--- a/engine/sqlite/src/btreeInt.h Wed May 26 10:44:32 2010 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,649 +0,0 @@
-/*
-** 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.
-**
-*************************************************************************
-** $Id: btreeInt.h 1282 2008-11-13 09:31:33Z LarsPson $
-**
-** This file implements a external (disk-based) database using BTrees.
-** For a detailed discussion of BTrees, refer to
-**
-** Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
-** "Sorting And Searching", pages 473-480. Addison-Wesley
-** Publishing Company, Reading, Massachusetts.
-**
-** The basic idea is that each page of the file contains N database
-** entries and N+1 pointers to subpages.
-**
-** ----------------------------------------------------------------
-** | Ptr(0) | Key(0) | Ptr(1) | Key(1) | ... | Key(N-1) | Ptr(N) |
-** ----------------------------------------------------------------
-**
-** All of the keys on the page that Ptr(0) points to have values less
-** than Key(0). All of the keys on page Ptr(1) and its subpages have
-** values greater than Key(0) and less than Key(1). All of the keys
-** on Ptr(N) and its subpages have values greater than Key(N-1). And
-** so forth.
-**
-** Finding a particular key requires reading O(log(M)) pages from the
-** disk where M is the number of entries in the tree.
-**
-** In this implementation, a single file can hold one or more separate
-** BTrees. Each BTree is identified by the index of its root page. The
-** key and data for any entry are combined to form the "payload". A
-** fixed amount of payload can be carried directly on the database
-** page. If the payload is larger than the preset amount then surplus
-** bytes are stored on overflow pages. The payload for an entry
-** and the preceding pointer are combined to form a "Cell". Each
-** page has a small header which contains the Ptr(N) pointer and other
-** information such as the size of key and data.
-**
-** FORMAT DETAILS
-**
-** The file is divided into pages. The first page is called page 1,
-** the second is page 2, and so forth. A page number of zero indicates
-** "no such page". The page size can be anything between 512 and 65536.
-** Each page can be either a btree page, a freelist page or an overflow
-** page.
-**
-** The first page is always a btree page. The first 100 bytes of the first
-** page contain a special header (the "file header") that describes the file.
-** The format of the file header is as follows:
-**
-** OFFSET SIZE DESCRIPTION
-** 0 16 Header string: "SQLite format 3\000"
-** 16 2 Page size in bytes.
-** 18 1 File format write version
-** 19 1 File format read version
-** 20 1 Bytes of unused space at the end of each page
-** 21 1 Max embedded payload fraction
-** 22 1 Min embedded payload fraction
-** 23 1 Min leaf payload fraction
-** 24 4 File change counter
-** 28 4 Reserved for future use
-** 32 4 First freelist page
-** 36 4 Number of freelist pages in the file
-** 40 60 15 4-byte meta values passed to higher layers
-**
-** All of the integer values are big-endian (most significant byte first).
-**
-** The file change counter is incremented when the database is changed
-** This counter allows other processes to know when the file has changed
-** and thus when they need to flush their cache.
-**
-** The max embedded payload fraction is the amount of the total usable
-** space in a page that can be consumed by a single cell for standard
-** B-tree (non-LEAFDATA) tables. A value of 255 means 100%. The default
-** is to limit the maximum cell size so that at least 4 cells will fit
-** on one page. Thus the default max embedded payload fraction is 64.
-**
-** If the payload for a cell is larger than the max payload, then extra
-** payload is spilled to overflow pages. Once an overflow page is allocated,
-** as many bytes as possible are moved into the overflow pages without letting
-** the cell size drop below the min embedded payload fraction.
-**
-** The min leaf payload fraction is like the min embedded payload fraction
-** except that it applies to leaf nodes in a LEAFDATA tree. The maximum
-** payload fraction for a LEAFDATA tree is always 100% (or 255) and it
-** not specified in the header.
-**
-** Each btree pages is divided into three sections: The header, the
-** cell pointer array, and the cell content area. Page 1 also has a 100-byte
-** file header that occurs before the page header.
-**
-** |----------------|
-** | file header | 100 bytes. Page 1 only.
-** |----------------|
-** | page header | 8 bytes for leaves. 12 bytes for interior nodes
-** |----------------|
-** | cell pointer | | 2 bytes per cell. Sorted order.
