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Diffstat (limited to 'lib/models/revision.js')
| -rw-r--r-- | lib/models/revision.js | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/lib/models/revision.js b/lib/models/revision.js new file mode 100644 index 00000000..5300d725 --- /dev/null +++ b/lib/models/revision.js @@ -0,0 +1,276 @@ +"use strict"; + +// external modules +var Sequelize = require("sequelize"); +var LZString = require('lz-string'); +var async = require('async'); +var moment = require('moment'); +var DiffMatchPatch = require('diff-match-patch'); +var dmp = new DiffMatchPatch(); + +// core +var config = require("../config.js"); +var logger = require("../logger.js"); + +module.exports = function (sequelize, DataTypes) { + var Revision = sequelize.define("Revision", { + id: { + type: DataTypes.UUID, + primaryKey: true, + defaultValue: Sequelize.UUIDV4 + }, + patch: { + type: DataTypes.TEXT + }, + lastContent: { + type: DataTypes.TEXT + }, + content: { + type: DataTypes.TEXT + }, + length: { + type: DataTypes.INTEGER + } + }, { + classMethods: { + associate: function (models) { + Revision.belongsTo(models.User, { + foreignKey: "noteId", + as: "note", + constraints: false + }); + }, + createPatch: function (lastDoc, CurrDoc) { + var ms_start = (new Date()).getTime(); + var diff = dmp.diff_main(lastDoc, CurrDoc); + dmp.diff_cleanupSemantic(diff); + var patch = dmp.patch_make(lastDoc, diff); + patch = dmp.patch_toText(patch); + var ms_end = (new Date()).getTime(); + if (config.debug) { + logger.info(patch); + logger.info((ms_end - ms_start) + 'ms'); + } + return patch; + }, + getNoteRevisions: function (note, callback) { + Revision.findAll({ + where: { + noteId: note.id + }, + order: '"createdAt" DESC' + }).then(function (revisions) { + var data = []; + for (var i = 0, l = revisions.length; i < l; i++) { + var revision = revisions[i]; + data.push({ + time: moment(revision.createdAt).valueOf(), + length: revision.length + }); + } + callback(null, data); + }).catch(function (err) { + callback(err, null); + }); + }, + getPatchedNoteRevisionByTime: function (note, time, callback) { + // find all revisions to prepare for all possible calculation + Revision.findAll({ + where: { + noteId: note.id + }, + order: '"createdAt" DESC' + }).then(function (revisions) { + if (revisions.length <= 0) return callback(null, null); + // measure target revision position + Revision.count({ + where: { + noteId: note.id, + createdAt: { + $gte: time + } + }, + order: '"createdAt" DESC' + }).then(function (count) { + if (count <= 0) return callback(null, null); + var ms_start = (new Date()).getTime(); + var startContent = null; + var lastPatch = []; + var applyPatches = []; + if (count <= Math.round(revisions.length / 2)) { + // start from top to target + for (var i = 0; i < count; i++) { + var revision = revisions[i]; + if (i == 0) { + startContent = LZString.decompressFromBase64(revision.content || revision.lastContent); + } + if (i != count - 1) { + var patch = dmp.patch_fromText(LZString.decompressFromBase64(revision.patch)); + applyPatches = applyPatches.concat(patch); + } + lastPatch = revision.patch; + } + // swap DIFF_INSERT and DIFF_DELETE to achieve unpatching + for (var i = 0, l = applyPatches.length; i < l; i++) { + for (var j = 0, m = applyPatches[i].diffs.length; j < m; j++) { + var diff = applyPatches[i].diffs[j]; + if (diff[0] == DiffMatchPatch.DIFF_INSERT) + diff[0] = DiffMatchPatch.DIFF_DELETE; + else if (diff[0] == DiffMatchPatch.DIFF_DELETE) + diff[0] = DiffMatchPatch.DIFF_INSERT; + } + } + } else { + // start from bottom to target + var l = revisions.length - 1; + for (var i = l; i >= count - 1; i--) { + var revision = revisions[i]; + if (i == l) { + startContent = LZString.decompressFromBase64(revision.lastContent); + } + if (revision.patch) { + var patch = dmp.patch_fromText(LZString.decompressFromBase64(revision.patch)); + applyPatches = applyPatches.concat(patch); + } + lastPatch = revision.patch; + } + } + try { + var finalContent = dmp.patch_apply(applyPatches, startContent)[0]; + } catch (err) { + return callback(err, null); + } + var data = { + content: finalContent, + patch: dmp.patch_fromText(LZString.decompressFromBase64(lastPatch)) + }; + var ms_end = (new Date()).getTime(); + if (config.debug) { + logger.info((ms_end - ms_start) + 'ms'); + } + return callback(null, data); + }).catch(function (err) { + return callback(err, null); + }); + }).catch(function (err) { + return callback(err, null); + }); + }, + checkAllNotesRevision: function (callback) { + Revision.saveAllNotesRevision(function (err, notes) { + if (err) return callback(err, null); + if (notes.length <= 0) { + return callback(null, notes); + } else { + Revision.checkAllNotesRevision(callback); + } + }); + }, + saveAllNotesRevision: function (callback) { + sequelize.models.Note.findAll({ + where: { + $and: [ + { + lastchangeAt: { + $or: { + $eq: null, + $and: { + $ne: null, + $gt: sequelize.col('createdAt') + } + } + } + }, + { + savedAt: { + $or: { + $eq: null, + $lt: sequelize.col('lastchangeAt') + } + } + } + ] + } + }).then(function (notes) { + if (notes.length <= 0) return callback(null, notes); + async.each(notes, function (note, _callback) { + Revision.saveNoteRevision(note, _callback); + }, function (err) { + if (err) return callback(err, null); + return callback(null, notes); + }); + }).catch(function (err) { + return callback(err, null); + }); + }, + saveNoteRevision: function (note, callback) { + Revision.findAll({ + where: { + noteId: note.id + }, + order: '"createdAt" DESC' + }).then(function (revisions) { + if (revisions.length <= 0) { + // if no revision available + Revision.create({ + noteId: note.id, + lastContent: note.content, + length: LZString.decompressFromBase64(note.content).length + }).then(function (revision) { + Revision.finishSaveNoteRevision(note, revision, callback); + }).catch(function (err) { + return callback(err, null); + }); + } else { + var latestRevision = revisions[0]; + var lastContent = LZString.decompressFromBase64(latestRevision.content || latestRevision.lastContent); + var content = LZString.decompressFromBase64(note.content); + var patch = Revision.createPatch(lastContent, content); + if (!patch) { + // if patch is empty (means no difference) then just update the latest revision updated time + latestRevision.changed('updatedAt', true); + latestRevision.update({ + updatedAt: Date.now() + }).then(function (revision) { + Revision.finishSaveNoteRevision(note, revision, callback); + }).catch(function (err) { + return callback(err, null); + }); + } else { + Revision.create({ + noteId: note.id, + patch: LZString.compressToBase64(patch), + content: note.content, + length: LZString.decompressFromBase64(note.content).length + }).then(function (revision) { + // clear last revision content to reduce db size + latestRevision.update({ + content: null + }).then(function () { + Revision.finishSaveNoteRevision(note, revision, callback); + }).catch(function (err) { + return callback(err, null); + }); + }).catch(function (err) { + return callback(err, null); + }); + } + } + }).catch(function (err) { + return callback(err, null); + }); + }, + finishSaveNoteRevision: function (note, revision, callback) { + note.update({ + savedAt: revision.updatedAt + }).then(function () { + return callback(null, revision); + }).catch(function (err) { + return callback(err, null); + }); + } + } + }); + + return Revision; +};
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