more templates back into cli
This commit is contained in:
Thomas Reynolds
parent
be5fad55ca
commit
ba01a0a72b
121 changed files with 5 additions and 42 deletions
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@ -0,0 +1,503 @@
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/*
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Copyright 2009 Google Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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/**
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* @fileoverview A concrete example of the cache pattern for building an offline
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* webapplication: a cache for SimpleNotes.
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*/
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google.wspl.simplenotes = google.wspl.simplenotes || {};
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google.logger('start simplenotes.js');
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/**
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* Status keys for the write buffer.
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* @enum {number}
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*/
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google.wspl.simplenotes.WriteBufferStates = {
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/**
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* The update is in flight to the server.
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*/
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INFLIGHT: 1,
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/**
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* The update needs to be (re)sent to the server but is not in flight.
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*/
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SEND: 2,
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/**
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* The update needs to be applied to the cached notes.
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*/
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REAPPLY: 8
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};
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/**
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* Creates a SimpleNotes cache wrapping a backing database.
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* @constructor
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*/
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google.wspl.simplenotes.Cache = function() {
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this.dbms_ = google.wspl.DatabaseFactory.createDatabase(
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'simple-notes', 'http://yourdomain/dbworker.js');
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/**
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* Cache directory is a two-tuple over a range. (Holes
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* must be allowed to support delection.)
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* This is the lower (inclusive) bound of the cached range.
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* @type {number}
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* @private
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*/
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this.start_ = -1;
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/**
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*
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* This is the upper (inclusive) bound of the cached range.
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* @type {number}
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* @private
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*/
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this.end_ = -1;
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/**
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* Start of range of notes known to exist on server at time of last
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* response.
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* @param {number}
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*/
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this.serverStart_ = -1;
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/**
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* End of range of notes known to exist on server at time of last
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* response.
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* @param {number}
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*/
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this.serverEnd_ = -1;
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/**
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* Time of last refresh.
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* @type {number}
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* @private
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*/
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this.lastRefresh_ = -1;
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/**
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* Last missing query.
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* @type {Object}
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* @private
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*/
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this.lastMiss_ = undefined;
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};
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/**
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* Interval between refreshes in milliseconds.
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* @type {number}
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* @private
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*/
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google.wspl.simplenotes.Cache.TIME_BETWEEN_REFRESH_ = 2000;
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google.wspl.simplenotes.Cache.CREATE_CACHED_NOTES_ =
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new google.wspl.Statement(
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'CREATE TABLE IF NOT EXISTS cached_notes (' +
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'noteKey INTEGER UNIQUE PRIMARY KEY,' +
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'subject TEXT,' +
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'body TEXT' +
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');'
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);
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google.wspl.simplenotes.Cache.CREATE_WRITE_BUFFER_ =
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new google.wspl.Statement(
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'CREATE TABLE IF NOT EXISTS write_buffer (' +
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'sequence INTEGER UNIQUE PRIMARY KEY AUTOINCREMENT,' +
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'noteKey INTEGER,' +
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'status INTEGER,' +
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'subject TEXT,' +
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'body TEXT' +
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');'
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);
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google.wspl.simplenotes.Cache.DETERMINE_MIN_KEY_ =
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new google.wspl.Statement(
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'SELECT MIN(noteKey) as minNoteKey FROM cached_notes;');
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google.wspl.simplenotes.Cache.DETERMINE_MAX_KEY_ =
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new google.wspl.Statement(
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'SELECT MAX(noteKey) as maxNoteKey FROM cached_notes;');
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/**
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* Builds a cache and writebuffer combination for notes and then
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* invokes the given callback.
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* @param {function) callback.
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*/
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google.wspl.simplenotes.Cache.prototype.startCache = function(callback) {
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google.logger('startCache');
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var statc = 0;
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var self = this;
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var perStatCallback = function(tx, result) {
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google.logger('perStatCallback');
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if (statc == 4) {
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self.start_ = (result.isValidRow()) ? result.getRow().minNoteKey : -1;
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self.serverStart_ = self.start_; // Temporary. Remove when server exists.
