diff options
Diffstat (limited to 'kopete/plugins/statistics/sqlite/delete.c')
| -rw-r--r-- | kopete/plugins/statistics/sqlite/delete.c | 419 |
1 files changed, 0 insertions, 419 deletions
diff --git a/kopete/plugins/statistics/sqlite/delete.c b/kopete/plugins/statistics/sqlite/delete.c deleted file mode 100644 index 866da61d..00000000 --- a/kopete/plugins/statistics/sqlite/delete.c +++ /dev/null @@ -1,419 +0,0 @@ -/* -** 2001 September 15 -** -** The author disclaims copyright to this source code. In place of -** a legal notice, here is a blessing: -** -** May you do good and not evil. -** May you find forgiveness for yourself and forgive others. -** May you share freely, never taking more than you give. -** -************************************************************************* -** This file contains C code routines that are called by the parser -** to handle DELETE FROM statements. -** -** $Id$ -*/ -#include "sqliteInt.h" - -/* -** Look up every table that is named in pSrc. If any table is not found, -** add an error message to pParse->zErrMsg and return NULL. If all tables -** are found, return a pointer to the last table. -*/ -Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){ - Table *pTab = 0; - int i; - struct SrcList_item *pItem; - for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){ - pTab = sqlite3LocateTable(pParse, pItem->zName, pItem->zDatabase); - pItem->pTab = pTab; - } - return pTab; -} - -/* -** Check to make sure the given table is writable. If it is not -** writable, generate an error message and return 1. If it is -** writable return 0; -*/ -int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){ - if( pTab->readOnly ){ - sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName); - return 1; - } - if( !viewOk && pTab->pSelect ){ - sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName); - return 1; - } - return 0; -} - -/* -** Generate code that will open a table for reading. -*/ -void sqlite3OpenTableForReading( - Vdbe *v, /* Generate code into this VDBE */ - int iCur, /* The cursor number of the table */ - Table *pTab /* The table to be opened */ -){ - sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0); - sqlite3VdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum); - VdbeComment((v, "# %s", pTab->zName)); - sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol); -} - - -/* -** Process a DELETE FROM statement. -*/ -void sqlite3DeleteFrom( - Parse *pParse, /* The parser context */ - SrcList *pTabList, /* The table from which we should delete things */ - Expr *pWhere /* The WHERE clause. May be null */ -){ - Vdbe *v; /* The virtual database engine */ - Table *pTab; /* The table from which records will be deleted */ - const char *zDb; /* Name of database holding pTab */ - int end, addr = 0; /* A couple addresses of generated code */ - int i; /* Loop counter */ - WhereInfo *pWInfo; /* Information about the WHERE clause */ - Index *pIdx; /* For looping over indices of the table */ - int iCur; /* VDBE Cursor number for pTab */ - sqlite3 *db; /* Main database structure */ - int isView; /* True if attempting to delete from a view */ - AuthContext sContext; /* Authorization context */ - - int row_triggers_exist = 0; /* True if any triggers exist */ - int before_triggers; /* True if there are BEFORE triggers */ - int after_triggers; /* True if there are AFTER triggers */ - int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */ - - sContext.pParse = 0; - if( pParse->nErr || sqlite3_malloc_failed ){ - pTabList = 0; - goto delete_from_cleanup; - } - db = pParse->db; - assert( pTabList->nSrc==1 ); - - /* Locate the table which we want to delete. This table has to be - ** put in an SrcList structure because some of the subroutines we - ** will be calling are designed to work with multiple tables and expect - ** an SrcList* parameter instead of just a Table* parameter. - */ - pTab = sqlite3SrcListLookup(pParse, pTabList); - if( pTab==0 ) goto delete_from_cleanup; - before_triggers = sqlite3TriggersExist(pParse, pTab->pTrigger, - TK_DELETE, TK_BEFORE, TK_ROW, 0); - after_triggers = sqlite3TriggersExist(pParse, pTab->pTrigger, - TK_DELETE, TK_AFTER, TK_ROW, 0); - row_triggers_exist = before_triggers || after_triggers; - isView = pTab->pSelect!=0; - if( sqlite3IsReadOnly(pParse, pTab, before_triggers) ){ - goto delete_from_cleanup; - } - assert( pTab->iDb<db->nDb ); - zDb = db->aDb[pTab->iDb].zName; - if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){ - goto delete_from_cleanup; - } - - /* If pTab is really a view, make sure it has been initialized. - */ - if( isView && sqlite3ViewGetColumnNames(pParse, pTab) ){ - goto delete_from_cleanup; - } - - /* Allocate a cursor used to store the old.