-** | array | | Grows downward
-** | | v
-** |----------------|
-** | unallocated |
-** | space |
-** |----------------| ^ Grows upwards
-** | cell content | | Arbitrary order interspersed with freeblocks.
-** | area | | and free space fragments.
-** |----------------|
-**
-** The page headers looks like this:
-**
-** OFFSET SIZE DESCRIPTION
-** 0 1 Flags. 1: intkey, 2: zerodata, 4: leafdata, 8: leaf
-** 1 2 byte offset to the first freeblock
-** 3 2 number of cells on this page
-** 5 2 first byte of the cell content area
-** 7 1 number of fragmented free bytes
-** 8 4 Right child (the Ptr(N) value). Omitted on leaves.
-**
-** The flags define the format of this btree page. The leaf flag means that
-** this page has no children. The zerodata flag means that this page carries
-** only keys and no data. The intkey flag means that the key is a integer
-** which is stored in the key size entry of the cell header rather than in
-** the payload area.
-**
-** The cell pointer array begins on the first byte after the page header.
-** The cell pointer array contains zero or more 2-byte numbers which are
-** offsets from the beginning of the page to the cell content in the cell
-** content area. The cell pointers occur in sorted order. The system strives
-** to keep free space after the last cell pointer so that new cells can
-** be easily added without having to defragment the page.
-**
-** Cell content is stored at the very end of the page and grows toward the
-** beginning of the page.
-**
-** Unused space within the cell content area is collected into a linked list of
-** freeblocks. Each freeblock is at least 4 bytes in size. The byte offset
-** to the first freeblock is given in the header. Freeblocks occur in
-** increasing order. Because a freeblock must be at least 4 bytes in size,
-** any group of 3 or fewer unused bytes in the cell content area cannot
-** exist on the freeblock chain. A group of 3 or fewer free bytes is called
-** a fragment. The total number of bytes in all fragments is recorded.
-** in the page header at offset 7.
-**
-** SIZE DESCRIPTION
-** 2 Byte offset of the next freeblock
-** 2 Bytes in this freeblock
-**
-** Cells are of variable length. Cells are stored in the cell content area at
-** the end of the page. Pointers to the cells are in the cell pointer array
-** that immediately follows the page header. Cells is not necessarily
-** contiguous or in order, but cell pointers are contiguous and in order.
-**
-** Cell content makes use of variable length integers. A variable
-** length integer is 1 to 9 bytes where the lower 7 bits of each
-** byte are used. The integer consists of all bytes that have bit 8 set and
-** the first byte with bit 8 clear. The most significant byte of the integer
-** appears first. A variable-length integer may not be more than 9 bytes long.
-** As a special case, all 8 bytes of the 9th byte are used as data. This
-** allows a 64-bit integer to be encoded in 9 bytes.
-**
-** 0x00 becomes 0x00000000
-** 0x7f becomes 0x0000007f
-** 0x81 0x00 becomes 0x00000080
-** 0x82 0x00 becomes 0x00000100
-** 0x80 0x7f becomes 0x0000007f
-** 0x8a 0x91 0xd1 0xac 0x78 becomes 0x12345678
-** 0x81 0x81 0x81 0x81 0x01 becomes 0x10204081
-**
-** Variable length integers are used for rowids and to hold the number of
-** bytes of key and data in a btree cell.
-**
-** The content of a cell looks like this:
-**
-** SIZE DESCRIPTION
-** 4 Page number of the left child. Omitted if leaf flag is set.
-** var Number of bytes of data. Omitted if the zerodata flag is set.
-** var Number of bytes of key. Or the key itself if intkey flag is set.
-** * Payload
-** 4 First page of the overflow chain. Omitted if no overflow
-**
-** Overflow pages form a linked list. Each page except the last is completely
-** filled with data (pagesize - 4 bytes). The last page can have as little
-** as 1 byte of data.
-**
-** SIZE DESCRIPTION
-** 4 Page number of next overflow page
-** * Data
-**
-** Freelist pages come in two subtypes: trunk pages and leaf pages. The
-** file header points to the first in a linked list of trunk page. Each trunk
-** page points to multiple leaf pages. The content of a leaf page is
-** unspecified. A trunk page looks like this:
-**
-** SIZE DESCRIPTION
-** 4 Page number of next trunk page
-** 4 Number of leaf pointers on this page
-** * zero or more pages numbers of leaves
-*/
-#include "sqliteInt.h"
-#include "pager.h"
-#include "btree.h"
-#include "os.h"
-#include <assert.h>
-
-/* Round up a number to the next larger multiple of 8. This is used
-** to force 8-byte alignment on 64-bit architectures.
