build.c

sqlite数据库管理系统开放源码

    sqliteVdbeAddOp(v, OP_NewRecno, 0, 0);
    sqliteVdbeOp3(v, OP_String, 0, 0, "index", P3_STATIC);
    sqliteVdbeOp3(v, OP_String, 0, 0, pIndex->zName, 0);
    sqliteVdbeOp3(v, OP_String, 0, 0, pTab->zName, 0);
    sqliteVdbeOp3(v, OP_CreateIndex, 0, isTemp,(char*)&pIndex->tnum,P3_POINTER);
    pIndex->tnum = 0;
    if( pTable ){
      sqliteVdbeCode(v,
          OP_Dup,       0,      0,
          OP_Integer,   isTemp, 0,
          OP_OpenWrite, 1,      0,
      0);
    }
    addr = sqliteVdbeAddOp(v, OP_String, 0, 0);
    if( pStart && pEnd ){
      n = Addr(pEnd->z) - Addr(pStart->z) + 1;
      sqliteVdbeChangeP3(v, addr, pStart->z, n);
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, 5, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, 0, 0);
    if( pTable ){
      sqliteVdbeAddOp(v, OP_Integer, pTab->iDb, 0);
      sqliteVdbeOp3(v, OP_OpenRead, 2, pTab->tnum, pTab->zName, 0);
      lbl2 = sqliteVdbeMakeLabel(v);
      sqliteVdbeAddOp(v, OP_Rewind, 2, lbl2);
      lbl1 = sqliteVdbeAddOp(v, OP_Recno, 2, 0);
      for(i=0; i<pIndex->nColumn; i++){
        int iCol = pIndex->aiColumn[i];
        if( pTab->iPKey==iCol ){
          sqliteVdbeAddOp(v, OP_Dup, i, 0);
        }else{
          sqliteVdbeAddOp(v, OP_Column, 2, iCol);
        }
      }
      sqliteVdbeAddOp(v, OP_MakeIdxKey, pIndex->nColumn, 0);
      if( db->file_format>=4 ) sqliteAddIdxKeyType(v, pIndex);
      sqliteVdbeOp3(v, OP_IdxPut, 1, pIndex->onError!=OE_None,
                      "indexed columns are not unique", P3_STATIC);
      sqliteVdbeAddOp(v, OP_Next, 2, lbl1);
      sqliteVdbeResolveLabel(v, lbl2);
      sqliteVdbeAddOp(v, OP_Close, 2, 0);
      sqliteVdbeAddOp(v, OP_Close, 1, 0);
    }
    if( pTable!=0 ){
      if( !isTemp ){
        sqliteChangeCookie(db, v);
      }
      sqliteVdbeAddOp(v, OP_Close, 0, 0);
      sqliteEndWriteOperation(pParse);
    }
  }

  /* Clean up before exiting */
exit_create_index:
  sqliteIdListDelete(pList);
  sqliteSrcListDelete(pTable);
  sqliteFree(zName);
  return;
}

/*
** This routine will drop an existing named index.  This routine
** implements the DROP INDEX statement.
*/
void sqliteDropIndex(Parse *pParse, SrcList *pName){
  Index *pIndex;
  Vdbe *v;
  sqlite *db = pParse->db;

  if( pParse->nErr || sqlite_malloc_failed ) return;
  assert( pName->nSrc==1 );
  pIndex = sqliteFindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
  if( pIndex==0 ){
    sqliteErrorMsg(pParse, "no such index: %S", pName, 0);
    goto exit_drop_index;
  }
  if( pIndex->autoIndex ){
    sqliteErrorMsg(pParse, "index associated with UNIQUE "
      "or PRIMARY KEY constraint cannot be dropped", 0);
    goto exit_drop_index;
  }
  if( pIndex->iDb>1 ){
    sqliteErrorMsg(pParse, "cannot alter schema of attached "
       "databases", 0);
    goto exit_drop_index;
  }
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code = SQLITE_DROP_INDEX;
    Table *pTab = pIndex->pTable;
    const char *zDb = db->aDb[pIndex->iDb].zName;
    const char *zTab = SCHEMA_TABLE(pIndex->iDb);
    if( sqliteAuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
      goto exit_drop_index;
    }
    if( pIndex->iDb ) code = SQLITE_DROP_TEMP_INDEX;
    if( sqliteAuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){
      goto exit_drop_index;
    }
  }
#endif

