tclsqlite.c

来自「sqlite最新源码」· C语言 代码 · 共 2,068 行 · 第 1/5 页

          /* When a prepared statement is found, unlink it from the
          ** cache list.  It will later be added back to the beginning
          ** of the cache list in order to implement LRU replacement.
          */
          if( pPreStmt->pPrev ){
            pPreStmt->pPrev->pNext = pPreStmt->pNext;
          }else{
            pDb->stmtList = pPreStmt->pNext;
          }
          if( pPreStmt->pNext ){
            pPreStmt->pNext->pPrev = pPreStmt->pPrev;
          }else{
            pDb->stmtLast = pPreStmt->pPrev;
          }
          pDb->nStmt--;
          break;
        }
      }
  
      /* If no prepared statement was found.  Compile the SQL text
      */
      if( pStmt==0 ){
        if( SQLITE_OK!=sqlite3_prepare_v2(pDb->db, zSql, -1, &pStmt, &zLeft) ){
          Tcl_SetObjResult(interp, dbTextToObj(sqlite3_errmsg(pDb->db)));
          rc = TCL_ERROR;
          break;
        }
        if( pStmt==0 ){
          if( SQLITE_OK!=sqlite3_errcode(pDb->db) ){
            /* A compile-time error in the statement
            */
            Tcl_SetObjResult(interp, dbTextToObj(sqlite3_errmsg(pDb->db)));
            rc = TCL_ERROR;
            break;
          }else{
            /* The statement was a no-op.  Continue to the next statement
            ** in the SQL string.
            */
            zSql = zLeft;
            continue;
          }
        }
        assert( pPreStmt==0 );
      }

      /* Bind values to parameters that begin with $ or :
      */  
      nVar = sqlite3_bind_parameter_count(pStmt);
      nParm = 0;
      if( nVar>sizeof(aParm)/sizeof(aParm[0]) ){
        apParm = (Tcl_Obj**)Tcl_Alloc(nVar*sizeof(apParm[0]));
      }else{
        apParm = aParm;
      }
      for(i=1; i<=nVar; i++){
        const char *zVar = sqlite3_bind_parameter_name(pStmt, i);
        if( zVar!=0 && (zVar[0]=='$' || zVar[0]==':' || zVar[0]=='@') ){
          Tcl_Obj *pVar = Tcl_GetVar2Ex(interp, &zVar[1], 0, 0);
          if( pVar ){
            int n;
            u8 *data;
            char *zType = pVar->typePtr ? pVar->typePtr->name : "";
            char c = zType[0];
            if( zVar[0]=='@' ||
               (c=='b' && strcmp(zType,"bytearray")==0 && pVar->bytes==0) ){
              /* Load a BLOB type if the Tcl variable is a bytearray and
              ** it has no string representation or the host
              ** parameter name begins with "@". */
              data = Tcl_GetByteArrayFromObj(pVar, &n);
              sqlite3_bind_blob(pStmt, i, data, n, SQLITE_STATIC);
              Tcl_IncrRefCount(pVar);
              apParm[nParm++] = pVar;
            }else if( c=='b' && strcmp(zType,"boolean")==0 ){
              Tcl_GetIntFromObj(interp, pVar, &n);
              sqlite3_bind_int(pStmt, i, n);
            }else if( c=='d' && strcmp(zType,"double")==0 ){
              double r;
              Tcl_GetDoubleFromObj(interp, pVar, &r);
              sqlite3_bind_double(pStmt, i, r);
            }else if( (c=='w' && strcmp(zType,"wideInt")==0) ||
                  (c=='i' && strcmp(zType,"int")==0) ){
              Tcl_WideInt v;
              Tcl_GetWideIntFromObj(interp, pVar, &v);
              sqlite3_bind_int64(pStmt, i, v);
            }else{
              data = (unsigned char *)Tcl_GetStringFromObj(pVar, &n);
              sqlite3_bind_text(pStmt, i, (char *)data, n, SQLITE_STATIC);
              Tcl_IncrRefCount(pVar);
              apParm[nParm++] = pVar;
            }
          }else{
            sqlite3_bind_null( pStmt, i );
          }
        }
      }

