You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@olingo.apache.org by bi...@apache.org on 2014/05/09 09:22:31 UTC
[22/24] a) Convert all the DataJS supported functionality from V3 to
V4. 1. Remove all the Json verbose logic,
make the DataJS accepted and returned javascript object be in Json light
format. (Since Json verbose has been completely removed on V4, making
http://git-wip-us.apache.org/repos/asf/olingo-odata4-js/blob/e387fc92/JSLib/src/cache.js
----------------------------------------------------------------------
diff --git a/JSLib/src/cache.js b/JSLib/src/cache.js
index b3a3a01..fd43093 100644
--- a/JSLib/src/cache.js
+++ b/JSLib/src/cache.js
@@ -1,1349 +1,1361 @@
-/// <reference path="odata-utils.js" />
-
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
-// files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,
-// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
-// Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
-// WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-// cache.js
-
-(function (window, undefined) {
-
- var datajs = window.datajs || {};
-
- var assigned = datajs.assigned;
- var delay = datajs.delay;
- var extend = datajs.extend;
- var djsassert = datajs.djsassert;
- var isArray = datajs.isArray;
- var normalizeURI = datajs.normalizeURI;
- var parseInt10 = datajs.parseInt10;
- var undefinedDefault = datajs.undefinedDefault;
-
- var createDeferred = datajs.createDeferred;
- var DjsDeferred = datajs.DjsDeferred;
- var ODataCacheSource = datajs.ODataCacheSource;
-
- // CONTENT START
-
- var appendPage = function (operation, page) {
- /// <summary>Appends a page's data to the operation data.</summary>
- /// <param name="operation" type="Object">Operation with (i)ndex, (c)ount and (d)ata.</param>
- /// <param name="page" type="Object">Page with (i)ndex, (c)ount and (d)ata.</param>
-
- var intersection = intersectRanges(operation, page);
- if (intersection) {
- var start = intersection.i - page.i;
- var end = start + (operation.c - operation.d.length);
- operation.d = operation.d.concat(page.d.slice(start, end));
- }
- };
-
- var intersectRanges = function (x, y) {
- /// <summary>Returns the {(i)ndex, (c)ount} range for the intersection of x and y.</summary>
- /// <param name="x" type="Object">Range with (i)ndex and (c)ount members.</param>
- /// <param name="y" type="Object">Range with (i)ndex and (c)ount members.</param>
- /// <returns type="Object">The intersection (i)ndex and (c)ount; undefined if there is no intersection.</returns>
-
- var xLast = x.i + x.c;
- var yLast = y.i + y.c;
- var resultIndex = (x.i > y.i) ? x.i : y.i;
- var resultLast = (xLast < yLast) ? xLast : yLast;
- var result;
- if (resultLast >= resultIndex) {
- result = { i: resultIndex, c: resultLast - resultIndex };
- }
-
- return result;
- };
-
- var checkZeroGreater = function (val, name) {
- /// <summary>Checks whether val is a defined number with value zero or greater.</summary>
- /// <param name="val" type="Number">Value to check.</param>
- /// <param name="name" type="String">Parameter name to use in exception.</param>
-
- if (val === undefined || typeof val !== "number") {
- throw { message: "'" + name + "' must be a number." };
- }
-
- if (isNaN(val) || val < 0 || !isFinite(val)) {
- throw { message: "'" + name + "' must be greater than or equal to zero." };
- }
- };
-
- var checkUndefinedGreaterThanZero = function (val, name) {
- /// <summary>Checks whether val is undefined or a number with value greater than zero.</summary>
- /// <param name="val" type="Number">Value to check.</param>
- /// <param name="name" type="String">Parameter name to use in exception.</param>
-
- if (val !== undefined) {
- if (typeof val !== "number") {
- throw { message: "'" + name + "' must be a number." };
- }
-
- if (isNaN(val) || val <= 0 || !isFinite(val)) {
- throw { message: "'" + name + "' must be greater than zero." };
- }
- }
- };
-
- var checkUndefinedOrNumber = function (val, name) {
- /// <summary>Checks whether val is undefined or a number</summary>
- /// <param name="val" type="Number">Value to check.</param>
- /// <param name="name" type="String">Parameter name to use in exception.</param>
- if (val !== undefined && (typeof val !== "number" || isNaN(val) || !isFinite(val))) {
- throw { message: "'" + name + "' must be a number." };
- }
- };
-
- var removeFromArray = function (arr, item) {
- /// <summary>Performs a linear search on the specified array and removes the first instance of 'item'.</summary>
- /// <param name="arr" type="Array">Array to search.</param>
- /// <param name="item">Item being sought.</param>
- /// <returns type="Boolean">Whether the item was removed.</returns>
-
- var i, len;
- for (i = 0, len = arr.length; i < len; i++) {
- if (arr[i] === item) {
- arr.splice(i, 1);
- return true;
- }
- }
-
- return false;
- };
-
- var estimateSize = function (obj) {
- /// <summary>Estimates the size of an object in bytes.</summary>
- /// <param name="obj" type="Object">Object to determine the size of.</param>
- /// <returns type="Integer">Estimated size of the object in bytes.</returns>
- var size = 0;
- var type = typeof obj;
-
- if (type === "object" && obj) {
- for (var name in obj) {
- size += name.length * 2 + estimateSize(obj[name]);
- }
- } else if (type === "string") {
- size = obj.length * 2;
- } else {
- size = 8;
- }
- return size;
- };
-
- var snapToPageBoundaries = function (lowIndex, highIndex, pageSize) {
- /// <summary>Snaps low and high indices into page sizes and returns a range.</summary>
- /// <param name="lowIndex" type="Number">Low index to snap to a lower value.</param>
- /// <param name="highIndex" type="Number">High index to snap to a higher value.</param>
- /// <param name="pageSize" type="Number">Page size to snap to.</param>
- /// <returns type="Object">A range with (i)ndex and (c)ount of elements.</returns>
-
- lowIndex = Math.floor(lowIndex / pageSize) * pageSize;
- highIndex = Math.ceil((highIndex + 1) / pageSize) * pageSize;
- return { i: lowIndex, c: highIndex - lowIndex };
- };
-
- // The DataCache is implemented using state machines. The following constants are used to properly
- // identify and label the states that these machines transition to.
-
- // DataCache state constants
-
- var CACHE_STATE_DESTROY = "destroy";
- var CACHE_STATE_IDLE = "idle";
- var CACHE_STATE_INIT = "init";
- var CACHE_STATE_READ = "read";
- var CACHE_STATE_PREFETCH = "prefetch";
- var CACHE_STATE_WRITE = "write";
-
- // DataCacheOperation state machine states.
- // Transitions on operations also depend on the cache current of the cache.
