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Conflict detection
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Conflict detection implemented.
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@MysticJay
MysticJay committed Jul 13, 2021
1 parent bc371bd commit c9a3415
Showing 1 changed file with 131 additions and 31 deletions.
162 changes: 131 additions & 31 deletions plugins/sync.js
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Original file line number Diff line number Diff line change
Expand Up @@ -98,7 +98,12 @@ window.plugin.sync.RegisteredMap = function(options) {
this.initializing = false;
this.initialized = false;
this.failed = false;

this.doSync = 'remote'; // normal 'sync'
// 'no' sync needed
// force 'remote' (1st sync)
// force 'local'
// sync is on 'stop'

this.initialize = this.initialize.bind(this);
this.loadDocument = this.loadDocument.bind(this);
};
Expand All @@ -124,11 +129,6 @@ window.plugin.sync.RegisteredMap.prototype.updateMap = function(keyArray) {
}
};

window.plugin.sync.RegisteredMap.prototype.isUpdatedByOthers = function() {
var remoteUUID = this.lastUpdateUUID.toString();
return (remoteUUID !== '') && (remoteUUID !== this.uuid);
};

// concatenate a the filename for the drive "pluginName[fieldName]"
window.plugin.sync.RegisteredMap.prototype.getFileName = function() {
return this.pluginName + '[' + this.fieldName + ']'
Expand Down Expand Up @@ -195,41 +195,97 @@ window.plugin.sync.RegisteredMap.prototype.loadDocument = function(callback) {
setTimeout(function() {_this.loadDocument();}, window.plugin.sync.checkInterval);
};

// this function called when the document is loaded
// update local data if the document is updated by other (overwrite!)
// and adding a timer to further check for updates
// this function gets called when the document is loaded
onFileLoaded = function(data) {
_this.map = data['map'];
_this.lastUpdateUUID = data['last-update-uuid'];


if (!_this.intervalID) { // if the DL-interval is not set
_this.intervalID = setInterval(function() { // create a new timer to load
_this.loadDocument(); // the file from drive
}, window.plugin.sync.checkInterval); // every <checkInterval> ms
}

// Replace local value if data is changed by others
if(_this.isUpdatedByO\thers()) {
plugin.sync.logger.log(_this.getFileName(), 'Updated by others, replacing content from ';
/* Sync only checks the drive every 3 mins. But changes to local data get pushed
immediately. Two or more clients that do changes might might store data, that the
other is not aware of. We are trying to identify crititcal changes. Following
situations have been identified and should be coverd by the logic:
Status-table:
0: init, first start, always load from remote
1: lastUUID and remoteUUID show the same UUID, load from remote
2: lastUUID and remoteUUID show local UUID, no load needed
3: lastUUID and remoteUUID show different, not local UUIDs, load remote
4: lastUUID is local and remoteUIID is different, CONFLICT! Stop sync and ask user
*/
_this.remoteUUID = data['last-update-uuid']; // get the UUID of the data on drive
// -----------------------------------------------------------------------------------------
// the initial value for doSync is 'remote', so initially loading from drive
if (_this.doSync == 'sync') {
let conflict = true; //
// check for conflict
if (_this.remoteUUID == _this.lastUpdateUUID) { // last Update was done on drive
conflict = false; // so there is not a conflict
};
if (_this.remoteUUID != _this.lastUpdateUUID && // 3rd client modified the drive
_this.lastUpdateUUID != _this.uuid) {
// maybe issue a warning
console.log ('SYNC detected a 3rd client that modified the drive');
conflict = false; // but not a conflict here
};

if (conflict) { // some other client changed the
_this.doSync = 'stop'; // data on the drive, after we
// did a change. So we need
_this.conflictHandler(); // to stop sync and ask the user
plugin.sync.logger.log(_this.getFileName(), 'SYNC detected a conflict caused by '+ _this.lastRemoteUUID);
} else { // ELSE no conflict found:
if (_this.remoteUUID == _this.uuid) { // local data still is on drive?
_this.doSync = 'sync'; // no need to do anything
} else { // otherwise
_this.doSync = 'remote'; // load remote data
}; // (it might have changed)
};
};
// -----------------------------------------------------------------------------------------
if (_this.doSync == 'remote') {
// load the remote data to the plugin's dataobject
_this.lastUpdateUUID = _this.remoteUUID; // remember last client on drive
_this.map = data['map']; // map from the loaded data