      /* Execute the SQL
      */
      while( rc==TCL_OK && pStmt && SQLITE_ROW==sqlite3_step(pStmt) ){

	/* Compute column names. This must be done after the first successful
	** call to sqlite3_step(), in case the query is recompiled and the
        ** number or names of the returned columns changes. 
        */
        assert(!pArray||pScript);
        if (nCol < 0) {
          Tcl_Obj ***ap = (pScript?&apColName:0);
          nCol = computeColumnNames(interp, pStmt, ap, pArray);
        }

        for(i=0; i<nCol; i++){
          Tcl_Obj *pVal;
          
          /* Set pVal to contain the i'th column of this row. */
          switch( sqlite3_column_type(pStmt, i) ){
            case SQLITE_BLOB: {
              int bytes = sqlite3_column_bytes(pStmt, i);
              const char *zBlob = sqlite3_column_blob(pStmt, i);
              if( !zBlob ) bytes = 0;
              pVal = Tcl_NewByteArrayObj((u8*)zBlob, bytes);
              break;
            }
            case SQLITE_INTEGER: {
              sqlite_int64 v = sqlite3_column_int64(pStmt, i);
              if( v>=-2147483647 && v<=2147483647 ){
                pVal = Tcl_NewIntObj(v);
              }else{
                pVal = Tcl_NewWideIntObj(v);
              }
              break;
            }
            case SQLITE_FLOAT: {
              double r = sqlite3_column_double(pStmt, i);
              pVal = Tcl_NewDoubleObj(r);
              break;
            }
            case SQLITE_NULL: {
              pVal = dbTextToObj(pDb->zNull);
              break;
            }
            default: {
              pVal = dbTextToObj((char *)sqlite3_column_text(pStmt, i));
              break;
            }
          }
  
          if( pScript ){
            if( pArray==0 ){
              Tcl_ObjSetVar2(interp, apColName[i], 0, pVal, 0);
            }else{
              Tcl_ObjSetVar2(interp, pArray, apColName[i], pVal, 0);
            }
          }else if( choice==DB_ONECOLUMN ){
            assert( pRet==0 );
            if( pRet==0 ){
              pRet = pVal;
              Tcl_IncrRefCount(pRet);
            }
            rc = TCL_BREAK;
            i = nCol;
          }else if( choice==DB_EXISTS ){
            Tcl_DecrRefCount(pRet);
            pRet = Tcl_NewBooleanObj(1);
            Tcl_IncrRefCount(pRet);
            rc = TCL_BREAK;
            i = nCol;
          }else{
            Tcl_ListObjAppendElement(interp, pRet, pVal);
          }
        }
  
        if( pScript ){
          pDb->nStep = sqlite3_stmt_status(pStmt, 
                                  SQLITE_STMTSTATUS_FULLSCAN_STEP, 0);
          pDb->nSort = sqlite3_stmt_status(pStmt,
                                  SQLITE_STMTSTATUS_SORT, 0);
          rc = Tcl_EvalObjEx(interp, pScript, 0);
          if( rc==TCL_CONTINUE ){
            rc = TCL_OK;
          }
        }
      }
      if( rc==TCL_BREAK ){
        rc = TCL_OK;
      }

      /* Free the column name objects */
      if( pScript ){
        /* If the query returned no rows, but an array variable was 
        ** specified, call computeColumnNames() now to populate the 
        ** arrayname(*) variable.
        */
        if (pArray && nCol < 0) {
          Tcl_Obj ***ap = (pScript?&apColName:0);
          nCol = computeColumnNames(interp, pStmt, ap, pArray);
        }
        for(i=0; i<nCol; i++){
          Tcl_DecrRefCount(apColName[i]);
        }
        Tcl_Free((char*)apColName);
      }

