This commit is contained in:
Hongze Cheng 2022-02-21 10:07:13 +00:00
parent e37711199f
commit c7cb16d4dd
2 changed files with 1197 additions and 1215 deletions

View File

@ -21,7 +21,6 @@
#include "sqliteInt.h" #include "sqliteInt.h"
// #include "wal.h" // #include "wal.h"
// /******************* NOTES ON THE DESIGN OF THE PAGER ************************ // /******************* NOTES ON THE DESIGN OF THE PAGER ************************
// ** // **
// ** This comment block describes invariants that hold when using a rollback // ** This comment block describes invariants that hold when using a rollback
@ -413,7 +412,6 @@
// */ // */
// #define MAX_SECTOR_SIZE 0x10000 // #define MAX_SECTOR_SIZE 0x10000
// /* // /*
// ** An instance of the following structure is allocated for each active // ** An instance of the following structure is allocated for each active
// ** savepoint and statement transaction in the system. All such structures // ** savepoint and statement transaction in the system. All such structures
@ -447,175 +445,175 @@
// #define SPILLFLAG_ROLLBACK 0x02 /* Current rolling back, so do not spill */ // #define SPILLFLAG_ROLLBACK 0x02 /* Current rolling back, so do not spill */
// #define SPILLFLAG_NOSYNC 0x04 /* Spill is ok, but do not sync */ // #define SPILLFLAG_NOSYNC 0x04 /* Spill is ok, but do not sync */
// /* /*
// ** An open page cache is an instance of struct Pager. A description of ** An open page cache is an instance of struct Pager. A description of
// ** some of the more important member variables follows: ** some of the more important member variables follows:
// ** **
// ** eState ** eState
// ** **
// ** The current 'state' of the pager object. See the comment and state ** The current 'state' of the pager object. See the comment and state
// ** diagram above for a description of the pager state. ** diagram above for a description of the pager state.
// ** **
// ** eLock ** eLock
// ** **
// ** For a real on-disk database, the current lock held on the database file - ** For a real on-disk database, the current lock held on the database file -
// ** NO_LOCK, SHARED_LOCK, RESERVED_LOCK or EXCLUSIVE_LOCK. ** NO_LOCK, SHARED_LOCK, RESERVED_LOCK or EXCLUSIVE_LOCK.
// ** **
// ** For a temporary or in-memory database (neither of which require any ** For a temporary or in-memory database (neither of which require any
// ** locks), this variable is always set to EXCLUSIVE_LOCK. Since such ** locks), this variable is always set to EXCLUSIVE_LOCK. Since such
// ** databases always have Pager.exclusiveMode==1, this tricks the pager ** databases always have Pager.exclusiveMode==1, this tricks the pager
// ** logic into thinking that it already has all the locks it will ever ** logic into thinking that it already has all the locks it will ever
// ** need (and no reason to release them). ** need (and no reason to release them).
// ** **
// ** In some (obscure) circumstances, this variable may also be set to ** In some (obscure) circumstances, this variable may also be set to
// ** UNKNOWN_LOCK. See the comment above the #define of UNKNOWN_LOCK for ** UNKNOWN_LOCK. See the comment above the #define of UNKNOWN_LOCK for
// ** details. ** details.
// ** **
// ** changeCountDone ** changeCountDone
// ** **
// ** This boolean variable is used to make sure that the change-counter ** This boolean variable is used to make sure that the change-counter
// ** (the 4-byte header field at byte offset 24 of the database file) is ** (the 4-byte header field at byte offset 24 of the database file) is
// ** not updated more often than necessary. ** not updated more often than necessary.
// ** **
// ** It is set to true when the change-counter field is updated, which ** It is set to true when the change-counter field is updated, which
// ** can only happen if an exclusive lock is held on the database file. ** can only happen if an exclusive lock is held on the database file.
// ** It is cleared (set to false) whenever an exclusive lock is ** It is cleared (set to false) whenever an exclusive lock is
// ** relinquished on the database file. Each time a transaction is committed, ** relinquished on the database file. Each time a transaction is committed,
// ** The changeCountDone flag is inspected. If it is true, the work of ** The changeCountDone flag is inspected. If it is true, the work of
// ** updating the change-counter is omitted for the current transaction. ** updating the change-counter is omitted for the current transaction.
