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Add a C-source spell-checking facility. make misspell (on Nix)

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FossilOrigin-Name: 26c1bb4bd9e9f56613c3aa87407a7f562fd4ebde5bfd6dece02078001d9a45f8
This commit is contained in:
larrybr
2023-06-07 08:40:31 +00:00
parent 25e87ed1ba
commit bc91738e66
69 changed files with 5573 additions and 4133 deletions
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318
src/wal.c
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@@ -10,7 +10,7 @@
**
*************************************************************************
**
** This file contains the implementation of a write-ahead log (WAL) used in
** This file contains the implementation of a write-ahead log (WAL) used in
** "journal_mode=WAL" mode.
**
** WRITE-AHEAD LOG (WAL) FILE FORMAT
@@ -19,7 +19,7 @@
** Each frame records the revised content of a single page from the
** database file. All changes to the database are recorded by writing
** frames into the WAL. Transactions commit when a frame is written that
** contains a commit marker. A single WAL can and usually does record
** contains a commit marker. A single WAL can and usually does record
** multiple transactions. Periodically, the content of the WAL is
** transferred back into the database file in an operation called a
** "checkpoint".
@@ -45,11 +45,11 @@
**
** Immediately following the wal-header are zero or more frames. Each
** frame consists of a 24-byte frame-header followed by a <page-size> bytes
** of page data. The frame-header is six big-endian 32-bit unsigned
** of page data. The frame-header is six big-endian 32-bit unsigned
** integer values, as follows:
**
** 0: Page number.
** 4: For commit records, the size of the database image in pages
** 4: For commit records, the size of the database image in pages
** after the commit. For all other records, zero.
** 8: Salt-1 (copied from the header)
** 12: Salt-2 (copied from the header)
@@ -75,7 +75,7 @@
** the checksum. The checksum is computed by interpreting the input as
** an even number of unsigned 32-bit integers: x[0] through x[N]. The
** algorithm used for the checksum is as follows:
**
**
** for i from 0 to n-1 step 2:
** s0 += x[i] + s1;
** s1 += x[i+1] + s0;
@@ -83,7 +83,7 @@
**
** Note that s0 and s1 are both weighted checksums using fibonacci weights
** in reverse order (the largest fibonacci weight occurs on the first element
** of the sequence being summed.) The s1 value spans all 32-bit
** of the sequence being summed.) The s1 value spans all 32-bit
** terms of the sequence whereas s0 omits the final term.
**
** On a checkpoint, the WAL is first VFS.xSync-ed, then valid content of the
@@ -116,19 +116,19 @@
** multiple concurrent readers to view different versions of the database
** content simultaneously.
**
** The reader algorithm in the previous paragraphs works correctly, but
** The reader algorithm in the previous paragraphs works correctly, but
** because frames for page P can appear anywhere within the WAL, the
** reader has to scan the entire WAL looking for page P frames. If the
** WAL is large (multiple megabytes is typical) that scan can be slow,
** and read performance suffers. To overcome this problem, a separate
** data structure called the wal-index is maintained to expedite the
** search for frames of a particular page.
**
**
** WAL-INDEX FORMAT
**
** Conceptually, the wal-index is shared memory, though VFS implementations
** might choose to implement the wal-index using a mmapped file. Because
** the wal-index is shared memory, SQLite does not support journal_mode=WAL
** the wal-index is shared memory, SQLite does not support journal_mode=WAL
** on a network filesystem. All users of the database must be able to
** share memory.
**
@@ -146,19 +146,19 @@
** byte order of the host computer.
**
** The purpose of the wal-index is to answer this question quickly: Given
** a page number P and a maximum frame index M, return the index of the
** a page number P and a maximum frame index M, return the index of the
** last frame in the wal before frame M for page P in the WAL, or return
** NULL if there are no frames for page P in the WAL prior to M.
**
** The wal-index consists of a header region, followed by an one or
** more index blocks.
** more index blocks.
**
** The wal-index header contains the total number of frames within the WAL
** in the mxFrame field.
**
** Each index block except for the first contains information on
** Each index block except for the first contains information on
** HASHTABLE_NPAGE frames. The first index block contains information on
** HASHTABLE_NPAGE_ONE frames. The values of HASHTABLE_NPAGE_ONE and
** HASHTABLE_NPAGE_ONE frames. The values of HASHTABLE_NPAGE_ONE and
** HASHTABLE_NPAGE are selected so that together the wal-index header and
** first index block are the same size as all other index blocks in the
** wal-index. The values are:
@@ -167,10 +167,10 @@
** HASHTABLE_NPAGE_ONE 4062
**
** Each index block contains two sections, a page-mapping that contains the
** database page number associated with each wal frame, and a hash-table
** database page number associated with each wal frame, and a hash-table
** that allows readers to query an index block for a specific page number.
** The page-mapping is an array of HASHTABLE_NPAGE (or HASHTABLE_NPAGE_ONE
** for the first index block) 32-bit page numbers. The first entry in the
** for the first index block) 32-bit page numbers. The first entry in the
** first index-block contains the database page number corresponding to the
** first frame in the WAL file. The first entry in the second index block
** in the WAL file corresponds to the (HASHTABLE_NPAGE_ONE+1)th frame in
@@ -191,8 +191,8 @@