-*/
-#define ROUND8(x) ((x+7)&~7)
-
-
-/* The following value is the maximum cell size assuming a maximum page
-** size give above.
-*/
-#define MX_CELL_SIZE(pBt) (pBt->pageSize-8)
-
-/* The maximum number of cells on a single page of the database. This
-** assumes a minimum cell size of 3 bytes. Such small cells will be
-** exceedingly rare, but they are possible.
-*/
-#define MX_CELL(pBt) ((pBt->pageSize-8)/3)
-
-/* Forward declarations */
-typedef struct MemPage MemPage;
-typedef struct BtLock BtLock;
-
-/*
-** 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
-** databases generated by the standard tools and the standard tools
-** will not be able to read databases created by your custom library.
-*/
-#ifndef SQLITE_FILE_HEADER /* 123456789 123456 */
-# define SQLITE_FILE_HEADER "SQLite format 3"
-#endif
-
-/*
-** Page type flags. An ORed combination of these flags appear as the
-** first byte of on-disk image of every BTree page.
-*/
-#define PTF_INTKEY 0x01
-#define PTF_ZERODATA 0x02
-#define PTF_LEAFDATA 0x04
-#define PTF_LEAF 0x08
-
-/*
-** As each page of the file is loaded into memory, an instance of the following
-** structure is appended and initialized to zero. This structure stores
-** information about the page that is decoded from the raw file page.
-**
-** The pParent field points back to the parent page. This allows us to
-** walk up the BTree from any leaf to the root. Care must be taken to
-** unref() the parent page pointer when this page is no longer referenced.
-** The pageDestructor() routine handles that chore.
-**
-** Access to all fields of this structure is controlled by the mutex
-** stored in MemPage.pBt->mutex.
-*/
-struct MemPage {
- u8 isInit; /* True if previously initialized. MUST BE FIRST! */
- u8 idxShift; /* True if Cell indices have changed */
- u8 nOverflow; /* Number of overflow cell bodies in aCell[] */
- u8 intKey; /* True if intkey flag is set */
- u8 leaf; /* True if leaf flag is set */
- u8 zeroData; /* True if table stores keys only */
- u8 leafData; /* True if tables stores data on leaves only */
- u8 hasData; /* True if this page stores data */
- u8 hdrOffset; /* 100 for page 1. 0 otherwise */
- u8 childPtrSize; /* 0 if leaf==1. 4 if leaf==0 */
- 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 idxParent; /* Index in parent of this node */
- u16 nFree; /* Number of free bytes on the page */
- u16 nCell; /* Number of cells on this page, local and ovfl */
- struct _OvflCell { /* Cells that will not fit on aData[] */
- u8 *pCell; /* Pointers to the body of the overflow cell */
- u16 idx; /* Insert this cell before idx-th non-overflow cell */
- } aOvfl[5];
- BtShared *pBt; /* Pointer to BtShared that this page is part of */
- u8 *aData; /* Pointer to disk image of the page data */
- DbPage *pDbPage; /* Pager page handle */
- Pgno pgno; /* Page number for this page */
- MemPage *pParent; /* The parent of this page. NULL for root */
-};
-
-/*
-** 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)
-
-/* A Btree handle
-**
-** A database connection contains a pointer to an instance of
-** this object for every database file that it has open. This structure
-** is opaque to the database connection. The database connection cannot
-** see the internals of this structure and only deals with pointers to
-** this structure.
-**
-** For some database files, the same underlying database cache might be
-** shared between multiple connections. In that case, each contection
-** has it own pointer to this object. But each instance of this object
-** points to the same BtShared object. The database cache and the
-** schema associated with the database file are all contained within
-** the BtShared object.
-**
-** All fields in this structure are accessed under sqlite3.mutex.
-** The pBt pointer itself may not be changed while there exists cursors
-** in the referenced BtShared that point back to this Btree since those
-** cursors have to do 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 */
- int wantToLock; /* Number of nested calls to sqlite3BtreeEnter() */
- Btree *pNext; /* List of other sharable Btrees from the same db */
- Btree *pPrev; /* Back pointer of the same list */
-};
-
-/*
-** Btree.inTrans may take one of the following values.