-
- var OPERATION_STATE_CANCEL = "cancel";
- var OPERATION_STATE_END = "end";
- var OPERATION_STATE_ERROR = "error";
- var OPERATION_STATE_START = "start";
- var OPERATION_STATE_WAIT = "wait";
-
- // Destroy state machine states
-
- var DESTROY_STATE_CLEAR = "clear";
-
- // Read / Prefetch state machine states
-
- var READ_STATE_DONE = "done";
- var READ_STATE_LOCAL = "local";
- var READ_STATE_SAVE = "save";
- var READ_STATE_SOURCE = "source";
-
- var DataCacheOperation = function (stateMachine, promise, isCancelable, index, count, data, pending) {
- /// <summary>Creates a new operation object.</summary>
- /// <param name="stateMachine" type="Function">State machine that describes the specific behavior of the operation.</param>
- /// <param name="promise" type ="DjsDeferred">Promise for requested values.</param>
- /// <param name="isCancelable" type ="Boolean">Whether this operation can be canceled or not.</param>
- /// <param name="index" type="Number">Index of first item requested.</param>
- /// <param name="count" type="Number">Count of items requested.</param>
- /// <param name="data" type="Array">Array with the items requested by the operation.</param>
- /// <param name="pending" type="Number">Total number of pending prefetch records.</param>
- /// <returns type="DataCacheOperation">A new data cache operation instance.</returns>
-
- /// <field name="p" type="DjsDeferred">Promise for requested values.</field>
- /// <field name="i" type="Number">Index of first item requested.</field>
- /// <field name="c" type="Number">Count of items requested.</field>
- /// <field name="d" type="Array">Array with the items requested by the operation.</field>
- /// <field name="s" type="Array">Current state of the operation.</field>
- /// <field name="canceled" type="Boolean">Whether the operation has been canceled.</field>
- /// <field name="pending" type="Number">Total number of pending prefetch records.</field>
- /// <field name="oncomplete" type="Function">Callback executed when the operation reaches the end state.</field>
-
- var stateData;
- var cacheState;
- var that = this;
-
- that.p = promise;
- that.i = index;
- that.c = count;
- that.d = data;
- that.s = OPERATION_STATE_START;
-
- that.canceled = false;
- that.pending = pending;
- that.oncomplete = null;
-
- that.cancel = function () {
- /// <summary>Transitions this operation to the cancel state and sets the canceled flag to true.</summary>
- /// <remarks>The function is a no-op if the operation is non-cancelable.</summary>
-
- if (!isCancelable) {
- return;
- }
-
- var state = that.s;
- if (state !== OPERATION_STATE_ERROR && state !== OPERATION_STATE_END && state !== OPERATION_STATE_CANCEL) {
- that.canceled = true;
- transition(OPERATION_STATE_CANCEL, stateData);
- }
- };
-
- that.complete = function () {
- /// <summary>Transitions this operation to the end state.</summary>
-
- djsassert(that.s !== OPERATION_STATE_END, "DataCacheOperation.complete() - operation is in the end state", that);
- transition(OPERATION_STATE_END, stateData);
- };
-
- that.error = function (err) {
- /// <summary>Transitions this operation to the error state.</summary>
- if (!that.canceled) {
- djsassert(that.s !== OPERATION_STATE_END, "DataCacheOperation.error() - operation is in the end state", that);
- djsassert(that.s !== OPERATION_STATE_ERROR, "DataCacheOperation.error() - operation is in the error state", that);
- transition(OPERATION_STATE_ERROR, err);
- }
- };
-
- that.run = function (state) {
- /// <summary>Executes the operation's current state in the context of a new cache state.</summary>
- /// <param name="state" type="Object">New cache state.</param>
-
- cacheState = state;
- that.transition(that.s, stateData);
- };
-
- that.wait = function (data) {
- /// <summary>Transitions this operation to the wait state.</summary>
-
- djsassert(that.s !== OPERATION_STATE_END, "DataCacheOperation.wait() - operation is in the end state", that);
- transition(OPERATION_STATE_WAIT, data);
- };
-
- var operationStateMachine = function (opTargetState, cacheState, data) {
- /// <summary>State machine that describes all operations common behavior.</summary>
- /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
- /// <param name="cacheState" type="Object">Current cache state.</param>
- /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
-
- switch (opTargetState) {
- case OPERATION_STATE_START:
- // Initial state of the operation. The operation will remain in this state until the cache has been fully initialized.
- if (cacheState !== CACHE_STATE_INIT) {
- stateMachine(that, opTargetState, cacheState, data);
- }
- break;
-
- case OPERATION_STATE_WAIT:
- // Wait state indicating that the operation is active but waiting for an asynchronous operation to complete.
- stateMachine(that, opTargetState, cacheState, data);
- break;
-
- case OPERATION_STATE_CANCEL:
- // Cancel state.
- stateMachine(that, opTargetState, cacheState, data);
- that.fireCanceled();
- transition(OPERATION_STATE_END);
- break;
-
- case OPERATION_STATE_ERROR:
- // Error state. Data is expected to be an object detailing the error condition.
- stateMachine(that, opTargetState, cacheState, data);
- that.canceled = true;
- that.fireRejected(data);
- transition(OPERATION_STATE_END);
- break;
-
- case OPERATION_STATE_END:
- // Final state of the operation.
- if (that.oncomplete) {
- that.oncomplete(that);
- }
- if (!that.canceled) {
- that.fireResolved();
- }
- stateMachine(that, opTargetState, cacheState, data);
- break;
-
- default:
- // Any other state is passed down to the state machine describing the operation's specific behavior.
- // DATAJS INTERNAL START
- if (true) {
- // Check that the state machine actually handled the sate.
- var handled = stateMachine(that, opTargetState, cacheState, data);
- djsassert(handled, "Bad operation state: " + opTargetState + " cacheState: " + cacheState, this);
- } else {
- // DATAJS INTERNAL END
- stateMachine(that, opTargetState, cacheState, data);
- // DATAJS INTERNAL START
- }
- // DATAJS INTERNAL END
- break;
- }
- };
-
- var transition = function (state, data) {
- /// <summary>Transitions this operation to a new state.</summary>
- /// <param name="state" type="Object">State to transition the operation to.</param>
- /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
-
- that.s = state;
- stateData = data;
- operationStateMachine(state, cacheState, data);
- };
-
- that.transition = transition;
-
- return that;
- };
-
- DataCacheOperation.prototype.fireResolved = function () {
- /// <summary>Fires a resolved notification as necessary.</summary>
-
- // Fire the resolve just once.
- var p = this.p;
- if (p) {
- this.p = null;
- p.resolve(this.d);
- }
- };
-
- DataCacheOperation.prototype.fireRejected = function (reason) {
- /// <summary>Fires a rejected notification as necessary.</summary>
-
- // Fire the rejection just once.
- var p = this.p;
- if (p) {
- this.p = null;
- p.reject(reason);
- }
- };
-
- DataCacheOperation.prototype.fireCanceled = function () {
- /// <summary>Fires a canceled notification as necessary.</summary>
-
- this.fireRejected({ canceled: true, message: "Operation canceled" });
- };
-
-
- var DataCache = function (options) {
- /// <summary>Creates a data cache for a collection that is efficiently loaded on-demand.</summary>
- /// <param name="options">
- /// Options for the data cache, including name, source, pageSize,
- /// prefetchSize, cacheSize, storage mechanism, and initial prefetch and local-data handler.
- /// </param>
- /// <returns type="DataCache">A new data cache instance.</returns>
-
- var state = CACHE_STATE_INIT;
- var stats = { counts: 0, netReads: 0, prefetches: 0, cacheReads: 0 };
-
- var clearOperations = [];
- var readOperations = [];
- var prefetchOperations = [];
-
- var actualCacheSize = 0; // Actual cache size in bytes.
- var allDataLocal = false; // Whether all data is local.
- var cacheSize = undefinedDefault(options.cacheSize, 1048576); // Requested cache size in bytes, default 1 MB.
- var collectionCount = 0; // Number of elements in the server collection.
- var highestSavedPage = 0; // Highest index of all the saved pages.
- var highestSavedPageSize = 0; // Item count of the saved page with the highest index.
- var overflowed = cacheSize === 0; // If the cache has overflowed (actualCacheSize > cacheSize or cacheSize == 0);
- var pageSize = undefinedDefault(options.pageSize, 50); // Number of elements to store per page.
- var prefetchSize = undefinedDefault(options.prefetchSize, pageSize); // Number of elements to prefetch from the source when the cache is idling.
- var version = "1.0";
- var cacheFailure;
-
- var pendingOperations = 0;
-
- var source = options.source;
- if (typeof source === "string") {
- // Create a new cache source.
- source = new ODataCacheSource(options);
- }
- source.options = options;
-
- // Create a cache local store.
- var store = datajs.createStore(options.name, options.mechanism);
-
- var that = this;
-
- that.onidle = options.idle;
- that.stats = stats;
-
- that.count = function () {
- /// <summary>Counts the number of items in the collection.</summary>
- /// <returns type="Object">A promise with the number of items.</returns>
-
- if (cacheFailure) {
- throw cacheFailure;
- }
-
- var deferred = createDeferred();
- var canceled = false;
-
- if (allDataLocal) {
- delay(function () {
- deferred.resolve(collectionCount);
- });
-
- return deferred.promise();
- }
-
- // TODO: Consider returning the local data count instead once allDataLocal flag is set to true.
- var request = source.count(function (count) {
- request = null;
- stats.counts++;
- deferred.resolve(count);
- }, function (err) {
- request = null;
- deferred.reject(extend(err, { canceled: canceled }));
- });
-
- return extend(deferred.promise(), {
- cancel: function () {
- /// <summary>Aborts the count operation.</summary>
- if (request) {
- canceled = true;
- request.abort();
- request = null;
- }
- }
- });
- };
-
- that.clear = function () {
- /// <summary>Cancels all running operations and clears all local data associated with this cache.</summary>
- /// <remarks>
- /// New read requests made while a clear operation is in progress will not be canceled.
- /// Instead they will be queued for execution once the operation is completed.