// ** **
// ** This mechanism means that when running in exclusive mode, a connection ** This mechanism means that when running in exclusive mode, a connection
// ** need only update the change-counter once, for the first transaction ** need only update the change-counter once, for the first transaction
// ** committed. ** committed.
// ** **
// ** setSuper ** setSuper
// ** **
// ** When PagerCommitPhaseOne() is called to commit a transaction, it may ** When PagerCommitPhaseOne() is called to commit a transaction, it may
// ** (or may not) specify a super-journal name to be written into the ** (or may not) specify a super-journal name to be written into the
// ** journal file before it is synced to disk. ** journal file before it is synced to disk.
// ** **
// ** Whether or not a journal file contains a super-journal pointer affects ** Whether or not a journal file contains a super-journal pointer affects
// ** the way in which the journal file is finalized after the transaction is ** the way in which the journal file is finalized after the transaction is
// ** committed or rolled back when running in "journal_mode=PERSIST" mode. ** committed or rolled back when running in "journal_mode=PERSIST" mode.
// ** If a journal file does not contain a super-journal pointer, it is ** If a journal file does not contain a super-journal pointer, it is
// ** finalized by overwriting the first journal header with zeroes. If ** finalized by overwriting the first journal header with zeroes. If
// ** it does contain a super-journal pointer the journal file is finalized ** it does contain a super-journal pointer the journal file is finalized
// ** by truncating it to zero bytes, just as if the connection were ** by truncating it to zero bytes, just as if the connection were
// ** running in "journal_mode=truncate" mode. ** running in "journal_mode=truncate" mode.
// ** **
// ** Journal files that contain super-journal pointers cannot be finalized ** Journal files that contain super-journal pointers cannot be finalized
// ** simply by overwriting the first journal-header with zeroes, as the ** simply by overwriting the first journal-header with zeroes, as the
// ** super-journal pointer could interfere with hot-journal rollback of any ** super-journal pointer could interfere with hot-journal rollback of any
// ** subsequently interrupted transaction that reuses the journal file. ** subsequently interrupted transaction that reuses the journal file.
// ** **
// ** The flag is cleared as soon as the journal file is finalized (either ** The flag is cleared as soon as the journal file is finalized (either
// ** by PagerCommitPhaseTwo or PagerRollback). If an IO error prevents the ** by PagerCommitPhaseTwo or PagerRollback). If an IO error prevents the
// ** journal file from being successfully finalized, the setSuper flag ** journal file from being successfully finalized, the setSuper flag
// ** is cleared anyway (and the pager will move to ERROR state). ** is cleared anyway (and the pager will move to ERROR state).
// ** **
// ** doNotSpill ** doNotSpill
// ** **
// ** This variables control the behavior of cache-spills (calls made by ** This variables control the behavior of cache-spills (calls made by
// ** the pcache module to the pagerStress() routine to write cached data ** the pcache module to the pagerStress() routine to write cached data
// ** to the file-system in order to free up memory). ** to the file-system in order to free up memory).
// ** **
// ** When bits SPILLFLAG_OFF or SPILLFLAG_ROLLBACK of doNotSpill are set, ** When bits SPILLFLAG_OFF or SPILLFLAG_ROLLBACK of doNotSpill are set,
// ** writing to the database from pagerStress() is disabled altogether. ** writing to the database from pagerStress() is disabled altogether.
// ** The SPILLFLAG_ROLLBACK case is done in a very obscure case that ** The SPILLFLAG_ROLLBACK case is done in a very obscure case that
// ** comes up during savepoint rollback that requires the pcache module ** comes up during savepoint rollback that requires the pcache module
// ** to allocate a new page to prevent the journal file from being written ** to allocate a new page to prevent the journal file from being written
// ** while it is being traversed by code in pager_playback(). The SPILLFLAG_OFF ** while it is being traversed by code in pager_playback(). The SPILLFLAG_OFF
// ** case is a user preference. ** case is a user preference.
// ** **
// ** If the SPILLFLAG_NOSYNC bit is set, writing to the database from ** If the SPILLFLAG_NOSYNC bit is set, writing to the database from
// ** pagerStress() is permitted, but syncing the journal file is not. ** pagerStress() is permitted, but syncing the journal file is not.
