yjs/lib/Engine.coffee
2014-08-04 23:35:50 +02:00

62 lines
1.3 KiB
CoffeeScript

#
# The Engine handles how and in which order to execute operations and add operations to the HistoryBuffer.
#
class Engine
constructor: (@HB, @parser)->
@unprocessed_ops = []
parseOperation: (json)->
typeParser = @parser[json.type]
if typeParser?
typeParser json
else
throw new Error "You forgot to specify a parser for type #{json.type}. The message is #{JSON.stringify json}."
applyOps: (ops_json)->
ops = []
for o in ops_json
ops.push @parseOperation o
for o in ops
@HB.addOperation o
for o in ops
if not o.execute()
@unprocessed_ops.push o
@tryUnprocessed()
applyOp: (op_json)->
# $parse_and_execute will return false if $o_json was parsed and executed, otherwise the parsed operadion
o = @parseOperation op_json
@HB.addOperation o
if not o.execute()
@unprocessed_ops.push o
@tryUnprocessed()
tryUnprocessed: ()->
while true
old_length = @unprocessed_ops.length
unprocessed = []
for op in @unprocessed_ops
if not op.execute()
unprocessed.push op
@unprocessed_ops = unprocessed
if @unprocessed_ops.length is old_length
break
module.exports = Engine