- /// </remarks>
- /// <returns type="Object">A promise that has no value and can't be canceled.</returns>
-
- if (cacheFailure) {
- throw cacheFailure;
- }
-
- if (clearOperations.length === 0) {
- var deferred = createDeferred();
- var op = new DataCacheOperation(destroyStateMachine, deferred, false);
- queueAndStart(op, clearOperations);
- return deferred.promise();
- }
- return clearOperations[0].p;
- };
-
- that.filterForward = function (index, count, predicate) {
- /// <summary>Filters the cache data based a predicate.</summary>
- /// <param name="index" type="Number">The index of the item to start filtering forward from.</param>
- /// <param name="count" type="Number">Maximum number of items to include in the result.</param>
- /// <param name="predicate" type="Function">Callback function returning a boolean that determines whether an item should be included in the result or not.</param>
- /// <remarks>
- /// Specifying a negative count value will yield all the items in the cache that satisfy the predicate.
- /// </remarks>
- /// <returns type="DjsDeferred">A promise for an array of results.</returns>
- return filter(index, count, predicate, false);
- };
-
- that.filterBack = function (index, count, predicate) {
- /// <summary>Filters the cache data based a predicate.</summary>
- /// <param name="index" type="Number">The index of the item to start filtering backward from.</param>
- /// <param name="count" type="Number">Maximum number of items to include in the result.</param>
- /// <param name="predicate" type="Function">Callback function returning a boolean that determines whether an item should be included in the result or not.</param>
- /// <remarks>
- /// Specifying a negative count value will yield all the items in the cache that satisfy the predicate.
- /// </remarks>
- /// <returns type="DjsDeferred">A promise for an array of results.</returns>
- return filter(index, count, predicate, true);
- };
-
- that.readRange = function (index, count) {
- /// <summary>Reads a range of adjacent records.</summary>
- /// <param name="index" type="Number">Zero-based index of record range to read.</param>
- /// <param name="count" type="Number">Number of records in the range.</param>
- /// <remarks>
- /// New read requests made while a clear operation is in progress will not be canceled.
- /// Instead they will be queued for execution once the operation is completed.
- /// </remarks>
- /// <returns type="DjsDeferred">
- /// A promise for an array of records; less records may be returned if the
- /// end of the collection is found.
- /// </returns>
-
- checkZeroGreater(index, "index");
- checkZeroGreater(count, "count");
-
- if (cacheFailure) {
- throw cacheFailure;
- }
-
- var deferred = createDeferred();
-
- // Merging read operations would be a nice optimization here.
- var op = new DataCacheOperation(readStateMachine, deferred, true, index, count, [], 0);
- queueAndStart(op, readOperations);
-
- return extend(deferred.promise(), {
- cancel: function () {
- /// <summary>Aborts the readRange operation.</summary>
- op.cancel();
- }
- });
- };
-
- that.ToObservable = that.toObservable = function () {
- /// <summary>Creates an Observable object that enumerates all the cache contents.</summary>
- /// <returns>A new Observable object that enumerates all the cache contents.</returns>
- if (!window.Rx || !window.Rx.Observable) {
- throw { message: "Rx library not available - include rx.js" };
- }
-
- if (cacheFailure) {
- throw cacheFailure;
- }
-
- return window.Rx.Observable.CreateWithDisposable(function (obs) {
- var disposed = false;
- var index = 0;
-
- var errorCallback = function (error) {
- if (!disposed) {
- obs.OnError(error);
- }
- };
-
- var successCallback = function (data) {
- if (!disposed) {
- var i, len;
- for (i = 0, len = data.length; i < len; i++) {
- // The wrapper automatically checks for Dispose
- // on the observer, so we don't need to check it here.
- obs.OnNext(data[i]);
- }
-
- if (data.length < pageSize) {
- obs.OnCompleted();
- } else {
- index += pageSize;
- that.readRange(index, pageSize).then(successCallback, errorCallback);
- }
- }
- };
-
- that.readRange(index, pageSize).then(successCallback, errorCallback);
-
- return { Dispose: function () { disposed = true; } };
- });
- };
-
- var cacheFailureCallback = function (message) {
- /// <summary>Creates a function that handles a callback by setting the cache into failure mode.</summary>
- /// <param name="message" type="String">Message text.</param>
- /// <returns type="Function">Function to use as error callback.</returns>
- /// <remarks>
- /// This function will specifically handle problems with critical store resources
- /// during cache initialization.
- /// </remarks>
-
- return function (error) {
- cacheFailure = { message: message, error: error };
-
- // Destroy any pending clear or read operations.
- // At this point there should be no prefetch operations.
- // Count operations will go through but are benign because they
- // won't interact with the store.
- djsassert(prefetchOperations.length === 0, "prefetchOperations.length === 0");
- var i, len;
- for (i = 0, len = readOperations.length; i < len; i++) {
- readOperations[i].fireRejected(cacheFailure);
- }
- for (i = 0, len = clearOperations.length; i < len; i++) {
- clearOperations[i].fireRejected(cacheFailure);
- }
-
- // Null out the operation arrays.
- readOperations = clearOperations = null;
- };
- };
-
- var changeState = function (newState) {
- /// <summary>Updates the cache's state and signals all pending operations of the change.</summary>
- /// <param name="newState" type="Object">New cache state.</param>
- /// <remarks>This method is a no-op if the cache's current state and the new state are the same.</remarks>
-
- if (newState !== state) {
- state = newState;
- var operations = clearOperations.concat(readOperations, prefetchOperations);
- var i, len;
- for (i = 0, len = operations.length; i < len; i++) {
- operations[i].run(state);
- }
- }
- };
-
- var clearStore = function () {
- /// <summary>Removes all the data stored in the cache.</summary>
- /// <returns type="DjsDeferred">A promise with no value.</returns>
- djsassert(state === CACHE_STATE_DESTROY || state === CACHE_STATE_INIT, "DataCache.clearStore() - cache is not on the destroy or initialize state, current sate = " + state);
-
- var deferred = new DjsDeferred();
- store.clear(function () {
-
- // Reset the cache settings.
- actualCacheSize = 0;
- allDataLocal = false;
- collectionCount = 0;
- highestSavedPage = 0;
- highestSavedPageSize = 0;
- overflowed = cacheSize === 0;
-
- // version is not reset, in case there is other state in eg V1.1 that is still around.
-
- // Reset the cache stats.
- stats = { counts: 0, netReads: 0, prefetches: 0, cacheReads: 0 };
- that.stats = stats;
-
- store.close();
- deferred.resolve();
- }, function (err) {
- deferred.reject(err);
- });
- return deferred;
- };
-
- var dequeueOperation = function (operation) {
- /// <summary>Removes an operation from the caches queues and changes the cache state to idle.</summary>
- /// <param name="operation" type="DataCacheOperation">Operation to dequeue.</param>
- /// <remarks>This method is used as a handler for the operation's oncomplete event.</remarks>
-
- var removed = removeFromArray(clearOperations, operation);
- if (!removed) {
- removed = removeFromArray(readOperations, operation);
- if (!removed) {
- removeFromArray(prefetchOperations, operation);
- }
- }
-
- pendingOperations--;
- changeState(CACHE_STATE_IDLE);
- };
-
- var fetchPage = function (start) {
- /// <summary>Requests data from the cache source.</summary>
- /// <param name="start" type="Number">Zero-based index of items to request.</param>
- /// <returns type="DjsDeferred">A promise for a page object with (i)ndex, (c)ount, (d)ata.</returns>
-
- djsassert(state !== CACHE_STATE_DESTROY, "DataCache.fetchPage() - cache is on the destroy state");
- djsassert(state !== CACHE_STATE_IDLE, "DataCache.fetchPage() - cache is on the idle state");
-
- var deferred = new DjsDeferred();
- var canceled = false;
-
- var request = source.read(start, pageSize, function (data) {
- var page = { i: start, c: data.length, d: data };
- deferred.resolve(page);
- }, function (err) {
- deferred.reject(err);
- });
-
- return extend(deferred, {
- cancel: function () {
- if (request) {
- request.abort();
- canceled = true;
- request = null;
- }
- }
- });
- };
-
- var filter = function (index, count, predicate, backwards) {
- /// <summary>Filters the cache data based a predicate.</summary>
- /// <param name="index" type="Number">The index of the item to start filtering from.</param>
- /// <param name="count" type="Number">Maximum number of items to include in the result.</param>
- /// <param name="predicate" type="Function">Callback function returning a boolean that determines whether an item should be included in the result or not.</param>
- /// <param name="backwards" type="Boolean">True if the filtering should move backward from the specified index, falsey otherwise.</param>
- /// <remarks>
- /// Specifying a negative count value will yield all the items in the cache that satisfy the predicate.
