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If replace triggers are run during uniqueness checking, then rerun all

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uniqueness checks a second time using the ABORT algorithm.
Fix for ticket [c1e19e12046d23fe]

FossilOrigin-Name: fbac0c65d8464b126d385262d176864add55452ec9e3d5eb76ffee06e820cb9c
This commit is contained in:
drh
2019-10-26 00:04:21 +00:00
parent db561bceda
commit a407eccb61
4 changed files with 154 additions and 30 deletions
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143
src/insert.c
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@@ -1319,6 +1319,13 @@ void sqlite3GenerateConstraintChecks(
int upsertJump = 0; /* Address of Goto that jumps into upsert subroutine */
int ipkTop = 0; /* Top of the IPK uniqueness check */
int ipkBottom = 0; /* OP_Goto at the end of the IPK uniqueness check */
/* Variables associated with retesting uniqueness constraints after
** replace triggers fire have run */
int regTrigCnt; /* Register used to count replace trigger invocations */
int addrRecheck = 0; /* Jump here to recheck all uniqueness constraints */
int lblRecheckOk = 0; /* Each recheck jumps to this label if it passes */
Trigger *pTrigger; /* List of DELETE triggers on the table pTab */
int nReplaceTrig = 0; /* Number of replace triggers coded */
isUpdate = regOldData!=0;
db = pParse->db;
@@ -1483,6 +1490,50 @@ void sqlite3GenerateConstraintChecks(
}
}
/* Determine if it is possible that triggers (either explicitly coded
** triggers or FK resolution actions) might run as a result of deletes
** that happen when OE_Replace conflict resolution occurs. (Call these
** "replace triggers".) If any replace triggers run, we will need to
** recheck all of the uniqueness constraints after they have all run.
** But on the recheck, the resolution is OE_Abort instead of OE_Replace.
**
** If replace triggers are a possibility, then
**
** (1) Allocate register regTrigCnt and initialize it to zero.
** That register will count the number of replace triggers that
** fire. Constraint recheck only occurs if the number if positive.
** (2) Initialize pTrigger to the set of all DELETE triggers.
** (3) Initialize addrRecheck and lblRecheckOk
**
** The uniqueness rechecking code will create a series of tests to run
** in a second pass. The addrRecheck and lblRecheckOk variables are
** used to link together these tests which are separated from each other
** in the generate bytecode.
*/
if( (db->flags & (SQLITE_RecTriggers|SQLITE_ForeignKeys))==0 ){
/* There are not DELETE triggers nor FK constraints. No constraint
** rechecks are needed. */
pTrigger = 0;
regTrigCnt = 0;
}else{
if( db->flags&SQLITE_RecTriggers ){
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
regTrigCnt = pTrigger!=0 || sqlite3FkRequired(pParse, pTab, 0, 0);
}else{
pTrigger = 0;
regTrigCnt = sqlite3FkRequired(pParse, pTab, 0, 0);
}
if( regTrigCnt ){
/* Replace triggers might exist. Allocate the counter and
** initialize it to zero. */
regTrigCnt = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regTrigCnt);
VdbeComment((v, "trigger count"));
lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
addrRecheck = lblRecheckOk;