**
** The hash table consists of HASHTABLE_NSLOT 16-bit unsigned integers.
** HASHTABLE_NSLOT = 2*HASHTABLE_NPAGE, and there is one entry in the
** hash table for each page number in the mapping section, so the hash
** table is never more than half full. The expected number of collisions
** hash table for each page number in the mapping section, so the hash
** table is never more than half full. The expected number of collisions
** prior to finding a match is 1. Each entry of the hash table is an
** 1-based index of an entry in the mapping section of the same
** index block. Let K be the 1-based index of the largest entry in
@@ -211,12 +211,12 @@
** reached) until an unused hash slot is found. Let the first unused slot
** be at index iUnused. (iUnused might be less than iKey if there was
** wrap-around.) Because the hash table is never more than half full,
** the search is guaranteed to eventually hit an unused entry. Let
** the search is guaranteed to eventually hit an unused entry. Let
** iMax be the value between iKey and iUnused, closest to iUnused,
** where aHash[iMax]==P. If there is no iMax entry (if there exists
** no hash slot such that aHash[i]==p) then page P is not in the
** current index block. Otherwise the iMax-th mapping entry of the
** current index block corresponds to the last entry that references
** current index block corresponds to the last entry that references
** page P.
**
** A hash search begins with the last index block and moves toward the
@@ -241,7 +241,7 @@
** if no values greater than K0 had ever been inserted into the hash table
** in the first place - which is what reader one wants. Meanwhile, the
** second reader using K1 will see additional values that were inserted
** later, which is exactly what reader two wants.
** later, which is exactly what reader two wants.
**
** When a rollback occurs, the value of K is decreased. Hash table entries
** that correspond to frames greater than the new K value are removed
@@ -269,7 +269,7 @@ int sqlite3WalTrace = 0;
** values in the wal-header are correct and (b) the version field is not
** WAL_MAX_VERSION, recovery fails and SQLite returns SQLITE_CANTOPEN.
**
** Similarly, if a client successfully reads a wal-index header (i.e. the
** Similarly, if a client successfully reads a wal-index header (i.e. the
** checksum test is successful) and finds that the version field is not
** WALINDEX_MAX_VERSION, then no read-transaction is opened and SQLite
** returns SQLITE_CANTOPEN.
@@ -284,7 +284,7 @@ int sqlite3WalTrace = 0;
**
** Technically, the various VFSes are free to implement these locks however
** they see fit. However, compatibility is encouraged so that VFSes can
** interoperate. The standard implemention used on both unix and windows
** interoperate. The standard implementation used on both unix and windows
** is for the index number to indicate a byte offset into the
** WalCkptInfo.aLock[] array in the wal-index header. In other words, all
** locks are on the shm file. The WALINDEX_LOCK_OFFSET constant (which
@@ -316,7 +316,7 @@ typedef struct WalCkptInfo WalCkptInfo;
**
** The szPage value can be any power of 2 between 512 and 32768, inclusive.
** Or it can be 1 to represent a 65536-byte page. The latter case was
** added in 3.7.1 when support for 64K pages was added.
** added in 3.7.1 when support for 64K pages was added.
*/
struct WalIndexHdr {
u32 iVersion; /* Wal-index version */
@@ -358,9 +358,9 @@ struct WalIndexHdr {
** There is one entry in aReadMark[] for each reader lock. If a reader
** holds read-lock K, then the value in aReadMark[K] is no greater than
** the mxFrame for that reader. The value READMARK_NOT_USED (0xffffffff)
** for any aReadMark[] means that entry is unused. aReadMark[0] is
** for any aReadMark[] means that entry is unused. aReadMark[0] is
** a special case; its value is never used and it exists as a place-holder
** to avoid having to offset aReadMark[] indexs by one. Readers holding
** to avoid having to offset aReadMark[] indexes by one. Readers holding
** WAL_READ_LOCK(0) always ignore the entire WAL and read all content
** directly from the database.
**
@@ -378,7 +378,7 @@ struct WalIndexHdr {
** previous sentence is when nBackfill equals mxFrame (meaning that everything
** in the WAL has been backfilled into the database) then new readers
** will choose aReadMark[0] which has value 0 and hence such reader will
** get all their all content directly from the database file and ignore
** get all their all content directly from the database file and ignore
** the WAL.
**
** Writers normally append new frames to the end of the WAL. However,
@@ -484,14 +484,14 @@ struct WalCkptInfo {
** big-endian format in the first 4 bytes of a WAL file.
**
** If the LSB is set, then the checksums for each frame within the WAL
** file are calculated by treating all data as an array of 32-bit
** big-endian words. Otherwise, they are calculated by interpreting
** file are calculated by treating all data as an array of 32-bit
** big-endian words. Otherwise, they are calculated by interpreting
** all data as 32-bit little-endian words.
*/
#define WAL_MAGIC 0x377f0682
/*
** Return the offset of frame iFrame in the write-ahead log file,
** Return the offset of frame iFrame in the write-ahead log file,
** assuming a database page size of szPage bytes. The offset returned
** is to the start of the write-ahead log frame-header.
*/
@@ -543,7 +543,7 @@ struct Wal {
** Candidate values for Wal.exclusiveMode.
*/
#define WAL_NORMAL_MODE 0
#define WAL_EXCLUSIVE_MODE 1
#define WAL_EXCLUSIVE_MODE 1
#define WAL_HEAPMEMORY_MODE 2
/*
@@ -562,7 +562,7 @@ typedef u16 ht_slot;