- /// </remarks>
- /// <returns type="DjsDeferred">A promise for an array of results.</returns>
- index = parseInt10(index);
- count = parseInt10(count);
-
- if (isNaN(index)) {
- throw { message: "'index' must be a valid number.", index: index };
- }
- if (isNaN(count)) {
- throw { message: "'count' must be a valid number.", count: count };
- }
-
- if (cacheFailure) {
- throw cacheFailure;
- }
-
- index = Math.max(index, 0);
-
- var deferred = createDeferred();
- var arr = [];
- var canceled = false;
- var pendingReadRange = null;
-
- var readMore = function (readIndex, readCount) {
- if (!canceled) {
- if (count >= 0 && arr.length >= count) {
- deferred.resolve(arr);
- } else {
- pendingReadRange = that.readRange(readIndex, readCount).then(function (data) {
- for (var i = 0, length = data.length; i < length && (count < 0 || arr.length < count); i++) {
- var dataIndex = backwards ? length - i - 1 : i;
- var item = data[dataIndex];
- if (predicate(item)) {
- var element = {
- index: readIndex + dataIndex,
- item: item
- };
-
- backwards ? arr.unshift(element) : arr.push(element);
- }
- }
-
- // Have we reached the end of the collection?
- if ((!backwards && data.length < readCount) || (backwards && readIndex <= 0)) {
- deferred.resolve(arr);
- } else {
- var nextIndex = backwards ? Math.max(readIndex - pageSize, 0) : readIndex + readCount;
- readMore(nextIndex, pageSize);
- }
- }, function (err) {
- deferred.reject(err);
- });
- }
- }
- };
-
- // Initially, we read from the given starting index to the next/previous page boundary
- var initialPage = snapToPageBoundaries(index, index, pageSize);
- var initialIndex = backwards ? initialPage.i : index;
- var initialCount = backwards ? index - initialPage.i + 1 : initialPage.i + initialPage.c - index;
- readMore(initialIndex, initialCount);
-
- return extend(deferred.promise(), {
- cancel: function () {
- /// <summary>Aborts the filter operation</summary>
- if (pendingReadRange) {
- pendingReadRange.cancel();
- }
- canceled = true;
- }
- });
- };
-
- var fireOnIdle = function () {
- /// <summary>Fires an onidle event if any functions are assigned.</summary>
-
- if (that.onidle && pendingOperations === 0) {
- that.onidle();
- }
- };
-
- var prefetch = function (start) {
- /// <summary>Creates and starts a new prefetch operation.</summary>
- /// <param name="start" type="Number">Zero-based index of the items to prefetch.</param>
- /// <remarks>
- /// This method is a no-op if any of the following conditions is true:
- /// 1.- prefetchSize is 0
- /// 2.- All data has been read and stored locally in the cache.
- /// 3.- There is already an all data prefetch operation queued.
- /// 4.- The cache has run out of available space (overflowed).
- /// <remarks>
-
- if (allDataLocal || prefetchSize === 0 || overflowed) {
- return;
- }
-
- djsassert(state === CACHE_STATE_READ, "DataCache.prefetch() - cache is not on the read state, current state: " + state);
-
- if (prefetchOperations.length === 0 || (prefetchOperations[0] && prefetchOperations[0].c !== -1)) {
- // Merging prefetch operations would be a nice optimization here.
- var op = new DataCacheOperation(prefetchStateMachine, null, true, start, prefetchSize, null, prefetchSize);
- queueAndStart(op, prefetchOperations);
- }
- };
-
- var queueAndStart = function (op, queue) {
- /// <summary>Queues an operation and runs it.</summary>
- /// <param name="op" type="DataCacheOperation">Operation to queue.</param>
- /// <param name="queue" type="Array">Array that will store the operation.</param>
-
- op.oncomplete = dequeueOperation;
- queue.push(op);
- pendingOperations++;
- op.run(state);
- };
-
- var readPage = function (key) {
- /// <summary>Requests a page from the cache local store.</summary>
- /// <param name="key" type="Number">Zero-based index of the reuqested page.</param>
- /// <returns type="DjsDeferred">A promise for a found flag and page object with (i)ndex, (c)ount, (d)ata, and (t)icks.</returns>
-
- djsassert(state !== CACHE_STATE_DESTROY, "DataCache.readPage() - cache is on the destroy state");
-
- var canceled = false;
- var deferred = extend(new DjsDeferred(), {
- cancel: function () {
- /// <summary>Aborts the readPage operation.</summary>
- canceled = true;
- }
- });
-
- var error = storeFailureCallback(deferred, "Read page from store failure");
-
- store.contains(key, function (contained) {
- if (canceled) {
- return;
- }
- if (contained) {
- store.read(key, function (_, data) {
- if (!canceled) {
- deferred.resolve(data !== undefined, data);
- }
- }, error);
- return;
- }
- deferred.resolve(false);
- }, error);
- return deferred;
- };
-
- var savePage = function (key, page) {
- /// <summary>Saves a page to the cache local store.</summary>
- /// <param name="key" type="Number">Zero-based index of the requested page.</param>
- /// <param name="page" type="Object">Object with (i)ndex, (c)ount, (d)ata, and (t)icks.</param>
- /// <returns type="DjsDeferred">A promise with no value.</returns>
-
- djsassert(state !== CACHE_STATE_DESTROY, "DataCache.savePage() - cache is on the destroy state");
- djsassert(state !== CACHE_STATE_IDLE, "DataCache.savePage() - cache is on the idle state");
-
- var canceled = false;
-
- var deferred = extend(new DjsDeferred(), {
- cancel: function () {
- /// <summary>Aborts the readPage operation.</summary>
- canceled = true;
- }
- });
-
- var error = storeFailureCallback(deferred, "Save page to store failure");
-
- var resolve = function () {
- deferred.resolve(true);
- };
-
- if (page.c > 0) {
- var pageBytes = estimateSize(page);
- overflowed = cacheSize >= 0 && cacheSize < actualCacheSize + pageBytes;
-
- if (!overflowed) {
- store.addOrUpdate(key, page, function () {
- updateSettings(page, pageBytes);
- saveSettings(resolve, error);
- }, error);
- } else {
- resolve();
- }
- } else {
- updateSettings(page, 0);
- saveSettings(resolve, error);
- }
- return deferred;
- };
-
- var saveSettings = function (success, error) {
- /// <summary>Saves the cache's current settings to the local store.</summary>
- /// <param name="success" type="Function">Success callback.</param>
- /// <param name="error" type="Function">Errror callback.</param>
-
- var settings = {
- actualCacheSize: actualCacheSize,
- allDataLocal: allDataLocal,
- cacheSize: cacheSize,
- collectionCount: collectionCount,
- highestSavedPage: highestSavedPage,
- highestSavedPageSize: highestSavedPageSize,
- pageSize: pageSize,
- sourceId: source.identifier,
- version: version
- };
-
- store.addOrUpdate("__settings", settings, success, error);
- };
-
- var storeFailureCallback = function (deferred/*, message*/) {
- /// <summary>Creates a function that handles a store error.</summary>
- /// <param name="deferred" type="DjsDeferred">Deferred object to resolve.</param>
- /// <param name="message" type="String">Message text.</param>
- /// <returns type="Function">Function to use as error callback.</returns>
- /// <remarks>
- /// This function will specifically handle problems when interacting with the store.
- /// </remarks>
-
- return function (/*error*/) {
- // var console = window.console;
- // if (console && console.log) {
- // console.log(message);
- // console.dir(error);
- // }
- deferred.resolve(false);
- };
- };
-
- var updateSettings = function (page, pageBytes) {
- /// <summary>Updates the cache's settings based on a page object.</summary>
- /// <param name="page" type="Object">Object with (i)ndex, (c)ount, (d)ata.</param>
- /// <param name="pageBytes" type="Number">Size of the page in bytes.</param>
-
- var pageCount = page.c;
- var pageIndex = page.i;
-
- // Detect the collection size.