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} else if (statc == 5) {
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self.end_ = (result.isValidRow()) ? result.getRow().maxNoteKey : -1;
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self.serverEnd_ = self.end_; // Temporary. Remove when server exists.
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}
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statc++;
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};
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this.dbms_.executeAll([
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google.wspl.simplenotes.Cache.CREATE_CACHED_NOTES_,
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google.wspl.simplenotes.Cache.CREATE_WRITE_BUFFER_,
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google.wspl.simplenotes.Cache.CREATE_UPDATE_TRIGGER_,
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google.wspl.simplenotes.Cache.CREATE_REPLAY_TRIGGER_,
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google.wspl.simplenotes.Cache.DETERMINE_MIN_KEY_,
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google.wspl.simplenotes.Cache.DETERMINE_MAX_KEY_],
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{onSuccess: perStatCallback, onFailure: this.logError_},
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{onSuccess: callback, onFailure: this.logError_});
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google.logger('finished startCache');
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};
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/**
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* Stub function to be replaced with a server communication.
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* @param {Array.<Object>} updates Payload to send to server.
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*/
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google.wspl.simplenotes.Cache.prototype.sendXhrPost = function(updates) {
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google.logger('Should dispatch XHR to server now.');
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};
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/**
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* @type {google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.LIST_CACHED_NOTES_ =
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new google.wspl.Statement(
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'SELECT noteKey, subject from cached_notes WHERE ' +
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'noteKey >= ? AND ' +
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'noteKey <= ? ' +
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';'
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);
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/**
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* Tests if the given range is stored in the cache.
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* Note that this mechanism requires extension to handle the
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* creation of new notes.
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* @param {number} start Lower bound (inclusive) on range.
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* @param {number} end Uppder bound (inclusive) on range.
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* @private
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*/
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google.wspl.simplenotes.Cache.prototype.isCacheHit_ = function(start, end) {
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return start >= this.start_ && end <= this.end_
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};
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/**
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* Logs a possibly useful error message.
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* @param {Object} error An error descriptor.
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* @private
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*/
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google.wspl.simplenotes.Cache.prototype.logError_ = function(error) {
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google.logger('Simple Notes Cache is sad: ' + error);
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};
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/**
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* Queries the cache for a list of note headers.
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* @param {number} start The lower id in a range of notes.
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* @param {number} end The higher id in a range of notes.
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* @param {function(Array.<Object>)} valuesCallback A function to call
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* with the result set after the transaction has completed.
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* @private
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*/
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google.wspl.simplenotes.Cache.prototype.getNoteList_ = function(start, end,
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valuesCallback) {
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var notes = [];
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var accumulateResults = function(tx, result) {
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for(; result.isValidRow(); result.next()) {
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notes.push(result.getRow());
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google.logger('pushed...');
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}
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};
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var inTransactionGetNotes = function(tx) {
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tx.execute(google.wspl.simplenotes.Cache.LIST_CACHED_NOTES_.
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createStatement([start, end]), {
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onSuccess: accumulateResults,
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onFailure: this.logError_});
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};
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var hit = this.isCacheHit_(start, end);
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this.dbms_.createTransaction(inTransactionGetNotes, {onSuccess: function() {
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valuesCallback(notes, hit);
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}, onFailure: this.logError_});
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if (hit) {
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this.fetchFromServer(this.start_, this.end_); // Refresh
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} else {
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this.fetchFromServer(Math.min(this.start_, start), Math.max(this.end_, end));
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this.lastMiss_ = {callback: valuesCallback, start: start, end: end};
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}
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};
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/**
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* @type {google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.GET_ONE_NOTE_ =
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new google.wspl.Statement(
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'SELECT noteKey, subject, body from cached_notes WHERE ' +
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'noteKey = ? ' +
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';'
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);
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/**
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* Queries the cache for a list of note headers.
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* @param {number} noteId The note to get from the cache.
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* @param {function(Array.<Object>)} valuesCallback A function to call
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* with the result set after the transaction has completed.
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* @private
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*/
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google.wspl.simplenotes.Cache.prototype.getOneNote_ = function(noteId,
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callback) {
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var note;
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this.dbms_.execute(google.wspl.simplenotes.Cache.GET_ONE_NOTE_.