/*
** This structure is used to implement an iterator that loops through
** all frames in the WAL in database page order. Where two or more frames
** correspond to the same database page, the iterator visits only the
** correspond to the same database page, the iterator visits only the
** frame most recently written to the WAL (in other words, the frame with
** the largest index).
**
@@ -598,7 +598,7 @@ struct WalIterator {
#define HASHTABLE_HASH_1 383 /* Should be prime */
#define HASHTABLE_NSLOT (HASHTABLE_NPAGE*2) /* Must be a power of 2 */
/*
/*
** The block of page numbers associated with the first hash-table in a
** wal-index is smaller than usual. This is so that there is a complete
** hash-table on each aligned 32KB page of the wal-index.
@@ -624,7 +624,7 @@ struct WalIterator {
**
** (1) rc==SQLITE_OK and *ppPage==Requested-Wal-Index-Page
** (2) rc>=SQLITE_ERROR and *ppPage==NULL
** (3) rc==SQLITE_OK and *ppPage==NULL // only if iPage==0
** (3) rc==SQLITE_OK and *ppPage==NULL // only if iPage==0
**
** Scenario (3) can only occur when pWal->writeLock is false and iPage==0
*/
@@ -656,7 +656,7 @@ static SQLITE_NOINLINE int walIndexPageRealloc(
pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);
if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;
}else{
rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ,
rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ,
pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
);
assert( pWal->apWiData[iPage]!=0
@@ -717,7 +717,7 @@ static volatile WalIndexHdr *walIndexHdr(Wal *pWal){
)
/*
** Generate or extend an 8 byte checksum based on the data in
** Generate or extend an 8 byte checksum based on the data in
** array aByte[] and the initial values of aIn[0] and aIn[1] (or
** initial values of 0 and 0 if aIn==NULL).
**
@@ -829,11 +829,11 @@ static SQLITE_NO_TSAN void walIndexWriteHdr(Wal *pWal){
/*
** This function encodes a single frame header and writes it to a buffer
** supplied by the caller. A frame-header is made up of a series of
** supplied by the caller. A frame-header is made up of a series of
** 4-byte big-endian integers, as follows:
**
** 0: Page number.
** 4: For commit records, the size of the database image in pages
** 4: For commit records, the size of the database image in pages
** after the commit. For all other records, zero.
** 8: Salt-1 (copied from the wal-header)
** 12: Salt-2 (copied from the wal-header)
@@ -884,13 +884,13 @@ static int walDecodeFrame(
assert( WAL_FRAME_HDRSIZE==24 );
/* A frame is only valid if the salt values in the frame-header
** match the salt values in the wal-header.
** match the salt values in the wal-header.
*/
if( memcmp(&pWal->hdr.aSalt, &aFrame[8], 8)!=0 ){
return 0;
}
/* A frame is only valid if the page number is creater than zero.
/* A frame is only valid if the page number is greater than zero.
*/
pgno = sqlite3Get4byte(&aFrame[0]);
if( pgno==0 ){
@@ -898,15 +898,15 @@ static int walDecodeFrame(
}
/* A frame is only valid if a checksum of the WAL header,
** all prior frams, the first 16 bytes of this frame-header,
** and the frame-data matches the checksum in the last 8
** all prior frames, the first 16 bytes of this frame-header,
** and the frame-data matches the checksum in the last 8
** bytes of this frame-header.
*/
nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);
walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);
walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);
if( aCksum[0]!=sqlite3Get4byte(&aFrame[16])
|| aCksum[1]!=sqlite3Get4byte(&aFrame[20])
if( aCksum[0]!=sqlite3Get4byte(&aFrame[16])
|| aCksum[1]!=sqlite3Get4byte(&aFrame[20])
){
/* Checksum failed. */
return 0;
@@ -941,7 +941,7 @@ static const char *walLockName(int lockIdx){
}
}
#endif /*defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */
/*
** Set or release locks on the WAL. Locks are either shared or exclusive.
@@ -1010,15 +1010,15 @@ struct WalHashLoc {
u32 iZero; /* One less than the frame number of first indexed*/
};
/*
/*
** Return pointers to the hash table and page number array stored on
** page iHash of the wal-index. The wal-index is broken into 32KB pages
** numbered starting from 0.
**
** Set output variable pLoc->aHash to point to the start of the hash table
** in the wal-index file. Set pLoc->iZero to one less than the frame
** in the wal-index file. Set pLoc->iZero to one less than the frame
** number of the first frame indexed by this hash table. If a
** slot in the hash table is set to N, it refers to frame number
** slot in the hash table is set to N, it refers to frame number
** (pLoc->iZero+N) in the log.
**
** Finally, set pLoc->aPgno so that pLoc->aPgno[0] is the page number of the
@@ -1051,7 +1051,7 @@ static int walHashGet(
/*
** Return the number of the wal-index page that contains the hash-table
** and page-number array that contain entries corresponding to WAL frame
** iFrame. The wal-index is broken up into 32KB pages. Wal-index pages
** iFrame. The wal-index is broken up into 32KB pages. Wal-index pages
** are numbered starting from 0.
*/
static int walFramePage(u32 iFrame){
@@ -1102,7 +1102,7 @@ static void walCleanupHash(Wal *pWal){
if( pWal->hdr.mxFrame==0 ) return;
/* Obtain pointers to the hash-table and page-number array containing
/* Obtain pointers to the hash-table and page-number array containing
** the entry that corresponds to frame pWal->hdr.mxFrame. It is guaranteed
** that the page said hash-table and array reside on is already mapped.(1)
*/
@@ -1121,9 +1121,9 @@ static void walCleanupHash(Wal *pWal){
sLoc.aHash[i] = 0;
}
}
/* Zero the entries in the aPgno array that correspond to frames with
** frame numbers greater than pWal->hdr.mxFrame.
** frame numbers greater than pWal->hdr.mxFrame.
*/
nByte = (int)((char *)sLoc.aHash - (char *)&sLoc.aPgno[iLimit]);
assert( nByte>=0 );
@@ -1167,9 +1167,9 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
idx = iFrame - sLoc.iZero;
assert( idx <= HASHTABLE_NSLOT/2 + 1 );
/* If this is the first entry to be added to this hash-table, zero the
** entire hash table and aPgno[] array before proceeding.
** entire hash table and aPgno[] array before proceeding.
*/
if( idx==1 ){
int nByte = (int)((u8*)&sLoc.aHash[HASHTABLE_NSLOT] - (u8*)sLoc.aPgno);