- if (pageCount === 0) {
- if (highestSavedPage === pageIndex - pageSize) {
- collectionCount = highestSavedPage + highestSavedPageSize;
- }
- } else {
- highestSavedPage = Math.max(highestSavedPage, pageIndex);
- if (highestSavedPage === pageIndex) {
- highestSavedPageSize = pageCount;
- }
- actualCacheSize += pageBytes;
- if (pageCount < pageSize && !collectionCount) {
- collectionCount = pageIndex + pageCount;
- }
- }
-
- // Detect the end of the collection.
- if (!allDataLocal && collectionCount === highestSavedPage + highestSavedPageSize) {
- allDataLocal = true;
- }
- };
-
- var cancelStateMachine = function (operation, opTargetState, cacheState, data) {
- /// <summary>State machine describing the behavior for cancelling a read or prefetch operation.</summary>
- /// <param name="operation" type="DataCacheOperation">Operation being run.</param>
- /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
- /// <param name="cacheState" type="Object">Current cache state.</param>
- /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
- /// <remarks>
- /// This state machine contains behavior common to read and prefetch operations.
- /// </remarks>
-
- var canceled = operation.canceled && opTargetState !== OPERATION_STATE_END;
- if (canceled) {
- if (opTargetState === OPERATION_STATE_CANCEL) {
- // Cancel state.
- // Data is expected to be any pending request made to the cache.
- if (data && data.cancel) {
- data.cancel();
- }
- }
- }
- return canceled;
- };
-
- var destroyStateMachine = function (operation, opTargetState, cacheState) {
- /// <summary>State machine describing the behavior of a clear operation.</summary>
- /// <param name="operation" type="DataCacheOperation">Operation being run.</param>
- /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
- /// <param name="cacheState" type="Object">Current cache state.</param>
- /// <remarks>
- /// Clear operations have the highest priority and can't be interrupted by other operations; however,
- /// they will preempt any other operation currently executing.
- /// </remarks>
-
- var transition = operation.transition;
-
- // Signal the cache that a clear operation is running.
- if (cacheState !== CACHE_STATE_DESTROY) {
- changeState(CACHE_STATE_DESTROY);
- return true;
- }
-
- switch (opTargetState) {
- case OPERATION_STATE_START:
- // Initial state of the operation.
- transition(DESTROY_STATE_CLEAR);
- break;
-
- case OPERATION_STATE_END:
- // State that signals the operation is done.
- fireOnIdle();
- break;
-
- case DESTROY_STATE_CLEAR:
- // State that clears all the local data of the cache.
- clearStore().then(function () {
- // Terminate the operation once the local store has been cleared.
- operation.complete();
- });
- // Wait until the clear request completes.
- operation.wait();
- break;
-
- default:
- return false;
- }
- return true;
- };
-
- var prefetchStateMachine = function (operation, opTargetState, cacheState, data) {
- /// <summary>State machine describing the behavior of a prefetch operation.</summary>
- /// <param name="operation" type="DataCacheOperation">Operation being run.</param>
- /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
- /// <param name="cacheState" type="Object">Current cache state.</param>
- /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
- /// <remarks>
- /// Prefetch operations have the lowest priority and will be interrupted by operations of
- /// other kinds. A preempted prefetch operation will resume its execution only when the state
- /// of the cache returns to idle.
- ///
- /// If a clear operation starts executing then all the prefetch operations are canceled,
- /// even if they haven't started executing yet.
- /// </remarks>
-
- // Handle cancelation
- if (!cancelStateMachine(operation, opTargetState, cacheState, data)) {
-
- var transition = operation.transition;
-
- // Handle preemption
- if (cacheState !== CACHE_STATE_PREFETCH) {
- if (cacheState === CACHE_STATE_DESTROY) {
- if (opTargetState !== OPERATION_STATE_CANCEL) {
- operation.cancel();
- }
- } else if (cacheState === CACHE_STATE_IDLE) {
- // Signal the cache that a prefetch operation is running.
- changeState(CACHE_STATE_PREFETCH);
- }
- return true;
- }
-
- switch (opTargetState) {
- case OPERATION_STATE_START:
- // Initial state of the operation.
- if (prefetchOperations[0] === operation) {
- transition(READ_STATE_LOCAL, operation.i);
- }
- break;
-
- case READ_STATE_DONE:
- // State that determines if the operation can be resolved or has to
- // continue processing.
- // Data is expected to be the read page.
- var pending = operation.pending;
-
- if (pending > 0) {
- pending -= Math.min(pending, data.c);
- }
-
- // Are we done, or has all the data been stored?
- if (allDataLocal || pending === 0 || data.c < pageSize || overflowed) {
- operation.complete();
- } else {
- // Continue processing the operation.
- operation.pending = pending;
- transition(READ_STATE_LOCAL, data.i + pageSize);
- }
- break;
-
- default:
- return readSaveStateMachine(operation, opTargetState, cacheState, data, true);
- }
- }
- return true;
- };
-
- var readStateMachine = function (operation, opTargetState, cacheState, data) {
- /// <summary>State machine describing the behavior of a read operation.</summary>
- /// <param name="operation" type="DataCacheOperation">Operation being run.</param>
- /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
- /// <param name="cacheState" type="Object">Current cache state.</param>
- /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
- /// <remarks>
- /// Read operations have a higher priority than prefetch operations, but lower than
- /// clear operations. They will preempt any prefetch operation currently running
- /// but will be interrupted by a clear operation.
- ///
- /// If a clear operation starts executing then all the currently running
- /// read operations are canceled. Read operations that haven't started yet will
- /// wait in the start state until the destory operation finishes.
- /// </remarks>
-
- // Handle cancelation
- if (!cancelStateMachine(operation, opTargetState, cacheState, data)) {
-
- var transition = operation.transition;
-
- // Handle preemption
- if (cacheState !== CACHE_STATE_READ && opTargetState !== OPERATION_STATE_START) {
- if (cacheState === CACHE_STATE_DESTROY) {
- if (opTargetState !== OPERATION_STATE_START) {
- operation.cancel();
- }
- } else if (cacheState !== CACHE_STATE_WRITE) {
- // Signal the cache that a read operation is running.
- djsassert(state == CACHE_STATE_IDLE || state === CACHE_STATE_PREFETCH, "DataCache.readStateMachine() - cache is not on the read or idle state.");
- changeState(CACHE_STATE_READ);
- }
-
- return true;
- }
-
- switch (opTargetState) {
- case OPERATION_STATE_START:
- // Initial state of the operation.
- // Wait until the cache is idle or prefetching.
- if (cacheState === CACHE_STATE_IDLE || cacheState === CACHE_STATE_PREFETCH) {
- // Signal the cache that a read operation is running.
- changeState(CACHE_STATE_READ);
- if (operation.c > 0) {
- // Snap the requested range to a page boundary.
- var range = snapToPageBoundaries(operation.i, operation.c, pageSize);
- transition(READ_STATE_LOCAL, range.i);
- } else {
- transition(READ_STATE_DONE, operation);
- }
- }
- break;
-
- case READ_STATE_DONE:
- // State that determines if the operation can be resolved or has to
- // continue processing.
- // Data is expected to be the read page.
- appendPage(operation, data);
- var len = operation.d.length;
- // Are we done?
- if (operation.c === len || data.c < pageSize) {
- // Update the stats, request for a prefetch operation.
- stats.cacheReads++;
- prefetch(data.i + data.c);
- // Terminate the operation.
- operation.complete();
- } else {
- // Continue processing the operation.
- transition(READ_STATE_LOCAL, data.i + pageSize);
- }
- break;
-
- default:
- return readSaveStateMachine(operation, opTargetState, cacheState, data, false);
- }
- }
-
- return true;
- };
-
- var readSaveStateMachine = function (operation, opTargetState, cacheState, data, isPrefetch) {
- /// <summary>State machine describing the behavior for reading and saving data into the cache.</summary>
- /// <param name="operation" type="DataCacheOperation">Operation being run.</param>
- /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
- /// <param name="cacheState" type="Object">Current cache state.</param>
- /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
- /// <param name="isPrefetch" type="Boolean">Flag indicating whether a read (false) or prefetch (true) operation is running.
- /// <remarks>
- /// This state machine contains behavior common to read and prefetch operations.
- /// </remarks>
-
- var error = operation.error;
- var transition = operation.transition;
- var wait = operation.wait;
- var request;
-
- switch (opTargetState) {
- case OPERATION_STATE_END:
- // State that signals the operation is done.
- fireOnIdle();
- break;
-
- case READ_STATE_LOCAL:
- // State that requests for a page from the local store.