      /* Free the bound string and blob parameters */
      for(i=0; i<nParm; i++){
        Tcl_DecrRefCount(apParm[i]);
      }
      if( apParm!=aParm ){
        Tcl_Free((char*)apParm);
      }

      /* Reset the statement.  If the result code is SQLITE_SCHEMA, then
      ** flush the statement cache and try the statement again.
      */
      rc2 = sqlite3_reset(pStmt);
      pDb->nStep = sqlite3_stmt_status(pStmt, 
                                  SQLITE_STMTSTATUS_FULLSCAN_STEP, 1);
      pDb->nSort = sqlite3_stmt_status(pStmt,
                                  SQLITE_STMTSTATUS_SORT, 1);
      if( SQLITE_OK!=rc2 ){
        /* If a run-time error occurs, report the error and stop reading
        ** the SQL
        */
        Tcl_SetObjResult(interp, dbTextToObj(sqlite3_errmsg(pDb->db)));
        sqlite3_finalize(pStmt);
        rc = TCL_ERROR;
        if( pPreStmt ) Tcl_Free((char*)pPreStmt);
        break;
      }else if( pDb->maxStmt<=0 ){
        /* If the cache is turned off, deallocated the statement */
        if( pPreStmt ) Tcl_Free((char*)pPreStmt);
        sqlite3_finalize(pStmt);
      }else{
        /* Everything worked and the cache is operational.
        ** Create a new SqlPreparedStmt structure if we need one.
        ** (If we already have one we can just reuse it.)
        */
        if( pPreStmt==0 ){
          len = zLeft - zSql;
          pPreStmt = (SqlPreparedStmt*)Tcl_Alloc( sizeof(*pPreStmt) );
          if( pPreStmt==0 ) return TCL_ERROR;
          pPreStmt->pStmt = pStmt;
          pPreStmt->nSql = len;
          pPreStmt->zSql = sqlite3_sql(pStmt);
          assert( strlen30(pPreStmt->zSql)==len );
          assert( 0==memcmp(pPreStmt->zSql, zSql, len) );
        }

        /* Add the prepared statement to the beginning of the cache list
        */
        pPreStmt->pNext = pDb->stmtList;
        pPreStmt->pPrev = 0;
        if( pDb->stmtList ){
         pDb->stmtList->pPrev = pPreStmt;
        }
        pDb->stmtList = pPreStmt;
        if( pDb->stmtLast==0 ){
          assert( pDb->nStmt==0 );
          pDb->stmtLast = pPreStmt;
        }else{
          assert( pDb->nStmt>0 );
        }
        pDb->nStmt++;
   
        /* If we have too many statement in cache, remove the surplus from the
        ** end of the cache list.
        */
        while( pDb->nStmt>pDb->maxStmt ){
          sqlite3_finalize(pDb->stmtLast->pStmt);
          pDb->stmtLast = pDb->stmtLast->pPrev;
          Tcl_Free((char*)pDb->stmtLast->pNext);
          pDb->stmtLast->pNext = 0;
          pDb->nStmt--;
        }
      }

      /* Proceed to the next statement */
      zSql = zLeft;
    }
    Tcl_DecrRefCount(objv[2]);

    if( pRet ){
      if( rc==TCL_OK ){
        Tcl_SetObjResult(interp, pRet);
      }
      Tcl_DecrRefCount(pRet);
    }else if( rc==TCL_OK ){
      Tcl_ResetResult(interp);
    }
    break;
  }

