x)[1])
+#endif