tclsqlite.c

sqlite 嵌入式数据库的源码

*/
static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
  SqliteDb *pDb = (SqliteDb*)cd;
  int choice;
  int rc = TCL_OK;
  static const char *DB_strs[] = {
    "authorizer",         "busy",              "cache",
    "changes",            "close",             "collate",
    "collation_needed",   "commit_hook",       "complete",
    "copy",               "errorcode",         "eval",
    "function",           "last_insert_rowid", "nullvalue",
    "onecolumn",          "progress",          "rekey",
    "timeout",            "total_changes",     "trace",
    "version",
    0                    
  };
  enum DB_enum {
    DB_AUTHORIZER,        DB_BUSY,             DB_CACHE,
    DB_CHANGES,           DB_CLOSE,            DB_COLLATE,
    DB_COLLATION_NEEDED,  DB_COMMIT_HOOK,      DB_COMPLETE,
    DB_COPY,              DB_ERRORCODE,        DB_EVAL,
    DB_FUNCTION,          DB_LAST_INSERT_ROWID,DB_NULLVALUE,
    DB_ONECOLUMN,         DB_PROGRESS,         DB_REKEY,
    DB_TIMEOUT,           DB_TOTAL_CHANGES,    DB_TRACE,
    DB_VERSION
  };
  /* don't leave trailing commas on DB_enum, it confuses the AIX xlc compiler */

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
    return TCL_ERROR;
  }
  if( Tcl_GetIndexFromObj(interp, objv[1], DB_strs, "option", 0, &choice) ){
    return TCL_ERROR;
  }

  switch( (enum DB_enum)choice ){

  /*    $db authorizer ?CALLBACK?
  **
  ** Invoke the given callback to authorize each SQL operation as it is
  ** compiled.  5 arguments are appended to the callback before it is
  ** invoked:
  **
  **   (1) The authorization type (ex: SQLITE_CREATE_TABLE, SQLITE_INSERT, ...)
  **   (2) First descriptive name (depends on authorization type)
  **   (3) Second descriptive name
  **   (4) Name of the database (ex: "main", "temp")
  **   (5) Name of trigger that is doing the access
  **
  ** The callback should return on of the following strings: SQLITE_OK,
  ** SQLITE_IGNORE, or SQLITE_DENY.  Any other return value is an error.
  **
  ** If this method is invoked with no arguments, the current authorization
  ** callback string is returned.
  */
  case DB_AUTHORIZER: {
#ifdef SQLITE_OMIT_AUTHORIZATION
    Tcl_AppendResult(interp, "authorization not available in this build", 0);
    return TCL_ERROR;
#else
    if( objc>3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
      return TCL_ERROR;
    }else if( objc==2 ){
      if( pDb->zAuth ){
        Tcl_AppendResult(interp, pDb->zAuth, 0);
      }
    }else{
      char *zAuth;
      int len;
      if( pDb->zAuth ){
        Tcl_Free(pDb->zAuth);
      }
      zAuth = Tcl_GetStringFromObj(objv[2], &len);
      if( zAuth && len>0 ){
        pDb->zAuth = Tcl_Alloc( len + 1 );
        strcpy(pDb->zAuth, zAuth);
      }else{
        pDb->zAuth = 0;
      }
      if( pDb->zAuth ){
        pDb->interp = interp;
        sqlite3_set_authorizer(pDb->db, auth_callback, pDb);
      }else{
        sqlite3_set_authorizer(pDb->db, 0, 0);
      }
    }
#endif
    break;
  }

  /*    $db busy ?CALLBACK?
  **
  ** Invoke the given callback if an SQL statement attempts to open
  ** a locked database file.
  */
  case DB_BUSY: {
    if( objc>3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "CALLBACK");
      return TCL_ERROR;
    }else if( objc==2 ){
      if( pDb->zBusy ){
        Tcl_AppendResult(interp, pDb->zBusy, 0);
      }
    }else{
      char *zBusy;
      int len;
      if( pDb->zBusy ){
        Tcl_Free(pDb->zBusy);
      }
      zBusy = Tcl_GetStringFromObj(objv[2], &len);
      if( zBusy && len>0 ){
        pDb->zBusy = Tcl_Alloc( len + 1 );
        strcpy(pDb->zBusy, zBusy);
      }else{
        pDb->zBusy = 0;
      }
      if( pDb->zBusy ){
        pDb->interp = interp;
        sqlite3_busy_handler(pDb->db, DbBusyHandler, pDb);
      }else{
        sqlite3_busy_handler(pDb->db, 0, 0);
      }
    }
    break;
  }