// ** This flag is set by sqlite3PagerWrite() when the file-system sector-size ** This flag is set by sqlite3PagerWrite() when the file-system sector-size
// ** is larger than the database page-size in order to prevent a journal sync ** is larger than the database page-size in order to prevent a journal sync
// ** from happening in between the journalling of two pages on the same sector. ** from happening in between the journalling of two pages on the same sector.
// ** **
// ** subjInMemory ** subjInMemory
// ** **
// ** This is a boolean variable. If true, then any required sub-journal ** This is a boolean variable. If true, then any required sub-journal
// ** is opened as an in-memory journal file. If false, then in-memory ** is opened as an in-memory journal file. If false, then in-memory
// ** sub-journals are only used for in-memory pager files. ** sub-journals are only used for in-memory pager files.
// ** **
// ** This variable is updated by the upper layer each time a new ** This variable is updated by the upper layer each time a new
// ** write-transaction is opened. ** write-transaction is opened.
// ** **
// ** dbSize, dbOrigSize, dbFileSize ** dbSize, dbOrigSize, dbFileSize
// ** **
// ** Variable dbSize is set to the number of pages in the database file. ** Variable dbSize is set to the number of pages in the database file.
// ** It is valid in PAGER_READER and higher states (all states except for ** It is valid in PAGER_READER and higher states (all states except for
// ** OPEN and ERROR). ** OPEN and ERROR).
// ** **
// ** dbSize is set based on the size of the database file, which may be ** dbSize is set based on the size of the database file, which may be
// ** larger than the size of the database (the value stored at offset ** larger than the size of the database (the value stored at offset
// ** 28 of the database header by the btree). If the size of the file ** 28 of the database header by the btree). If the size of the file
// ** is not an integer multiple of the page-size, the value stored in ** is not an integer multiple of the page-size, the value stored in
// ** dbSize is rounded down (i.e. a 5KB file with 2K page-size has dbSize==2). ** dbSize is rounded down (i.e. a 5KB file with 2K page-size has dbSize==2).
// ** Except, any file that is greater than 0 bytes in size is considered ** Except, any file that is greater than 0 bytes in size is considered
// ** to have at least one page. (i.e. a 1KB file with 2K page-size leads ** to have at least one page. (i.e. a 1KB file with 2K page-size leads
// ** to dbSize==1). ** to dbSize==1).
// ** **
// ** During a write-transaction, if pages with page-numbers greater than ** During a write-transaction, if pages with page-numbers greater than
// ** dbSize are modified in the cache, dbSize is updated accordingly. ** dbSize are modified in the cache, dbSize is updated accordingly.
// ** Similarly, if the database is truncated using PagerTruncateImage(), ** Similarly, if the database is truncated using PagerTruncateImage(),
// ** dbSize is updated. ** dbSize is updated.
// ** **
// ** Variables dbOrigSize and dbFileSize are valid in states ** Variables dbOrigSize and dbFileSize are valid in states
// ** PAGER_WRITER_LOCKED and higher. dbOrigSize is a copy of the dbSize ** PAGER_WRITER_LOCKED and higher. dbOrigSize is a copy of the dbSize
// ** variable at the start of the transaction. It is used during rollback, ** variable at the start of the transaction. It is used during rollback,
// ** and to determine whether or not pages need to be journalled before ** and to determine whether or not pages need to be journalled before
// ** being modified. ** being modified.
// ** **
// ** Throughout a write-transaction, dbFileSize contains the size of ** Throughout a write-transaction, dbFileSize contains the size of
// ** the file on disk in pages. It is set to a copy of dbSize when the ** the file on disk in pages. It is set to a copy of dbSize when the
// ** write-transaction is first opened, and updated when VFS calls are made ** write-transaction is first opened, and updated when VFS calls are made
// ** to write or truncate the database file on disk. ** to write or truncate the database file on disk.
// ** **
// ** The only reason the dbFileSize variable is required is to suppress ** The only reason the dbFileSize variable is required is to suppress
// ** unnecessary calls to xTruncate() after committing a transaction. If, ** unnecessary calls to xTruncate() after committing a transaction. If,
// ** when a transaction is committed, the dbFileSize variable indicates ** when a transaction is committed, the dbFileSize variable indicates
// ** that the database file is larger than the database image (Pager.dbSize), ** that the database file is larger than the database image (Pager.dbSize),
// ** pager_truncate() is called. The pager_truncate() call uses xFilesize() ** pager_truncate() is called. The pager_truncate() call uses xFilesize()
// ** to measure the database file on disk, and then truncates it if required. ** to measure the database file on disk, and then truncates it if required.