  /* Generate code to remove the index and from the master table */
  v = sqliteGetVdbe(pParse);
  if( v ){
    static VdbeOpList dropIndex[] = {
      { OP_Rewind,     0, ADDR(9), 0}, 
      { OP_String,     0, 0,       0}, /* 1 */
      { OP_MemStore,   1, 1,       0},
      { OP_MemLoad,    1, 0,       0}, /* 3 */
      { OP_Column,     0, 1,       0},
      { OP_Eq,         0, ADDR(8), 0},
      { OP_Next,       0, ADDR(3), 0},
      { OP_Goto,       0, ADDR(9), 0},
      { OP_Delete,     0, 0,       0}, /* 8 */
    };
    int base;

    sqliteBeginWriteOperation(pParse, 0, pIndex->iDb);
    sqliteOpenMasterTable(v, pIndex->iDb);
    base = sqliteVdbeAddOpList(v, ArraySize(dropIndex), dropIndex);
    sqliteVdbeChangeP3(v, base+1, pIndex->zName, 0);
    if( pIndex->iDb==0 ){
      sqliteChangeCookie(db, v);
    }
    sqliteVdbeAddOp(v, OP_Close, 0, 0);
    sqliteVdbeAddOp(v, OP_Destroy, pIndex->tnum, pIndex->iDb);
    sqliteEndWriteOperation(pParse);
  }

  /* Delete the in-memory description of this index.
  */
  if( !pParse->explain ){
    sqliteUnlinkAndDeleteIndex(db, pIndex);
    db->flags |= SQLITE_InternChanges;
  }

exit_drop_index:
  sqliteSrcListDelete(pName);
}

/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.
**
** A new IdList is returned, or NULL if malloc() fails.
*/
IdList *sqliteIdListAppend(IdList *pList, Token *pToken){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(IdList) );
    if( pList==0 ) return 0;
    pList->nAlloc = 0;
  }
  if( pList->nId>=pList->nAlloc ){
    struct IdList_item *a;
    pList->nAlloc = pList->nAlloc*2 + 5;
    a = sqliteRealloc(pList->a, pList->nAlloc*sizeof(pList->a[0]) );
    if( a==0 ){
      sqliteIdListDelete(pList);
      return 0;
    }
    pList->a = a;
  }
  memset(&pList->a[pList->nId], 0, sizeof(pList->a[0]));
  if( pToken ){
    char **pz = &pList->a[pList->nId].zName;
    sqliteSetNString(pz, pToken->z, pToken->n, 0);
    if( *pz==0 ){
      sqliteIdListDelete(pList);
      return 0;
    }else{
      sqliteDequote(*pz);
    }
  }
  pList->nId++;
  return pList;
}

/*
** Append a new table name to the given SrcList.  Create a new SrcList if
** need be.  A new entry is created in the SrcList even if pToken is NULL.
**
** A new SrcList is returned, or NULL if malloc() fails.
**
** If pDatabase is not null, it means that the table has an optional
** database name prefix.  Like this:  "database.table".  The pDatabase
** points to the table name and the pTable points to the database name.
** The SrcList.a[].zName field is filled with the table name which might
** come from pTable (if pDatabase is NULL) or from pDatabase.  
** SrcList.a[].zDatabase is filled with the database name from pTable,
** or with NULL if no database is specified.
**
** In other words, if call like this:
**
**         sqliteSrcListAppend(A,B,0);
**
** Then B is a table name and the database name is unspecified.  If called
** like this:
**
**         sqliteSrcListAppend(A,B,C);
**
** Then C is the table name and B is the database name.
*/
SrcList *sqliteSrcListAppend(SrcList *pList, Token *pTable, Token *pDatabase){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(SrcList) );
    if( pList==0 ) return 0;
    pList->nAlloc = 1;
  }
  if( pList->nSrc>=pList->nAlloc ){
    SrcList *pNew;
    pList->nAlloc *= 2;
    pNew = sqliteRealloc(pList,
               sizeof(*pList) + (pList->nAlloc-1)*sizeof(pList->a[0]) );
    if( pNew==0 ){
      sqliteSrcListDelete(pList);
      return 0;
    }
    pList = pNew;
  }
  memset(&pList->a[pList->nSrc], 0, sizeof(pList->a[0]));
  if( pDatabase && pDatabase->z==0 ){
    pDatabase = 0;
  }
  if( pDatabase && pTable ){
    Token *pTemp = pDatabase;
    pDatabase = pTable;
    pTable = pTemp;
  }
  if( pTable ){
    char **pz = &pList->a[pList->nSrc].zName;
    sqliteSetNString(pz, pTable->z, pTable->n, 0);
    if( *pz==0 ){
      sqliteSrcListDelete(pList);
      return 0;
    }else{
      sqliteDequote(*pz);
    }
  }
  if( pDatabase ){
    char **pz = &pList->a[pList->nSrc].zDatabase;
    sqliteSetNString(pz, pDatabase->z, pDatabase->n, 0);
    if( *pz==0 ){
      sqliteSrcListDelete(pList);
      return 0;
    }else{
      sqliteDequote(*pz);
    }
  }
  pList->a[pList->nSrc].iCursor = -1;
  pList->nSrc++;
  return pList;
}