@@ -1179,8 +1179,8 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
/* If the entry in aPgno[] is already set, then the previous writer
** must have exited unexpectedly in the middle of a transaction (after
** writing one or more dirty pages to the WAL to free up memory).
** Remove the remnants of that writers uncommitted transaction from
** writing one or more dirty pages to the WAL to free up memory).
** Remove the remnants of that writers uncommitted transaction from
** the hash-table before writing any new entries.
*/
if( sLoc.aPgno[idx-1] ){
@@ -1231,7 +1231,7 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
/*
** Recover the wal-index by reading the write-ahead log file.
** Recover the wal-index by reading the write-ahead log file.
**
** This routine first tries to establish an exclusive lock on the
** wal-index to prevent other threads/processes from doing anything
@@ -1291,16 +1291,16 @@ static int walIndexRecover(Wal *pWal){
}
/* If the database page size is not a power of two, or is greater than
** SQLITE_MAX_PAGE_SIZE, conclude that the WAL file contains no valid
** SQLITE_MAX_PAGE_SIZE, conclude that the WAL file contains no valid
** data. Similarly, if the 'magic' value is invalid, ignore the whole
** WAL file.
*/
magic = sqlite3Get4byte(&aBuf[0]);
szPage = sqlite3Get4byte(&aBuf[8]);
if( (magic&0xFFFFFFFE)!=WAL_MAGIC
|| szPage&(szPage-1)
|| szPage>SQLITE_MAX_PAGE_SIZE
|| szPage<512
if( (magic&0xFFFFFFFE)!=WAL_MAGIC
|| szPage&(szPage-1)
|| szPage>SQLITE_MAX_PAGE_SIZE
|| szPage<512
){
goto finished;
}
@@ -1310,7 +1310,7 @@ static int walIndexRecover(Wal *pWal){
memcpy(&pWal->hdr.aSalt, &aBuf[16], 8);
/* Verify that the WAL header checksum is correct */
walChecksumBytes(pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN,
walChecksumBytes(pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN,
aBuf, WAL_HDRSIZE-2*4, 0, pWal->hdr.aFrameCksum
);
if( pWal->hdr.aFrameCksum[0]!=sqlite3Get4byte(&aBuf[24])
@@ -1349,7 +1349,7 @@ static int walIndexRecover(Wal *pWal){
assert( aShare!=0 || rc!=SQLITE_OK );
if( aShare==0 ) break;
pWal->apWiData[iPg] = aPrivate;
for(iFrame=iFirst; iFrame<=iLast; iFrame++){
i64 iOffset = walFrameOffset(iFrame, szPage);
u32 pgno; /* Database page number for frame */
@@ -1419,8 +1419,8 @@ finished:
pWal->hdr.aFrameCksum[1] = aFrameCksum[1];
walIndexWriteHdr(pWal);
/* Reset the checkpoint-header. This is safe because this thread is
** currently holding locks that exclude all other writers and
/* Reset the checkpoint-header. This is safe because this thread is
** currently holding locks that exclude all other writers and
** checkpointers. Then set the values of read-mark slots 1 through N.
*/
pInfo = walCkptInfo(pWal);
@@ -1476,8 +1476,8 @@ static void walIndexClose(Wal *pWal, int isDelete){
}
}
/*
** Open a connection to the WAL file zWalName. The database file must
/*
** Open a connection to the WAL file zWalName. The database file must
** already be opened on connection pDbFd. The buffer that zWalName points
** to must remain valid for the lifetime of the returned Wal* handle.
**
@@ -1487,7 +1487,7 @@ static void walIndexClose(Wal *pWal, int isDelete){
** were to do this just after this client opened one of these files, the
** system would be badly broken.
**
** If the log file is successfully opened, SQLITE_OK is returned and
** If the log file is successfully opened, SQLITE_OK is returned and
** *ppWal is set to point to a new WAL handle. If an error occurs,
** an SQLite error code is returned and *ppWal is left unmodified.
*/
@@ -1592,7 +1592,7 @@ int sqlite3WalOpen(
}
/*
** Change the size to which the WAL file is trucated on each reset.
** Change the size to which the WAL file is truncated on each reset.
*/
void sqlite3WalLimit(Wal *pWal, i64 iLimit){
if( pWal ) pWal->mxWalSize = iLimit;
@@ -1680,7 +1680,7 @@ static void walMerge(
ht_slot logpage;
Pgno dbpage;
if( (iLeft<nLeft)
if( (iLeft<nLeft)
&& (iRight>=nRight || aContent[aLeft[iLeft]]<aContent[aRight[iRight]])
){
logpage = aLeft[iLeft++];
@@ -1778,7 +1778,7 @@ static void walMergesort(
#endif
}
/*
/*
** Free an iterator allocated by walIteratorInit().
*/
static void walIteratorFree(WalIterator *p){
@@ -1786,7 +1786,7 @@ static void walIteratorFree(WalIterator *p){
}
/*
** Construct a WalInterator object that can be used to loop over all
** Construct a WalInterator object that can be used to loop over all
** pages in the WAL following frame nBackfill in ascending order. Frames
** nBackfill or earlier may be included - excluding them is an optimization
** only. The caller must hold the checkpoint lock.
@@ -1815,7 +1815,7 @@ static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){
/* Allocate space for the WalIterator object. */
nSegment = walFramePage(iLast) + 1;
nByte = sizeof(WalIterator)
nByte = sizeof(WalIterator)
+ (nSegment-1)*sizeof(struct WalSegment)
+ iLast*sizeof(ht_slot);
p = (WalIterator *)sqlite3_malloc64(nByte);
@@ -1851,7 +1851,7 @@ static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){
}
aIndex = &((ht_slot *)&p->aSegment[p->nSegment])[sLoc.iZero];
sLoc.iZero++;
for(j=0; j<nEntry; j++){
aIndex[j] = (ht_slot)j;
}
@@ -1875,8 +1875,8 @@ static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){
