Alex A. Naanou 11aa8be206 notes...
Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
2017-03-01 04:22:42 +03:00

473 lines
12 KiB
JavaScript
Executable File

/**********************************************************************
*
* Setup a node.js child_process communications channel and listen and
* exec commands...
*
*
**********************************************************************/
((typeof define)[0]=='u'?function(f){module.exports=f(require)}:define)
(function(require){ var module={} // make module AMD/node compatible...
/*********************************************************************/
if(typeof(process) != 'undefined'){
var child_process = requirejs('child_process')
}
var actions = require('lib/actions')
var features = require('lib/features')
var core = require('features/core')
var object = require('lib/object')
/*********************************************************************/
// helpers...
// Cooperative promise object...
//
// This is like a promise but is not resolved internally, rather this
// resolves (is set) via a different promise of value passed to it via
// the .set(..) method...
//
// Example:
// // create a promise...
// var p = (new CooperativePromise())
// // bind normally...
// .then(function(){ .. })
//
// // this will resolve p and trigger all the .then(..) callbacks...
// p.set(new Promise(function(resolve, reject){ resolve() }))
//
// Note that .set(..) can be passed any value, passing a non-promise has
// the same effect as passing the same value to resolve(..) of a Promise
// object...
//
// XXX should this be a separate package???
// XXX can we make this an instance of Promise for passing the
// x instanceof Promise test???
var CooperativePromisePrototype = {
__base: null,
__promise: null,
// XXX error if already set...
set: function(promise){
if(this.__promise == null){
// setting a non-promise...
if(promise.catch == null && promise.then == null){
Object.defineProperty(this, '__promise', {
value: false,
enumerable: false,
})
this.__resolve(promise)
// setting a promise...
} else {
Object.defineProperty(this, '__promise', {
value: promise,
enumerable: false,
})
// connect the base and the set promises...
promise.catch(this.__reject.bind(this))
promise.then(this.__resolve.bind(this))
// cleanup...
delete this.__base
}
// cleanup...
delete this.__resolve
delete this.__reject
} else {
// XXX throw err???
console.error('Setting a cooperative promise twice', this)
}
},
// Promise API...
catch: function(func){
return (this.__promise || this.__base).catch(func) },
then: function(func){
return (this.__promise || this.__base).then(func) },
__init__: function(){
var that = this
var base = new Promise(function(resolve, reject){
Object.defineProperties(that, {
__resolve: {
value: resolve,
enumerable: false,
configurable: true,
},
__reject: {
value: reject,
enumerable: false,
configurable: true,
},
})
})
Object.defineProperty(this, '__base', {
value: base,
enumerable: false,
configurable: true,
})
},
}
var CooperativePromise =
module.CooperativePromise =
object.makeConstructor('CooperativePromise',
Promise,
CooperativePromisePrototype)
//---------------------------------------------------------------------
// XXX would be nice to list the protocols supported by the action in
// an action attr...
var makeProtocolHandler =
module.makeProtocolHandler =
function(protocol, func){
return function(id){
return id.startsWith(protocol + ':')
&& function(res){
res.set(func.apply(this, [].slice.call(arguments, 1))) }}}
/*********************************************************************/
// XXX this is a generic API, add ability to define protocols...
// Protocols:
// - child_process
// - PeerJS
// - https
// - rpc (???)
// - mq (???)
// - ...
// XXX should this do "sync"???
// XXX should the couch api be implemented over this of independently???
var PeerActions = actions.Actions({
// Format:
// {
// <id>: <spec>,
// }
//
// XXX <spec> format???
// ...should flow from the protocol definition and architecture...
// XXX should url and id be the same thing???
// ...this might simplify things, and to make things pretty
// implementing aliases will do the trick...
// XXX Q: should peer adapter be a feature that defines/extnds a set
// of actions???
// ...e.g. base peerCreate(..) defines the protocol but does
// nothing, while each implementation checks if the url is
// compatible and handles it accordingly...
__peers: null,
// XXX need more control...
// - get proxies to specific peer...
get peeractions(){
return this.getPeerActions() },
getPeerActions: ['- Peer/',
function(id){
var that = this
return this.actions.filter(id ?
function(action){
return that.getActionAttr(action, '__peer__') == id }
// get all peer actions...
: function(action){
return that.getActionAttr(action, '__peer__') })
}],
// XXX should this also check props???
isPeerAction: ['- Peer/',
function(name){
return !!this.getActionAttr(name, '__peer__') }],
//
// NOTE: it is the responsibility of the overloading action to trigger
// the appropriate events...
//
// XXX should this be sync or async???
// XXX this should create or connect to a peer depending on protocol...
// XXX the events should get called on the peer too -- who is
// responsible for this???
peerConnect: ['- Peer/',
function(id, options){ return new CooperativePromise() }],
peerDisconnect: ['- Peer/',
function(id){ return new CooperativePromise() }],
// event...
peerConnected: ['- Peer/',
core.notUserCallable(function(id){
// XXX
})],
// event...
peerDisconnected: ['- Peer/',
core.notUserCallable(function(id){
// XXX
})],
peerCall: ['- Peer/',
function(id, action){ return new CooperativePromise() }],
peerApply: ['- Peer/',
function(id, action, args){ return new CooperativePromise() }],
peerList: ['- Peer/',
function(){ return Object.keys(this.__peers || {}) }],
// XXX format spec!!!
peerSpec: ['- Peer/',
function(id){
// XXX
}],
peerProxy: ['- Peer/',
function(id){
// XXX
}],
// XXX if no actions are given, proxy all...