/*
** Assign cursors to all tables in a SrcList
*/
void sqliteSrcListAssignCursors(Parse *pParse, SrcList *pList){
  int i;
  for(i=0; i<pList->nSrc; i++){
    if( pList->a[i].iCursor<0 ){
      pList->a[i].iCursor = pParse->nTab++;
    }
  }
}

/*
** Add an alias to the last identifier on the given identifier list.
*/
void sqliteSrcListAddAlias(SrcList *pList, Token *pToken){
  if( pList && pList->nSrc>0 ){
    int i = pList->nSrc - 1;
    sqliteSetNString(&pList->a[i].zAlias, pToken->z, pToken->n, 0);
    sqliteDequote(pList->a[i].zAlias);
  }
}

/*
** Delete an IdList.
*/
void sqliteIdListDelete(IdList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nId; i++){
    sqliteFree(pList->a[i].zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** Return the index in pList of the identifier named zId.  Return -1
** if not found.
*/
int sqliteIdListIndex(IdList *pList, const char *zName){
  int i;
  if( pList==0 ) return -1;
  for(i=0; i<pList->nId; i++){
    if( sqliteStrICmp(pList->a[i].zName, zName)==0 ) return i;
  }
  return -1;
}

/*
** Delete an entire SrcList including all its substructure.
*/
void sqliteSrcListDelete(SrcList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nSrc; i++){
    sqliteFree(pList->a[i].zDatabase);
    sqliteFree(pList->a[i].zName);
    sqliteFree(pList->a[i].zAlias);
    if( pList->a[i].pTab && pList->a[i].pTab->isTransient ){
      sqliteDeleteTable(0, pList->a[i].pTab);
    }
    sqliteSelectDelete(pList->a[i].pSelect);
    sqliteExprDelete(pList->a[i].pOn);
    sqliteIdListDelete(pList->a[i].pUsing);
  }
  sqliteFree(pList);
}

/*
** Begin a transaction
*/
void sqliteBeginTransaction(Parse *pParse, int onError){
  sqlite *db;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite_malloc_failed ) return;
  if( sqliteAuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ) return;
  if( db->flags & SQLITE_InTrans ){
    sqliteErrorMsg(pParse, "cannot start a transaction within a transaction");
    return;
  }
  sqliteBeginWriteOperation(pParse, 0, 0);
  if( !pParse->explain ){
    db->flags |= SQLITE_InTrans;
    db->onError = onError;
  }
}

/*
** Commit a transaction
*/
void sqliteCommitTransaction(Parse *pParse){
  sqlite *db;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite_malloc_failed ) return;
  if( sqliteAuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ) return;
  if( (db->flags & SQLITE_InTrans)==0 ){
    sqliteErrorMsg(pParse, "cannot commit - no transaction is active");
    return;
  }
  if( !pParse->explain ){
    db->flags &= ~SQLITE_InTrans;
  }
  sqliteEndWriteOperation(pParse);
  if( !pParse->explain ){
    db->onError = OE_Default;
  }
}

/*
** Rollback a transaction
*/
void sqliteRollbackTransaction(Parse *pParse){
  sqlite *db;
  Vdbe *v;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite_malloc_failed ) return;
  if( sqliteAuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;
  if( (db->flags & SQLITE_InTrans)==0 ){
    sqliteErrorMsg(pParse, "cannot rollback - no transaction is active");
    return; 
  }
  v = sqliteGetVdbe(pParse);
  if( v ){
    sqliteVdbeAddOp(v, OP_Rollback, 0, 0);
  }
  if( !pParse->explain ){
    db->flags &= ~SQLITE_InTrans;
    db->onError = OE_Default;
  }
}

/*
** Generate VDBE code that will verify the schema cookie for all
** named database files.
*/
void sqliteCodeVerifySchema(Parse *pParse, int iDb){
  sqlite *db = pParse->db;
  Vdbe *v = sqliteGetVdbe(pParse);
  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pBt!=0 );
  if( iDb!=1 && !DbHasProperty(db, iDb, DB_Cookie) ){
    sqliteVdbeAddOp(v, OP_VerifyCookie, iDb, db->aDb[iDb].schema_cookie);
    DbSetProperty(db, iDb, DB_Cookie);
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.
**
** This routine starts a new transaction if we are not already within
** a transaction.  If we are already within a transaction, then a checkpoint
** is set if the setCheckpoint parameter is true.  A checkpoint should
** be set for operations that might fail (due to a constraint) part of
** the way through and which will need to undo some writes without having to
** rollback the whole transaction.  For operations where all constraints
** can be checked before any changes are made to the database, it is never
** necessary to undo a write and the checkpoint should not be set.
**
** Only database iDb and the temp database are made writable by this call.
** If iDb==0, then the main and te