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Refactoring some variable names in wal.c.

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FossilOrigin-Name: 1d201ff51f7c5ecdf71a91ed25204b7130894282
This commit is contained in:
drh
2010-05-19 17:49:50 +00:00
parent 027a128a78
commit 6e81096fa2
3 changed files with 48 additions and 48 deletions
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76
src/wal.c
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@@ -187,12 +187,12 @@ typedef struct WalIterator WalIterator;
** is currently empty.
*/
struct WalIndexHdr {
u32 iChange; /* Counter incremented each transaction */
u32 pgsz; /* Database page size in bytes */
u32 mxFrame; /* Index of last valid frame in the WAL */
u32 nPage; /* Size of database in pages */
u32 iCheck1; /* Checkpoint value 1 */
u32 iCheck2; /* Checkpoint value 2 */
u32 iChange; /* Counter incremented each transaction */
u32 szPage; /* Database page size in bytes */
u32 mxFrame; /* Index of last valid frame in the WAL */
u32 nPage; /* Size of database in pages */
u32 iCheck1; /* Checksum value 1 */
u32 iCheck2; /* Checksum value 2 */
};
/* Size of serialized WalIndexHdr object. */
@@ -214,11 +214,11 @@ struct WalIndexHdr {
/*
** Return the offset of frame iFrame in the write-ahead log file,
** assuming a database page size of pgsz bytes. The offset returned
** assuming a database page size of szPage bytes. The offset returned
** is to the start of the write-ahead log frame-header.
*/
#define walFrameOffset(iFrame, pgsz) ( \
WAL_HDRSIZE + ((iFrame)-1)*((pgsz)+WAL_FRAME_HDRSIZE) \
#define walFrameOffset(iFrame, szPage) ( \
WAL_HDRSIZE + ((iFrame)-1)*((szPage)+WAL_FRAME_HDRSIZE) \
)
/*
@@ -649,7 +649,7 @@ static int walIndexRecover(Wal *pWal){
u8 *aData; /* Pointer to data part of aFrame buffer */
int iFrame; /* Index of last frame read */
i64 iOffset; /* Next offset to read from log file */
int nPgsz; /* Page size according to the log */
int szPage; /* Page size according to the log */
u32 aCksum[2]; /* Running checksum */
/* Read in the first frame header in the file (to determine the
@@ -661,17 +661,17 @@ 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 log file contains no valid data.
** SQLITE_MAX_PAGE_SIZE, conclude that the WAL file contains no valid data.
*/
nPgsz = sqlite3Get4byte(&aBuf[0]);
if( nPgsz&(nPgsz-1) || nPgsz>SQLITE_MAX_PAGE_SIZE || nPgsz<512 ){
szPage = sqlite3Get4byte(&aBuf[0]);
if( szPage&(szPage-1) || szPage>SQLITE_MAX_PAGE_SIZE || szPage<512 ){
goto finished;
}
aCksum[0] = sqlite3Get4byte(&aBuf[4]);
aCksum[1] = sqlite3Get4byte(&aBuf[8]);
/* Malloc a buffer to read frames into. */
nFrame = nPgsz + WAL_FRAME_HDRSIZE;
nFrame = szPage + WAL_FRAME_HDRSIZE;
aFrame = (u8 *)sqlite3_malloc(nFrame);
if( !aFrame ){
return SQLITE_NOMEM;
@@ -688,7 +688,7 @@ static int walIndexRecover(Wal *pWal){
/* Read and decode the next log frame. */
rc = sqlite3OsRead(pWal->pWalFd, aFrame, nFrame, iOffset);
if( rc!=SQLITE_OK ) break;
isValid = walDecodeFrame(aCksum, &pgno, &nTruncate, nPgsz, aData, aFrame);
isValid = walDecodeFrame(aCksum, &pgno, &nTruncate, szPage, aData, aFrame);
