WIP: Cancellation

.gitignore

@@ -3,3 +3,4 @@ experiments/
 node_modules/
 build/
 coverage/
+perf/logs/

.jsinspectrc

@@ -1,3 +1,4 @@
 {
+	"identifiers": true,
     "threshold": 35
 }

package.json

@@ -6,7 +6,8 @@
   "jsnext:main": "dist/creed.es.js",
   "files": [
     "dist/creed.js",
-    "dist/creed.es.js"
+    "dist/creed.es.js",
+    "dist/creed.node.js"
   ],
   "repository": {
     "type": "git",
@@ -28,13 +29,13 @@
   "scripts": {
     "compile": "npm run compile-src",
     "compile-src": "mkdirp build/src && buble -m -i src -o build/src --no modules",
-    "build-dist": "npm run compile && mkdirp dist && rollup -c",
-    "build": "npm run build-dist && uglifyjs -c 'warnings=false' -m -o dist/creed.min.js -- dist/creed.js",
+    "build-dist": "npm run compile && mkdirp dist && rollup -c && rollup -f cjs -o dist/creed.node.js src/main.js",
+    "build": "npm run build-dist && uglifyjs -c \"warnings=false\" -m -o dist/creed.min.js -- dist/creed.js",
     "preversion": "npm run build",
     "check-coverage": "istanbul check-coverage --statements 100 --branches 100 --lines 100 --functions 100 coverage/coverage*.json",
     "lint": "jsinspect src && eslint src",
     "pretest": "npm run lint",
-    "test": "istanbul cover _mocha",
+    "test": "istanbul cover node_modules/mocha/bin/_mocha",
     "posttest": "npm run test-aplus",
     "test-aplus": "promises-aplus-tests test/aplus.js --reporter dot"
   },

perf/doxbee-sequential-errors/promises-creed-algebraic.js

@@ -2,7 +2,7 @@ global.useCreed = true;
 global.useQ = false;
 global.useBluebird = false;
 
-var creed = require('../../dist/creed');
+var creed = require('../..');
 
 require('../lib/fakesP');
 

perf/doxbee-sequential-errors/promises-creed-generator.js

@@ -2,7 +2,7 @@ global.useCreed = true;
 global.useQ = false;
 global.useBluebird = false;
 
-var creed = require('../../dist/creed');
+var creed = require('../..');
 
 require('../lib/fakesP');
 

perf/doxbee-sequential-errors/promises-creed.js

@@ -2,7 +2,7 @@ global.useCreed = true;
 global.useQ = false;
 global.useBluebird = false;
 
-var creed = require('../../dist/creed');
+var creed = require('../..');
 
 require('../lib/fakesP');
 

perf/doxbee-sequential/promises-creed-algebraic.js

@@ -2,7 +2,7 @@ global.useCreed = true;
 global.useQ = false;
 global.useBluebird = false;
 
-var creed = require('../../dist/creed');
+var creed = require('../..');
 
 require('../lib/fakesP');
 
@@ -52,7 +52,7 @@ module.exports = function upload(stream, idOrPath, tag, done) {
     }).chain(function() {
         return File.whereUpdate({id: fileId}, {version: version.id})
             .execWithin(tx);
-    }).map(function() {
+    }).then(function() {
         tx.commit();
         return done();
     }, function(err) {

perf/doxbee-sequential/promises-creed-generator.js

@@ -1,7 +1,7 @@
 global.useBluebird = false;
 global.useQ = false;
 global.useCreed = true;
-var creed = require('../../dist/creed');
+var creed = require('../..');
 require('../lib/fakesP');
 
 module.exports = creed.coroutine(function* upload(stream, idOrPath, tag, done) {

perf/doxbee-sequential/promises-creed.js

@@ -2,7 +2,7 @@ global.useCreed = true;
 global.useQ = false;
 global.useBluebird = false;
 
-var creed = require('../../dist/creed');
+var creed = require('../..');
 
 require('../lib/fakesP');
 

perf/lib/fakesP.js

@@ -83,7 +83,7 @@ else if (global.useNative) {
     };
 }
 else if (global.useCreed) {
-    var lifter = require('../../dist/creed').fromNode;
+    var lifter = require('../..').fromNode;
 }
 else {
     var lifter = require('when/node').lift;

perf/madeup-parallel/promises-creed-generator.js

@@ -3,7 +3,7 @@ global.useQ = false;
 global.useWhen = false;
 
 global.useCreed = true;
-var creed = require('../../dist/creed');
+var creed = require('../..');
 require('../lib/fakesP');
 
 module.exports = creed.coroutine(function* upload(stream, idOrPath, tag, done) {

perf/madeup-parallel/promises-creed.js

@@ -4,7 +4,7 @@ global.useWhen = false;
 
 global.useCreed = true;
 
