overleaf/services/document-updater/app/coffee/ShareJsUpdateManager.coffee
2017-10-23 15:59:32 +01:00

55 lines
2.2 KiB
CoffeeScript

ShareJsModel = require "./sharejs/server/model"
ShareJsDB = require "./ShareJsDB"
logger = require "logger-sharelatex"
Settings = require('settings-sharelatex')
Keys = require "./UpdateKeys"
{EventEmitter} = require "events"
util = require "util"
RealTimeRedisManager = require "./RealTimeRedisManager"
ShareJsModel:: = {}
util.inherits ShareJsModel, EventEmitter
MAX_AGE_OF_OP = 80
module.exports = ShareJsUpdateManager =
getNewShareJsModel: (project_id, doc_id, lines, version) ->
db = new ShareJsDB(project_id, doc_id, lines, version)
model = new ShareJsModel(db, maxDocLength: Settings.max_doc_length, maximumAge: MAX_AGE_OF_OP)
model.db = db
return model
applyUpdate: (project_id, doc_id, update, lines, version, callback = (error, updatedDocLines) ->) ->
logger.log project_id: project_id, doc_id: doc_id, update: update, "applying sharejs updates"
jobs = []
# We could use a global model for all docs, but we're hitting issues with the
# internal state of ShareJS not being accessible for clearing caches, and
# getting stuck due to queued callbacks (line 260 of sharejs/server/model.coffee)
# This adds a small but hopefully acceptable overhead (~12ms per 1000 updates on
# my 2009 MBP).
model = @getNewShareJsModel(project_id, doc_id, lines, version)
@_listenForOps(model)
doc_key = Keys.combineProjectIdAndDocId(project_id, doc_id)
model.applyOp doc_key, update, (error) ->
if error?
if error == "Op already submitted"
logger.warn {project_id, doc_id, update}, "op has already been submitted"
update.dup = true
ShareJsUpdateManager._sendOp(project_id, doc_id, update)
else
return callback(error)
logger.log project_id: project_id, doc_id: doc_id, error: error, "applied update"
model.getSnapshot doc_key, (error, data) =>
return callback(error) if error?
docLines = data.snapshot.split(/\r\n|\n|\r/)
callback(null, docLines, data.v, model.db.appliedOps[doc_key] or [])
_listenForOps: (model) ->
model.on "applyOp", (doc_key, opData) ->
[project_id, doc_id] = Keys.splitProjectIdAndDocId(doc_key)
ShareJsUpdateManager._sendOp(project_id, doc_id, opData)
_sendOp: (project_id, doc_id, op) ->
RealTimeRedisManager.sendData {project_id, doc_id, op}