- // Data is expected to be the index of the page to request.
- request = readPage(data).then(function (found, page) {
- // Signal the cache that a read operation is running.
- if (!operation.canceled) {
- if (found) {
- // The page is in the local store, check if the operation can be resolved.
- transition(READ_STATE_DONE, page);
- } else {
- // The page is not in the local store, request it from the source.
- transition(READ_STATE_SOURCE, data);
- }
- }
- });
- break;
-
- case READ_STATE_SOURCE:
- // State that requests for a page from the cache source.
- // Data is expected to be the index of the page to request.
- request = fetchPage(data).then(function (page) {
- // Signal the cache that a read operation is running.
- if (!operation.canceled) {
- // Update the stats and save the page to the local store.
- if (isPrefetch) {
- stats.prefetches++;
- } else {
- stats.netReads++;
- }
- transition(READ_STATE_SAVE, page);
- }
- }, error);
- break;
-
- case READ_STATE_SAVE:
- // State that saves a page to the local store.
- // Data is expected to be the page to save.
- // Write access to the store is exclusive.
- if (cacheState !== CACHE_STATE_WRITE) {
- changeState(CACHE_STATE_WRITE);
- request = savePage(data.i, data).then(function (saved) {
- if (!operation.canceled) {
- if (!saved && isPrefetch) {
- operation.pending = 0;
- }
- // Check if the operation can be resolved.
- transition(READ_STATE_DONE, data);
- }
- changeState(CACHE_STATE_IDLE);
- });
- }
- break;
-
- default:
- // Unknown state that can't be handled by this state machine.
- return false;
- }
-
- if (request) {
- // The operation might have been canceled between stack frames do to the async calls.
- if (operation.canceled) {
- request.cancel();
- } else if (operation.s === opTargetState) {
- // Wait for the request to complete.
- wait(request);
- }
- }
-
- return true;
- };
-
- // Initialize the cache.
- store.read("__settings", function (_, settings) {
- if (assigned(settings)) {
- var settingsVersion = settings.version;
- if (!settingsVersion || settingsVersion.indexOf("1.") !== 0) {
- cacheFailureCallback("Unsupported cache store version " + settingsVersion)();
- return;
- }
-
- if (pageSize !== settings.pageSize || source.identifier !== settings.sourceId) {
- // The shape or the source of the data was changed so invalidate the store.
- clearStore().then(function () {
- // Signal the cache is fully initialized.
- changeState(CACHE_STATE_IDLE);
- }, cacheFailureCallback("Unable to clear store during initialization"));
- } else {
- // Restore the saved settings.
- actualCacheSize = settings.actualCacheSize;
- allDataLocal = settings.allDataLocal;
- cacheSize = settings.cacheSize;
- collectionCount = settings.collectionCount;
- highestSavedPage = settings.highestSavedPage;
- highestSavedPageSize = settings.highestSavedPageSize;
- version = settingsVersion;
-
- // Signal the cache is fully initialized.
- changeState(CACHE_STATE_IDLE);
- }
- } else {
- // This is a brand new cache.
- saveSettings(function () {
- // Signal the cache is fully initialized.
- changeState(CACHE_STATE_IDLE);
- }, cacheFailureCallback("Unable to write settings during initialization."));
- }
- }, cacheFailureCallback("Unable to read settings from store."));
-
- return that;
- };
-
- datajs.createDataCache = function (options) {
- /// <summary>Creates a data cache for a collection that is efficiently loaded on-demand.</summary>
- /// <param name="options">
- /// Options for the data cache, including name, source, pageSize,
- /// prefetchSize, cacheSize, storage mechanism, and initial prefetch and local-data handler.
- /// </param>
- /// <returns type="DataCache">A new data cache instance.</returns>
- checkUndefinedGreaterThanZero(options.pageSize, "pageSize");
- checkUndefinedOrNumber(options.cacheSize, "cacheSize");
- checkUndefinedOrNumber(options.prefetchSize, "prefetchSize");
-
- if (!assigned(options.name)) {
- throw { message: "Undefined or null name", options: options };
- }
-
- if (!assigned(options.source)) {
- throw { message: "Undefined source", options: options };
- }
-
- return new DataCache(options);
- };
-
- // DATAJS INTERNAL START
- window.datajs.estimateSize = estimateSize;
- // DATAJS INTERNAL END
-
- // CONTENT END
+/// <reference path="odata-utils.js" />
+
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,
+// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+// WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// cache.js
+
+(function (window, undefined) {
+
+ var datajs = window.datajs || {};
+
+ var assigned = datajs.assigned;
+ var delay = datajs.delay;
+ var extend = datajs.extend;
+ var djsassert = datajs.djsassert;
+ var isArray = datajs.isArray;
+ var normalizeURI = datajs.normalizeURI;
+ var parseInt10 = datajs.parseInt10;
+ var undefinedDefault = datajs.undefinedDefault;
+
+ var createDeferred = datajs.createDeferred;
+ var DjsDeferred = datajs.DjsDeferred;
+ var ODataCacheSource = datajs.ODataCacheSource;
+ var getJsonValueArraryLength = datajs.getJsonValueArraryLength;
+ var sliceJsonValueArray = datajs.sliceJsonValueArray;
+ var concatJsonValueArray = datajs.concatJsonValueArray;
+
+ // CONTENT START
+
+ var appendPage = function (operation, page) {
+ /// <summary>Appends a page's data to the operation data.</summary>
+ /// <param name="operation" type="Object">Operation with (i)ndex, (c)ount and (d)ata.</param>
+ /// <param name="page" type="Object">Page with (i)ndex, (c)ount and (d)ata.</param>
+
+ var intersection = intersectRanges(operation, page);
+ var start = 0;
+ var end = 0;
+ if (intersection) {
+ start = intersection.i - page.i;
+ end = start + (operation.c - getJsonValueArraryLength(operation.d));
+ }
+
+ operation.d = concatJsonValueArray(operation.d, sliceJsonValueArray(page.d, start, end));
+ };
+
+ var intersectRanges = function (x, y) {
+ /// <summary>Returns the {(i)ndex, (c)ount} range for the intersection of x and y.</summary>
+ /// <param name="x" type="Object">Range with (i)ndex and (c)ount members.</param>
+ /// <param name="y" type="Object">Range with (i)ndex and (c)ount members.</param>
+ /// <returns type="Object">The intersection (i)ndex and (c)ount; undefined if there is no intersection.</returns>
+
+ var xLast = x.i + x.c;
+ var yLast = y.i + y.c;
+ var resultIndex = (x.i > y.i) ? x.i : y.i;
+ var resultLast = (xLast < yLast) ? xLast : yLast;
+ var result;
+ if (resultLast >= resultIndex) {
+ result = { i: resultIndex, c: resultLast - resultIndex };
+ }
+
+ return result;
+ };
+
+ var checkZeroGreater = function (val, name) {
+ /// <summary>Checks whether val is a defined number with value zero or greater.</summary>
+ /// <param name="val" type="Number">Value to check.</param>
+ /// <param name="name" type="String">Parameter name to use in exception.</param>
+
+ if (val === undefined || typeof val !== "number") {
+ throw { message: "'" + name + "' must be a number." };
+ }
+
+ if (isNaN(val) || val < 0 || !isFinite(val)) {
+ throw { message: "'" + name + "' must be greater than or equal to zero." };
+ }
+ };
+
+ var checkUndefinedGreaterThanZero = function (val, name) {
+ /// <summary>Checks whether val is undefined or a number with value greater than zero.</summary>
+ /// <param name="val" type="Number">Value to check.</param>
+ /// <param name="name" type="String">Parameter name to use in exception.</param>
+
+ if (val !== undefined) {
+ if (typeof val !== "number") {
+ throw { message: "'" + name + "' must be a number." };
+ }
+
+ if (isNaN(val) || val <= 0 || !isFinite(val)) {
+ throw { message: "'" + name + "' must be greater than zero." };
+ }
+ }
+ };
+
+ var checkUndefinedOrNumber = function (val, name) {
+ /// <summary>Checks whether val is undefined or a number</summary>
+ /// <param name="val" type="Number">Value to check.</param>
+ /// <param name="name" type="String">Parameter name to use in exception.</param>
+ if (val !== undefined && (typeof val !== "number" || isNaN(val) || !isFinite(val))) {
+ throw { message: "'" + name + "' must be a number." };
+ }
+ };
+
+ var removeFromArray = function (arr, item) {
+ /// <summary>Performs a linear search on the specified array and removes the first instance of 'item'.</summary>
+ /// <param name="arr" type="Array">Array to search.</param>
+ /// <param name="item">Item being sought.</param>
+ /// <returns type="Boolean">Whether the item was removed.</returns>
+
+ var i, len;
+ for (i = 0, len = arr.length; i < len; i++) {
+ if (arr[i] === item) {
+ arr.splice(i, 1);
+ return true;
+ }
+ }
+
+ return false;
+ };
+
+ var estimateSize = function (obj) {
+ /// <summary>Estimates the size of an object in bytes.</summary>
+ /// <param name="obj" type="Object">Object to determine the size of.</param>
+ /// <returns type="Integer">Estimated size of the object in bytes.</returns>
+ var size = 0;
+ var type = typeof obj;
+
+ if (type === "object" && obj) {
+ for (var name in obj) {
+ size += name.length * 2 + estimateSize(obj[name]);
+ }
+ } else if (type === "string") {
+ size = obj.length * 2;
+ } else {
+ size = 8;
+ }
+ return size;
+ };
+
+ var snapToPageBoundaries = function (lowIndex, highIndex, pageSize) {
+ /// <summary>Snaps low and high indices into page sizes and returns a range.</summary>
+ /// <param name="lowIndex" type="Number">Low index to snap to a lower value.</param>
+ /// <param name="highIndex" type="Number">High index to snap to a higher value.</param>
+ /// <param name="pageSize" type="Number">Page size to snap to.</param>
+ /// <returns type="Object">A range with (i)ndex and (c)ount of elements.</returns>
+
+ lowIndex = Math.floor(lowIndex / pageSize) * pageSize;
+ highIndex = Math.ceil((highIndex + 1) / pageSize) * pageSize;
+ return { i: lowIndex, c: highIndex - lowIndex };
+ };
+
+ // The DataCache is implemented using state machines. The following constants are used to properly
+ // identify and label the states that these machines transition to.
