sqlite.js

/*
Copyright (c) 2009, Eric Fredricksen <e@fredricksen.net>

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

// TODO: async

function mixin(target, source) {
  for (var name in source) {
    if (source.hasOwnProperty(name))
      target[name] = source[name];
  }
}

var bindings = require("./sqlite3_bindings");
mixin(GLOBAL, bindings);
mixin(exports, bindings);

var EventEmitter = require('events').EventEmitter;
extend(true, DatabaseSync.prototype, EventEmitter.prototype);

/**
 * Adopted from jquery's extend method. Under the terms of MIT License.
 *
 * http://code.jquery.com/jquery-1.4.2.js
 *
 * Modified by Brian White to use Array.isArray instead of the custom isArray
 * method
 */
function extend() {
  // copy reference to target object
  var target = arguments[0] || {},
      i = 1,
      length = arguments.length,
      deep = false,
      options,
      name,
      src,
      copy;

  // Handle a deep copy situation
  if (typeof target === "boolean") {
    deep = target;
    target = arguments[1] || {};
    // skip the boolean and the target
    i = 2;
  }

  // Handle case when target is a string or something (possible in deep copy)
  if (typeof target !== "object" && !typeof target === 'function')
    target = {};

  var isPlainObject = function(obj) {
    // Must be an Object.
    // Because of IE, we also have to check the presence of the constructor
    // property.
    // Make sure that DOM nodes and window objects don't pass through, as well
    if (!obj || toString.call(obj) !== "[object Object]" || obj.nodeType
        || obj.setInterval)
      return false;
    
    var has_own_constructor = hasOwnProperty.call(obj, "constructor");
    var has_is_prop_of_method = hasOwnProperty.call(obj.constructor.prototype,
                                                    "isPrototypeOf");
    // Not own constructor property must be Object
    if (obj.constructor && !has_own_constructor && !has_is_prop_of_method)
      return false;
    
    // Own properties are enumerated firstly, so to speed up,
    // if last one is own, then all properties are own.

    var last_key;
    for (key in obj)
      last_key = key;
    
    return typeof last_key === "undefined" || hasOwnProperty.call(obj, last_key);
  };


  for (; i < length; i++) {
    // Only deal with non-null/undefined values
    if ((options = arguments[i]) !== null) {
      // Extend the base object
      for (name in options) {
        src = target[name];
        copy = options[name];

        // Prevent never-ending loop
        if (target === copy)
            continue;

        // Recurse if we're merging object literal values or arrays
        if (deep && copy && (isPlainObject(copy) || Array.isArray(copy))) {
          var clone = src && (isPlainObject(src) || Array.isArray(src)
                              ? src : (Array.isArray(copy) ? [] : {}));

          // Never move original objects, clone them
          target[name] = extend(deep, clone, copy);

        // Don't bring in undefined values
        } else if (typeof copy !== "undefined")
          target[name] = copy;
      }
    }
  }

  // Return the modified object
  return target;
};

// Conform somewhat to http://dev.w3.org/html5/webdatabase/#sql

exports.SQLITE_DELETE = 9;
exports.SQLITE_INSERT = 18;
exports.SQLITE_UPDATE = 23;


exports.openDatabaseSync = function (name, version, displayName, 
                                     estimatedSize, creationCallback) {
  // 2nd-4th parameters are ignored
  var db = new DatabaseSync(name);
  if (creationCallback) creationCallback(db);
  return db;
}


DatabaseSync.prototype.query = function (sql, bindings, callback) {
  // TODO: error callback
  if (typeof(bindings) == "function") {
    var tmp = bindings;
    bindings = callback;
    callback = tmp;
  }

  var all = [];
  
  var stmt = this.prepare(sql);
  while(stmt) {
    if (bindings) {
      if (Object.prototype.toString.call(bindings) === "[object Array]") {
        for (var i = 0; i < stmt.bindParameterCount(); ++i)
          stmt.bind(i+1, bindings.shift());
      } else {
        for (var key in bindings) 
          if (bindings.hasOwnProperty(key))
            stmt.bind(key, bindings[key]);
      }
    }
      
    var rows = [];

    while (true) {
      var row = stmt.step();
      if (!row) break;
      rows.push(row);
    }

    rows.rowsAffected = this.changes();
    rows.insertId = this.lastInsertRowid();

    all.push(rows);

    stmt.finalize();
    stmt = this.prepare(stmt.tail);
  }

  if (all.length == 0) {
    var result = null;
  } else {
    for (var i = 0; i < all.length; ++i) {
      var resultset = all[i];
      resultset.all = all;
      resultset.rows = {item: function (index) { return resultset[index]; },
                        length: resultset.length};
    }
    var result = all[0];
  }
  if (typeof(callback) == "function") {
    callback.apply(result, all);
  }
  return result;
}



// TODO: void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
// TODO: void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);


function SQLTransactionSync(db, txCallback, errCallback, successCallback) {
  this.database = db;

  this.rolledBack = false;

  this.executeSql = function(sqlStatement, arguments, callback) {
    if (this.rolledBack) return;
    var result = db.query(sqlStatement, arguments);
    if (callback) {
      var tx = this;
      callback.apply(result, [tx].concat(result.all));
    }
    return result;
  }

  var that = this;
  function unroll() {
    that.rolledBack = true;
  }
    
  db.addListener("rollback", unroll);

  this.executeSql("BEGIN TRANSACTION");
  txCallback(this);
  this.executeSql("COMMIT");

  db.removeListener("rollback", unroll);

  if (!this.rolledBack && successCallback) {
    successCallback(this);
  } else if (this.rolledBack && errCallback) {
    errCallback(this);
  }
}


DatabaseSync.prototype.transaction = function (txCallback, errCallback, 
                                               successCallback) {
  var tx = new SQLTransactionSync(this, txCallback, 
                                  errCallback, successCallback);
}

// TODO: readTransaction()