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A partial fix for ticket #3292. This fixes the original problem but there

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are other similar problems lurking in the code still. (CVS 5561)

FossilOrigin-Name: 055f173ab1b6fb657bf817faa3a37335d8fa60d5
This commit is contained in:
drh
2008-08-13 14:07:40 +00:00
parent ec444fc163
commit ec1fc80ca3
9 changed files with 157 additions and 71 deletions
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65
src/vdbeaux.c
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@@ -14,7 +14,7 @@
** to version 2.8.7, all this code was combined into the vdbe.c source file.
** But that file was getting too big so this subroutines were split out.
**
** $Id: vdbeaux.c,v 1.405 2008/08/02 03:50:39 drh Exp $
** $Id: vdbeaux.c,v 1.406 2008/08/13 14:07:41 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -2274,18 +2274,32 @@ void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord *p){
** sqlite3VdbeParseRecord.
**
** Key1 and Key2 do not have to contain the same number of fields.
** But if the lengths differ, Key2 must be the shorter of the two.
** The key with fewer fields is usually considered lessor than the
** longer. However if pPKey2->pKeyInfo->incrKey is set and
** the common prefixes are equal, then key1 is less than key2.
** Or if pPKey2->pKeyInfo->ckPrefixOnly flag is set and the
** prefixes are equal, then the keys are considered to be equal and
** the parts beyond the common prefix are ignored.
**
** The last nHdrIgnore1 bytes of the header of pKey1 are ignored,
** as if they do not exist. Usually nHdrIgnore1 is 0 which means
** that we look at the entire key. But sometimes nHdrIgnore1 is 1.
** When nHdrIgnore1 is 1, the keys are index records and so the last
** column is a rowid. The type code is always one byte in length.
** Hence, setting nHdrIgnore1 to 1 means that the final rowid at the
** end of the record should be treated as if it does not exist.
**
** Historical note: In earlier versions of this routine both Key1
** and Key2 were blobs obtained from OP_MakeRecord. But we found
** that in typical use the same Key2 would be submitted multiple times
** in a row. So an optimization was added to parse the Key2 key
** separately and submit the parsed version. In this way, we avoid
** parsing the same Key2 multiple times in a row.
** parsing the same Key2 multiple times.
*/
int sqlite3VdbeRecordCompare(
int nKey1, const void *pKey1,
UnpackedRecord *pPKey2
int nKey1, const void *pKey1, /* Left key */
int nHdrIgnore1, /* Omit this much from end of key1 header */
UnpackedRecord *pPKey2 /* Right key */
){
u32 d1; /* Offset into aKey[] of next data element */
u32 idx1; /* Offset into aKey[] of next header element */
@@ -2305,6 +2319,7 @@ int sqlite3VdbeRecordCompare(
idx1 = getVarint32(aKey1, szHdr1);
d1 = szHdr1;
szHdr1 -= nHdrIgnore1;
nField = pKeyInfo->nField;
while( idx1<szHdr1 && i<pPKey2->nField ){
u32 serial_type1;
@@ -2328,17 +2343,21 @@ int sqlite3VdbeRecordCompare(
}
if( mem1.zMalloc ) sqlite3VdbeMemRelease(&mem1);
/* One of the keys ran out of fields, but all the fields up to that point
** were equal. If the incrKey flag is true, then the second key is
** treated as larger.
*/
if( rc==0 ){
/* rc==0 here means that one of the keys ran out of fields and
** all the fields up to that point were equal. If the incrKey
** flag is true, then break the tie by treating the second key
** as larger. If ckPrefixOnly is true, then keys with common prefixes
** are considered to be equal. Otherwise, the longer key is the
** larger. As it happens, the pPKey2 will always be the longer
** if there is a difference.
*/
if( pKeyInfo->incrKey ){
rc = -1;
}else if( !pKeyInfo->prefixIsEqual ){
if( d1<nKey1 ){
rc = 1;
}
}else if( pKeyInfo->ckPrefixOnly ){
/* Leave rc==0 */
}else if( idx1<szHdr1 ){
rc = 1;
}
}else if( pKeyInfo->aSortOrder && i<pKeyInfo->nField
&& pKeyInfo->aSortOrder[i] ){
@@ -2347,7 +2366,7 @@ int sqlite3VdbeRecordCompare(
return rc;
}
/*
** The argument is an index entry composed using the OP_MakeRecord opcode.
** The last entry in this record should be an integer (specifically
@@ -2366,7 +2385,7 @@ int sqlite3VdbeIdxRowidLen(const u8 *aKey, int nKey, int *pRowidLen){
*pRowidLen = sqlite3VdbeSerialTypeLen(typeRowid);
return SQLITE_OK;
}
/*
** pCur points at an index entry created using the OP_MakeRecord opcode.
@@ -2409,18 +2428,21 @@ int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
**
** pKey is either created without a rowid or is truncated so that it
** omits the rowid at the end. The rowid at the end of the index entry
** is ignored as well.
** is ignored as well. Hence, this routine only compares the prefixes
** of the keys prior to the final rowid, not the entire key.
**
** pUnpacked may be an unpacked version of pKey,nKey. If pUnpacked is
** supplied it is used in place of pKey,nKey.
*/
int sqlite3VdbeIdxKeyCompare(
Cursor *pC, /* The cursor to compare against */
UnpackedRecord *pUnpacked,
UnpackedRecord *pUnpacked, /* Unpacked version of pKey and nKey */
int nKey, const u8 *pKey, /* The key to compare */
int *res /* Write the comparison result here */
){
i64 nCellKey = 0;
int rc;
BtCursor *pCur = pC->pCursor;
int lenRowid;
Mem m;
UnpackedRecord *pRec;
char zSpace[200];
@@ -2433,9 +2455,8 @@ int sqlite3VdbeIdxKeyCompare(
m.db = 0;
m.flags = 0;
m.zMalloc = 0;
if( (rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, nCellKey, 1, &m))
|| (rc = sqlite3VdbeIdxRowidLen((u8*)m.z, m.n, &lenRowid))
){
rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, nCellKey, 1, &m);
if( rc ){
return rc;
}
if( !pUnpacked ){
@@ -2447,7 +2468,7 @@ int sqlite3VdbeIdxKeyCompare(
if( pRec==0 ){
return SQLITE_NOMEM;
}
*res = sqlite3VdbeRecordCompare(m.n-lenRowid, m.z, pRec);
*res = sqlite3VdbeRecordCompare(m.n, m.z, 1, pRec);
if( !pUnpacked ){
sqlite3VdbeDeleteUnpackedRecord(pRec);
}