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richdocuments/js/editor/server/pullbox/OperationRouter.js

509 lines
20 KiB
JavaScript

/**
* @license
* Copyright (C) 2013 KO GmbH <copyright@kogmbh.com>
*
* @licstart
* The JavaScript code in this page is free software: you can redistribute it
* and/or modify it under the terms of the GNU Affero General Public License
* (GNU AGPL) as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version. The code is distributed
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU AGPL for more details.
*
* As additional permission under GNU AGPL version 3 section 7, you
* may distribute non-source (e.g., minimized or compacted) forms of
* that code without the copy of the GNU GPL normally required by
* section 4, provided you include this license notice and a URL
* through which recipients can access the Corresponding Source.
*
* As a special exception to the AGPL, any HTML file which merely makes function
* calls to this code, and for that purpose includes it by reference shall be
* deemed a separate work for copyright law purposes. In addition, the copyright
* holders of this code give you permission to combine this code with free
* software libraries that are released under the GNU LGPL. You may copy and
* distribute such a system following the terms of the GNU AGPL for this code
* and the LGPL for the libraries. If you modify this code, you may extend this
* exception to your version of the code, but you are not obligated to do so.
* If you do not wish to do so, delete this exception statement from your
* version.
*
* This license applies to this entire compilation.
* @licend
* @source: http://www.webodf.org/
* @source: http://gitorious.org/webodf/webodf/
*/
/*global runtime, ops*/
define("webodf/editor/server/pullbox/OperationRouter", [], function () {
"use strict";
runtime.loadClass("ops.OperationTransformer");
/**
* route operations in a networked collaborative manner.
*
* incoming operations (from controller) are sent to a server,
* who will distribute them.
*
* incoming operations (from the server are played on the DOM.
*/
/**
* @constructor
* @implements ops.OperationRouter
*/
return function PullBoxOperationRouter(sessionId, memberId, server, odfContainer) {
"use strict";
var operationFactory,
singleTimeCallbackOnCompleteServerOpSpecsPlay,
/**@type{function(!ops.Operation)}*/
playbackFunction,
/**@type{?{active:!boolean}}*/
pullingTimeOutFlag = null,
/**@type{!boolean}*/
triggerPushingOpsActivated = false,
/**@type{!boolean}*/
playUnplayedServerOpSpecsTriggered = false,
/**@type{!boolean}*/
syncLock = false,
/**@type{!boolean}*/
hasUnresolvableConflict = false,
/**@type{!boolean}*/
syncingBlocked = false,
/** @type {!string} id of latest op stack state known on the server */
lastServerSeq = "",
/** @type {!Array.<!Object>} ops created since the last sync call to the server */
unsyncedClientOpspecQueue = [],
/** @type {!Array.<!Object>} ops created since the last sync call to the server */
unplayedServerOpspecQueue = [],
/** @type {!Array.<!function(!boolean):undefined>} ops created since the last sync call to the server */
hasLocalUnsyncedOpsStateSubscribers = [],
/**@type{!boolean}*/
hasLocalUnsyncedOps = false,
/**@type{!boolean} tells if any local ops have been modifying ops */
hasPushedModificationOps = false,
operationTransformer = new ops.OperationTransformer(),
/**@const*/replayTime = 500,
/**@const*/pushingIntervall = 3000,
/**@const*/pullingIntervall = 8000;
function updateHasLocalUnsyncedOpsState() {
var i,
hasLocalUnsyncedOpsNow = (unsyncedClientOpspecQueue.length > 0);
// no change?
if (hasLocalUnsyncedOps === hasLocalUnsyncedOpsNow) {
return;
}
hasLocalUnsyncedOps = hasLocalUnsyncedOpsNow;
for (i=0; i<hasLocalUnsyncedOpsStateSubscribers.length; i+=1) {
hasLocalUnsyncedOpsStateSubscribers[i](hasLocalUnsyncedOps);
}
}
/**
* @param {!Array.<!Object>} opspecs
* @return {!Array.<!Object>}
*/
function compressOpSpecs(opspecs) {
var i, j, op,
result = [];
i = 0;
while (i < opspecs.length) {
// use factory to create an instance, and playback!
op = operationFactory.create(opspecs[i]);
// is known op and can do merge?
if (op !== null && op.merge) {
// go over the following and try to merge them
for (j = i+1; j < opspecs.length; j += 1) {
if (!op.merge(opspecs[j])) {
break;
}
runtime.log("Merged: "+opspecs[i].optype+" with "+opspecs[j].optype);
}
// add the resulting op to the results
result.push(op.spec());
// and continue with the one which could not be merged, or behind end
i = j;
} else {
// just pass on
result.push(opspecs[i]);
i += 1;
}
}
runtime.log("Merged: from "+opspecs.length+" to "+result.length+" specs");
return result;
}
/**
* @return {undefined}
*/
function playUnplayedServerOpSpecs() {
/**
* @return {undefined}
*/
function doPlayUnplayedServerOpSpecs() {
var opspec, op, startTime;
playUnplayedServerOpSpecsTriggered = false;
// take start time
startTime = (new Date()).getTime();
// apply as much as possible in the given time
while (unplayedServerOpspecQueue.length > 0) {
// time over?