-**
-** If the shared-data extension is enabled, there may be multiple users
-** of the Btree structure. At most one of these may open a write transaction,
-** but any number may have active read transactions.
-*/
-#define TRANS_NONE 0
-#define TRANS_READ 1
-#define TRANS_WRITE 2
-
-/*
-** An instance of this object represents a single database file.
-**
-** A single database file can be in use as the same time by two
-** or more database connections. When two or more connections are
-** sharing the same database file, each connection has it own
-** private Btree object for the file and each of those Btrees points
-** to this one BtShared object. BtShared.nRef is the number of
-** connections currently sharing this database file.
-**
-** Fields in this structure are accessed under the BtShared.mutex
-** mutex, except for nRef and pNext which are accessed under the
-** global SQLITE_MUTEX_STATIC_MASTER mutex. The pPager field
-** may not be modified once it is initially set as long as nRef>0.
-** The pSchema field may be set once under BtShared.mutex and
-** thereafter is unchanged as long as nRef>0.
-*/
-struct BtShared {
- Pager *pPager; /* The page cache */
- sqlite3 *db; /* Database connection currently using this Btree */
- BtCursor *pCursor; /* A list of all open cursors */
- MemPage *pPage1; /* First page of the database */
- u8 inStmt; /* True if we are in a statement subtransaction */
- u8 readOnly; /* True if the underlying file is readonly */
- u8 maxEmbedFrac; /* Maximum payload as % of total page size */
- u8 minEmbedFrac; /* Minimum payload as % of total page size */
- u8 minLeafFrac; /* Minimum leaf payload as % of total page size */
- u8 pageSizeFixed; /* True if the page size can no longer be changed */
-#ifndef SQLITE_OMIT_AUTOVACUUM
- u8 autoVacuum; /* True if auto-vacuum is enabled */
- u8 incrVacuum; /* True if incr-vacuum is enabled */
- Pgno nTrunc; /* Non-zero if the db will be truncated (incr vacuum) */
-#endif
- u16 pageSize; /* Total number of bytes on a page */
- u16 usableSize; /* Number of usable bytes on each page */
- int maxLocal; /* Maximum local payload in non-LEAFDATA tables */
- int minLocal; /* Minimum local payload in non-LEAFDATA tables */
- int maxLeaf; /* Maximum local payload in a LEAFDATA table */
- int minLeaf; /* Minimum local payload in a LEAFDATA table */
- u8 inTransaction; /* Transaction state */
- int nTransaction; /* Number of open transactions (read + write) */
- void *pSchema; /* Pointer to space allocated by sqlite3BtreeSchema() */
- void (*xFreeSchema)(void*); /* Destructor for BtShared.pSchema */
- sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */
- BusyHandler busyHdr; /* The busy handler for this btree */
-#ifndef SQLITE_OMIT_SHARED_CACHE
- int nRef; /* Number of references to this structure */
- BtShared *pNext; /* Next on a list of sharable BtShared structs */
- BtLock *pLock; /* List of locks held on this shared-btree struct */
-#endif
-};
-
-/*
-** 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 {
- u8 *pCell; /* Pointer to the start of cell content */
- i64 nKey; /* The key for INTKEY tables, or number of bytes in key */
- u32 nData; /* Number of bytes of data */
- u32 nPayload; /* Total amount of payload */
- u16 nHeader; /* Size of the cell content header in bytes */
- u16 nLocal; /* Amount of payload held locally */
- u16 iOverflow; /* Offset to overflow page number. Zero if no overflow */
- u16 nSize; /* Size of the cell content on the main b-tree page */
-};
-
-/*
-** A cursor is a pointer to a particular entry within a particular
-** b-tree within a database file.
-**
-** The entry is identified by its MemPage and the index in
-** MemPage.aCell[] of the entry.
-**
-** When a single database file can shared by two more database connections,
-** but cursors cannot be shared. Each cursor is associated with a
-** particular database connection identified BtCursor.pBtree.db.
-**
-** Fields in this structure are accessed under the BtShared.mutex
-** found at self->pBt->mutex.
