async-lock - npm Package Compare versions

Comparing version 0.1.2 to 0.2.0

History.md

@@ -0,3 +1,8 @@
+0.2.0 / 2015-02-21
+==================
+* Support promise mode
+* Pending task limit
+
 0.1.0 / 2015-01-13
 ==================
 * Initial version

lib/index.js

 'use strict';
 
+var Q = require('q');
+
 var AsyncLock = function(opts){
@@ -11,5 +13,7 @@ opts = opts || {};
     this.timeout = opts.timeout || AsyncLock.DEFAULT_TIMEOUT;
+    this.maxPending = opts.maxPending || AsyncLock.DEFAULT_MAX_PENDING;
 };
 
-AsyncLock.DEFAULT_TIMEOUT = 2000;
+AsyncLock.DEFAULT_TIMEOUT = 10 * 1000;
+AsyncLock.DEFAULT_MAX_PENDING = 1000;
 
@@ -21,3 +25,3 @@ /**
  * @param {function} fn 	async function
- * @param {function} cb 	(optional) callback function
+ * @param {function} cb 	(optional) callback function, otherwise will return a promise
  * @param {Object} opts 	(optional) options
@@ -30,2 +34,15 @@ */
 
+    if(typeof(fn) !== 'function'){
+    	throw new Error('You must pass a function to execute');
+    }
+
+    var deferred = null;
+    if(typeof(cb) !== 'function'){
+    	opts = cb;
+    	cb = null;
+
+    	// will return a promise
+    	deferred = Q.defer();
+    }
+
     opts = opts || {};
@@ -37,3 +54,3 @@
 
-    var done = function(){
+    var done = function(err, ret){
     	// Make sure done is only called once
@@ -51,6 +68,17 @@ if(finished){
 
-        //callback
-        if(typeof(cb) === 'function'){
-            cb.apply(null, arguments);
+        //callback mode
+        if(!deferred){
+        	if(typeof(cb) === 'function'){
+            	cb.apply(null, arguments);
+        	}
         }
+        else{
+        	//promise mode
+        	if(err){
+        		deferred.reject(err);
+        	}
+        	else{
+        		deferred.resolve(ret);
+        	}
+        }
 
@@ -64,4 +92,19 @@ //run next func
     var exec = function(){
-        timer = setTimeout(done.bind(null, new Error('async-lock timed out')), opts.timeout ? opts.timeout : self.timeout);
-        fn(done);
+    	var timeout = opts.timeout ? opts.timeout : self.timeout;
+        timer = setTimeout(done.bind(null, new Error('async-lock timed out')), timeout);
+
+	    // Callback mode
+	    if(fn.length === 1){
+	    	fn(done);
+	    }
+        else{
+        	// Promise mode
+        	Q.fcall(function(){
+        		return fn();
+        	}).then(function(ret){
+        		done(null, ret);
+        	}, function(err){
+        		done(err);
+        	});
+        }
     };
@@ -74,4 +117,13 @@
     else{
-        this.queues[key].push(exec);
+    	if(this.queues[key].length >= this.maxPending){
+    		done(new Error('Too much pending tasks'));
+    	}
+    	else{
+    		this.queues[key].push(exec);
+    	}
     }
+
+    if(deferred){
+    	return deferred.promise;
+    }
 };
@@ -78,0 +130,0 @@

package.json

 {
 	"name": "async-lock",
 	"description": "",
-	"version": "0.1.2",
+	"version": "0.2.0",
 	"author": "rain1017",
@@ -29,3 +29,4 @@ "private" : false,
 	"dependencies": {
-
+		"q": "~1.1.2",
+		"lodash": "~3.2.0"
 	},
@@ -32,0 +33,0 @@ "devDependencies": {

README.md

@@ -17,8 +17,23 @@ # async-lock
  * @param {function} fn 	async function with node.js style
- * @param {function} cb 	(optional) callback function
+ * @param {function} cb 	(optional) callback function, otherwise will return a promise
  * @param {Object} opts 	(optional) options
  */
-lock.acquire(key, fn, cb, opts);
+lock.acquire(key, function(done){
+	// async work
+	done(err, ret);
+}, function(err, ret){
+	// lock released
+}, opts);
 ```
 
+## Promise mode
+
+```
+lock.acquire(key, function(){
+	// return value or promise
+}).then(function(){
+	// lock released
+});
+```
+
 ## Acquire multiple keys
@@ -30,21 +45,25 @@
 
-## Specify timeout
+## Options
 
 ```
+// Specify timeout
 var lock = new AsyncLock({timeout : 5000});
-lock.acquire(key, fn, function(err){
+lock.acquire(key, fn, cb, function(err, ret){
 	// timed out error will be returned here if fn has not return within given time
 });
 
-//Specify timeout for one function
+// Specify timeout for one function
 lock.acquire(key, fn, cb, {timeout : 5000});
-```
 
-## Get running state
+// Set max pending tasks
+var lock = new AsyncLock({maxPending : 1000});
+lock.acquire(key, fn, cb, function(err, ret){
+	// Handle too much pending error
+})
 
-```
-// Where there is any running or pending async function
+// Whether there is any running or pending async function
 lock.isBusy();
 ```
 
+
 ## License
@@ -51,0 +70,0 @@ (The MIT License)

test/test.js

 'use strict';
 
+var Q = require('q');
+var _ = require('lodash');
 var AsyncLock = require('../index.js');
 var assert = require('assert');
 
+Q.longStackSupport = true;
+
 describe('AsyncLock Tests', function(){
@@ -123,2 +127,54 @@ it('Single key test', function(done){
 	});
+
+	it('Promise mode', function(done){
+		var lock = new AsyncLock();
+		var value = 0;
+		var concurrency = 8;
+
+		Q.all(_.range(concurrency).map(function(){
+			return lock.acquire('key', function(){
+				var tmp = null;
+				// Simulate non-atomic check and set
+				return Q() // jshint ignore:line
+				.delay(_.random(10))
+				.then(function(){
+					tmp = value;
+				})
+				.delay(_.random(20))
+				.then(function(){
+					value = tmp + 1;
+				});
+			});
+		})).then(function(){
+			assert(value === concurrency);
+			done();
+		}, function(err){
+			done(err);
+		});
+	});
+
+	it('Error handling', function(done){
+		var lock = new AsyncLock();
+		lock.acquire('key', function(){
+			throw new Error('error');
+		}).catch(function(e){
+			assert(e.message === 'error');
+			done();
+		});
+	});
+
+	it('Too much pending', function(done){
+		var lock = new AsyncLock({maxPending : 1});
+		lock.acquire('key', function(){
+			return Q().delay(20); // jshint ignore:line
+		});
+		lock.acquire('key', function(){
+			return Q().delay(20); // jshint ignore:line
+		});
+
+		lock.acquire('key', function(){})
+		.catch(function(e){
+			done();
+		});
+	});
 });

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Improved metrics

Total package byte prevSize

16867

increased by20.22%

Lines of code

372

increased by34.78%

Number of lines in readme file

87

increased by27.94%

Worsened metrics

Dependency count

2

increased byInfinity%

Dependency changes

• + Addedlodash@~3.2.0

• + Addedq@~1.1.2

• + Addedlodash@3.2.0(transitive)

• + Addedq@1.1.2(transitive)