if ((new Date().getTime()) - startTime > replayTime) {
break;
}
opspec = unplayedServerOpspecQueue.shift();
// use factory to create an instance, and playback!
op = operationFactory.create(opspec);
runtime.log(" op in: "+runtime.toJson(opspec));
if (op !== null) {
playbackFunction(op);
} else {
runtime.log("ignoring invalid incoming opspec: " + opspec);
}
}
// still unplayed opspecs?
if (unplayedServerOpspecQueue.length > 0) {
// let other events be handled. then continue
playUnplayedServerOpSpecsTriggered = true;
runtime.getWindow().setTimeout(doPlayUnplayedServerOpSpecs, 1);
} else {
// This is such a sad hack. But there is no other way for now to inject
// the callback after the initial replay.
if (singleTimeCallbackOnCompleteServerOpSpecsPlay) {
singleTimeCallbackOnCompleteServerOpSpecsPlay();
singleTimeCallbackOnCompleteServerOpSpecsPlay = null;
}
}
}
if (playUnplayedServerOpSpecsTriggered) {
return;
}
doPlayUnplayedServerOpSpecs();
}
/**
* @param {Array.<!Object>} opspecs
* @return {undefined}
*/
function receiveOpSpecsFromNetwork(opspecs) {
// append to existing unplayed
unplayedServerOpspecQueue = unplayedServerOpspecQueue.concat(opspecs);
}
/**
* Transforms the unsynced client ops and the server ops,
* applies the server ops after transformation
* @param {Array.<!Object>} serverOpspecs
* @return {!boolean}
*/
function handleOpsSyncConflict(serverOpspecs) {
var i,
transformResult;
if (! serverOpspecs) {
// TODO: proper error message, stop working
runtime.assert(false, "no opspecs received!");
return false;
} // TODO: more checking of proper content in serverOpspecs
transformResult = operationTransformer.transform(unsyncedClientOpspecQueue, /**@type{!Array.<!Object>}*/(serverOpspecs));
if (!transformResult) {
return false;
}
// store transformed server ops
for (i = 0; i < transformResult.opsB.length; i += 1) {
unplayedServerOpspecQueue.push(transformResult.opsB[i].spec());
}
// store opspecs of all transformed client opspecs
unsyncedClientOpspecQueue = [];
for (i = 0; i < transformResult.opsA.length; i += 1) {
unsyncedClientOpspecQueue.push(transformResult.opsA[i].spec());
}
return true;
}
/**
* @return {undefined}
*/
function syncOps() {
function triggerPullingOps() {
var flag = {active: true};
// provide flag globally
pullingTimeOutFlag = flag;
runtime.getWindow().setTimeout(function() {
runtime.log("Pulling activated:" + flag.active);
// remove our flag
pullingTimeOutFlag = null;
if (flag.active) {
syncOps();
}
}, pullingIntervall);
}
/**
* @return {undefined}
*/
function doSyncOps() {
var syncedClientOpspecs;
if (syncLock || hasUnresolvableConflict) {
return;
}
// TODO: hack, remove
if (syncingBlocked) {
return;
}
syncLock = true;
// take specs from queue, if any
syncedClientOpspecs = unsyncedClientOpspecQueue;
unsyncedClientOpspecQueue = [];
server.call({
command: 'sync_ops',
args: {
es_id: sessionId,
member_id: memberId,
seq_head: String(lastServerSeq),
client_ops: syncedClientOpspecs
}
}, function(responseData) {
var shouldRetryInstantly = false,
response = /** @type{{result:string, head_seq:string, ops:Array.<!Object>}} */(runtime.fromJson(responseData));
// TODO: hack, remove
if (syncingBlocked) {
return;
}
runtime.log("sync-ops reply: " + responseData);
// just new ops?
if (response.result === "new_ops") {
if (response.ops.length > 0) {
// no new locally in the meantime?
if (unsyncedClientOpspecQueue.length === 0) {
receiveOpSpecsFromNetwork(compressOpSpecs(response.ops));
} else {
// transform server ops against new local ones and apply,
// transform and send new local ops to server
runtime.log("meh, have new ops locally meanwhile, have to do transformations.");
hasUnresolvableConflict = !handleOpsSyncConflict(compressOpSpecs(response.ops));
}
// and note server state
lastServerSeq = response.head_seq;
}
} else if (response.result === "added") {
runtime.log("All added to server");
// note server state
lastServerSeq = response.head_seq;
updateHasLocalUnsyncedOpsState();
} else if (response.result === "conflict") {
// put the send ops back into the outgoing queue
unsyncedClientOpspecQueue = syncedClientOpspecs.concat(unsyncedClientOpspecQueue);
// transform server ops against new local ones and apply,
// transform and request new send new local ops to server
runtime.log("meh, server has new ops meanwhile, have to do transformations.");
hasUnresolvableConflict = !handleOpsSyncConflict(compressOpSpecs(response.ops));
// and note server state
lastServerSeq = response.head_seq;
// try again instantly
if (!hasUnresolvableConflict) {
shouldRetryInstantly = true;
}
} else {
runtime.assert(false, "Unexpected result on sync-ops call: "+response.result);
}
syncLock = false;
if (hasUnresolvableConflict) {
// TODO: offer option to reload session automatically?
