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80 lines
3.3 KiB
CoffeeScript
80 lines
3.3 KiB
CoffeeScript
ShareJsModel = require "./sharejs/server/model"
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ShareJsDB = require "./ShareJsDB"
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logger = require "logger-sharelatex"
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Settings = require('settings-sharelatex')
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Keys = require "./UpdateKeys"
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{EventEmitter} = require "events"
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util = require "util"
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RealTimeRedisManager = require "./RealTimeRedisManager"
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crypto = require "crypto"
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metrics = require('./Metrics')
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Errors = require("./Errors")
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ShareJsModel:: = {}
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util.inherits ShareJsModel, EventEmitter
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MAX_AGE_OF_OP = 80
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module.exports = ShareJsUpdateManager =
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getNewShareJsModel: (project_id, doc_id, lines, version) ->
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db = new ShareJsDB(project_id, doc_id, lines, version)
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model = new ShareJsModel(db, maxDocLength: Settings.max_doc_length, maximumAge: MAX_AGE_OF_OP)
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model.db = db
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return model
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applyUpdate: (project_id, doc_id, update, lines, version, callback = (error, updatedDocLines) ->) ->
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logger.log project_id: project_id, doc_id: doc_id, update: update, "applying sharejs updates"
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jobs = []
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# record the update version before it is modified
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incomingUpdateVersion = update.v
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# We could use a global model for all docs, but we're hitting issues with the
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# internal state of ShareJS not being accessible for clearing caches, and
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# getting stuck due to queued callbacks (line 260 of sharejs/server/model.coffee)
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# This adds a small but hopefully acceptable overhead (~12ms per 1000 updates on
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# my 2009 MBP).
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model = @getNewShareJsModel(project_id, doc_id, lines, version)
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@_listenForOps(model)
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doc_key = Keys.combineProjectIdAndDocId(project_id, doc_id)
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model.applyOp doc_key, update, (error) ->
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if error?
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if error == "Op already submitted"
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metrics.inc "sharejs.already-submitted"
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logger.warn {project_id, doc_id, update}, "op has already been submitted"
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update.dup = true
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ShareJsUpdateManager._sendOp(project_id, doc_id, update)
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else if /^Delete component/.test(error)
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metrics.inc "sharejs.delete-mismatch"
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logger.warn {project_id, doc_id, update, shareJsErr: error}, "sharejs delete does not match"
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error = new Errors.DeleteMismatchError("Delete component does not match")
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return callback(error)
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else
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metrics.inc "sharejs.other-error"
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return callback(error)
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logger.log project_id: project_id, doc_id: doc_id, error: error, "applied update"
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model.getSnapshot doc_key, (error, data) =>
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return callback(error) if error?
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# only check hash when present and no other updates have been applied
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if update.hash? and incomingUpdateVersion == version
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ourHash = ShareJsUpdateManager._computeHash(data.snapshot)
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if ourHash != update.hash
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metrics.inc "sharejs.hash-fail"
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return callback(new Error("Invalid hash"))
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else
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metrics.inc "sharejs.hash-pass", 0.001
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docLines = data.snapshot.split(/\r\n|\n|\r/)
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callback(null, docLines, data.v, model.db.appliedOps[doc_key] or [])
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_listenForOps: (model) ->
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model.on "applyOp", (doc_key, opData) ->
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[project_id, doc_id] = Keys.splitProjectIdAndDocId(doc_key)
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ShareJsUpdateManager._sendOp(project_id, doc_id, opData)
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_sendOp: (project_id, doc_id, op) ->
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RealTimeRedisManager.sendData {project_id, doc_id, op}
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_computeHash: (content) ->
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return crypto.createHash('sha1')
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.update("blob " + content.length + "\x00")
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.update(content, 'utf8')
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.digest('hex')
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