-*/
-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 */
- int (*xCompare)(void*,int,const void*,int,const void*); /* Key comp func */
- void *pArg; /* First arg to xCompare() */
- Pgno pgnoRoot; /* The root page of this tree */
- MemPage *pPage; /* Page that contains the entry */
- int idx; /* Index of the entry in pPage->aCell[] */
- CellInfo info; /* A parse of the cell we are pointing at */
- u8 wrFlag; /* True if writable */
- u8 eState; /* One of the CURSOR_XXX constants (see below) */
- void *pKey; /* Saved key that was cursor's last known position */
- i64 nKey; /* Size of pKey, or last integer key */
- int skip; /* (skip<0) -> Prev() is a no-op. (skip>0) -> Next() is */
-#ifndef SQLITE_OMIT_INCRBLOB
- u8 isIncrblobHandle; /* True if this cursor is an incr. io handle */
- Pgno *aOverflow; /* Cache of overflow page locations */
-#endif
-};
-
-/*
-** Potential values for BtCursor.eState.
-**
-** CURSOR_VALID:
-** Cursor points to a valid entry. getPayload() etc. may be called.
-**
-** 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_REQUIRESEEK:
-** The table that this cursor was opened on still exists, but has been
-** modified since the cursor was last used. The cursor position is saved
-** in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in
-** this state, restoreOrClearCursorPosition() can be called to attempt to
-** seek the cursor to the saved position.
-**
-** CURSOR_FAULT:
-** A unrecoverable error (an I/O error or a malloc failure) has occurred
-** on a different connection that shares the BtShared cache with this
-** cursor. The error has left the cache in an inconsistent state.
-** Do nothing else with this cursor. Any attempt to use the cursor
-** should return the error code stored in BtCursor.skip
-*/
-#define CURSOR_INVALID 0
-#define CURSOR_VALID 1
-#define CURSOR_REQUIRESEEK 2
-#define CURSOR_FAULT 3
-
-/*
-** The TRACE macro will print high-level status information about the
-** btree operation when the global variable sqlite3_btree_trace is
-** enabled.
-*/
-#if SQLITE_TEST
-# define TRACE(X) if( sqlite3_btree_trace ){ printf X; fflush(stdout); }
-#else
-# define TRACE(X)
-#endif
-
-/*
-** Routines to read and write variable-length integers. These used to
-** be defined locally, but now we use the varint routines in the util.c
-** file.
-*/
-#define getVarint sqlite3GetVarint
-#define getVarint32(A,B) ((*B=*(A))<=0x7f?1:sqlite3GetVarint32(A,B))
-#define putVarint sqlite3PutVarint
-
-/* The database page the PENDING_BYTE occupies. This page is never used.
-** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
-** should possibly be consolidated (presumably in pager.h).
-**
-** If disk I/O is omitted (meaning that the database is stored purely
-** in memory) then there is no pending byte.
-*/
-#ifdef SQLITE_OMIT_DISKIO
-# define PENDING_BYTE_PAGE(pBt) 0x7fffffff
-#else
-# define PENDING_BYTE_PAGE(pBt) ((PENDING_BYTE/(pBt)->pageSize)+1)
-#endif
-
-/*
-** A linked list of the following structures is stored at BtShared.pLock.
-** Locks are added (or upgraded from READ_LOCK to WRITE_LOCK) when a cursor
-** is opened on the table with root page BtShared.iTable. Locks are removed
-** from this list when a transaction is committed or rolled back, or when
-** a btree handle is closed.
-*/
-struct BtLock {
- Btree *pBtree; /* Btree handle holding this lock */
- Pgno iTable; /* Root page of table */
- u8 eLock; /* READ_LOCK or WRITE_LOCK */
- BtLock *pNext; /* Next in BtShared.pLock list */
-};
-
-/* Candidate values for BtLock.eLock */
-#define READ_LOCK 1
-#define WRITE_LOCK 2
-
-/*
-** These macros define the location of the pointer-map entry for a
-** database page. The first argument to each is the number of usable
-** bytes on each page of the database (often 1024). The second is the
-** page number to look up in the pointer map.
-**
-** PTRMAP_PAGENO returns the database page number of the pointer-map
-** page that stores the required pointer. PTRMAP_PTROFFSET returns
-** the offset of the requested map entry.
-**
-** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,
-** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be
-** used to test if pgno is a pointer-map page. PTRMAP_ISPAGE implements
-** this test.