#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
/*
** Attempt to enable blocking locks. Blocking locks are enabled only if (a)
** they are supported by the VFS, and (b) the database handle is configured
** with a busy-timeout. Return 1 if blocking locks are successfully enabled,
** they are supported by the VFS, and (b) the database handle is configured
** with a busy-timeout. Return 1 if blocking locks are successfully enabled,
** or 0 otherwise.
*/
static int walEnableBlocking(Wal *pWal){
@@ -1905,7 +1905,7 @@ static void walDisableBlocking(Wal *pWal){
/*
** If parameter bLock is true, attempt to enable blocking locks, take
** the WRITER lock, and then disable blocking locks. If blocking locks
** cannot be enabled, no attempt to obtain the WRITER lock is made. Return
** cannot be enabled, no attempt to obtain the WRITER lock is made. Return
** an SQLite error code if an error occurs, or SQLITE_OK otherwise. It is not
** an error if blocking locks can not be enabled.
**
@@ -2002,8 +2002,8 @@ static int walPagesize(Wal *pWal){
** client to write to the database (which may be this one) does so by
** writing frames into the start of the log file.
**
** The value of parameter salt1 is used as the aSalt[1] value in the
** new wal-index header. It should be passed a pseudo-random value (i.e.
** The value of parameter salt1 is used as the aSalt[1] value in the
** new wal-index header. It should be passed a pseudo-random value (i.e.
** one obtained from sqlite3_randomness()).
*/
static void walRestartHdr(Wal *pWal, u32 salt1){
@@ -2031,8 +2031,8 @@ static void walRestartHdr(Wal *pWal, u32 salt1){
** that a concurrent reader might be using.
**
** All I/O barrier operations (a.k.a fsyncs) occur in this routine when
** SQLite is in WAL-mode in synchronous=NORMAL. That means that if
** checkpoints are always run by a background thread or background
** SQLite is in WAL-mode in synchronous=NORMAL. That means that if
** checkpoints are always run by a background thread or background
** process, foreground threads will never block on a lengthy fsync call.
**
** Fsync is called on the WAL before writing content out of the WAL and
@@ -2045,7 +2045,7 @@ static void walRestartHdr(Wal *pWal, u32 salt1){
** database file.
**
** This routine uses and updates the nBackfill field of the wal-index header.
** This is the only routine that will increase the value of nBackfill.
** This is the only routine that will increase the value of nBackfill.
** (A WAL reset or recovery will revert nBackfill to zero, but not increase
** its value.)
**
@@ -2135,7 +2135,7 @@ static int walCheckpoint(
if( (nSize+65536+(i64)pWal->hdr.mxFrame*szPage)<nReq ){
/* If the size of the final database is larger than the current
** database plus the amount of data in the wal file, plus the
** maximum size of the pending-byte page (65536 bytes), then
** maximum size of the pending-byte page (65536 bytes), then
** must be corruption somewhere. */
rc = SQLITE_CORRUPT_BKPT;
}else{
@@ -2194,8 +2194,8 @@ static int walCheckpoint(
}
/* If this is an SQLITE_CHECKPOINT_RESTART or TRUNCATE operation, and the
** entire wal file has been copied into the database file, then block
** until all readers have finished using the wal file. This ensures that
** entire wal file has been copied into the database file, then block
** until all readers have finished using the wal file. This ensures that
** the next process to write to the database restarts the wal file.
*/
if( rc==SQLITE_OK && eMode!=SQLITE_CHECKPOINT_PASSIVE ){
@@ -2219,7 +2219,7 @@ static int walCheckpoint(
** writer clients should see that the entire log file has been
** checkpointed and behave accordingly. This seems unsafe though,
** as it would leave the system in a state where the contents of
** the wal-index header do not match the contents of the
** the wal-index header do not match the contents of the
** file-system. To avoid this, update the wal-index header to
** indicate that the log file contains zero valid frames. */
walRestartHdr(pWal, salt1);
@@ -2281,7 +2281,7 @@ int sqlite3WalClose(
if( pWal->exclusiveMode==WAL_NORMAL_MODE ){
pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
}
rc = sqlite3WalCheckpoint(pWal, db,
rc = sqlite3WalCheckpoint(pWal, db,
SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
);
if( rc==SQLITE_OK ){
@@ -2291,7 +2291,7 @@ int sqlite3WalClose(
);
if( bPersist!=1 ){
/* Try to delete the WAL file if the checkpoint completed and
** fsyned (rc==SQLITE_OK) and if we are not in persistent-wal
** fsynced (rc==SQLITE_OK) and if we are not in persistent-wal
** mode (!bPersist) */
isDelete = 1;
}else if( pWal->mxWalSize>=0 ){
@@ -2368,7 +2368,7 @@ static SQLITE_NO_TSAN int walIndexTryHdr(Wal *pWal, int *pChanged){
if( memcmp(&h1, &h2, sizeof(h1))!=0 ){
return 1; /* Dirty read */
}
}
if( h1.isInit==0 ){
return 1; /* Malformed header - probably all zeros */
}
@@ -2404,7 +2404,7 @@ static SQLITE_NO_TSAN int walIndexTryHdr(Wal *pWal, int *pChanged){