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createStatement([noteId]),
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{onSuccess: function(tx, result) { note = result.getRow(); },
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onFailure: this.logError_},
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{onSuccess: function() { callback(note, true); },
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onFailure: this.logError_});
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};
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/**
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* Queries the cache for either a list of notes or a single note including
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* its body.
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* @param {string} type The kind of values desired: 'list' or 'fullnote'.
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* @param {Array.<number>} query The query for the values.
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* @param {function(Array.<Object>)} valuesCallback A function to call
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* with the result set after the transaction has completed.
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*/
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google.wspl.simplenotes.Cache.prototype.getValues = function(type,
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query, valuesCallback) {
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// Reduce any query to what would be available from the server
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query[0] = Math.max(this.serverStart_, query[0]);
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query[1] = Math.min(this.serverEnd_, query[1]);
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if (type == 'list') {
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this.getNoteList_(query[0], query[1], valuesCallback);
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} else if (type == 'fullnote') {
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this.getOneNote_(query[0], valuesCallback);
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}
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};
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/**
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* SQL trigger to insert a new change from write buffer to
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* cache.
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* @private
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*/
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google.wspl.simplenotes.Cache.CREATE_UPDATE_TRIGGER_ =
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new google.wspl.Statement(
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'CREATE TRIGGER IF NOT EXISTS updateTrigger ' +
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'AFTER INSERT ON write_buffer ' +
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'BEGIN ' +
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' REPLACE INTO cached_notes ' +
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' SELECT noteKey, subject, body ' +
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' FROM write_buffer WHERE status & 8 = 8; ' +
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' UPDATE write_buffer SET status = status & ~ 8; ' +
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'END;'
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);
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/**
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* SQL trigger to replay changes from the write buffer to
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* the cache.
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* @private
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*/
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google.wspl.simplenotes.Cache.CREATE_REPLAY_TRIGGER_ =
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new google.wspl.Statement(
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'CREATE TRIGGER IF NOT EXISTS replayTrigger ' +
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'AFTER UPDATE ON write_buffer WHEN NEW.status & 8 = 8 ' +
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'BEGIN ' +
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' REPLACE INTO cached_notes ' +
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' SELECT noteKey, subject, body ' +
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' FROM write_buffer ' +
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' WHERE noteKey = NEW.noteKey ' +
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' ORDER BY sequence ASC;' +
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' UPDATE write_buffer SET status = status & ~ 8; ' +
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'END;'
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);
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/**
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* SQL statement to mark actions for replay.
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*/
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google.wspl.simplenotes.Cache.MARK_FOR_REPLAY =
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new google.wspl.Statement(
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'UPDATE write_buffer SET status = status | 8;');
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/**
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* SQL statement to insert notes updates.
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* @type {!google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.INSERT_UI_UPDATE_ =
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new google.wspl.Statement(
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'INSERT INTO write_buffer (' +
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'noteKey, status, subject, body' +
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') ' + 'VALUES(?,?,?,?);');
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/**
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* Updates the given entry and write a new write buffer entry.
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* @param {number} noteKey
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* @param {string} subject
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* @param {string} body
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* @param {function(number)} ackCallback
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*/
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google.wspl.simplenotes.Cache.prototype.applyUiChange = function(noteKey,
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subject, body, ackCallback) {
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var self = this;
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var update = [noteKey, 2 | 8, subject, body];
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var stat = google.wspl.simplenotes.Cache.INSERT_UI_UPDATE_.createStatement(
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update);
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this.dbms_.execute(stat, null, {onSuccess: function() {
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google.logger('applyUiChange cb');
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ackCallback(noteKey);
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}, onFailure: function (error) {
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self.logError_(error);
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ackCallback(-1);
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}});
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};
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/**
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* SQL statement to insert notes updates.
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* @type {!google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.INSERT_NOTE_ =
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new google.wspl.Statement(
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'REPLACE INTO cached_notes (noteKey, subject, body) ' +
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'VALUES(?,?,?);' );
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/**
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* SQL statement to force replay of pending actions by setting a bit
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* flag on each write-buffer row indicating that it should be reapplied
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* to the contents of the cache.
