diff options
Diffstat (limited to 'src/vdbeapi.c')
| -rw-r--r-- | src/vdbeapi.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/src/vdbeapi.c b/src/vdbeapi.c index b29338eb3..6bc186e0b 100644 --- a/src/vdbeapi.c +++ b/src/vdbeapi.c @@ -1484,6 +1484,187 @@ int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){ return (int)v; } +#ifdef SQLITE_ENABLE_PREUPDATE_HOOK +/* +** Allocate and populate an UnpackedRecord structure based on the serialized +** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure +** if successful, or a NULL pointer if an OOM error is encountered. +*/ +static UnpackedRecord *vdbeUnpackRecord( + KeyInfo *pKeyInfo, + int nKey, + const void *pKey +){ + char *dummy; /* Dummy argument for AllocUnpackedRecord() */ + UnpackedRecord *pRet; /* Return value */ + + pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo, 0, 0, &dummy); + if( pRet ){ + memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nField+1)); + sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet); + } + return pRet; +} + +/* +** This function is called from within a pre-update callback to retrieve +** a field of the row currently being updated or deleted. +*/ +int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){ + PreUpdate *p = db->pPreUpdate; + int rc = SQLITE_OK; + + /* Test that this call is being made from within an SQLITE_DELETE or + ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */ + if( !p || p->op==SQLITE_INSERT ){ + rc = SQLITE_MISUSE_BKPT; + goto preupdate_old_out; + } + if( iIdx>=p->pCsr->nField || iIdx<0 ){ + rc = SQLITE_RANGE; + goto preupdate_old_out; + } + + /* If the old.* record has not yet been loaded into memory, do so now. */ + if( p->pUnpacked==0 ){ + u32 nRec; + u8 *aRec; + + rc = sqlite3BtreeDataSize(p->pCsr->pCursor, &nRec); + if( rc!=SQLITE_OK ) goto preupdate_old_out; + aRec = sqlite3DbMallocRaw(db, nRec); + if( !aRec ) goto preupdate_old_out; + rc = sqlite3BtreeData(p->pCsr->pCursor, 0, nRec, aRec); + if( rc==SQLITE_OK ){ + p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec); + if( !p->pUnpacked ) rc = SQLITE_NOMEM; + } + if( rc!=SQLITE_OK ){ + sqlite3DbFree(db, aRec); + goto preupdate_old_out; + } + p->aRecord = aRec; + } + + if( iIdx>=p->pUnpacked->nField ){ + *ppValue = (sqlite3_value *)columnNullValue(); + }else{ + *ppValue = &p->pUnpacked->aMem[iIdx]; + if( iIdx==p->iPKey ){ + sqlite3VdbeMemSetInt64(*ppValue, p->iKey1); + } + } + + preupdate_old_out: + sqlite3Error(db, rc); + return sqlite3ApiExit(db, rc); +} +#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */ + +#ifdef SQLITE_ENABLE_PREUPDATE_HOOK +/* +** This function is called from within a pre-update callback to retrieve +** the number of columns in the row being updated, deleted or inserted. +*/ +int sqlite3_preupdate_count(sqlite3 *db){ + PreUpdate *p = db->pPreUpdate; + return (p ? p->keyinfo.nField : 0); +} +#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */ + +#ifdef SQLITE_ENABLE_PREUPDATE_HOOK +/* +** This function is designed to be called from within a pre-update callback +** only. It returns zero if the change that caused the callback was made +** immediately by a user SQL statement. Or, if the change was made by a +** trigger program, it returns the number of trigger programs currently +** on the stack (1 for a top-level trigger, 2 for a trigger fired by a +** top-level trigger etc.). +** +** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL +** or SET DEFAULT action is considered a trigger. +*/ +int sqlite3_preupdate_depth(sqlite3 *db){ + PreUpdate *p = db->pPreUpdate; + return (p ? p->v->nFrame : 0); +} +#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */ + +#ifdef SQLITE_ENABLE_PREUPDATE_HOOK +/* +** This function is called from within a pre-update callback to retrieve +** a field of the row currently being updated or inserted. +*/ +int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){ + PreUpdate *p = db->pPreUpdate; + int rc = SQLITE_OK; + Mem *pMem; + + if( !p || p->op==SQLITE_DELETE ){ + rc = SQLITE_MISUSE_BKPT; + goto preupdate_new_out; + } + if( iIdx>=p->pCsr->nField || iIdx<0 ){ + rc = SQLITE_RANGE; + goto preupdate_new_out; + } + + if( p->op==SQLITE_INSERT ){ + /* For an INSERT, memory cell p->iNewReg contains the serialized record + ** that is being inserted. Deserialize it. */ + UnpackedRecord *pUnpack = p->pNewUnpacked; + if( !pUnpack ){ + Mem *pData = &p->v->aMem[p->iNewReg]; + rc = sqlite3VdbeMemExpandBlob(pData); + if( rc!=SQLITE_OK ) goto preupdate_new_out; + pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z); + if( !pUnpack ){ + rc = SQLITE_NOMEM; + goto preupdate_new_out; + } + p->pNewUnpacked = pUnpack; + } + if( iIdx>=pUnpack->nField ){ + pMem = (sqlite3_value *)columnNullValue(); + }else{ + pMem = &pUnpack->aMem[iIdx]; + if( iIdx==p->iPKey ){ + sqlite3VdbeMemSetInt64(pMem, p->iKey2); + } + } + }else{ + /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required + ** value. Make a copy of the cell contents and return a pointer to it. + ** It is not safe to return a pointer to the memory cell itself as the + ** caller may modify the value text encoding. + */ + assert( p->op==SQLITE_UPDATE ); + if( !p->aNew ){ + p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField); + if( !p->aNew ){ + rc = SQLITE_NOMEM; + goto preupdate_new_out; + } + } + assert( iIdx>=0 && iIdx<p->pCsr->nField ); + pMem = &p->aNew[iIdx]; + if( pMem->flags==0 ){ + if( iIdx==p->iPKey ){ + sqlite3VdbeMemSetInt64(pMem, p->iKey2); + }else{ + rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]); + if( rc!=SQLITE_OK ) goto preupdate_new_out; + } + } + } + *ppValue = pMem; + + preupdate_new_out: + sqlite3Error(db, rc); + return sqlite3ApiExit(db, rc); +} +#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */ + #ifdef SQLITE_ENABLE_STMT_SCANSTATUS /* ** Return status data for a single loop within query pStmt. |