+
+ // DataCache state constants
+
+ var CACHE_STATE_DESTROY = "destroy";
+ var CACHE_STATE_IDLE = "idle";
+ var CACHE_STATE_INIT = "init";
+ var CACHE_STATE_READ = "read";
+ var CACHE_STATE_PREFETCH = "prefetch";
+ var CACHE_STATE_WRITE = "write";
+
+ // DataCacheOperation state machine states.
+ // Transitions on operations also depend on the cache current of the cache.
+
+ var OPERATION_STATE_CANCEL = "cancel";
+ var OPERATION_STATE_END = "end";
+ var OPERATION_STATE_ERROR = "error";
+ var OPERATION_STATE_START = "start";
+ var OPERATION_STATE_WAIT = "wait";
+
+ // Destroy state machine states
+
+ var DESTROY_STATE_CLEAR = "clear";
+
+ // Read / Prefetch state machine states
+
+ var READ_STATE_DONE = "done";
+ var READ_STATE_LOCAL = "local";
+ var READ_STATE_SAVE = "save";
+ var READ_STATE_SOURCE = "source";
+
+ var DataCacheOperation = function (stateMachine, promise, isCancelable, index, count, data, pending) {
+ /// <summary>Creates a new operation object.</summary>
+ /// <param name="stateMachine" type="Function">State machine that describes the specific behavior of the operation.</param>
+ /// <param name="promise" type ="DjsDeferred">Promise for requested values.</param>
+ /// <param name="isCancelable" type ="Boolean">Whether this operation can be canceled or not.</param>
+ /// <param name="index" type="Number">Index of first item requested.</param>
+ /// <param name="count" type="Number">Count of items requested.</param>
+ /// <param name="data" type="Array">Array with the items requested by the operation.</param>
+ /// <param name="pending" type="Number">Total number of pending prefetch records.</param>
+ /// <returns type="DataCacheOperation">A new data cache operation instance.</returns>
+
+ /// <field name="p" type="DjsDeferred">Promise for requested values.</field>
+ /// <field name="i" type="Number">Index of first item requested.</field>
+ /// <field name="c" type="Number">Count of items requested.</field>
+ /// <field name="d" type="Array">Array with the items requested by the operation.</field>
+ /// <field name="s" type="Array">Current state of the operation.</field>
+ /// <field name="canceled" type="Boolean">Whether the operation has been canceled.</field>
+ /// <field name="pending" type="Number">Total number of pending prefetch records.</field>
+ /// <field name="oncomplete" type="Function">Callback executed when the operation reaches the end state.</field>
+
+ var stateData;
+ var cacheState;
+ var that = this;
+
+ that.p = promise;
+ that.i = index;
+ that.c = count;
+ that.d = data;
+ that.s = OPERATION_STATE_START;
+
+ that.canceled = false;
+ that.pending = pending;
+ that.oncomplete = null;
+
+ that.cancel = function () {
+ /// <summary>Transitions this operation to the cancel state and sets the canceled flag to true.</summary>
+ /// <remarks>The function is a no-op if the operation is non-cancelable.</summary>
+
+ if (!isCancelable) {
+ return;
+ }
+
+ var state = that.s;
+ if (state !== OPERATION_STATE_ERROR && state !== OPERATION_STATE_END && state !== OPERATION_STATE_CANCEL) {
+ that.canceled = true;
+ transition(OPERATION_STATE_CANCEL, stateData);
+ }
+ };
+
+ that.complete = function () {
+ /// <summary>Transitions this operation to the end state.</summary>
+
+ djsassert(that.s !== OPERATION_STATE_END, "DataCacheOperation.complete() - operation is in the end state", that);
+ transition(OPERATION_STATE_END, stateData);
+ };
+
+ that.error = function (err) {
+ /// <summary>Transitions this operation to the error state.</summary>
+ if (!that.canceled) {
+ djsassert(that.s !== OPERATION_STATE_END, "DataCacheOperation.error() - operation is in the end state", that);
+ djsassert(that.s !== OPERATION_STATE_ERROR, "DataCacheOperation.error() - operation is in the error state", that);
+ transition(OPERATION_STATE_ERROR, err);
+ }
+ };
+
+ that.run = function (state) {
+ /// <summary>Executes the operation's current state in the context of a new cache state.</summary>
+ /// <param name="state" type="Object">New cache state.</param>
+
+ cacheState = state;
+ that.transition(that.s, stateData);
+ };
+
+ that.wait = function (data) {
+ /// <summary>Transitions this operation to the wait state.</summary>
+
+ djsassert(that.s !== OPERATION_STATE_END, "DataCacheOperation.wait() - operation is in the end state", that);
+ transition(OPERATION_STATE_WAIT, data);
+ };
+
+ var operationStateMachine = function (opTargetState, cacheState, data) {
+ /// <summary>State machine that describes all operations common behavior.</summary>
+ /// <param name="opTargetState" type="Object">Operation state to transition to.</param>
+ /// <param name="cacheState" type="Object">Current cache state.</param>
+ /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
+
+ switch (opTargetState) {
+ case OPERATION_STATE_START:
+ // Initial state of the operation. The operation will remain in this state until the cache has been fully initialized.
+ if (cacheState !== CACHE_STATE_INIT) {
+ stateMachine(that, opTargetState, cacheState, data);
+ }
+ break;
+
+ case OPERATION_STATE_WAIT:
+ // Wait state indicating that the operation is active but waiting for an asynchronous operation to complete.
+ stateMachine(that, opTargetState, cacheState, data);
+ break;
+
+ case OPERATION_STATE_CANCEL:
+ // Cancel state.
+ stateMachine(that, opTargetState, cacheState, data);
+ that.fireCanceled();
+ transition(OPERATION_STATE_END);
+ break;
+
+ case OPERATION_STATE_ERROR:
+ // Error state. Data is expected to be an object detailing the error condition.
+ stateMachine(that, opTargetState, cacheState, data);
+ that.canceled = true;
+ that.fireRejected(data);
+ transition(OPERATION_STATE_END);
+ break;
+
+ case OPERATION_STATE_END:
+ // Final state of the operation.
+ if (that.oncomplete) {
+ that.oncomplete(that);
+ }
+ if (!that.canceled) {
+ that.fireResolved();
+ }
+ stateMachine(that, opTargetState, cacheState, data);
+ break;
+
+ default:
+ // Any other state is passed down to the state machine describing the operation's specific behavior.
+ // DATAJS INTERNAL START
+ if (true) {
+ // Check that the state machine actually handled the sate.