  /*     $db cache flush
  **     $db cache size n
  **
  ** Flush the prepared statement cache, or set the maximum number of
  ** cached statements.
  */
  case DB_CACHE: {
    char *subCmd;
    int n;

    if( objc<=2 ){
      Tcl_WrongNumArgs(interp, 1, objv, "cache option ?arg?");
      return TCL_ERROR;
    }
    subCmd = Tcl_GetStringFromObj( objv[2], 0 );
    if( *subCmd=='f' && strcmp(subCmd,"flush")==0 ){
      if( objc!=3 ){
        Tcl_WrongNumArgs(interp, 2, objv, "flush");
        return TCL_ERROR;
      }else{
        flushStmtCache( pDb );
      }
    }else if( *subCmd=='s' && strcmp(subCmd,"size")==0 ){
      if( objc!=4 ){
        Tcl_WrongNumArgs(interp, 2, objv, "size n");
        return TCL_ERROR;
      }else{
        if( TCL_ERROR==Tcl_GetIntFromObj(interp, objv[3], &n) ){
          Tcl_AppendResult( interp, "cannot convert \"", 
               Tcl_GetStringFromObj(objv[3],0), "\" to integer", 0);
          return TCL_ERROR;
        }else{
          if( n<0 ){
            flushStmtCache( pDb );
            n = 0;
          }else if( n>MAX_PREPARED_STMTS ){
            n = MAX_PREPARED_STMTS;
          }
          pDb->maxStmt = n;
        }
      }
    }else{
      Tcl_AppendResult( interp, "bad option \"", 
          Tcl_GetStringFromObj(objv[0],0), "\": must be flush or size", 0);
      return TCL_ERROR;
    }
    break;
  }

  /*     $db changes
  **
  ** Return the number of rows that were modified, inserted, or deleted by
  ** the most recent INSERT, UPDATE or DELETE statement, not including 
  ** any changes made by trigger programs.
  */
  case DB_CHANGES: {
    Tcl_Obj *pResult;
    if( objc!=2 ){
      Tcl_WrongNumArgs(interp, 2, objv, "");
      return TCL_ERROR;
    }
    pResult = Tcl_GetObjResult(interp);
    Tcl_SetIntObj(pResult, sqlite3_changes(pDb->db));
    break;
  }

  /*    $db close
  **
  ** Shutdown the database
  */
  case DB_CLOSE: {
    Tcl_DeleteCommand(interp, Tcl_GetStringFromObj(objv[0], 0));
    break;
  }

  /*    $db commit_hook ?CALLBACK?
  **
  ** Invoke the given callback just before committing every SQL transaction.
  ** If the callback throws an exception or returns non-zero, then the
  ** transaction is aborted.  If CALLBACK is an empty string, the callback
  ** is disabled.
  */
  case DB_COMMIT_HOOK: {
    if( objc>3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
      return TCL_ERROR;
    }else if( objc==2 ){
      if( pDb->zCommit ){
        Tcl_AppendResult(interp, pDb->zCommit, 0);
      }
    }else{
      char *zCommit;
      int len;
      if( pDb->zCommit ){
        Tcl_Free(pDb->zCommit);
      }
      zCommit = Tcl_GetStringFromObj(objv[2], &len);
      if( zCommit && len>0 ){
        pDb->zCommit = Tcl_Alloc( len + 1 );
        strcpy(pDb->zCommit, zCommit);
      }else{
        pDb->zCommit = 0;
      }
      if( pDb->zCommit ){
        pDb->interp = interp;
        sqlite3_commit_hook(pDb->db, DbCommitHandler, pDb);
      }else{
        sqlite3_commit_hook(pDb->db, 0, 0);
      }
    }
    break;
  }

  /*
  **     $db collate NAME SCRIPT
  **
  ** Create a new SQL collation function called NAME.  Whenever
  ** that function is called, invoke SCRIPT to evaluate the function.
  */
  case DB_COLLATE: {
    SqlCollate *pCollate;
    char *zName;
    char *zScript;
    int nScript;
    if( objc!=4 ){
      Tcl_WrongNumArgs(interp, 2, objv, "NAME SCRIPT");
      return TCL_ERROR;
    }
    zName = Tcl_GetStringFromObj(objv[2], 0);
    zScript = Tcl_GetStringFromObj(objv[3], &nScript);
    pCollate = (SqlCollate*)Tcl_Alloc( sizeof(*pCollate) + nScript + 1 );
    if( pCollate==0 ) return TCL_ERROR;
    pCollate->interp = interp;
    pCollate->pNext = pDb->pCollate;
    pCollate->zScript = (char*)&pCollate[1];
    pDb->pCollate = pCollate;
    strcpy(pCollate->zScript, zScript);
    if( sqlite3_create_collation(pDb->db, zName, SQLITE_UTF8, 
        pCollate, tclSqlCollate) ){
      Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
      return TCL_ERROR;
    }
    break;
  }