// ** dbFileSize is not used when rolling back a transaction. In this case ** dbFileSize is not used when rolling back a transaction. In this case
// ** pager_truncate() is called unconditionally (which means there may be ** pager_truncate() is called unconditionally (which means there may be
// ** a call to xFilesize() that is not strictly required). In either case, ** a call to xFilesize() that is not strictly required). In either case,
// ** pager_truncate() may cause the file to become smaller or larger. ** pager_truncate() may cause the file to become smaller or larger.
// ** **
// ** dbHintSize ** dbHintSize
// ** **
// ** The dbHintSize variable is used to limit the number of calls made to ** The dbHintSize variable is used to limit the number of calls made to
// ** the VFS xFileControl(FCNTL_SIZE_HINT) method. ** the VFS xFileControl(FCNTL_SIZE_HINT) method.
// ** **
// ** dbHintSize is set to a copy of the dbSize variable when a ** dbHintSize is set to a copy of the dbSize variable when a
// ** write-transaction is opened (at the same time as dbFileSize and ** write-transaction is opened (at the same time as dbFileSize and
// ** dbOrigSize). If the xFileControl(FCNTL_SIZE_HINT) method is called, ** dbOrigSize). If the xFileControl(FCNTL_SIZE_HINT) method is called,
// ** dbHintSize is increased to the number of pages that correspond to the ** dbHintSize is increased to the number of pages that correspond to the
// ** size-hint passed to the method call. See pager_write_pagelist() for ** size-hint passed to the method call. See pager_write_pagelist() for
// ** details. ** details.
// ** **
// ** errCode ** errCode
// ** **
// ** The Pager.errCode variable is only ever used in PAGER_ERROR state. It ** The Pager.errCode variable is only ever used in PAGER_ERROR state. It
// ** is set to zero in all other states. In PAGER_ERROR state, Pager.errCode ** is set to zero in all other states. In PAGER_ERROR state, Pager.errCode
// ** is always set to SQLITE_FULL, SQLITE_IOERR or one of the SQLITE_IOERR_XXX ** is always set to SQLITE_FULL, SQLITE_IOERR or one of the SQLITE_IOERR_XXX
// ** sub-codes. ** sub-codes.
// ** **
// ** syncFlags, walSyncFlags ** syncFlags, walSyncFlags
// ** **
// ** syncFlags is either SQLITE_SYNC_NORMAL (0x02) or SQLITE_SYNC_FULL (0x03). ** syncFlags is either SQLITE_SYNC_NORMAL (0x02) or SQLITE_SYNC_FULL (0x03).
// ** syncFlags is used for rollback mode. walSyncFlags is used for WAL mode ** syncFlags is used for rollback mode. walSyncFlags is used for WAL mode
// ** and contains the flags used to sync the checkpoint operations in the ** and contains the flags used to sync the checkpoint operations in the
// ** lower two bits, and sync flags used for transaction commits in the WAL ** lower two bits, and sync flags used for transaction commits in the WAL
// ** file in bits 0x04 and 0x08. In other words, to get the correct sync flags ** file in bits 0x04 and 0x08. In other words, to get the correct sync flags
// ** for checkpoint operations, use (walSyncFlags&0x03) and to get the correct ** for checkpoint operations, use (walSyncFlags&0x03) and to get the correct
// ** sync flags for transaction commit, use ((walSyncFlags>>2)&0x03). Note ** sync flags for transaction commit, use ((walSyncFlags>>2)&0x03). Note
// ** that with synchronous=NORMAL in WAL mode, transaction commit is not synced ** that with synchronous=NORMAL in WAL mode, transaction commit is not synced
// ** meaning that the 0x04 and 0x08 bits are both zero. ** meaning that the 0x04 and 0x08 bits are both zero.