+ var handled = stateMachine(that, opTargetState, cacheState, data);
+ djsassert(handled, "Bad operation state: " + opTargetState + " cacheState: " + cacheState, this);
+ } else {
+ // DATAJS INTERNAL END
+ stateMachine(that, opTargetState, cacheState, data);
+ // DATAJS INTERNAL START
+ }
+ // DATAJS INTERNAL END
+ break;
+ }
+ };
+
+ var transition = function (state, data) {
+ /// <summary>Transitions this operation to a new state.</summary>
+ /// <param name="state" type="Object">State to transition the operation to.</param>
+ /// <param name="data" type="Object" optional="true">Additional data passed to the state.</param>
+
+ that.s = state;
+ stateData = data;
+ operationStateMachine(state, cacheState, data);
+ };
+
+ that.transition = transition;
+
+ return that;
+ };
+
+ DataCacheOperation.prototype.fireResolved = function () {
+ /// <summary>Fires a resolved notification as necessary.</summary>
+
+ // Fire the resolve just once.
+ var p = this.p;
+ if (p) {
+ this.p = null;
+ p.resolve(this.d);
+ }
+ };
+
+ DataCacheOperation.prototype.fireRejected = function (reason) {
+ /// <summary>Fires a rejected notification as necessary.</summary>
+
+ // Fire the rejection just once.
+ var p = this.p;
+ if (p) {
+ this.p = null;
+ p.reject(reason);
+ }
+ };
+
+ DataCacheOperation.prototype.fireCanceled = function () {
+ /// <summary>Fires a canceled notification as necessary.</summary>
+
+ this.fireRejected({ canceled: true, message: "Operation canceled" });
+ };
+
+
+ var DataCache = function (options) {
+ /// <summary>Creates a data cache for a collection that is efficiently loaded on-demand.</summary>
+ /// <param name="options">
+ /// Options for the data cache, including name, source, pageSize,
+ /// prefetchSize, cacheSize, storage mechanism, and initial prefetch and local-data handler.
+ /// </param>
+ /// <returns type="DataCache">A new data cache instance.</returns>
+
+ var state = CACHE_STATE_INIT;
+ var stats = { counts: 0, netReads: 0, prefetches: 0, cacheReads: 0 };
+
+ var clearOperations = [];
+ var readOperations = [];
+ var prefetchOperations = [];
+
+ var actualCacheSize = 0; // Actual cache size in bytes.
+ var allDataLocal = false; // Whether all data is local.
+ var cacheSize = undefinedDefault(options.cacheSize, 1048576); // Requested cache size in bytes, default 1 MB.
+ var collectionCount = 0; // Number of elements in the server collection.
+ var highestSavedPage = 0; // Highest index of all the saved pages.
+ var highestSavedPageSize = 0; // Item count of the saved page with the highest index.
+ var overflowed = cacheSize === 0; // If the cache has overflowed (actualCacheSize > cacheSize or cacheSize == 0);
+ var pageSize = undefinedDefault(options.pageSize, 50); // Number of elements to store per page.
+ var prefetchSize = undefinedDefault(options.prefetchSize, pageSize); // Number of elements to prefetch from the source when the cache is idling.
+ var version = "1.0";
+ var cacheFailure;
+
+ var pendingOperations = 0;
+
+ var source = options.source;
+ if (typeof source === "string") {
+ // Create a new cache source.
+ source = new ODataCacheSource(options);
+ }
+ source.options = options;
+
+ // Create a cache local store.
+ var store = datajs.createStore(options.name, options.mechanism);
+
+ var that = this;
+
+ that.onidle = options.idle;
+ that.stats = stats;
+
+ that.count = function () {
+ /// <summary>Counts the number of items in the collection.</summary>
+ /// <returns type="Object">A promise with the number of items.</returns>
+
+ if (cacheFailure) {
+ throw cacheFailure;
+ }
+
+ var deferred = createDeferred();
+ var canceled = false;
+
+ if (allDataLocal) {
+ delay(function () {
+ deferred.resolve(collectionCount);
+ });
+
+ return deferred.promise();
+ }
+
+ // TODO: Consider returning the local data count instead once allDataLocal flag is set to true.
+ var request = source.count(function (count) {
+ request = null;
+ stats.counts++;
+ deferred.resolve(count);
+ }, function (err) {
+ request = null;
+ deferred.reject(extend(err, { canceled: canceled }));
+ });
+
+ return extend(deferred.promise(), {
+ cancel: function () {
+ /// <summary>Aborts the count operation.</summary>
+ if (request) {
+ canceled = true;
+ request.abort();
+ request = null;
+ }
+ }
+ });
+ };
+
+ that.clear = function () {
+ /// <summary>Cancels all running operations and clears all local data associated with this cache.</summary>
+ /// <remarks>
+ /// New read requests made while a clear operation is in progress will not be canceled.
+ /// Instead they will be queued for execution once the operation is completed.
+ /// </remarks>
+ /// <returns type="Object">A promise that has no value and can't be canceled.</returns>
+
+ if (cacheFailure) {
+ throw cacheFailure;
+ }
+
+ if (clearOperations.length === 0) {
+ var deferred = createDeferred();
+ var op = new DataCacheOperation(destroyStateMachine, deferred, false);
+ queueAndStart(op, clearOperations);
+ return deferred.promise();
+ }
+ return clearOperations[0].p;
+ };
+
+ that.filterForward = function (index, count, predicate) {
+ /// <summary>Filters the cache data based a predicate.</summary>
+ /// <param name="index" type="Number">The index of the item to start filtering forward from.</param>
+ /// <param name="count" type="Number">Maximum number of items to include in the result.</param>
+ /// <param name="predicate" type="Function">Callback function returning a boolean that determines whether an item should be included in the result or not.</param>
+ /// <remarks>
+ /// Specifying a negative count value will yield all the items in the cache that satisfy the predicate.
+ /// </remarks>
+ /// <returns type="DjsDeferred">A promise for an array of results.</returns>
+ return filter(index, count, predicate, false);
+ };
+
+ that.filterBack = function (index, count, predicate) {
+ /// <summary>Filters the cache data based a predicate.</summary>
+ /// <param name="index" type="Number">The index of the item to start filtering backward from.</param>
+ /// <param name="count" type="Number">Maximum number of items to include in the result.</param>
+ /// <param name="predicate" type="Function">Callback function returning a boolean that determines whether an item should be included in the result or not.</param>
+ /// <remarks>
+ /// Specifying a negative count value will yield all the items in the cache that satisfy the predicate.
+ /// </remarks>
+ /// <returns type="DjsDeferred">A promise for an array of results.</returns>
+ return filter(index, count, predicate, true);
+ };
+
+ that.readRange = function (index, count) {
+ /// <summary>Reads a range of adjacent records.</summary>
+ /// <param name="index" type="Number">Zero-based index of record range to read.</param>
+ /// <param name="count" type="Number">Number of records in the range.</param>
+ /// <remarks>
+ /// New read requests made while a clear operation is in progress will not be canceled.
+ /// Instead they will be queued for execution once the operation is completed.
+ /// </remarks>
+ /// <returns type="DjsDeferred">
+ /// A promise for an array of records; less records may be returned if the
+ /// end of the collection is found.
+ /// </returns>
+
+ checkZeroGreater(index, "index");
+ checkZeroGreater(count, "count");
+
+ if (cacheFailure) {
+ throw cacheFailure;
+ }
+
+ var deferred = createDeferred();
+
+ // Merging read operations would be a nice optimization here.
+ var op = new DataCacheOperation(readStateMachine, deferred, true, index, count, {}, 0);
+ queueAndStart(op, readOperations);
+
+ return extend(deferred.promise(), {
+ cancel: function () {
+ /// <summary>Aborts the readRange operation.</summary>
+ op.cancel();
+ }
+ });
+ };
+
+ that.ToObservable = that.toObservable = function () {
+ /// <summary>Creates an Observable object that enumerates all the cache contents.</summary>
+ /// <returns>A new Observable object that enumerates all the cache contents.</returns>
+ if (!window.Rx || !window.Rx.Observable) {
+ throw { message: "Rx library not available - include rx.js" };
+ }
+
+ if (cacheFailure) {
+ throw cacheFailure;
+ }
+
+ return window.Rx.Observable.CreateWithDisposable(function (obs) {
+ var disposed = false;
+ var inde
<TRUNCATED>