** changed by this operation. If pWal->hdr is unchanged, set *pChanged
** to 0.
**
** If the wal-index header is successfully read, return SQLITE_OK.
** If the wal-index header is successfully read, return SQLITE_OK.
** Otherwise an SQLite error code.
*/
static int walIndexReadHdr(Wal *pWal, int *pChanged){
@@ -2412,7 +2412,7 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
int badHdr; /* True if a header read failed */
volatile u32 *page0; /* Chunk of wal-index containing header */
/* Ensure that page 0 of the wal-index (the page that contains the
/* Ensure that page 0 of the wal-index (the page that contains the
** wal-index header) is mapped. Return early if an error occurs here.
*/
assert( pChanged );
@@ -2444,7 +2444,7 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
/* If the first page of the wal-index has been mapped, try to read the
** wal-index header immediately, without holding any lock. This usually
** works, but may fail if the wal-index header is corrupt or currently
** works, but may fail if the wal-index header is corrupt or currently
** being modified by another thread or process.
*/
badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);
@@ -2519,15 +2519,15 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
**
** The *-wal file has been read and an appropriate wal-index has been
** constructed in pWal->apWiData[] using heap memory instead of shared
** memory.
** memory.
**
** If this function returns SQLITE_OK, then the read transaction has
** been successfully opened. In this case output variable (*pChanged)
** been successfully opened. In this case output variable (*pChanged)
** is set to true before returning if the caller should discard the
** contents of the page cache before proceeding. Or, if it returns
** WAL_RETRY, then the heap memory wal-index has been discarded and
** the caller should retry opening the read transaction from the
** beginning (including attempting to map the *-shm file).
** contents of the page cache before proceeding. Or, if it returns
** WAL_RETRY, then the heap memory wal-index has been discarded and
** the caller should retry opening the read transaction from the
** beginning (including attempting to map the *-shm file).
**
** If an error occurs, an SQLite error code is returned.
*/
@@ -2640,8 +2640,8 @@ static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
** the caller. */
aSaveCksum[0] = pWal->hdr.aFrameCksum[0];
aSaveCksum[1] = pWal->hdr.aFrameCksum[1];
for(iOffset=walFrameOffset(pWal->hdr.mxFrame+1, pWal->szPage);
iOffset+szFrame<=szWal;
for(iOffset=walFrameOffset(pWal->hdr.mxFrame+1, pWal->szPage);
iOffset+szFrame<=szWal;
iOffset+=szFrame
){
u32 pgno; /* Database page number for frame */
@@ -2689,10 +2689,10 @@ static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
**
** The useWal parameter is true to force the use of the WAL and disable
** the case where the WAL is bypassed because it has been completely
** checkpointed. If useWal==0 then this routine calls walIndexReadHdr()
** to make a copy of the wal-index header into pWal->hdr. If the
** wal-index header has changed, *pChanged is set to 1 (as an indication
** to the caller that the local page cache is obsolete and needs to be
** checkpointed. If useWal==0 then this routine calls walIndexReadHdr()
** to make a copy of the wal-index header into pWal->hdr. If the
** wal-index header has changed, *pChanged is set to 1 (as an indication
** to the caller that the local page cache is obsolete and needs to be
** flushed.) When useWal==1, the wal-index header is assumed to already
** be loaded and the pChanged parameter is unused.
**
@@ -2707,7 +2707,7 @@ static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
** bad luck when there is lots of contention for the wal-index, but that
** possibility is so small that it can be safely neglected, we believe.
**
** On success, this routine obtains a read lock on
** On success, this routine obtains a read lock on
** WAL_READ_LOCK(pWal->readLock). The pWal->readLock integer is
** in the range 0 <= pWal->readLock < WAL_NREADER. If pWal->readLock==(-1)
** that means the Wal does not hold any read lock. The reader must not
@@ -2745,16 +2745,16 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
**
** Circumstances that cause a RETRY should only last for the briefest
** instances of time. No I/O or other system calls are done while the
** locks are held, so the locks should not be held for very long. But
** locks are held, so the locks should not be held for very long. But
** if we are unlucky, another process that is holding a lock might get
** paged out or take a page-fault that is time-consuming to resolve,
** paged out or take a page-fault that is time-consuming to resolve,
** during the few nanoseconds that it is holding the lock. In that case,
** it might take longer than normal for the lock to free.
**
** After 5 RETRYs, we begin calling sqlite3OsSleep(). The first few
** calls to sqlite3OsSleep() have a delay of 1 microsecond. Really this
** is more of a scheduler yield than an actual delay. But on the 10th
** an subsequent retries, the delays start becoming longer and longer,
** an subsequent retries, the delays start becoming longer and longer,
** so that on the 100th (and last) RETRY we delay for 323 milliseconds.
** The total delay time before giving up is less than 10 seconds.
*/
@@ -2785,9 +2785,9 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
if( pWal->apWiData[0]==0 ){
/* This branch is taken when the xShmMap() method returns SQLITE_BUSY.
** We assume this is a transient condition, so return WAL_RETRY. The
** xShmMap() implementation used by the default unix and win32 VFS
** modules may return SQLITE_BUSY due to a race condition in the
** code that determines whether or not the shared-memory region
** xShmMap() implementation used by the default unix and win32 VFS
** modules may return SQLITE_BUSY due to a race condition in the
** code that determines whether or not the shared-memory region
** must be zeroed before the requested page is returned.
*/
rc = WAL_RETRY;