runtime.assert(false,
"Sorry to tell:\n" +
"we hit a pair of operations in a state which yet need to be supported for transformation against each other.\n" +
"Client disconnected from session, no further editing accepted.\n\n" +
"Please reconnect manually for now.");
} else {
if (shouldRetryInstantly) {
doSyncOps();
} else {
runtime.log("Preparing next: " + (unsyncedClientOpspecQueue.length === 0));
// prepare next sync
// nothing to push right now?
if (unsyncedClientOpspecQueue.length === 0) {
triggerPullingOps();
}
}
playUnplayedServerOpSpecs();
}
});
}
doSyncOps();
}
function triggerPushingOps() {
if (syncLock || triggerPushingOpsActivated) {
return;
}
triggerPushingOpsActivated = true;
// disable current pulling timeout
if (pullingTimeOutFlag) {
pullingTimeOutFlag.active = false;
}
runtime.getWindow().setTimeout(function() {
runtime.log("Pushing activated");
triggerPushingOpsActivated = false;
syncOps();
}, pushingIntervall);
}
this.requestReplay = function (done_cb) {
singleTimeCallbackOnCompleteServerOpSpecsPlay = done_cb;
syncOps();
};
/**
* Sets the factory to use to create operation instances from operation specs.
*
* @param {!ops.OperationFactory} f
* @return {undefined}
*/
this.setOperationFactory = function (f) {
operationFactory = f;
operationTransformer.setOperationFactory(f);
};
/**
* Sets the method which should be called to apply operations.
*
* @param {!function(!ops.Operation)} playback_func
* @return {undefined}
*/
this.setPlaybackFunction = function (playback_func) {
playbackFunction = playback_func;
};
/**
* Brings the locally created operations into the game.
*
* @param {!ops.Operation} op
* @return {undefined}
*/
this.push = function (op) {
var timedOp,
opspec = op.spec();
if (hasUnresolvableConflict) {
return;
}
// TODO: should be an assert in the future
// there needs to be a flag telling that processing is happening,
// and thus any input should be dropped in the sessioncontroller
// ideally also have some UI element showing the processing state
if (unplayedServerOpspecQueue.length > 0) {
return;
}
// note if any local ops modified TODO: find less fragile way, perhaps have the operationFactory check it?
hasPushedModificationOps = hasPushedModificationOps || !/^(AddCursor|RemoveCursor)$/.test(opspec.optype);
// apply locally
opspec.timestamp = (new Date()).getTime();
timedOp = operationFactory.create(opspec);
playbackFunction(timedOp);
// send to server
unsyncedClientOpspecQueue.push(opspec);
triggerPushingOps();
updateHasLocalUnsyncedOpsState();
};
/**
* Requests a gracefull shutdown of the Operation Router.
* Buffered operations shall be sent to the server.
* A callback is called on success.
*/
this.close = function (cb) {
function writeSessionStateToFile() {
function cbSuccess(fileData) {
server.writeSessionStateToFile(sessionId, memberId, lastServerSeq, fileData, cb);
};
odfContainer.createByteArray(cbSuccess, cb);
}
// TODO: hack, rather add callback to syncOps for success and properly close things
syncOps();
runtime.getWindow().setTimeout(function() {
syncingBlocked = true;
if (hasPushedModificationOps) {
writeSessionStateToFile();
} else {
cb();
}
}, 2000);
};
this.getHasLocalUnsyncedOpsAndUpdates = function (subscriber) {
var i;
// detect double subscription
for (i=0; i<hasLocalUnsyncedOpsStateSubscribers.length; i+=1) {
if (subscribers[i] === subscriber) {
break;
}
}
if (i < hasLocalUnsyncedOpsStateSubscribers.length) {
// already subscribed
runtime.log("double subscription request in PullBoxMemberModel::getHasLocalUnsyncedOpsAndUpdates");
} else {
// subscribe
hasLocalUnsyncedOpsStateSubscribers.push(subscriber);
}
subscriber(hasLocalUnsyncedOps);
};
/*jslint emptyblock: true, unparam: true*/
this.unsubscribeHasLocalUnsyncedOpsUpdates = function (subscriber) {
var i;
for (i=0; i<hasLocalUnsyncedOpsStateSubscribers.length; i+=1) {
if (hasLocalUnsyncedOpsStateSubscribers[i] === subscriber) {
break;
}
}
runtime.assert((i < hasLocalUnsyncedOpsStateSubscribers.length),
"tried to unsubscribe when not subscribed in PullBoxMemberModel::getHasLocalUnsyncedOpsAndUpdates");
hasLocalUnsyncedOpsStateSubscribers.splice(i,1);
};
};
});