// */ */
// struct Pager { struct Pager {
// sqlite3_vfs *pVfs; /* OS functions to use for IO */ // sqlite3_vfs *pVfs; /* OS functions to use for IO */
// u8 exclusiveMode; /* Boolean. True if locking_mode==EXCLUSIVE */ // u8 exclusiveMode; /* Boolean. True if locking_mode==EXCLUSIVE */
// u8 journalMode; /* One of the PAGER_JOURNALMODE_* values */ // u8 journalMode; /* One of the PAGER_JOURNALMODE_* values */
@ -698,7 +696,7 @@
// Wal *pWal; /* Write-ahead log used by "journal_mode=wal" */ // Wal *pWal; /* Write-ahead log used by "journal_mode=wal" */
// char *zWal; /* File name for write-ahead log */ // char *zWal; /* File name for write-ahead log */
// #endif // #endif
// }; };
// /* // /*
// ** Indexes for use with Pager.aStat[]. The Pager.aStat[] array contains // ** Indexes for use with Pager.aStat[]. The Pager.aStat[] array contains
@ -724,8 +722,6 @@
// # define PAGER_INCR(v) // # define PAGER_INCR(v)
// #endif // #endif
// /* // /*
// ** Journal files begin with the following magic string. The data // ** Journal files begin with the following magic string. The data
// ** was obtained from /dev/random. It is used only as a sanity check. // ** was obtained from /dev/random. It is used only as a sanity check.
@ -1110,7 +1106,6 @@
// */ // */
// #define put32bits(A,B) sqlite3Put4byte((u8*)A,B) // #define put32bits(A,B) sqlite3Put4byte((u8*)A,B)
// /* // /*
// ** Write a 32-bit integer into the given file descriptor. Return SQLITE_OK // ** Write a 32-bit integer into the given file descriptor. Return SQLITE_OK
// ** on success or an error code is something goes wrong. // ** on success or an error code is something goes wrong.
@ -1658,7 +1653,6 @@
// return rc; // return rc;
// } // }
// /* // /*
// ** Write the supplied super-journal name into the journal file for pager // ** Write the supplied super-journal name into the journal file for pager
// ** pPager at the current location. The super-journal name must be the last // ** pPager at the current location. The super-journal name must be the last
@ -2578,7 +2572,6 @@
// return rc; // return rc;
// } // }
// /* // /*
// ** This function is used to change the actual size of the database // ** This function is used to change the actual size of the database
// ** file in the file-system. This only happens when committing a transaction, // ** file in the file-system. This only happens when committing a transaction,
@ -2946,7 +2939,6 @@
// return rc; // return rc;
// } // }
// /* // /*
// ** Read the content for page pPg out of the database file (or out of // ** Read the content for page pPg out of the database file (or out of
// ** the WAL if that is where the most recent copy if found) into // ** the WAL if that is where the most recent copy if found) into
@ -3857,7 +3849,6 @@
// *pnPage = (int)pPager->dbSize; // *pnPage = (int)pPager->dbSize;
// } // }
// /* // /*
// ** Try to obtain a lock of type locktype on the database file. If // ** Try to obtain a lock of type locktype on the database file. If
// ** a similar or greater lock is already held, this function is a no-op // ** a similar or greater lock is already held, this function is a no-op
@ -3953,7 +3944,6 @@
// ** is no longer correct. */ // ** is no longer correct. */
// } // }
// /* // /*
// ** This function is called before attempting a hot-journal rollback. It // ** This function is called before attempting a hot-journal rollback. It
// ** syncs the journal file to disk, then sets pPager->journalHdr to the // ** syncs the journal file to disk, then sets pPager->journalHdr to the
@ -4080,22 +4070,21 @@
// return rc; // return rc;
// } // }
/*
// /* ** Shutdown the page cache. Free all memory and close all files.
// ** Shutdown the page cache. Free all memory and close all files. **
// ** ** If a transaction was in progress when this routine is called, that
// ** If a transaction was in progress when this routine is called, that ** transaction is rolled back. All outstanding pages are invalidated
// ** transaction is rolled back. All outstanding pages are invalidated ** and their memory is freed. Any attempt to use a page associated
// ** and their memory is freed. Any attempt to use a page associated ** with this page cache after this function returns will likely
// ** with this page cache after this function returns will likely ** result in a coredump.
// ** result in a coredump. **
// ** ** This function always succeeds. If a transaction is active an attempt
// ** This function always succeeds. If a transaction is active an attempt ** is made to roll it back. If an error occurs during the rollback
// ** is made to roll it back. If an error occurs during the rollback ** a hot journal may be left in the filesystem but no error is returned
// ** a hot journal may be left in the filesystem but no error is returned ** to the caller.
