276 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			276 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| "use strict";
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| 
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| // external modules
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| var Sequelize = require("sequelize");
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| var LZString = require('lz-string');
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| var async = require('async');
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| var moment = require('moment');
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| var DiffMatchPatch = require('diff-match-patch');
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| var dmp = new DiffMatchPatch();
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| 
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| // core
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| var config = require("../config.js");
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| var logger = require("../logger.js");
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| 
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| module.exports = function (sequelize, DataTypes) {
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|     var Revision = sequelize.define("Revision", {
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|         id: {
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|             type: DataTypes.UUID,
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|             primaryKey: true,
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|             defaultValue: Sequelize.UUIDV4
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|         },
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|         patch: {
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|             type: DataTypes.TEXT
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|         },
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|         lastContent: {
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|             type: DataTypes.TEXT
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|         },
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|         content: {
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|             type: DataTypes.TEXT
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|         },
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|         length: {
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|             type: DataTypes.INTEGER
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|         }
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|     }, {
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|         classMethods: {
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|             associate: function (models) {
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|                 Revision.belongsTo(models.User, {
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|                     foreignKey: "noteId",
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|                     as: "note",
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|                     constraints: false
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|                 });
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|             },
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|             createPatch: function (lastDoc, CurrDoc) {
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|                 var ms_start = (new Date()).getTime();
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|                 var diff = dmp.diff_main(lastDoc, CurrDoc);
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|                 dmp.diff_cleanupSemantic(diff);
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|                 var patch = dmp.patch_make(lastDoc, diff);
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|                 patch = dmp.patch_toText(patch);
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|                 var ms_end = (new Date()).getTime();
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|                 if (config.debug) {
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|                     logger.info(patch);
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|                     logger.info((ms_end - ms_start) + 'ms');
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|                 }
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|                 return patch;
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|             },
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|             getNoteRevisions: function (note, callback) {
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|                 Revision.findAll({
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|                     where: {
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|                         noteId: note.id
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|                     },
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|                     order: '"createdAt" DESC'
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|                 }).then(function (revisions) {
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|                     var data = [];
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|                     for (var i = 0, l = revisions.length; i < l; i++) {
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|                         var revision = revisions[i];
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|                         data.push({
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|                             time: moment(revision.createdAt).valueOf(),
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|                             length: revision.length
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|                         });
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|                     }
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|                     callback(null, data);
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|                 }).catch(function (err) {
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|                     callback(err, null);
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|                 });
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|             },
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|             getPatchedNoteRevisionByTime: function (note, time, callback) {
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|                 // find all revisions to prepare for all possible calculation
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|                 Revision.findAll({
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|                     where: {
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|                         noteId: note.id
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|                     },
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|                     order: '"createdAt" DESC'
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|                 }).then(function (revisions) {
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|                     if (revisions.length <= 0) return callback(null, null);
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|                     // measure target revision position 
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|                     Revision.count({
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|                         where: {
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|                             noteId: note.id,
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|                             createdAt: {
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|                                 $gte: time
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|                             }
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|                         },
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|                         order: '"createdAt" DESC'
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|                     }).then(function (count) {
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|                         if (count <= 0) return callback(null, null);
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|                         var ms_start = (new Date()).getTime();
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|                         var startContent = null;
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|                         var lastPatch = [];
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|                         var applyPatches = [];
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|                         if (count <= Math.round(revisions.length / 2)) {
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|                             // start from top to target
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|                             for (var i = 0; i < count; i++) {
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|                                 var revision = revisions[i];
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|                                 if (i == 0) {
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|                                     startContent = LZString.decompressFromBase64(revision.content || revision.lastContent);
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|                                 }
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|                                 if (i != count - 1) {
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|                                     var patch = dmp.patch_fromText(LZString.decompressFromBase64(revision.patch));
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|                                     applyPatches = applyPatches.concat(patch);
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|                                 }
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|                                 lastPatch = revision.patch;
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|                             }
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|                             // swap DIFF_INSERT and DIFF_DELETE to achieve unpatching
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|                             for (var i = 0, l = applyPatches.length; i < l; i++) {
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|                                 for (var j = 0, m = applyPatches[i].diffs.length; j < m; j++) {
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|                                     var diff = applyPatches[i].diffs[j];
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|                                     if (diff[0] == DiffMatchPatch.DIFF_INSERT)
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|                                         diff[0] = DiffMatchPatch.DIFF_DELETE;
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|                                     else if (diff[0] == DiffMatchPatch.DIFF_DELETE)
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|                                         diff[0] = DiffMatchPatch.DIFF_INSERT;
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|                                 }
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|                             }
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|                         } else {
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|                             // start from bottom to target
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|                             var l = revisions.length - 1;
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|                             for (var i = l; i >= count - 1; i--) {
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|                                 var revision = revisions[i];
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|                                 if (i == l) {
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|                                     startContent = LZString.decompressFromBase64(revision.lastContent);
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|                                 }
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|                                 if (revision.patch) {
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|                                     var patch = dmp.patch_fromText(LZString.decompressFromBase64(revision.patch));
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|                                     applyPatches = applyPatches.concat(patch);
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|                                 }
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|                                 lastPatch = revision.patch;
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|                             }
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|                         }
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|                         try {
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|                             var finalContent = dmp.patch_apply(applyPatches, startContent)[0];