-*/
-#define PTRMAP_PAGENO(pBt, pgno) ptrmapPageno(pBt, pgno)
-#define PTRMAP_PTROFFSET(pBt, pgno) (5*(pgno-ptrmapPageno(pBt, pgno)-1))
-#define PTRMAP_ISPAGE(pBt, pgno) (PTRMAP_PAGENO((pBt),(pgno))==(pgno))
-
-/*
-** The pointer map is a lookup table that identifies the parent page for
-** each child page in the database file. The parent page is the page that
-** contains a pointer to the child. Every page in the database contains
-** 0 or 1 parent pages. (In this context 'database page' refers
-** to any page that is not part of the pointer map itself.) Each pointer map
-** entry consists of a single byte 'type' and a 4 byte parent page number.
-** The PTRMAP_XXX identifiers below are the valid types.
-**
-** The purpose of the pointer map is to facility moving pages from one
-** position in the file to another as part of autovacuum. When a page
-** is moved, the pointer in its parent must be updated to point to the
-** new location. The pointer map is used to locate the parent page quickly.
-**
-** PTRMAP_ROOTPAGE: The database page is a root-page. The page-number is not
-** used in this case.
-**
-** PTRMAP_FREEPAGE: The database page is an unused (free) page. The page-number
-** is not used in this case.
-**
-** PTRMAP_OVERFLOW1: The database page is the first page in a list of
-** overflow pages. The page number identifies the page that
-** contains the cell with a pointer to this overflow page.
-**
-** PTRMAP_OVERFLOW2: The database page is the second or later page in a list of
-** overflow pages. The page-number identifies the previous
-** page in the overflow page list.
-**
-** PTRMAP_BTREE: The database page is a non-root btree page. The page number
-** identifies the parent page in the btree.
-*/
-#define PTRMAP_ROOTPAGE 1
-#define PTRMAP_FREEPAGE 2
-#define PTRMAP_OVERFLOW1 3
-#define PTRMAP_OVERFLOW2 4
-#define PTRMAP_BTREE 5
-
-/* A bunch of assert() statements to check the transaction state variables
-** of handle p (type Btree*) are internally consistent.
-*/
-#define btreeIntegrity(p) \
- assert( p->pBt->inTransaction!=TRANS_NONE || p->pBt->nTransaction==0 ); \
- assert( p->pBt->inTransaction>=p->inTrans );
-
-
-/*
-** The ISAUTOVACUUM macro is used within balance_nonroot() to determine
-** if the database supports auto-vacuum or not. Because it is used
-** within an expression that is an argument to another macro
-** (sqliteMallocRaw), it is not possible to use conditional compilation.
-** So, this macro is defined instead.
-*/
-#ifndef SQLITE_OMIT_AUTOVACUUM
-#define ISAUTOVACUUM (pBt->autoVacuum)
-#else
-#define ISAUTOVACUUM 0
-#endif
-
-
-/*
-** This structure is passed around through all the sanity checking routines
-** in order to keep track of some global state information.
-*/
-typedef struct IntegrityCk IntegrityCk;
-struct IntegrityCk {
- BtShared *pBt; /* The tree being checked out */
- Pager *pPager; /* The associated pager. Also accessible by pBt->pPager */
- int nPage; /* Number of pages in the database */
- int *anRef; /* Number of times each page is referenced */
- int mxErr; /* Stop accumulating errors when this reaches zero */
- char *zErrMsg; /* An error message. NULL if no errors seen. */
- int nErr; /* Number of messages written to zErrMsg so far */
-};
-
-/*
-** 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] = (v)>>8, (p)[1] = (v))
-#define get4byte sqlite3Get4byte
-#define put4byte sqlite3Put4byte
-
-/*
-** Internal routines that should be accessed by the btree layer only.
-*/
-int sqlite3BtreeGetPage(BtShared*, Pgno, MemPage**, int);
-int sqlite3BtreeInitPage(MemPage *pPage, MemPage *pParent);
-void sqlite3BtreeParseCellPtr(MemPage*, u8*, CellInfo*);
-void sqlite3BtreeParseCell(MemPage*, int, CellInfo*);
-#ifdef SQLITE_TEST
-u8 *sqlite3BtreeFindCell(MemPage *pPage, int iCell);
-#endif
-int sqlite3BtreeRestoreOrClearCursorPosition(BtCursor *pCur);
-void sqlite3BtreeGetTempCursor(BtCursor *pCur, BtCursor *pTempCur);
-void sqlite3BtreeReleaseTempCursor(BtCursor *pCur);
-int sqlite3BtreeIsRootPage(MemPage *pPage);
-void sqlite3BtreeMoveToParent(BtCursor *pCur);