  /*
  **     $db function NAME [-argcount N] SCRIPT
  **
  ** Create a new SQL function called NAME.  Whenever that function is
  ** called, invoke SCRIPT to evaluate the function.
  */
  case DB_FUNCTION: {
    SqlFunc *pFunc;
    Tcl_Obj *pScript;
    char *zName;
    int nArg = -1;
    if( objc==6 ){
      const char *z = Tcl_GetString(objv[3]);
      int n = strlen30(z);
      if( n>2 && strncmp(z, "-argcount",n)==0 ){
        if( Tcl_GetIntFromObj(interp, objv[4], &nArg) ) return TCL_ERROR;
        if( nArg<0 ){
          Tcl_AppendResult(interp, "number of arguments must be non-negative",
                           (char*)0);
          return TCL_ERROR;
        }
      }
      pScript = objv[5];
    }else if( objc!=4 ){
      Tcl_WrongNumArgs(interp, 2, objv, "NAME [-argcount N] SCRIPT");
      return TCL_ERROR;
    }else{
      pScript = objv[3];
    }
    zName = Tcl_GetStringFromObj(objv[2], 0);
    pFunc = findSqlFunc(pDb, zName);
    if( pFunc==0 ) return TCL_ERROR;
    if( pFunc->pScript ){
      Tcl_DecrRefCount(pFunc->pScript);
    }
    pFunc->pScript = pScript;
    Tcl_IncrRefCount(pScript);
    pFunc->useEvalObjv = safeToUseEvalObjv(interp, pScript);
    rc = sqlite3_create_function(pDb->db, zName, nArg, SQLITE_UTF8,
        pFunc, tclSqlFunc, 0, 0);
    if( rc!=SQLITE_OK ){
      rc = TCL_ERROR;
      Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
    }
    break;
  }

  /*
  **     $db incrblob ?-readonly? ?DB? TABLE COLUMN ROWID
  */
  case DB_INCRBLOB: {
#ifdef SQLITE_OMIT_INCRBLOB
    Tcl_AppendResult(interp, "incrblob not available in this build", 0);
    return TCL_ERROR;
#else
    int isReadonly = 0;
    const char *zDb = "main";
    const char *zTable;
    const char *zColumn;
    sqlite_int64 iRow;

    /* Check for the -readonly option */
    if( objc>3 && strcmp(Tcl_GetString(objv[2]), "-readonly")==0 ){
      isReadonly = 1;
    }

    if( objc!=(5+isReadonly) && objc!=(6+isReadonly) ){
      Tcl_WrongNumArgs(interp, 2, objv, "?-readonly? ?DB? TABLE COLUMN ROWID");
      return TCL_ERROR;
    }

    if( objc==(6+isReadonly) ){
      zDb = Tcl_GetString(objv[2]);
    }
    zTable = Tcl_GetString(objv[objc-3]);
    zColumn = Tcl_GetString(objv[objc-2]);
    rc = Tcl_GetWideIntFromObj(interp, objv[objc-1], &iRow);

    if( rc==TCL_OK ){
      rc = createIncrblobChannel(
          interp, pDb, zDb, zTable, zColumn, iRow, isReadonly
      );
    }
#endif
    break;
  }

  /*
  **     $db interrupt
  **
  ** Interrupt the execution of the inner-most SQL interpreter.  This
  ** causes the SQL statement to return an error of SQLITE_INTERRUPT.
  */
  case DB_INTERRUPT: {
    sqlite3_interrupt(pDb->db);
    break;
  }

  /*
  **     $db nullvalue ?STRING?
  **
  ** Change text used when a NULL comes back from the database. If ?STRING?
  ** is not present, then the current string used for NULL is returned.
  ** If STRING is present, then STRING is returned.
  **
  */
  case DB_NULLVALUE: {
    if( objc!=2 && objc!=3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "NULLVALUE");
      return TCL_ERROR;
    }
    if( objc==3 ){
      int len;
      char *zNull = Tcl_GetStringFromObj(objv[2], &len);
      if( pDb->zNull ){
        Tcl_Free(pDb->zNull);
      }
      if( zNull && len>0 ){
        pDb->zNull = Tcl_Alloc( len + 1 );
        strn