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|                         } catch (err) {
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|                             return callback(err, null);
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|                         }
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|                         var data = {
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|                             content: finalContent,
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|                             patch: dmp.patch_fromText(LZString.decompressFromBase64(lastPatch))
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|                         };
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|                         var ms_end = (new Date()).getTime();
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|                         if (config.debug) {
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|                             logger.info((ms_end - ms_start) + 'ms');
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|                         }
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|                         return callback(null, data);
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|                     }).catch(function (err) {
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|                         return callback(err, null);
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|                     });
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|                 }).catch(function (err) {
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|                     return callback(err, null);
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|                 });
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|             },
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|             checkAllNotesRevision: function (callback) {
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|                 Revision.saveAllNotesRevision(function (err, notes) {
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|                     if (err) return callback(err, null);
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|                     if (notes.length <= 0) {
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|                         return callback(null, notes);
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|                     } else {
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|                         Revision.checkAllNotesRevision(callback);
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|                     }
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|                 });
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|             },
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|             saveAllNotesRevision: function (callback) {
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|                 sequelize.models.Note.findAll({
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|                     where: {
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|                         $and: [
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|                             {
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|                                 lastchangeAt: {
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|                                     $or: {
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|                                         $eq: null,
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|                                         $and: {
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|                                             $ne: null,
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|                                             $gt: sequelize.col('createdAt')
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|                                         }
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|                                     }
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|                                 }
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|                             },
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|                             {
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|                                 savedAt: {
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|                                     $or: {
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|                                         $eq: null,
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|                                         $lt: sequelize.col('lastchangeAt')
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|                                     }
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|                                 }
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|                             }
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|                         ]
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|                     }
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|                 }).then(function (notes) {
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|                     if (notes.length <= 0) return callback(null, notes);
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|                     async.each(notes, function (note, _callback) {
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|                         Revision.saveNoteRevision(note, _callback);
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|                     }, function (err) {
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|                         if (err) return callback(err, null);
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|                         return callback(null, notes);
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|                     });
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|                 }).catch(function (err) {
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|                     return callback(err, null);
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|                 });
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|             },
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|             saveNoteRevision: function (note, callback) {
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|                 Revision.findAll({
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|                     where: {
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|                         noteId: note.id
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|                     },
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|                     order: '"createdAt" DESC'
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|                 }).then(function (revisions) {
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|                     if (revisions.length <= 0) {
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|                         // if no revision available
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|                         Revision.create({
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|                             noteId: note.id,
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|                             lastContent: note.content,
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|                             length: LZString.decompressFromBase64(note.content).length
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|                         }).then(function (revision) {
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|                             Revision.finishSaveNoteRevision(note, revision, callback);
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|                         }).catch(function (err) {
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|                             return callback(err, null);
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|                         });
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|                     } else {
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|                         var latestRevision = revisions[0];
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|                         var lastContent = LZString.decompressFromBase64(latestRevision.content || latestRevision.lastContent);
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|                         var content = LZString.decompressFromBase64(note.content);
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|                         var patch = Revision.createPatch(lastContent, content);
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|                         if (!patch) {
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|                             // if patch is empty (means no difference) then just update the latest revision updated time 
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|                             latestRevision.changed('updatedAt', true); 
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|                             latestRevision.update({
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|                                 updatedAt: Date.now()
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|                             }).then(function (revision) {
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|                                 Revision.finishSaveNoteRevision(note, revision, callback);
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|                             }).catch(function (err) {
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|                                 return callback(err, null);
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|                             });
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|                         } else {
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|                             Revision.create({
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|                                 noteId: note.id,
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|                                 patch: LZString.compressToBase64(patch),
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|                                 content: note.content,
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|                                 length: LZString.decompressFromBase64(note.content).length
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|                             }).then(function (revision) {
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|                                 // clear last revision content to reduce db size
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|                                 latestRevision.update({
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|                                     content: null
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|                                 }).then(function () {
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|                                     Revision.finishSaveNoteRevision(note, revision, callback);
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|                                 }).catch(function (err) {
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|                                     return callback(err, null);
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|                                 });
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|                             }).catch(function (err) {
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|                                 return callback(err, null);
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|                             });
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|                         }
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|                     }
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|                 }).catch(function (err) {
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|                     return callback(err, null);
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|                 });
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|             },
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|             finishSaveNoteRevision: function (note, revision, callback) {
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|                 note.update({
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|                     savedAt: revision.updatedAt
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|                 }).then(function () {
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|                     return callback(null, revision);
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|                 }).catch(function (err) {
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|                     return callback(err, null);
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|                 });
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|             }
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|         }
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|     });
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| 
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|     return Revision;
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| }; |