@@ -2828,7 +2828,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
** snapshot. Since holding READ_LOCK(0) prevents a checkpoint from
** happening, this is usually correct.
**
** However, if frames have been appended to the log (or if the log
** However, if frames have been appended to the log (or if the log
** is wrapped and written for that matter) before the READ_LOCK(0)
** is obtained, that is not necessarily true. A checkpointer may
** have started to backfill the appended frames but crashed before
@@ -2910,9 +2910,9 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
** to read any frames earlier than minFrame from the wal file - they
** can be safely read directly from the database file.
**
** Because a ShmBarrier() call is made between taking the copy of
** Because a ShmBarrier() call is made between taking the copy of
** nBackfill and checking that the wal-header in shared-memory still
** matches the one cached in pWal->hdr, it is guaranteed that the
** matches the one cached in pWal->hdr, it is guaranteed that the
** checkpointer that set nBackfill was not working with a wal-index
** header newer than that cached in pWal->hdr. If it were, that could
** cause a problem. The checkpointer could omit to checkpoint
@@ -2940,15 +2940,15 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
#ifdef SQLITE_ENABLE_SNAPSHOT
/*
** Attempt to reduce the value of the WalCkptInfo.nBackfillAttempted
** Attempt to reduce the value of the WalCkptInfo.nBackfillAttempted
** variable so that older snapshots can be accessed. To do this, loop
** through all wal frames from nBackfillAttempted to (nBackfill+1),
** through all wal frames from nBackfillAttempted to (nBackfill+1),
** comparing their content to the corresponding page with the database
** file, if any. Set nBackfillAttempted to the frame number of the
** first frame for which the wal file content matches the db file.
**
** This is only really safe if the file-system is such that any page
** writes made by earlier checkpointers were atomic operations, which
** This is only really safe if the file-system is such that any page
** writes made by earlier checkpointers were atomic operations, which
** is not always true. It is also possible that nBackfillAttempted
** may be left set to a value larger than expected, if a wal frame
** contains content that duplicate of an earlier version of the same
@@ -3045,13 +3045,13 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
bChanged = 1;
}
/* It is possible that there is a checkpointer thread running
/* It is possible that there is a checkpointer thread running
** concurrent with this code. If this is the case, it may be that the
** checkpointer has already determined that it will checkpoint
** snapshot X, where X is later in the wal file than pSnapshot, but
** has not yet set the pInfo->nBackfillAttempted variable to indicate
** checkpointer has already determined that it will checkpoint
** snapshot X, where X is later in the wal file than pSnapshot, but
** has not yet set the pInfo->nBackfillAttempted variable to indicate
** its intent. To avoid the race condition this leads to, ensure that
** there is no checkpointer process by taking a shared CKPT lock
** there is no checkpointer process by taking a shared CKPT lock
** before checking pInfo->nBackfillAttempted. */
(void)walEnableBlocking(pWal);
rc = walLockShared(pWal, WAL_CKPT_LOCK);
@@ -3112,7 +3112,7 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
/* A client using a non-current snapshot may not ignore any frames
** from the start of the wal file. This is because, for a system
** where (minFrame < iSnapshot < maxFrame), a checkpointer may
** have omitted to checkpoint a frame earlier than minFrame in
** have omitted to checkpoint a frame earlier than minFrame in
** the file because there exists a frame after iSnapshot that
** is the same database page. */
pWal->minFrame = 1;
@@ -3168,8 +3168,8 @@ int sqlite3WalFindFrame(
/* If the "last page" field of the wal-index header snapshot is 0, then
** no data will be read from the wal under any circumstances. Return early
** in this case as an optimization. Likewise, if pWal->readLock==0,
** then the WAL is ignored by the reader so return early, as if the
** in this case as an optimization. Likewise, if pWal->readLock==0,
** then the WAL is ignored by the reader so return early, as if the
** WAL were empty.
*/
if( iLast==0 || (pWal->readLock==0 && pWal->bShmUnreliable==0) ){
@@ -3182,9 +3182,9 @@ int sqlite3WalFindFrame(
** hash table (each hash table indexes up to HASHTABLE_NPAGE frames).
**
** This code might run concurrently to the code in walIndexAppend()
** that adds entries to the wal-index (and possibly to this hash
** table). This means the value just read from the hash
** slot (aHash[iKey]) may have been added before or after the
** that adds entries to the wal-index (and possibly to this hash
** table). This means the value just read from the hash
** slot (aHash[iKey]) may have been added before or after the
** current read transaction was opened. Values added after the
** read transaction was opened may have been written incorrectly -
** i.e. these slots may contain garbage data. However, we assume
@@ -3192,13 +3192,13 @@ int sqlite3WalFindFrame(
** opened remain unmodified.
**
** For the reasons above, the if(...) condition featured in the inner
** loop of the following block is more stringent that would be required
** loop of the following block is more stringent that would be required
** if we had exclusive access to the hash-table:
**
** (aPgno[iFrame]==pgno):
** (aPgno[iFrame]==pgno):
** This condition filters out normal hash-table collisions.
**
** (iFrame<=iLast):
** (iFrame<=iLast):
** This condition filters out entries that were added to the hash
** table after the current read-transaction had started.
*/
@@ -3274,7 +3274,7 @@ int sqlite3WalReadFrame(
return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);
}
/*
/*
** Return the size of the database in pages (or zero, if unknown).
*/
Pgno sqlite3WalDbsize(Wal *pWal){
@@ -3285,7 +3285,7 @@ Pgno sqlite3WalDbsize(Wal *pWal){
}
/*
/*
** This function starts a write transaction on the WAL.
**
** A read transaction must have already been started by a prior call
@@ -3373,18 +3373,18 @@ int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){
if( ALWAYS(pWal->writeLock) ){
Pgno iMax = pWal->hdr.mxFrame;
Pgno iFrame;
/* Restore the clients cache of the wal-index header to the state it
** was in before the client began writing to the database.
** was in before the client began writing to the database.
*/
memcpy(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr));
for(iFrame=pWal->hdr.mxFrame+1;
ALWAYS(rc==SQLITE_OK) && iFrame<=iMax;
for(iFrame=pWal->hdr.mxFrame+1;
ALWAYS(rc==SQLITE_OK) && iFrame<=iMax;
iFrame++
){
/* This call cannot fail. Unless the page for which the page number
** is passed as the second argument is (a) in the cache and
** is passed as the second argument is (a) in the cache and
** (b) has an outstanding reference, then xUndo is either a no-op
** (if (a) is false) or simply expels the page from the cache (if (b)
** is false).
@@ -3402,10 +3402,10 @@ int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){
return rc;
