database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-05 15:55:57 +03:00
Code Activity

Streamline the decodeFlags() routine in btree.c for a small performance

Browse Source 
increase.

FossilOrigin-Name: 4cb285210b4a2b14c80962bf2ecb35be310d3444c329c15d86b3073096455704
This commit is contained in:
drh
2022-11-19 13:09:03 +00:00
parent 27a67968af
commit bf9b994f52
3 changed files with 53 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
src/btree.c
View File

@@ -1900,62 +1900,67 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
** Only the following combinations are supported. Anything different
** indicates a corrupt database files:
**
** PTF_ZERODATA
** PTF_ZERODATA | PTF_LEAF
** PTF_LEAFDATA | PTF_INTKEY
** PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF
** PTF_ZERODATA (0x02, 2)
** PTF_LEAFDATA | PTF_INTKEY (0x05, 5)
** PTF_ZERODATA | PTF_LEAF (0x0a, 10)
** PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF (0x0d, 13)
*/
static int decodeFlags(MemPage *pPage, int flagByte){
BtShared *pBt; /* A copy of pPage->pBt */
assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
pPage->leaf = (u8)(flagByte>>3); assert( PTF_LEAF == 1<<3 );
flagByte &= ~PTF_LEAF;
pPage->childPtrSize = 4-4*pPage->leaf;
pBt = pPage->pBt;
if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
/* EVIDENCE-OF: R-07291-35328 A value of 5 (0x05) means the page is an
** interior table b-tree page. */
assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
/* EVIDENCE-OF: R-26900-09176 A value of 13 (0x0d) means the page is a
** leaf table b-tree page. */
assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
pPage->intKey = 1;
if( pPage->leaf ){
pPage->max1bytePayload = pBt->max1bytePayload;
if( flagByte>=(PTF_ZERODATA | PTF_LEAF) ){
pPage->childPtrSize = 0;
pPage->leaf = 1;
if( flagByte==(PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF) ){
pPage->intKeyLeaf = 1;
pPage->xCellSize = cellSizePtrTableLeaf;
pPage->xParseCell = btreeParseCellPtr;
pPage->intKey = 1;
pPage->maxLocal = pBt->maxLeaf;
pPage->minLocal = pBt->minLeaf;
}else if( flagByte==(PTF_ZERODATA | PTF_LEAF) ){
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtr;
pPage->xParseCell = btreeParseCellPtrIndex;
pPage->maxLocal = pBt->maxLocal;
pPage->minLocal = pBt->minLocal;
}else{
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtr;
pPage->xParseCell = btreeParseCellPtrIndex;
return SQLITE_CORRUPT_PAGE(pPage);
}
}else{
pPage->childPtrSize = 4;
pPage->leaf = 0;
if( flagByte==(PTF_ZERODATA) ){
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtr;
pPage->xParseCell = btreeParseCellPtrIndex;
pPage->maxLocal = pBt->maxLocal;
pPage->minLocal = pBt->minLocal;
}else if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtrNoPayload;
pPage->xParseCell = btreeParseCellPtrNoPayload;
pPage->intKey = 1;
pPage->maxLocal = pBt->maxLeaf;
pPage->minLocal = pBt->minLeaf;
}else{
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtr;
pPage->xParseCell = btreeParseCellPtrIndex;
return SQLITE_CORRUPT_PAGE(pPage);
}
pPage->maxLocal = pBt->maxLeaf;
pPage->minLocal = pBt->minLeaf;
}else if( flagByte==PTF_ZERODATA ){
/* EVIDENCE-OF: R-43316-37308 A value of 2 (0x02) means the page is an
** interior index b-tree page. */
assert( (PTF_ZERODATA)==2 );
/* EVIDENCE-OF: R-59615-42828 A value of 10 (0x0a) means the page is a
** leaf index b-tree page. */
assert( (PTF_ZERODATA|PTF_LEAF)==10 );
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtr;
pPage->xParseCell = btreeParseCellPtrIndex;
pPage->maxLocal = pBt->maxLocal;
pPage->minLocal = pBt->minLocal;
}else{
/* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
** an error. */
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->xCellSize = cellSizePtr;
pPage->xParseCell = btreeParseCellPtrIndex;
return SQLITE_CORRUPT_PAGE(pPage);
}
pPage->max1bytePayload = pBt->max1bytePayload;
return SQLITE_OK;
}