// XXX also proxy descriptors???
peerMixin: ['- Peer/',
function(id, actions){
var that = this
var spec = this.peerSpec(id)
// XXX
actions = actions || Object.keys(spec.actions)
actions.forEach(function(action){
if(that[action]){
return
}
// XXX
var action_spec = []
that[action] = actions.Action(action, action_spec)
})
}],
// XXX should this be .peerMixout(..)
peerMixout: ['- Peer/',
function(id, actions){
// XXX
}],
})
var Peer =
module.Peer = core.ImageGridFeatures.Feature({
title: '',
doc: '',
tag: 'peer',
suggested: [
'child-process-peer',
],
actions: PeerActions,
})
//---------------------------------------------------------------------
// XXX all the return values here will be ignored -- need a way to figure
// out a cooperative mechanic to return promises...
var ChildProcessPeerActions = actions.Actions({
// XXX do better message handling...
peerConnect: ['- Peer/',
makeProtocolHandler('child', function(id, options){
return new Promise((function(resolve, reject){
// already connected...
// XXX check if child is alive...
if(this.__peers
&& id in this.__peers
&& this.__peers[id].peer.connected){
return resolve(id)
}
this.__peers = this.__peers || {}
var p = this.__peers[id] = {
id: id,
peer: child_process.fork('ig.js'),
}
var peer = p.peer
// XXX setup message handlers...
// ...should be about the same as in setup below...
// XXX use a standard handler....
peer.on('message', (function(msg){
if(msg.type == 'action-call-result'){
var callback = (this.__peer_result_callbacks || {})[msg.id]
callback
&& (delete this.__peer_result_callbacks[msg.id])
&& callback(msg.value, msg.error)
}
}).bind(this))
resolve(id)
}).bind(this))
})],
peerDisconnect: ['- Peer/',
makeProtocolHandler('child', function(id){
return new Promise((function(resolve, reject){
var that = this
// already disconnected...
if(this.__peers[id] == null){
return resolve(id)
}
// terminate child...
that.__peers[id].peer.kill()
delete that.__peers[id]
}).bind(this))
})],
peerCall: ['- Peer/',
makeProtocolHandler('child', function(id, action){
return new Promise((function(resolve, reject){
// XXX
}).bind(this))
})],
peerApply: ['- Peer/',
makeProtocolHandler('child', function(id, action, args){
return new Promise((function(resolve, reject){
// XXX is this the right way to go???
var call_id = id +'-'+ Date.now()
// do the call...
this.__peers[id].peer.send({
id: call_id,
type: 'action-call',
action: action,
args: args,
})
// handle return value...
var handlers = this.__peer_result_callbacks = this.__peer_result_callbacks || {}
handlers[call_id] = function(res, err){ err ? reject(err) : resolve(res) }
}).bind(this))
})],
})
var ChildProcessPeer =
module.ChildProcessPeer = core.ImageGridFeatures.Feature({
title: '',
doc: '',
tag: 'child-process-peer',
depends: [
'peer',
],
isApplicable: function(){
return this.runtime == 'nw' || this.runtime == 'node' },
actions: ChildProcessPeerActions,
handlers: [
// XXX check if we are a child and setup communications with the
// parent...
['start',
function(){
var that = this
// XXX do we need to handle stdout/stderr here???
// XXX need to handle both the child and parent processes...
process.on('message', function(msg){
// Handle action call...
//
// Format:
// {
// type: 'action-call',
//
// id: <id>,
//
// action: <action-name>,
//
// args: [<arg>, .. ] | null,
//
// ignore_return: <bool>,
// }
if(msg.type == 'action-call' && msg.action in that){
if(msg.action in that){
try{
// do the call...
var res = that[msg.action].apply(that, msg.args || [])
// XXX check if res is a promise/promise-like...
// return the value...
if(!msg.ignore_return){
process.send({
type: 'action-call-result',
id: msg.id,
value: res === that ? null : res,
})
}
// error...
} catch(err){
process.send({
type: 'action-call-result',
id: msg.id,
// XXX is this serializable???
error: err,
})
}
// error: action does not exist...
} else {
process.send({
type: 'action-call-result',
id: msg.id,
error: `Action "${msg.action}" does not exist.`,
})
}
// Handle action call result...
//
// Format:
// {
// type: 'action-call-result',
// id: <id>,
// value: <object> | null,
// }
} else if(msg.type == 'action-call-result'){
var callback = (this.__peer_result_callbacks || {})[msg.id]
callback
&& (delete this.__peer_result_callbacks[msg.id])
&& callback(msg.value, msg.error)
// Handle logger calls...
//
// Format:
// {
// type: 'logger-emit',
// value: [ .. ],
// }
} else if(msg.type == 'logger-emit' && this.logger){
this.logger.emit.apply(this.logger, msg.value)
}
})
}],
],
})
/**********************************************************************
* vim:set ts=4 sw=4 : */ return module })