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Change the interface to internal function walGetHash() to make it easier to follow.

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FossilOrigin-Name: 5e8e2e978ea48ce4ad93a936c838934f33d665df
This commit is contained in:
dan
2010-06-14 11:18:50 +00:00
parent 067f3165d8
commit d60bf11036
3 changed files with 23 additions and 26 deletions
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35
src/wal.c
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@@ -749,9 +749,8 @@ static int walNextHash(int iPriorHash){
** slot in the hash table is set to N, it refers to frame number
** (*piZero+N) in the log.
**
** Finally, set *paPgno such that for all frames F between (*piZero+1) and
** (*piZero+HASHTABLE_NPAGE), (*paPgno)[F] is the database page number
** associated with frame F.
** Finally, set *paPgno so that *paPgno[1] is the page number of the
** first frame indexed by the hash table, frame (*piZero+1).
*/
static int walHashGet(
Wal *pWal, /* WAL handle */
@@ -772,14 +771,13 @@ static int walHashGet(
aHash = (volatile ht_slot *)&aPgno[HASHTABLE_NPAGE];
if( iHash==0 ){
aPgno = &aPgno[WALINDEX_HDR_SIZE/sizeof(u32)-1];
aPgno = &aPgno[WALINDEX_HDR_SIZE/sizeof(u32)];
iZero = 0;
}else{
iZero = HASHTABLE_NPAGE_ONE + (iHash-1)*HASHTABLE_NPAGE;
aPgno = &aPgno[-1*iZero-1];
}
*paPgno = aPgno;
*paPgno = &aPgno[-1];
*paHash = aHash;
*piZero = iZero;
}
@@ -863,8 +861,8 @@ static void walCleanupHash(Wal *pWal){
/* Zero the entries in the aPgno array that correspond to frames with
** frame numbers greater than pWal->hdr.mxFrame.
*/
nByte = ((char *)aHash - (char *)&aPgno[pWal->hdr.mxFrame+1]);
memset((void *)&aPgno[pWal->hdr.mxFrame+1], 0, nByte);
nByte = ((char *)aHash - (char *)&aPgno[iLimit+1]);
memset((void *)&aPgno[iLimit+1], 0, nByte);
#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
/* Verify that the every entry in the mapping region is still reachable
@@ -874,7 +872,7 @@ static void walCleanupHash(Wal *pWal){
int i; /* Loop counter */
int iKey; /* Hash key */
for(i=1; i<=iLimit; i++){
for(iKey=walHash(aPgno[i+iZero]); aHash[iKey]; iKey=walNextHash(iKey)){
for(iKey=walHash(aPgno[i]); aHash[iKey]; iKey=walNextHash(iKey)){
if( aHash[iKey]==i ) break;
}
assert( aHash[iKey]==i );
@@ -911,8 +909,8 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
** entire hash table and aPgno[] array before proceding.
*/
if( idx==1 ){
int nByte = (u8 *)&aHash[HASHTABLE_NSLOT] - (u8 *)&aPgno[1+iZero];
memset((void*)&aPgno[1+iZero], 0, nByte);
int nByte = (u8 *)&aHash[HASHTABLE_NSLOT] - (u8 *)&aPgno[1];
memset((void*)&aPgno[1], 0, nByte);
}
/* If the entry in aPgno[] is already set, then the previous writer
@@ -921,16 +919,16 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
** Remove the remnants of that writers uncommitted transaction from
** the hash-table before writing any new entries.
*/
if( aPgno[iFrame] ){
if( aPgno[idx] ){
walCleanupHash(pWal);
assert( !aPgno[iFrame] );
assert( !aPgno[idx] );
}
/* Write the aPgno[] array entry and the hash-table slot. */
for(iKey=walHash(iPage); aHash[iKey]; iKey=walNextHash(iKey)){
assert( nCollide++ < idx );
}
aPgno[iFrame] = iPage;
aPgno[idx] = iPage;
aHash[iKey] = idx;
#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
@@ -952,7 +950,7 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
if( (idx&0x3ff)==0 ){
int i; /* Loop counter */
for(i=1; i<=idx; i++){
for(iKey=walHash(aPgno[i+iZero]); aHash[iKey]; iKey=walNextHash(iKey)){
for(iKey=walHash(aPgno[i]); aHash[iKey]; iKey=walNextHash(iKey)){
if( aHash[iKey]==i ) break;
}
assert( aHash[iKey]==i );
@@ -1353,10 +1351,9 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
walIteratorFree(p);
return rc;
}
nEntry = ((i+1)==nSegment)?iLast-iZero:(u32 *)aHash-(u32 *)&aPgno[iZero+1];
aPgno++;
nEntry = ((i+1)==nSegment)?iLast-iZero:(u32 *)aHash-(u32 *)aPgno;
iZero++;
aPgno += iZero;
for(j=0; j<nEntry; j++){
aSpace[j] = j;
@@ -1965,7 +1962,7 @@ int sqlite3WalRead(
}
for(iKey=walHash(pgno); aHash[iKey]; iKey=walNextHash(iKey)){
u32 iFrame = aHash[iKey] + iZero;
if( iFrame<=iLast && aPgno[iFrame]==pgno ){
if( iFrame<=iLast && aPgno[aHash[iKey]]==pgno ){
assert( iFrame>iRead );
iRead = iFrame;
}