}
/*
** Argument aWalData must point to an array of WAL_SAVEPOINT_NDATA u32
** values. This function populates the array with values required to
** "rollback" the write position of the WAL handle back to the current
/*
** Argument aWalData must point to an array of WAL_SAVEPOINT_NDATA u32
** values. This function populates the array with values required to
** "rollback" the write position of the WAL handle back to the current
** point in the event of a savepoint rollback (via WalSavepointUndo()).
*/
void sqlite3WalSavepoint(Wal *pWal, u32 *aWalData){
@@ -3416,7 +3416,7 @@ void sqlite3WalSavepoint(Wal *pWal, u32 *aWalData){
aWalData[3] = pWal->nCkpt;
}
/*
/*
** Move the write position of the WAL back to the point identified by
** the values in the aWalData[] array. aWalData must point to an array
** of WAL_SAVEPOINT_NDATA u32 values that has been previously populated
@@ -3618,7 +3618,7 @@ static int walRewriteChecksums(Wal *pWal, u32 iLast){
return rc;
}
/*
/*
** Write a set of frames to the log. The caller must hold the write-lock
** on the log file (obtained using sqlite3WalBeginWriteTransaction()).
*/
@@ -3685,7 +3685,7 @@ int sqlite3WalFrames(
walChecksumBytes(1, aWalHdr, WAL_HDRSIZE-2*4, 0, aCksum);
sqlite3Put4byte(&aWalHdr[24], aCksum[0]);
sqlite3Put4byte(&aWalHdr[28], aCksum[1]);
pWal->szPage = szPage;
pWal->hdr.bigEndCksum = SQLITE_BIGENDIAN;
pWal->hdr.aFrameCksum[0] = aCksum[0];
@@ -3729,7 +3729,7 @@ int sqlite3WalFrames(
/* Check if this page has already been written into the wal file by
** the current transaction. If so, overwrite the existing frame and
** set Wal.writeLock to WAL_WRITELOCK_RECKSUM - indicating that
** set Wal.writeLock to WAL_WRITELOCK_RECKSUM - indicating that
** checksums must be recomputed when the transaction is committed. */
if( iFirst && (p->pDirty || isCommit==0) ){
u32 iWrite = 0;
@@ -3813,7 +3813,7 @@ int sqlite3WalFrames(
pWal->truncateOnCommit = 0;
}
/* Append data to the wal-index. It is not necessary to lock the
/* Append data to the wal-index. It is not necessary to lock the
** wal-index to do this as the SQLITE_SHM_WRITE lock held on the wal-index
** guarantees that there are no other writers, and no data that may
** be in use by existing readers is being overwritten.
@@ -3852,7 +3852,7 @@ int sqlite3WalFrames(
return rc;
}
/*
/*
** This routine is called to implement sqlite3_wal_checkpoint() and
** related interfaces.
**
@@ -3894,7 +3894,7 @@ int sqlite3WalCheckpoint(
sqlite3WalDb(pWal, db);
(void)walEnableBlocking(pWal);
/* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive
/* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive
** "checkpoint" lock on the database file.
** EVIDENCE-OF: R-10421-19736 If any other process is running a
** checkpoint operation at the same time, the lock cannot be obtained and
@@ -3957,7 +3957,7 @@ int sqlite3WalCheckpoint(
}
if( isChanged ){
/* If a new wal-index header was loaded before the checkpoint was
/* If a new wal-index header was loaded before the checkpoint was
** performed, then the pager-cache associated with pWal is now
** out of date. So zero the cached wal-index header to ensure that
** next time the pager opens a snapshot on this database it knows that
@@ -4008,7 +4008,7 @@ int sqlite3WalCallback(Wal *pWal){
** operation must occur while the pager is still holding the exclusive
** lock on the main database file.
**
** If op is one, then change from locking_mode=NORMAL into
** If op is one, then change from locking_mode=NORMAL into
** locking_mode=EXCLUSIVE. This means that the pWal->readLock must
** be released. Return 1 if the transition is made and 0 if the
** WAL is already in exclusive-locking mode - meaning that this
@@ -4025,8 +4025,8 @@ int sqlite3WalExclusiveMode(Wal *pWal, int op){
assert( pWal->writeLock==0 );
assert( pWal->exclusiveMode!=WAL_HEAPMEMORY_MODE || op==-1 );
/* pWal->readLock is usually set, but might be -1 if there was a
** prior error while attempting to acquire are read-lock. This cannot
/* pWal->readLock is usually set, but might be -1 if there was a
** prior error while attempting to acquire are read-lock. This cannot
** happen if the connection is actually in exclusive mode (as no xShmLock
** locks are taken in this case). Nor should the pager attempt to
** upgrade to exclusive-mode following such an error.
@@ -4057,10 +4057,10 @@ int sqlite3WalExclusiveMode(Wal *pWal, int op){
return rc;
}
/*
/*
** Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the
** WAL module is using shared-memory, return false.
** WAL module is using shared-memory, return false.
*/
int sqlite3WalHeapMemory(Wal *pWal){
return (pWal && pWal->exclusiveMode==WAL_HEAPMEMORY_MODE );
@@ -4096,13 +4096,13 @@ int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot){
/* Try to open on pSnapshot when the next read-transaction starts
*/
void sqlite3WalSnapshotOpen(
Wal *pWal,
Wal *pWal,
sqlite3_snapshot *pSnapshot
){
pWal->pSnapshot = (WalIndexHdr*)pSnapshot;
}
/*
/*
** Return a +ve value if snapshot p1 is newer than p2. A -ve value if
** p1 is older than p2 and zero if p1 and p2 are the same snapshot.
*/
@@ -4122,7 +4122,7 @@ int sqlite3_snapshot_cmp(sqlite3_snapshot *p1, sqlite3_snapshot *p2){
/*
** The caller currently has a read transaction open on the database.
** This function takes a SHARED lock on the CHECKPOINTER slot and then
** checks if the snapshot passed as the second argument is still
** checks if the snapshot passed as the second argument is still
** available. If so, SQLITE_OK is returned.
**
** If the snapshot is not available, SQLITE_ERROR is returned. Or, if