window.plugin[_this.pluginName][_this.fieldName] = {};// clear the plugin's dataobject
$.each(_this.map, function(key, value) { // fill the dataobject with data from drive
$.each(_this.map, function(key, value) { // fill the dataobject with data from drive
window.plugin[_this.pluginName][_this.fieldName][key] = _this.map[key];
});
if(_this.callback) _this.callback( // execute the callback functions with
_this.pluginName, // pluginName
_this.fieldName, // fieldName
null, // null (for backwards compatibility)
true // true = full file load from Drive
);
}

_this.initialized = true; // connection to drive is "initalized"
_this.initializing = false; // remove semaphore
plugin.sync.logger.log(_this.getFileName(), 'Data loaded from: ');
// execute the callback functions

if(_this.callback) _this.callback();
if(_this.initializedCallback) _this.initializedCallback(_this.pluginName, _this.fieldName);
// execute the callback functions
if(_this.callback) _this.callback( // execute the callback functions with
_this.pluginName, // pluginName
_this.fieldName, // fieldName
null, // null (for backwards compatibility)
true // true = full file load from Drive
);

if (_this.initializing) {
_this.initialized = true; // connection to drive is "initalized"
_this.initializing = false; // remove semaphore
if(_this.initializedCallback) _this.initializedCallback(
_this.pluginName,
_this.fieldName
);
}
plugin.sync.logger.log(_this.getFileName(), 'Data loaded from: '+ _this.lastUpdateUUID);
_this.doSync = 'sync'; // return to normal sync
};
// -----------------------------------------------------------------------------------------
if (_this.doSync == 'local') { // User decided for 'local' data.
_this.lastUpdateUUID = _this.uuid; //
_this.updateMap({}); // push local data to drive
_this.doSync = 'sync'; // resume normal sync
};
// -----------------------------------------------------------------------------------------
if (_this.doSync == 'stop') {
// do nothing
console.log('SYNC stopped synching data for plugin '+_this.pluginName);
};
};

// Stop the sync if any error occur and try to re-authorize
Expand All @@ -256,6 +312,50 @@ window.plugin.sync.RegisteredMap.prototype.loadDocument = function(callback) {
// finally execute readFile
this.dataStorage.readFile(initializeFile, onFileLoaded, handleError);
};

// conflict handler to decide between remote or local data
// results: 'remote', 'local', 'stop'
window.plugin.sync.RegisteredMap.prototype.conflictHandler = function () {
var _this;
_this = this;

window.dialog ({
title: "SYNC Conflict Handling",
html: "<div>SYNC found a conflict. The remote data stored on the drive "
+ "was changed while you did local changes . "
+ "Please decide which data shall be used. <br>"
+ "Your decission will overwrite the other changes. "
+ "It is impossible to merge the data!</div><br>"
+ "",
buttons: [
{ text: "remote",
click: function() {
_this.doSync = 'remote';
$( this ).dialog( "close" );
}
},
{ text: "local",
click: function() {
_this.doSync = 'local';
$( this ).dialog( "close" );
}
},
{ text: "STOP SYNC",
click: function() {
_this.doSync = 'stop';
$( this ).dialog( "close" );
}
}
],
closeCallback: function() {
_this.loadDocument();
},
maxHeight: 300
});

};


//// end RegisteredMap


Expand Down Expand Up @@ -771,7 +871,7 @@ window.plugin.sync.loadLocal = function(mapping) {
: obj;
};

//load a previously generated UUUID (or generate a new one)
//load a previously generated UUID (or generate a new one)
window.plugin.sync.loadUUID = function() {
plugin.sync.loadLocal(plugin.sync.KEY_UUID);
if(!plugin.sync.uuid) {
Expand Down

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