if( !isValid ) break;
rc = walIndexAppend(pWal, ++iFrame, pgno);
if( rc!=SQLITE_OK ) break;
@@ -699,7 +699,7 @@ static int walIndexRecover(Wal *pWal){
hdr.iCheck2 = aCksum[1];
hdr.mxFrame = iFrame;
hdr.nPage = nTruncate;
hdr.pgsz = nPgsz;
hdr.szPage = szPage;
}
}
@@ -985,7 +985,7 @@ static int walCheckpoint(
u8 *zBuf /* Temporary buffer to use */
){
int rc; /* Return code */
int pgsz = pWal->hdr.pgsz; /* Database page-size */
int szPage = pWal->hdr.szPage; /* Database page-size */
WalIterator *pIter = 0; /* Wal iterator context */
u32 iDbpage = 0; /* Next database page to write */
u32 iFrame = 0; /* Wal frame containing data for iDbpage */
@@ -996,7 +996,7 @@ static int walCheckpoint(
goto out;
}
if( pWal->hdr.pgsz!=nBuf ){
if( pWal->hdr.szPage!=nBuf ){
rc = SQLITE_CORRUPT_BKPT;
goto out;
}
@@ -1009,16 +1009,16 @@ static int walCheckpoint(
/* Iterate through the contents of the log, copying data to the db file. */
while( 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
rc = sqlite3OsRead(pWal->pWalFd, zBuf, pgsz,
walFrameOffset(iFrame, pgsz) + WAL_FRAME_HDRSIZE
rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage,
walFrameOffset(iFrame, szPage) + WAL_FRAME_HDRSIZE
);
if( rc!=SQLITE_OK ) goto out;
rc = sqlite3OsWrite(pWal->pDbFd, zBuf, pgsz, (iDbpage-1)*pgsz);
rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, (iDbpage-1)*szPage);
if( rc!=SQLITE_OK ) goto out;
}
/* Truncate the database file */
rc = sqlite3OsTruncate(pWal->pDbFd, ((i64)pWal->hdr.nPage*(i64)pgsz));
rc = sqlite3OsTruncate(pWal->pDbFd, ((i64)pWal->hdr.nPage*(i64)szPage));
if( rc!=SQLITE_OK ) goto out;
/* Sync the database file. If successful, update the wal-index. */
@@ -1308,7 +1308,7 @@ int sqlite3WalRead(
**
** This code may run concurrently to the code in walIndexAppend()
** that adds entries to the wal-index (and possibly to this hash
** table). This means the non-zero value just read from the 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 -
@@ -1331,17 +1331,17 @@ int sqlite3WalRead(
** This filters out a dangerous class of garbage data. The
** garbage hash slot may refer to a frame with the correct page
** number, but not the most recent version of the frame. For
** example, if at the start of the read-transaction the log
** example, if at the start of the read-transaction the WAL
** contains three copies of the desired page in frames 2, 3 and 4,
** the hash table may contain the following:
**
** { ..., 2, 3, 4, 0, 0, ..... }
** { ..., 2, 3, 4, 99, 99, ..... }
**
** The correct answer is to read data from frame 4. But a
** dirty-read may potentially cause the hash-table to appear as
** follows to the reader:
**
** { ..., 2, 3, 4, 3, 0, ..... }
** { ..., 2, 3, 4, 3, 99, ..... }
**
** Without this part of the if(...) clause, the reader might
** incorrectly read data from frame 3 instead of 4. This would be
@@ -1391,7 +1391,7 @@ int sqlite3WalRead(
*/
walIndexUnmap(pWal);
if( iRead ){
i64 iOffset = walFrameOffset(iRead, pWal->hdr.pgsz) + WAL_FRAME_HDRSIZE;
i64 iOffset = walFrameOffset(iRead, pWal->hdr.szPage) + WAL_FRAME_HDRSIZE;
*pInWal = 1;