-var creed = require('../../dist/creed');
+var creed = require('../..');
 
 require('../lib/fakesP');
 

perf/performance.js

@@ -1,6 +1,5 @@
 
 var args = require('optimist').argv;
-
 var path = require('path');
 
 global.LIKELIHOOD_OF_REJECTION = args.e || 0.1;
@@ -138,7 +137,7 @@ function measure(files, requests, time, parg, callback) {
     async.mapSeries(files, function(f, done) {
         console.log("benchmarking", f);
         var logFile = path.basename(f) + ".log";
-        var profileFlags = ["--prof", "--logfile=C:/etc/v8/" + logFile];
+        var profileFlags = ["--prof", "--logfile=logs/" + logFile];
 
         var argsFork = [__filename,
             '--n', requests,

src/Action.js

@@ -0,0 +1,106 @@
+import { noop } from './util'
+import { reject } from './Promise'
+
+export default class Action {
+	constructor (promise) {
+		// the Future which this Action tries to resolve
+		// when null, the action is cancelled and won't be executed
+		this.promise = promise
+	}
+
+	destroy () {
+		this.promise = null
+	}
+
+	cancel (p) {
+		/* istanbul ignore else */
+		if (this.promise._isResolved()) { // promise checks for cancellation itself
+			this.destroy()
+		}
+	}
+
+	// default onFulfilled action
+	fulfilled (p) {
+		this.put(p)
+	}
+
+	// default onRejected action
+	rejected (p) {
+		this.put(p)
+		return false
+	}
+
+	// default onCancelled action
+	cancelled (p) {
+		reject(p.near().value)._runAction(this)
+	}
+
+	// when this.promise is to be settled (possible having awaited the result)
+	put (p) {
+		// assert: isSettled(p) || p.token === this.promise.token
+		// asssert: this.promise != null
+		this.end().__become(p)
+	}
+
+	end () {
+		const promise = this.promise
+		const token = promise.token
+		this.promise = null
+		if (token != null) token._unsubscribe(this)
+		return promise
+	}
+}
+
+const sentinel = noop // Symbol('currently executing')
+
+export class CancellableAction extends Action {
+	constructor (f, promise) {
+		super(promise)
+		// the function that produces the resolution result for the promise
+		// when null, the function has been executed but the promise might still get cancelled
+		this.f = f
+	}
+
+	destroy () {
+		this.promise = null
+		this.f = null
+	}
+
+	cancel (results) {
+		if (this.promise._isResolved()) { // promise checks for cancellation itself
+			if (this.f !== sentinel) { // not currently running
+				this.destroy()
+			}
+			// otherwise keep the cancelled .promise so that it stays usable in handle()
+			// and ignores whatever is done with the f() result
+			return true
+		}
+		return false
+	}
+
+	fulfilled (p) {
+		if (this.f) {
+			this.tryCall(this.f, p.value)
+		} else {
+			this.put(p)
+		}
+	}
+
+	tryCall (f, x) {
+		this.f = sentinel
+		let result
+		try {
+			result = f(x)
+		} catch (e) {
+			this.f = null
+			this.end()._reject(e)
+			return
+		}
+		this.f = null
+		return this.handle(result)
+	}
+
+	handle (p) {
+		this.promise._resolve(p, this)
+	}
+}

src/Any.js

@@ -1,4 +1,5 @@
-import { silenceError } from './inspect.js'
+import { silenceError } from './Promise' // deferred
+import CancelReason from './CancelReason'
 
 export default class Any {
 	constructor () {
@@ -10,7 +11,9 @@ export default class Any {
 	}
 
 	fulfillAt (p, i, promise) {
+		const token = promise.token
 		promise._become(p)
+		token._cancel(new CancelReason('result is already fulfilled'))
 	}
 
 	rejectAt (p, i, promise) {

src/CancelReason.js

@@ -0,0 +1,2 @@
+export default class CancelReason extends Error {
+}