* data for a trigger. - */ - if( row_triggers_exist ){ - oldIdx = pParse->nTab++; - } - - /* Resolve the column names in all the expressions. - */ - assert( pTabList->nSrc==1 ); - iCur = pTabList->a[0].iCursor = pParse->nTab++; - if( sqlite3ExprResolveAndCheck(pParse, pTabList, 0, pWhere, 0, 0) ){ - goto delete_from_cleanup; - } - - /* Start the view context - */ - if( isView ){ - sqlite3AuthContextPush(pParse, &sContext, pTab->zName); - } - - /* Begin generating code. - */ - v = sqlite3GetVdbe(pParse); - if( v==0 ){ - goto delete_from_cleanup; - } - sqlite3VdbeCountChanges(v); - sqlite3BeginWriteOperation(pParse, row_triggers_exist, pTab->iDb); - - /* If we are trying to delete from a view, construct that view into - ** a temporary table. - */ - if( isView ){ - Select *pView = sqlite3SelectDup(pTab->pSelect); - sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0, 0); - sqlite3SelectDelete(pView); - } - - /* Initialize the counter of the number of rows deleted, if - ** we are counting rows. - */ - if( db->flags & SQLITE_CountRows ){ - sqlite3VdbeAddOp(v, OP_Integer, 0, 0); - } - - /* Special case: A DELETE without a WHERE clause deletes everything. - ** It is easier just to erase the whole table. Note, however, that - ** this means that the row change count will be incorrect. - */ - if( pWhere==0 && !row_triggers_exist ){ - if( db->flags & SQLITE_CountRows ){ - /* If counting rows deleted, just count the total number of - ** entries in the table. */ - int endOfLoop = sqlite3VdbeMakeLabel(v); - int addr; - if( !isView ){ - sqlite3OpenTableForReading(v, iCur, pTab); - } - sqlite3VdbeAddOp(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2); - addr = sqlite3VdbeAddOp(v, OP_AddImm, 1, 0); - sqlite3VdbeAddOp(v, OP_Next, iCur, addr); - sqlite3VdbeResolveLabel(v, endOfLoop); - sqlite3VdbeAddOp(v, OP_Close, iCur, 0); - } - if( !isView ){ - sqlite3VdbeAddOp(v, OP_Clear, pTab->tnum, pTab->iDb); - for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ - sqlite3VdbeAddOp(v, OP_Clear, pIdx->tnum, pIdx->iDb); - } - } - } - - /* The usual case: There is a WHERE clause so we have to scan through - ** the table and pick which records to delete. - */ - else{ - /* Ensure all required collation sequences are available. */ - for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ - if( sqlite3CheckIndexCollSeq(pParse, pIdx) ){ - goto delete_from_cleanup; - } - } - - /* Begin the database scan - */ - pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 1, 0); - if( pWInfo==0 ) goto delete_from_cleanup; - - /* Remember the key of every item to be deleted. - */ - sqlite3VdbeAddOp(v, OP_ListWrite, 0, 0); - if( db->flags & SQLITE_CountRows ){ - sqlite3VdbeAddOp(v, OP_AddImm, 1, 0); - } - - /* End the database scan loop. - */ - sqlite3WhereEnd(pWInfo); - - /* Open the pseudo-table used to store OLD if there are triggers. - */ - if( row_triggers_exist ){ - sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0); - sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol); - } - - /* Delete every item whose key was written to the list during the - ** database scan. We have to delete items after the scan is complete - ** because deleting an item can change the scan order. - */ - sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0); - end = sqlite3VdbeMakeLabel(v); - - /* This is the beginning of the delete loop when there are - ** row triggers. - */ - if( row_triggers_exist ){ - addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end); - sqlite3VdbeAddOp(v, OP_Dup, 0, 0); - if( !isView ){ - sqlite3OpenTableForReading(v, iCur, pTab); - } - sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0); - sqlite3VdbeAddOp(v, OP_Recno, iCur, 0); - sqlite3VdbeAddOp(v, OP_RowData, iCur, 0); - sqlite3VdbeAddOp(v, OP_PutIntKey, oldIdx, 0); - if( !isView ){ - sqlite3VdbeAddOp(v, OP_Close, iCur, 0); - } - - sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TK_BEFORE, pTab, -1, - oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default, - addr); - } - - if( !isView ){ - /* Open cursors for the table we are deleting from and all its - ** indices. If there are row triggers, this happens inside the - ** OP_ListRead loop because the cursor have to all be closed - ** before the trigger fires. If there are no row triggers, the - ** cursors are opened only once on the outside the loop. - */ - sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite); - - /* This is the beginning of the delete loop when there are no - ** row triggers */ - if( !row_triggers_exist ){ - addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end); - } - - /* Delete the row */ - sqlite3GenerateRowDelete(db, v, pTab, iCur, 1); - } - - /* If there are row triggers, close all cursors then invoke - ** the AFTER triggers - */ - if( row_triggers_exist ){ - if( !isView ){ - for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ - sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum); - } - sqlite3VdbeAddOp(v, OP_Close, iCur, 0); - } - sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TK_AFTER, pTab, -1, - oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default, - addr); - } - - /* End of the delete loop */ - sqlite3VdbeAddOp(v, OP_Goto, 0, addr); - sqlite3VdbeResolveLabel(v, end); - sqlite3VdbeAddOp(v, OP_ListReset, 0, 0); - - /* Close the cursors after the loop if there are no row triggers */ - if( !row_triggers_exist ){ - for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ - sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum); - } - sqlite3VdbeAddOp(v, OP_Close, iCur, 0); - } - } - - /* - ** Return the number of rows that were deleted. - */ - if( db->flags & SQLITE_CountRows ){ - sqlite3VdbeAddOp(v, OP_Callback, 1, 0); - sqlite3VdbeSetNumCols(v, 1); - sqlite3VdbeSetColName(v, 0, "rows deleted", P3_STATIC); - } - -delete_from_cleanup: - sqlite3AuthContextPop(&sContext); - sqlite3SrcListDelete(pTabList); - sqlite3ExprDelete(pWhere); - return; -} - -/* -** This routine generates VDBE code that causes a single row of a -** single table to be deleted. -** -** The VDBE must be in a particular state when this routine is called. -** These are the requirements: -** -** 1. A read/write cursor pointing to pTab, the table containing the row -** to be deleted, must be opened as cursor number "base". -** -** 2. Read/write cursors for all indices of pTab must be open as -** cursor number base+i for the i-th index. -** -** 3. The record number of the row to be deleted must be on the top -** of the stack. -** -** This routine pops the top of the stack to remove the record number -** and then generates code to remove both the table record and all index -** entries that point to that record. -*/ -void sqlite3GenerateRowDelete( - sqlite3 *db, /* The database containing the index */ - Vdbe *v, /* Generate code into this VDBE */ - Table *pTab, /* Table containing the row to be deleted */ - int iCur, /* Cursor number for the table */ - int count /* Increment the row change counter */ -){ - int addr; - addr = sqlite3VdbeAddOp(v, OP_NotExists, iCur, 0); - sqlite3GenerateRowIndexDelete(db, v, pTab, iCur, 0); - sqlite3VdbeAddOp(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0)); - sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v)); -} - -/* -** This routine generates VDBE code that causes the deletion of all -** index entries associated with a single row of a single table. -** -** The VDBE must be in a particular state when this routine is called. -** These are the requirements: -** -** 1. A read/write cursor pointing to pTab, the table containing the row -** to be deleted, must be opened as cursor number "iCur". -** -** 2. Read/write cursors for all indices of pTab must be open as -** cursor number iCur+i for the i-th index. -** -** 3. The "iCur" cursor must be pointing to the row that is to be -** deleted. -*/ -void sqlite3GenerateRowIndexDelete( - sqlite3 *db, /* The database containing the index */ - Vdbe *v, /* Generate code into this VDBE */ - Table *pTab, /* Table containing the row to be deleted */ - int iCur, /* Cursor number for the table */ - char *aIdxUsed /* Only delete if aIdxUsed!=0 && aIdxUsed[i]!=0 */ -){ - int i; - Index *pIdx; - - for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ - if( aIdxUsed!=0 && aIdxUsed[i-1]==0 ) continue; - sqlite3GenerateIndexKey(v, pIdx, iCur); - sqlite3VdbeAddOp(v, OP_IdxDelete, iCur+i, 0); - } -} - -/* -** Generate code that will assemble an index key and put it on the top -** of the tack. The key with be for index pIdx which is an index on pTab. -** iCur is the index of a cursor open on the pTab table and pointing to -** the entry that needs indexing. -*/ -void sqlite3GenerateIndexKey( - Vdbe *v, /* Generate code into this VDBE */ - Index *pIdx, /* The index for which to generate a key */ - int iCur /* Cursor number for the pIdx->pTable table */ -){ - int j; - Table *pTab = pIdx->pTable; - - sqlite3VdbeAddOp(v, OP_Recno, iCur, 0); - for(j=0; j<pIdx->nColumn; j++){ - int idx = pIdx->aiColumn[j]; - if( idx==pTab->iPKey ){ - sqlite3VdbeAddOp(v, OP_Dup, j, 0); - }else{ - sqlite3VdbeAddOp(v, OP_Column, iCur, idx); - } - } - sqlite3VdbeAddOp(v, OP_MakeRecord, pIdx->nColumn, (1<<24)); - sqlite3IndexAffinityStr(v, pIdx); -} |