  /*
  **     $db collation_needed SCRIPT
  **
  ** Create a new SQL collation function called NAME.  Whenever
  ** that function is called, invoke SCRIPT to evaluate the function.
  */
  case DB_COLLATION_NEEDED: {
    if( objc!=3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "SCRIPT");
      return TCL_ERROR;
    }
    if( pDb->pCollateNeeded ){
      Tcl_DecrRefCount(pDb->pCollateNeeded);
    }
    pDb->pCollateNeeded = Tcl_DuplicateObj(objv[2]);
    Tcl_IncrRefCount(pDb->pCollateNeeded);
    sqlite3_collation_needed(pDb->db, pDb, tclCollateNeeded);
    break;
  }

  /*    $db complete SQL
  **
  ** Return TRUE if SQL is a complete SQL statement.  Return FALSE if
  ** additional lines of input are needed.  This is similar to the
  ** built-in "info complete" command of Tcl.
  */
  case DB_COMPLETE: {
#ifndef SQLITE_OMIT_COMPLETE
    Tcl_Obj *pResult;
    int isComplete;
    if( objc!=3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "SQL");
      return TCL_ERROR;
    }
    isComplete = sqlite3_complete( Tcl_GetStringFromObj(objv[2], 0) );
    pResult = Tcl_GetObjResult(interp);
    Tcl_SetBooleanObj(pResult, isComplete);
#endif
    break;
  }

  /*
  **    $db errorcode
  **
  ** Return the numeric error code that was returned by the most recent
  ** call to sqlite3_exec().
  */
  case DB_ERRORCODE: {
    Tcl_SetObjResult(interp, Tcl_NewIntObj(sqlite3_errcode(pDb->db)));
    break;
  }
   
  /*
  **    $db eval $sql ?array? ?{  ...code... }?
  **    $db onecolumn $sql
  **
  ** The SQL statement in $sql is evaluated.  For each row, the values are
  ** placed in elements of the array named "array" and ...code... is executed.
  ** If "array" and "code" are omitted, then no callback is every invoked.
  ** If "array" is an empty string, then the values are placed in variables
  ** that have the same name as the fields extracted by the query.
  **
  ** The onecolumn method is the equivalent of:
  **     lindex [$db eval $sql] 0
  */
  case DB_ONECOLUMN:
  case DB_EVAL: {
    char const *zSql;      /* Next SQL statement to execute */
    char const *zLeft;     /* What is left after first stmt in zSql */
    sqlite3_stmt *pStmt;   /* Compiled SQL statment */
    Tcl_Obj *pArray;       /* Name of array into which results are written */
    Tcl_Obj *pScript;      /* Script to run for each result set */
    Tcl_Obj **apParm;      /* Parameters that need a Tcl_DecrRefCount() */
    int nParm;             /* Number of entries used in apParm[] */
    Tcl_Obj *aParm[10];    /* Static space for apParm[] in the common case */
    Tcl_Obj *pRet;         /* Value to be returned */
    SqlPreparedStmt *pPreStmt;  /* Pointer to a prepared statement */
    int rc2;

    if( choice==DB_ONECOLUMN ){
      if( objc!=3 ){
        Tcl_WrongNumArgs(interp, 2, objv, "SQL");
        return TCL_ERROR;
      }
      pRet = 0;
    }else{
      if( objc<3 || objc>5 ){
        Tcl_WrongNumArgs(interp, 2, objv, "SQL ?ARRAY-NAME? ?SCRIPT?");
        return TCL_ERROR;
      }
      pRet = Tcl_NewObj();
      Tcl_IncrRefCount(pRet);
    }
    if( objc==3 ){
      pArray = pScript = 0;
    }else if( objc==4 ){
      pArray = 0;
      pScript = objv[3];
    }else{
      pArray = objv[3];
      if( Tcl_GetString(pArray)[0]==0 ) pArray = 0;
      pScript = objv[4];
    }

    Tcl_IncrRefCount(objv[2]);
    zSql = Tcl_GetStringFromObj(objv[2], 0);
    while( rc==TCL_OK && zSql[0] ){
      int i;                     /* Loop counter */
      int nVar;                  /* Number of bind parameters in the pStmt */
      int nCol;                  /* Number of columns in the result set */
      Tcl_Obj **apColName = 0;   /* Array of column names */
      int len;                   /* String length of zSql */
  
      /* Try to find a SQL statement that has already been compiled and
      ** which matches the next sequence of SQL.
      */
      pStmt = 0;
      pPreStmt = pDb->stmtList;
      len = strlen(zSql);
      if( pPreStmt && sqlite3_expired(pPreStmt->pStmt) ){
        flushStmtCache(pDb);
        pPreStmt = 0;
      }
      for(; pPreStmt; pPreStmt=pPreStmt->pNext){
        int n = pPreStmt->nSql;
        if( len>=n 
            && memcmp(pPreStmt->zSql, zSql, n)==0
            && (zSql[n]==0 || zSql[n-1]==';')
        ){
          pStmt = pPreStmt->pStmt;
          zLeft = &zSql[pPreStmt->nSql];

          /* 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(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;