}
}
/* If rowid is changing, make sure the new rowid does not previously
** exist in the table.
*/
@@ -1572,17 +1623,12 @@ void sqlite3GenerateConstraintChecks(
** to run without a statement journal if there are no indexes on the
** table.
*/
Trigger *pTrigger = 0;
if( db->flags&SQLITE_RecTriggers ){
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
}
if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
if( regTrigCnt ){
sqlite3MultiWrite(pParse);
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
regNewData, 1, 0, OE_Replace, 1, -1);
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);
VdbeCoverage(v);
sqlite3RowidConstraint(pParse, OE_Abort, pTab);
sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
nReplaceTrig++;
}else{
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
assert( HasRowid(pTab) );
@@ -1632,6 +1678,7 @@ void sqlite3GenerateConstraintChecks(
int regR; /* Range of registers holding conflicting PK */
int iThisCur; /* Cursor for this UNIQUE index */
int addrUniqueOk; /* Jump here if the UNIQUE constraint is satisfied */
int addrConflictCk; /* First opcode in the conflict check logic */
if( aRegIdx[ix]==0 ) continue; /* Skip indices that do not change */
if( pUpIdx==pIdx ){
@@ -1745,8 +1792,9 @@ void sqlite3GenerateConstraintChecks(
/* Check to see if the new index entry will be unique */
sqlite3VdbeVerifyAbortable(v, onError);
sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
regIdx, pIdx->nKeyCol); VdbeCoverage(v);
addrConflictCk =
sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
regIdx, pIdx->nKeyCol); VdbeCoverage(v);
/* Generate code to handle collisions */
regR = (pIdx==pPk) ? regIdx : sqlite3GetTempRange(pParse, nPkField);
@@ -1829,23 +1877,59 @@ void sqlite3GenerateConstraintChecks(
break;
}
default: {
Trigger *pTrigger = 0;
int bRetryConstraintCheck = 0;
int nConflictCk; /* Number of opcodes in conflict check logic */
assert( onError==OE_Replace );
if( db->flags&SQLITE_RecTriggers ){
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
}
if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
nConflictCk = sqlite3VdbeCurrentAddr(v) - addrConflictCk;
if( regTrigCnt ){
sqlite3MultiWrite(pParse);
bRetryConstraintCheck = 1;
nReplaceTrig++;
}
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
regR, nPkField, 0, OE_Replace,
(pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
if( bRetryConstraintCheck ){
sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
regIdx, pIdx->nKeyCol); VdbeCoverage(v);
if( regTrigCnt ){
VdbeOp *pOp; /* Conflict check opcode to copy */
int p2; /* New P2 value for copied conflict check opcode */
int addrBypass; /* Jump destination to bypass recheck logic */
sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
addrBypass = sqlite3VdbeAddOp0(v, OP_Goto); /* Bypass recheck */
VdbeComment((v, "bypass recheck"));
/* Here we insert code that will be invoked after all constraint
** checks have run, if and only if one or more replace triggers
** fired. */
sqlite3VdbeResolveLabel(v, lblRecheckOk);
lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
if( pIdx->pPartIdxWhere ){
/* Bypass the recheck if this partial index is not defined
** for the current row */
sqlite3VdbeAddOp2(v, OP_IsNull, regIdx, lblRecheckOk);
VdbeCoverage(v);
}
/* Copy the constraint check code from above, except change
** the constraint-ok jump destination to be the address of
** the next retest block */
pOp = sqlite3VdbeGetOp(v, addrConflictCk);
while( nConflictCk>0 && !db->mallocFailed ){
if( sqlite3OpcodeProperty[pOp->opcode]&OPFLG_JUMP ){
p2 = lblRecheckOk;
}else{
p2 = pOp->p2;
}
if( pOp->opcode!=OP_IdxRowid ){
sqlite3VdbeAddOp4(v, pOp->opcode, pOp->p1, p2, pOp->p3,
pOp->p4.z, pOp->p4type);
sqlite3VdbeChangeP5(v, pOp->p5);
}
nConflictCk--;
pOp++;
}
/* If the retest fails, issue an abort */
sqlite3UniqueConstraint(pParse, OE_Abort, pIdx);
sqlite3VdbeJumpHere(v, addrBypass); /* Terminate the recheck bypass */
}
seenReplace = 1;
break;
@@ -1867,6 +1951,25 @@ void sqlite3GenerateConstraintChecks(
sqlite3VdbeJumpHere(v, ipkBottom);
}
/* Recheck all uniqueness constraints after replace triggers have run */
testcase( regTrigCnt!=0 && nReplaceTrig==0 );
if( nReplaceTrig ){
sqlite3VdbeAddOp2(v, OP_IfNot, regTrigCnt, lblRecheckOk);VdbeCoverage(v);
if( !pPk ){
if( isUpdate ){
sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRecheck, regOldData);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
VdbeCoverage(v);
}
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRecheck, regNewData);
VdbeCoverage(v);
sqlite3RowidConstraint(pParse, OE_Abort, pTab);
}else{
sqlite3VdbeGoto(v, addrRecheck);
}
sqlite3VdbeResolveLabel(v, lblRecheckOk);
}
/* Generate the table record */
if( HasRowid(pTab) ){
int regRec = aRegIdx[ix];