From f1e15b49a9945bc6a85c42bbd83607709a8ee79c Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Mon, 29 Apr 2013 18:24:37 +0800
Subject: [PATCH] Support passing callbacks from renderer to browser.

---
 browser/atom/rpc_server.coffee | 23 +++++++++++++++++++
 renderer/api/lib/remote.coffee | 42 +++++++++++++++++++++++++++++++---
 2 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/browser/atom/rpc_server.coffee b/browser/atom/rpc_server.coffee
index 69fdfa9e258c..deae80de6cbb 100644
--- a/browser/atom/rpc_server.coffee
+++ b/browser/atom/rpc_server.coffee
@@ -1,6 +1,23 @@
 ipc = require 'ipc'
 path = require 'path'
 objectsRegistry = require './objects_registry.js'
+v8_util = process.atomBinding 'v8_util'
+
+# Convert list of meta information into real arguments array, the main
+# purpose is to turn remote function's id into delegate function.
+argsToValues = (processId, routingId, metas) ->
+  constructCallback = (meta) ->
+    return meta.value if meta.type is 'value'
+
+    # Create a delegate function to do asynchronous RPC call.
+    ret = ->
+      args = new Meta(processId, routingId, arguments)
+      ipc.sendChannel processId, routingId, 'ATOM_INTERNAL_FUNCTION_CALL', meta.id, args
+    v8_util.setDestructor ret, ->
+      ipc.sendChannel processId, routingId, 'ATOM_INTERNAL_DEREFERENCE', meta.id
+    ret
+
+  constructCallback meta for meta in metas
 
 # Convert a real value into a POD structure which carries information of this
 # value.
@@ -10,6 +27,9 @@ class Meta
     @type = 'value' if value is null
     @type = 'array' if Array.isArray value
 
+    # Treat the arguments object as array.
+    @type = 'array' if @type is 'object' and value.callee? and value.length?
+
     if @type is 'array'
       @members = []
       @members.push new Meta(processId, routingId, el) for el in value
@@ -46,6 +66,7 @@ ipc.on 'ATOM_INTERNAL_CURRENT_WINDOW', (event, processId, routingId) ->
 
 ipc.on 'ATOM_INTERNAL_CONSTRUCTOR', (event, processId, routingId, id, args) ->
   try
+    args = argsToValues processId, routingId, args
     constructor = objectsRegistry.get id
     # Call new with array of arguments.
     # http://stackoverflow.com/questions/1606797/use-of-apply-with-new-operator-is-this-possible
@@ -56,6 +77,7 @@ ipc.on 'ATOM_INTERNAL_CONSTRUCTOR', (event, processId, routingId, id, args) ->
 
 ipc.on 'ATOM_INTERNAL_FUNCTION_CALL', (event, processId, routingId, id, args) ->
   try
+    args = argsToValues processId, routingId, args
     func = objectsRegistry.get id
     ret = func.apply global, args
     event.result = new Meta(processId, routingId, ret)
@@ -64,6 +86,7 @@ ipc.on 'ATOM_INTERNAL_FUNCTION_CALL', (event, processId, routingId, id, args) ->
 
 ipc.on 'ATOM_INTERNAL_MEMBER_CALL', (event, processId, routingId, id, method, args) ->
   try
+    args = argsToValues processId, routingId, args
     obj = objectsRegistry.get id
     ret = obj[method].apply(obj, args)
     event.result = new Meta(processId, routingId, ret)
diff --git a/renderer/api/lib/remote.coffee b/renderer/api/lib/remote.coffee
index 5f0d07563a68..54fdfd16173b 100644
--- a/renderer/api/lib/remote.coffee
+++ b/renderer/api/lib/remote.coffee
@@ -1,6 +1,33 @@
 ipc = require 'ipc'
+IDWeakMap = require 'id_weak_map'
 v8_util = process.atomBinding 'v8_util'
 
+class CallbacksRegistry
+  constructor: ->
+    @referencesMap = {}
+    @weakMap = new IDWeakMap
+
+  get: (id) -> @weakMap.get id
+  remove: (id) -> delete @referencesMap[id]
+
+  add: (callback) ->
+    id = @weakMap.add callback
+    @referencesMap[id] = callback
+    id
+
+# Translate arguments object into a list of meta data.
+# Unlike the Meta class in browser, this function only create delegate object
+# for functions, other types of value are transfered after serialization.
+callbacksRegistry = new CallbacksRegistry
+argumentsToMetaList = (args) ->
+  metas = []
+  for arg in args
+    if typeof arg is 'function'
+      metas.push type: 'function', id: callbacksRegistry.add(arg)
+    else
+      metas.push type: 'value', value: arg
+  metas
+
 # Transform the description of value into a value or delegate object.
 metaToValue = (meta) ->
   switch meta.type
@@ -15,7 +42,7 @@ metaToValue = (meta) ->
           constructor: ->
             if @constructor == RemoteFunction
               # Constructor call.
-              obj = ipc.sendChannelSync 'ATOM_INTERNAL_CONSTRUCTOR', meta.id, Array::slice.call(arguments)
+              obj = ipc.sendChannelSync 'ATOM_INTERNAL_CONSTRUCTOR', meta.id, argumentsToMetaList(arguments)
 
               # Returning object in constructor will replace constructed object
               # with the returned object.
@@ -23,7 +50,7 @@ metaToValue = (meta) ->
               return metaToValue obj
             else
               # Function call.
-              ret = ipc.sendChannelSync 'ATOM_INTERNAL_FUNCTION_CALL', meta.id, Array::slice.call(arguments)
+              ret = ipc.sendChannelSync 'ATOM_INTERNAL_FUNCTION_CALL', meta.id, argumentsToMetaList(arguments)
               return metaToValue ret
       else
         ret = v8_util.createObjectWithName meta.name
@@ -34,7 +61,7 @@ metaToValue = (meta) ->
           if member.type is 'function'
             ret[member.name] = ->
               # Call member function.
-              ret = ipc.sendChannelSync 'ATOM_INTERNAL_MEMBER_CALL', meta.id, member.name, Array::slice.call(arguments)
+              ret = ipc.sendChannelSync 'ATOM_INTERNAL_MEMBER_CALL', meta.id, member.name, argumentsToMetaList(arguments)
               metaToValue ret
           else
             ret.__defineSetter__ member.name, (value) ->
@@ -53,6 +80,15 @@ metaToValue = (meta) ->
 
       ret
 
+# Browser calls a callback in renderer.
+ipc.on 'ATOM_INTERNAL_FUNCTION_CALL', (callbackId, args) ->
+  callback = callbacksRegistry.get callbackId
+  callback.apply global, metaToValue(args)
+
+# Browser releases a callback in renderer.
+ipc.on 'ATOM_INTERNAL_DEREFERENCE', (callbackId) ->
+  callbacksRegistry.remove callbackId
+
 # Get remote module.
 exports.require = (module) ->
   meta = ipc.sendChannelSync 'ATOM_INTERNAL_REQUIRE', module