// ** to the caller. */
// */ int sqlite3PagerClose(Pager *pPager, sqlite3 *db) {
// int sqlite3PagerClose(Pager *pPager, sqlite3 *db){
// u8 *pTmp = (u8*)pPager->pTmpSpace; // u8 *pTmp = (u8*)pPager->pTmpSpace;
// assert( db || pagerUseWal(pPager)==0 ); // assert( db || pagerUseWal(pPager)==0 );
// assert( assert_pager_state(pPager) ); // assert( assert_pager_state(pPager) );
@ -4149,8 +4138,8 @@
// assert( !isOpen(pPager->jfd) && !isOpen(pPager->sjfd) ); // assert( !isOpen(pPager->jfd) && !isOpen(pPager->sjfd) );
// sqlite3_free(pPager); // sqlite3_free(pPager);
// return SQLITE_OK; return SQLITE_OK;
// } }
// #if !defined(NDEBUG) || defined(SQLITE_TEST) // #if !defined(NDEBUG) || defined(SQLITE_TEST)
// /* // /*
@ -4620,47 +4609,46 @@
// return rc; // return rc;
// } // }
// /* /*
// ** Allocate and initialize a new Pager object and put a pointer to it ** Allocate and initialize a new Pager object and put a pointer to it
// ** in *ppPager. The pager should eventually be freed by passing it ** in *ppPager. The pager should eventually be freed by passing it
// ** to sqlite3PagerClose(). ** to sqlite3PagerClose().
// ** **
// ** The zFilename argument is the path to the database file to open. ** The zFilename argument is the path to the database file to open.
// ** If zFilename is NULL then a randomly-named temporary file is created ** If zFilename is NULL then a randomly-named temporary file is created
// ** and used as the file to be cached. Temporary files are be deleted ** and used as the file to be cached. Temporary files are be deleted
// ** automatically when they are closed. If zFilename is ":memory:" then ** automatically when they are closed. If zFilename is ":memory:" then
// ** all information is held in cache. It is never written to disk. ** all information is held in cache. It is never written to disk.
// ** This can be used to implement an in-memory database. ** This can be used to implement an in-memory database.
// ** **
// ** The nExtra parameter specifies the number of bytes of space allocated ** The nExtra parameter specifies the number of bytes of space allocated
// ** along with each page reference. This space is available to the user ** along with each page reference. This space is available to the user
// ** via the sqlite3PagerGetExtra() API. When a new page is allocated, the ** via the sqlite3PagerGetExtra() API. When a new page is allocated, the
// ** first 8 bytes of this space are zeroed but the remainder is uninitialized. ** first 8 bytes of this space are zeroed but the remainder is uninitialized.
// ** (The extra space is used by btree as the MemPage object.) ** (The extra space is used by btree as the MemPage object.)
// ** **
// ** The flags argument is used to specify properties that affect the ** The flags argument is used to specify properties that affect the
// ** operation of the pager. It should be passed some bitwise combination ** operation of the pager. It should be passed some bitwise combination
// ** of the PAGER_* flags. ** of the PAGER_* flags.
// ** **
// ** The vfsFlags parameter is a bitmask to pass to the flags parameter ** The vfsFlags parameter is a bitmask to pass to the flags parameter
// ** of the xOpen() method of the supplied VFS when opening files. ** of the xOpen() method of the supplied VFS when opening files.
// ** **
// ** If the pager object is allocated and the specified file opened ** If the pager object is allocated and the specified file opened
// ** successfully, SQLITE_OK is returned and *ppPager set to point to ** successfully, SQLITE_OK is returned and *ppPager set to point to
// ** the new pager object. If an error occurs, *ppPager is set to NULL ** the new pager object. If an error occurs, *ppPager is set to NULL
// ** and error code returned. This function may return SQLITE_NOMEM ** and error code returned. This function may return SQLITE_NOMEM
// ** (sqlite3Malloc() is used to allocate memory), SQLITE_CANTOPEN or ** (sqlite3Malloc() is used to allocate memory), SQLITE_CANTOPEN or
// ** various SQLITE_IO_XXX errors. ** various SQLITE_IO_XXX errors.
