overleaf/services/track-changes/app/coffee/DiffManager.coffee
2015-12-18 12:38:42 +00:00

62 lines
2.5 KiB
CoffeeScript

UpdatesManager = require "./UpdatesManager"
DocumentUpdaterManager = require "./DocumentUpdaterManager"
DiffGenerator = require "./DiffGenerator"
logger = require "logger-sharelatex"
module.exports = DiffManager =
getLatestDocAndUpdates: (project_id, doc_id, fromVersion, toVersion, callback = (error, content, version, updates) ->) ->
# retrieve the document before retreiving the updates,
# because updates are written to mongo after the document
DocumentUpdaterManager.getDocument project_id, doc_id, (error, content, version) ->
return callback(error) if error?
UpdatesManager.getDocUpdatesWithUserInfo project_id, doc_id, from: fromVersion, to: toVersion, (error, updates) ->
return callback(error) if error?
callback(null, content, version, updates)
getDiff: (project_id, doc_id, fromVersion, toVersion, callback = (error, diff) ->) ->
logger.log project_id: project_id, doc_id: doc_id, from: fromVersion, to: toVersion, "getting diff"
DiffManager.getDocumentBeforeVersion project_id, doc_id, fromVersion, (error, startingContent, updates) ->
if error?
if error.message == "broken-history"
return callback(null, "history unavailable")
else
return callback(error)
updatesToApply = []
for update in updates.slice().reverse()
if update.v <= toVersion
updatesToApply.push update
try
diff = DiffGenerator.buildDiff startingContent, updatesToApply
catch e
return callback(e)
callback(null, diff)
getDocumentBeforeVersion: (project_id, doc_id, version, callback = (error, document, rewoundUpdates) ->) ->
logger.log project_id: project_id, doc_id: doc_id, version: version, "getting document before version"
DiffManager.getLatestDocAndUpdates project_id, doc_id, version, null, (error, content, version, updates) ->
return callback(error) if error?
# bail out if we hit a broken update
for u in updates when u.broken
return callback new Error "broken-history"
# discard any updates which are ahead of this document version
while updates[0]?.v >= version
updates.shift()
lastUpdate = updates[0]
if lastUpdate? and lastUpdate.v != version - 1
return callback new Error("latest update version, #{lastUpdate.v}, does not match doc version, #{version}")
tryUpdates = updates.slice().reverse()
try
startingContent = DiffGenerator.rewindUpdates content, tryUpdates
# tryUpdates is reversed, and any unapplied ops are marked as broken
catch e
return callback(e)
callback(null, startingContent, tryUpdates)