streaming-cache - npm Package Compare versions

Comparing version 0.3.2 to 0.4.0

examples/example.js

 'use strict';
-
 var Cache = require('../index.js');
-
-var cache = new Cache();
-
+var cache = new Cache({max: 5, maxAge: 15});
 var fs = require('fs');
-
-// var readstream = fs.createReadStream('readme.md');
-// var writestream = fs.createWriteStream('test.md');
-var writestream2 = fs.createWriteStream('test2.txt');
-
-// readstream.pipe(cache.put('a'));
-// readstream.pipe(writestream);
-// readstream.pipe(process.stderr);
-
-// setTimeout(function(){
-// 	writestream2.write('written from cache\n\n');
-// 	cache.get('a').pipe(writestream2);
-// }, 200);
-
-// setTimeout(function(){}, 2000);
-
-//process.stdin.pipe(cache.put('a'));
-
 var cnt = 0;
-var s = cache.set('a')
+var s = cache.set('a');
 var intervalId = setInterval(function () {
-    if (cnt >= 5) {
-        // console.log('cnt', cnt)
-        clearInterval(intervalId)
-        cache.get('a').pipe(process.stdout);
+    if (cnt >= 50) {
+        clearInterval(intervalId);
         s.end();
     } else {
-        s.write(cnt + ' hello', function () {})
+        s.write(cnt + ' hello\n');
         cnt++;
     }
-}, 1000)
+}, 100);
 
-//setTimeout(function () {
+s.pipe(process.stdout);
 cache.get('a').pipe(process.stdout);
-// }, 5000);
+
+
+    

index.js

@@ -26,2 +26,4 @@ 'use strict';
 var StreamingCache = function StreamingCache(options) {
+    options = options || {};
+    options.length = lruOptions.length;
     this.cache = LRU(options);
@@ -77,2 +79,3 @@ Object.defineProperty(this, 'length', {
 }
+
 StreamingCache.prototype.setMetadata = function (key, metadata) {
@@ -174,8 +177,8 @@ checkKey(key);
         var chunk = chunks.shift();
-        if(!chunk){
+        if (!chunk) {
             this.needRead = true;
         }
-        else{
-           this.push(chunk);
-           this.needRead = false;
+        else {
+            this.push(chunk);
+            this.needRead = false;
         }
@@ -186,8 +189,7 @@ }
         emitters[key].emit('data', chunk);
-        if(this.needRead){
+        if (this.needRead) {
             this.push(chunk);
         }
-        else{
+        else {
             chunks.push(chunk);
-
         }
@@ -207,11 +209,16 @@ next(null, chunk);
     stream.on('finish', function () {
-        if(this.needRead){
+        if (this.needRead) {
             this.push(null);
         }
-        else{
-        chunks.push(null);
+        else {
+            chunks.push(null);
         }
         var c = self.cache.get(key);
-
-        var buffer = Buffer.concat(emitters[key]._buffer)
+        chunks = null;
+        if (!c) {
+            emitters[key].emit('end', Buffer.concat(emitters[key]._buffer));
+            delete emitters[key];
+            return;
+        }
+        var buffer = Buffer.concat(emitters[key]._buffer);
         c.metadata = c.metadata || {};
@@ -218,0 +225,0 @@ c.metadata.length = buffer.toString().length;

package.json

 {
   "name": "streaming-cache",
-  "version": "0.3.2",
+  "version": "0.4.0",
   "description": "Cache and replay NodeJS streams",
@@ -5,0 +5,0 @@ "main": "index.js",

readme.md

@@ -6,10 +6,16 @@ [![Circle CI](https://circleci.com/gh/LaurentZuijdwijk/streaming-cache/tree/master.svg?style=svg)](https://circleci.com/gh/LaurentZuijdwijk/streaming-cache/tree/master)
 
+Speed up your services.
+
 Cache, queue and distribute streams immediately. Streams can be replayed immediately, even if the source is not finished.
 
+Uses a fixed size LRU-cache in the background. 
+
 Usefull for caching (slow) streaming connections, such as S3 requests or complex database queries.  
 
-We use it to stream data into the cache and make any waiting connections for the same data queue up until the data is in the cache.
+If there are for example 3 requests for a certain file in close succession, then we can pipe the result for the first request into the cache. The 2 other requests will receive a stream which will start even before the first one is finished.
 
-If there are for example 3 requests for a certain file in close succession, then we can pipe the result for the first request into the cache. The 2 other requests will receive a stream which will start when the first one is finished.
+Performance
+-----------
 
+Serving from this cache is extremely fast. On my local machine I get 2.5GB per second for a single process on localhost using AB. (4th gen i7).
 
@@ -42,3 +48,8 @@ Installation
 
+Options
+-------
 
+For a list of options see: https://www.npmjs.com/package/lru-cache
+
+
 API
@@ -48,3 +59,3 @@ ---
 ##### set(key)
-returns a transform stream that can be piped to
+returns a Duplex stream
 ```
@@ -55,3 +66,3 @@ fileStream.pipe(cache.set('key')).pipe(res);
 
-##### get(key):ReadableStream 
+##### get(key) => ReadableStream 
 
@@ -66,3 +77,3 @@ ```javascript
 
-#### setData(key, data)
+#### setData(key, data) => WriteableStream
 A set data synchronously to stream at a later moment
@@ -69,0 +80,0 @@

spec/streamingCacheSpec.js

@@ -77,3 +77,3 @@ /* jshint jasmine: true */
         expect(cache.getData).toThrow();
-        expect(function() { cache.getData('c') }).toThrow();
+        expect(function () { cache.getData('c') }).toThrow();
         expect(cache.getData('c', function (err, data) {
@@ -87,3 +87,3 @@ expect(data).toEqual(undefined);
     it('should handle setmetadata', function () {
-        cache.setMetadata('abc', {a:'c'});
+        cache.setMetadata('abc', {a: 'c'});
         cache.setData('abc', 'test');
@@ -96,3 +96,3 @@ expect(cache.setMetadata).toThrow();
     it('should save the length to metadata', function (done) {
-        cache.setMetadata('abc', {a:'b'});
+        cache.setMetadata('abc', {a: 'b'});
         var s = cache.set('abc');
@@ -103,3 +103,3 @@ s.write('a');
 
-        setTimeout(function(){
+        setTimeout(function () {
             expect(cache.cache.get('abc').data.toString()).toEqual('ab');
@@ -123,3 +123,3 @@ expect(cache.getMetadata('abc').a).toEqual('b');
 
-    it('should reset the cache when called', function() {
+    it('should reset the cache when called', function () {
         cache.setData('aaa', 'value');
@@ -144,3 +144,22 @@ cache.reset();
     });
+});
 
+describe('streaming cache short timeout', function () {
+    var s;
+    beforeEach(function () {
+        cache = new StreamingCache({maxAge: 100})
+        s = cache.set('b');
+    });
+    it('Writing to stream should set data', function (done) {
+        s.write('a');
+        s.write('b');
+        s.end(null);
+        setTimeout(function () {
+            expect(s.read().toString() + s.read().toString()).toEqual('ab')
+            cache.getData('b', function (err, data) {
+                expect(data.toString()).toEqual(null)
+                done();
+            });
+        }, 130);
+    });
 });

No alert changes

Improved metrics

Total package byte prevSize

308461

increased by0.16%

Lines of code

529

increased by2.32%

Number of lines in readme file

96

increased by12.94%

Worsened metrics

Number of package files

20

decreased by-4.76%

No dependency changes