// */ */
// int sqlite3PagerOpen( int sqlite3PagerOpen(sqlite3_vfs *pVfs, /* The virtual file system to use */
// sqlite3_vfs *pVfs, /* The virtual file system to use */ Pager ** ppPager, /* OUT: Return the Pager structure here */
// Pager **ppPager, /* OUT: Return the Pager structure here */ const char * zFilename, /* Name of the database file to open */
// const char *zFilename, /* Name of the database file to open */ int nExtra, /* Extra bytes append to each in-memory page */
// int nExtra, /* Extra bytes append to each in-memory page */ int flags, /* flags controlling this file */
// int flags, /* flags controlling this file */ int vfsFlags, /* flags passed through to sqlite3_vfs.xOpen() */
// int vfsFlags, /* flags passed through to sqlite3_vfs.xOpen() */ void (*xReinit)(DbPage *) /* Function to reinitialize pages */
// void (*xReinit)(DbPage*) /* Function to reinitialize pages */ ) {
// ){
// u8 *pPtr; // u8 *pPtr;
// Pager *pPager = 0; /* Pager object to allocate and return */ // Pager *pPager = 0; /* Pager object to allocate and return */
// int rc = SQLITE_OK; /* Return code */ // int rc = SQLITE_OK; /* Return code */
@ -4831,7 +4819,6 @@
// } // }
// } // }
// /* Fill in Pager.zJournal */ // /* Fill in Pager.zJournal */
// if( nPathname>0 ){ // if( nPathname>0 ){
// pPager->zJournal = (char*)pPtr; // pPager->zJournal = (char*)pPtr;
@ -5016,8 +5003,8 @@
// /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */ // /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */
// *ppPager = pPager; // *ppPager = pPager;
// return SQLITE_OK; return SQLITE_OK;
// } }
// /* // /*
// ** Return the sqlite3_file for the main database given the name // ** Return the sqlite3_file for the main database given the name
@ -5033,7 +5020,6 @@
// return pPager->fd; // return pPager->fd;
// } // }
// /* // /*
// ** This function is called after transitioning from PAGER_UNLOCK to // ** This function is called after transitioning from PAGER_UNLOCK to
// ** PAGER_SHARED state. It tests if there is a hot journal present in // ** PAGER_SHARED state. It tests if there is a hot journal present in
@ -5650,7 +5636,6 @@
// return pPager->errCode; // return pPager->errCode;
// } // }
// /* Dispatch all page fetch requests to the appropriate getter method. // /* Dispatch all page fetch requests to the appropriate getter method.
// */ // */
// int sqlite3PagerGet( // int sqlite3PagerGet(
@ -5790,7 +5775,6 @@
// assert( rc!=SQLITE_OK || isOpen(pPager->jfd) ); // assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
// } // }
// /* Write the first journal header to the journal file and open // /* Write the first journal header to the journal file and open
// ** the sub-journal if necessary. // ** the sub-journal if necessary.
// */ // */
@ -6589,7 +6573,6 @@
// return rc; // return rc;
// } // }
// /* // /*
// ** When this function is called, the database file has been completely // ** When this function is called, the database file has been completely
// ** updated to reflect the changes made by the current transaction and // ** updated to reflect the changes made by the current transaction and
@ -6879,7 +6862,6 @@
// } // }
// } // }
// /* // /*
// ** This function is called to rollback or release (commit) a savepoint. // ** This function is called to rollback or release (commit) a savepoint.
// ** The savepoint to release or rollback need not be the most recently // ** The savepoint to release or rollback need not be the most recently
@ -7401,7 +7383,6 @@
// } // }
// #endif // #endif
// #ifndef SQLITE_OMIT_WAL // #ifndef SQLITE_OMIT_WAL
// /* // /*
// ** This function is called when the user invokes "PRAGMA wal_checkpoint", // ** This function is called when the user invokes "PRAGMA wal_checkpoint",
@ -7496,7 +7477,6 @@
// return rc; // return rc;
// } // }
// /* // /*
// ** The caller must be holding a SHARED lock on the database file to call // ** The caller must be holding a SHARED lock on the database file to call
// ** this function. // ** this function.

View File

@ -46,6 +46,8 @@ typedef struct sqlite3_pcache_page {
typedef struct sqlite3_vfs sqlite3_vfs; typedef struct sqlite3_vfs sqlite3_vfs;
typedef struct sqlite3 sqlite3; typedef struct sqlite3 sqlite3;
#define SQLITE_DEFAULT_PAGE_SIZE 4096
#include "pager.h" #include "pager.h"
#include "pcache.h" #include "pcache.h"