return sqlite3OsRead(pWal->pWalFd, pOut, nOut, iOffset);
}
@@ -1491,7 +1491,7 @@ int sqlite3WalSavepointUndo(Wal *pWal, u32 iFrame){
pWal->hdr.mxFrame = iFrame;
if( iFrame>0 ){
i64 iOffset = walFrameOffset(iFrame, pWal->hdr.pgsz) + sizeof(u32)*2;
i64 iOffset = walFrameOffset(iFrame, pWal->hdr.szPage) + sizeof(u32)*2;
rc = sqlite3OsRead(pWal->pWalFd, aCksum, sizeof(aCksum), iOffset);
pWal->hdr.iCheck1 = sqlite3Get4byte(&aCksum[0]);
pWal->hdr.iCheck2 = sqlite3Get4byte(&aCksum[4]);
@@ -1506,7 +1506,7 @@ int sqlite3WalSavepointUndo(Wal *pWal, u32 iFrame){
*/
int sqlite3WalFrames(
Wal *pWal, /* Wal handle to write to */
int nPgsz, /* Database page-size in bytes */
int szPage, /* Database page-size in bytes */
PgHdr *pList, /* List of dirty pages to write */
Pgno nTruncate, /* Database size after this commit */
int isCommit, /* True if this is a commit */
@@ -1532,7 +1532,7 @@ int sqlite3WalFrames(
assert( WAL_FRAME_HDRSIZE>=WAL_HDRSIZE );
iFrame = pWal->hdr.mxFrame;
if( iFrame==0 ){
sqlite3Put4byte(aFrame, nPgsz);
sqlite3Put4byte(aFrame, szPage);
sqlite3_randomness(8, &aFrame[4]);
pWal->hdr.iCheck1 = sqlite3Get4byte(&aFrame[4]);
pWal->hdr.iCheck2 = sqlite3Get4byte(&aFrame[8]);
@@ -1550,18 +1550,18 @@ int sqlite3WalFrames(
u32 nDbsize; /* Db-size field for frame header */
i64 iOffset; /* Write offset in log file */
iOffset = walFrameOffset(++iFrame, nPgsz);
iOffset = walFrameOffset(++iFrame, szPage);
/* Populate and write the frame header */
nDbsize = (isCommit && p->pDirty==0) ? nTruncate : 0;
walEncodeFrame(aCksum, p->pgno, nDbsize, nPgsz, p->pData, aFrame);
walEncodeFrame(aCksum, p->pgno, nDbsize, szPage, p->pData, aFrame);
rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOffset);
if( rc!=SQLITE_OK ){
return rc;
}
/* Write the page data */
rc = sqlite3OsWrite(pWal->pWalFd, p->pData, nPgsz, iOffset+sizeof(aFrame));
rc = sqlite3OsWrite(pWal->pWalFd, p->pData, szPage, iOffset+sizeof(aFrame));
if( rc!=SQLITE_OK ){
return rc;
}
@@ -1571,26 +1571,26 @@ int sqlite3WalFrames(
/* Sync the log file if the 'isSync' flag was specified. */
if( sync_flags ){
i64 iSegment = sqlite3OsSectorSize(pWal->pWalFd);
i64 iOffset = walFrameOffset(iFrame+1, nPgsz);
i64 iOffset = walFrameOffset(iFrame+1, szPage);
assert( isCommit );
assert( iSegment>0 );
iSegment = (((iOffset+iSegment-1)/iSegment) * iSegment);
while( iOffset<iSegment ){
walEncodeFrame(aCksum,pLast->pgno,nTruncate,nPgsz,pLast->pData,aFrame);
walEncodeFrame(aCksum,pLast->pgno,nTruncate,szPage,pLast->pData,aFrame);
rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOffset);
if( rc!=SQLITE_OK ){
return rc;
}
iOffset += WAL_FRAME_HDRSIZE;
rc = sqlite3OsWrite(pWal->pWalFd, pLast->pData, nPgsz, iOffset);
rc = sqlite3OsWrite(pWal->pWalFd, pLast->pData, szPage, iOffset);
if( rc!=SQLITE_OK ){
return rc;
}
nLast++;
iOffset += nPgsz;
iOffset += szPage;
}
rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
@@ -1615,7 +1615,7 @@ int sqlite3WalFrames(
if( rc==SQLITE_OK ){
/* Update the private copy of the header. */
pWal->hdr.pgsz = nPgsz;
pWal->hdr.szPage = szPage;
pWal->hdr.mxFrame = iFrame;
if( isCommit ){
pWal->hdr.iChange++;