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* @type {!google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.FORCE_REPLAY_ =
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new google.wspl.Statement(
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'UPDATE write_buffer SET status = status | 8;' );
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/**
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* SQL statement to delete notes no longer to be cached.
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* @type {!google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.EVICT_ =
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new google.wspl.Statement(
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'DELETE FROM cached_notes WHERE noteKey < ? OR noteKey > ?;');
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/**
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* Applies the changes delivered from the server by first inserting
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* them into the cache and reapplying the write-buffer to the cache.
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* @param {!Array.<Object>} notes An array of arrays.
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*/
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google.wspl.simplenotes.Cache.prototype.insertUpdate = function(notes) {
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var self = this; var stats = [];
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var start = notes[0].noteKey;
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var end = notes[0].noteKey;
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for (var i = 0; i < notes.length; i++) {
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stats.push(google.wspl.simplenotes.Cache.INSERT_NOTE_.
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createStatement([notes[i].noteKey, notes[i].subject, notes[i].body]));
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start = Math.min(start, notes[0].noteKey);
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end = Math.max(end, notes[0].noteKey);
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}
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stats.push(google.wspl.simplenotes.Cache.EVICT_.createStatement([start, end]));
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stats.push(google.wspl.simplenotes.Cache.FORCE_REPLAY_);
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var inTrans = function(tx) {
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self.start_ = start;
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self.end_ = end;
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tx.executeAll(stats);
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};
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var afterInsert = function(tx) {
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if (this.lastMiss_ &&
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this.isCacheHit_(this.lastMiss_.start, this.lastMiss_.end)) {
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this.lastMiss_.callback(notes);
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this.lastMiss_ = undefined;
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}
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};
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this.dbms_.createTransaction(inTrans, {onSuccess: afterInsert,
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onError: this.logError_});
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};
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/**
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* SQL statement to force replay of pending actions by setting a bit
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* flag on each write-buffer row indicating that it should be reapplied
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* to the contents of the cache.
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* @type {!google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.GET_UPDATES_TO_RESEND_ =
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new google.wspl.Statement(
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'SELECT noteKey, subject, body FROM write_buffer WHERE status & 2 = 2;');
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/**
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* SQL statement to mark write buffer statements as inflight.
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* @type {!google.wspl.Statement}
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* @private
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*/
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google.wspl.simplenotes.Cache.MARK_AS_INFLIGHT_ =
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new google.wspl.Statement(
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'UPDATE write_buffer SET status = status & ~2 | 1 WHERE status & 2 = 2;');
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/**
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* Fetches new material from the server as required.
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* @param {number} start
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* @param {number} end
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* @param {function} opt_valueCallBack
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*/
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google.wspl.simplenotes.Cache.prototype.fetchFromServer = function(start,
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end) {
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google.logger('fetchFromServer');
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var now = this.dbms_.getCurrentTime();
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if (start >= this.start_ && end <= this.end_ &&
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now - this.lastRefresh_ <
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google.wspl.simplenotes.Cache.TIME_BETWEEN_REFRESH_) {
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return;
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}
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var updates = []; var self = this; var flag = 1; var sql = []
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sql.push(google.wspl.simplenotes.Cache.GET_UPDATES_TO_RESEND_);
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sql.push(google.wspl.simplenotes.Cache.MARK_AS_INFLIGHT_);
|
||||
|
||||
var accumulateUpdates = function(tx, rs) {
|
||||
if (flag == 1) {
|
||||
for(; rs.isValidRow(); rs.next()) { updates.push(['u', rs.getRow()]); }
|
||||
flag++;
|
||||
}
|
||||
};
|
||||
|
||||
var ackAndPost = function() {
|
||||
updates.push(['q', {start: start, end: end}]);
|
||||
self.sendXhrPost(updates);
|
||||
};
|
||||
|
||||
this.dbms_.executeAll(sql,
|
||||
{onSuccess: accumulateUpdates, onFailure: this.logError_},
|
||||
{onSuccess: ackAndPost, onFailure: this.logError_});
|
||||
};
|
||||
Loading…
Add table
Add a link
Reference in a new issue