Merge pull request fent#1 from andrewrk/master

expose dowloadFromInfo and drop some dependencies
azrafe7 · Jul 3, 2014 · a4b503c · a4b503c
2 parents 786443d + c76c9df
commit a4b503c
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Showing 4 changed files with 99 additions and 87 deletions.
diff --git a/README.md b/README.md
@@ -34,7 +34,7 @@ ytdl(url, { filter: function(format) { return format.container === 'mp4'; } })
 
 The returned readable stream emits these additional events.
 
-### Event: 'info'
+#### Event: 'info'
 * `Object` - Info.
 * `Object` - Format.
 
@@ -48,10 +48,17 @@ Use this if you only want to get metainfo from a video.
 
 `options` gets passed to the `request()`, it can also have a `downloadURL` property set to `true` if you want ytdl to include the download url instead of the regular one. In some cases, a signature needs to be deciphered, and will require ytdl to make additional requests.
 
-### ytdl.cache
+### ytdl.downloadFromInfo(info, options)
 
-A [memory cache](https://github.com/hij1nx/EventVat) is used to store information about recently retrieved videos. This is used to prevent double requests on videos that you want to retrieve the info of, and then download.
+Once you have received metadata from a video with the `getInfo` function,
+you may pass that `info`, along with other `options` to `downloadFromInfo`.
 
+The returned readable stream emits these additional events:
+
+#### Event: 'format'
+* `Object` - Format.
+
+Emitted when a format metadata has been chosen. `format.size` will also be available.
 
 # Install
 

diff --git a/lib/crequest.js b/lib/crequest.js
@@ -1,39 +1,11 @@
 var request  = require('request');
-var EventVat = require('eventvat');
 
-var ytdl = {};
-// Circular dependency.
-process.nextTick(function() {
-  // Cache for recently looked up video infos.
-  ytdl = require('./index');
-});
-
-/**
- * Makes a request and caches the body so that additional requests
- * to the same url don't require network IO.
- *
- * @param {Object|String} options
- * @param {Function} callback
- */
 module.exports = function(options, callback) {
-  var url = options.url || options.uri || options;
-  if (ytdl.cache && ytdl.cache.exists(url)) {
-    process.nextTick(function() {
-      callback(null, ytdl.cache.get(url));
-    });
-  } else {
-    request(options, function(err, res, body) {
-      if (err) return callback(err);
-      if (res.statusCode !== 200) {
-        return callback(new Error('status code ' + res.statusCode));
-      }
-      if (ytdl.cache) {
-        ytdl.cache.set(url, body);
-      }
-      callback(null, body);
-    });
-  }
+  request(options, function(err, res, body) {
+    if (err) return callback(err);
+    if (res.statusCode !== 200) {
+      return callback(new Error('status code ' + res.statusCode));
+    }
+    callback(null, body);
+  });
 };
-
-// Export cache.
-module.exports.cache = new EventVat({ autoexpire: 30 });
diff --git a/lib/index.js b/lib/index.js
@@ -1,65 +1,95 @@
-var http      = require('http');
-var streamify = require('streamify');
-var request   = require('request');
-var _         = require('underscore');
-var getInfo   = require('./info');
-var crequest  = require('./crequest');
-var util      = require('./util');
+var http        = require('http');
+var PassThrough = require('stream').PassThrough;
+var request     = require('request');
+var _           = require('underscore');
+var getInfo     = require('./info');
+var crequest    = require('./crequest');
+var util        = require('./util');
 
+module.exports = ytdl;
+ytdl.getInfo = getInfo;
+ytdl.downloadFromInfo = downloadFromInfo;
 
 /**
  * @param {String} link
  * @param {Object} options
  * @return {ReadableStream}
  */
-var ytdl = module.exports = function ytdl(link, options) {
-  var stream = streamify({
-    superCtor: http.ClientResponse,
-    readable: true,
-    writable: false
-  });
-
+function ytdl(link, options) {
   options = options || {};
   options.downloadURL = true;
 
+  var stream = new PassThrough();
+
   getInfo(link, options, function(err, info) {
     if (err) {
       stream.emit('error', err);
-      stream.readable = false;
       return;
     }
 
-    var format = util.chooseFormat(info.formats, options);
-    if (format instanceof Error) {
-      stream.emit('error', format);
-      return;
-    }
-
-    var requestOptions = _.clone(options);
-    requestOptions.url = format.url;
-    if (requestOptions.range) {
-      requestOptions.url += '&range=' + requestOptions.range;
-    }
-    delete requestOptions.quality;
-    delete requestOptions.range;
-    delete requestOptions.filter;
-
-    // Start downloading the video.
-    var req = request(requestOptions);
-    req.on('response', function(res) {
-      if (res.statusCode !== 200) {
-        stream.emit('error', new Error('status code ' + res.statusCode));
+    downloadFromInfoCallback(info, options, function(err, format, videoStream) {
+      if (err) {
+        stream.emit('error', err);
         return;
       }
-
-      format.size = res.headers['content-length'];
       stream.emit('info', info, format);
+      videoStream.pipe(stream);
     });
-    stream.resolve(req);
   });
 
   return stream;
-};
+}
 
-ytdl.getInfo = getInfo;
-ytdl.cache   = crequest.cache;
+function downloadFromInfoCallback(info, options, callback) {
+  options = options || {};
+
+  var format = util.chooseFormat(info.formats, options);
+  if (format instanceof Error) {
+    // The caller expects this function to be async.
+    setImmediate(callbackWithFormatError);
+    return;
+  }
+
+  var requestOptions = _.clone(options);
+  requestOptions.url = format.url;
+  if (requestOptions.range) {
+    requestOptions.url += '&range=' + requestOptions.range;
+  }
+  delete requestOptions.quality;
+  delete requestOptions.range;
+  delete requestOptions.filter;
+
+  // Start downloading the video.
+  var req = request(requestOptions);
+  req.on('error', callback);
+  req.on('response', function(res) {
+    if (res.statusCode !== 200) {
+      callback(new Error('status code ' + res.statusCode));
+      return;
+    }
+
+    format.size = res.headers['content-length'];
+    callback(null, format, req);
+  });
+
+  function callbackWithFormatError() {
+    callback(format);
+  }
+}
+
+function downloadFromInfo(info, options) {
+  var stream = new PassThrough();
+  options = options || {};
+
+  downloadFromInfoCallback(info, options, function(err, format, videoStream) {
+    if (err) {
+      stream.emit('error', err);
+      return;
+    }
+
+    stream.emit('format', format);
+    videoStream.pipe(stream);
+  });
+
+  return stream;
+}
diff --git a/package.json b/package.json
@@ -1,7 +1,11 @@
 {
   "name": "ytdl-core",
   "description": "Youtube video downloader in pure javascript.",
-  "keywords": ["youtube", "video", "download"],
+  "keywords": [
+    "youtube",
+    "video",
+    "download"
+  ],
   "version": "0.1.0",
   "repository": {
     "type": "git",
@@ -13,20 +17,19 @@
     "test": "mocha -R spec -t 2000 test/*-test.js"
   },
   "dependencies": {
-    "eventvat": "~0.2.1",
     "jstream": "~0.2.7",
     "request": "~2.36.0",
-    "streamify": "~0.2.0",
     "underscore": "~1.6.0"
   },
   "devDependencies": {
     "mocha": "*",
     "nock": "~0.34.1",
     "stream-equal": "~0.1.0"
-
   },
-  "licenses": [{
-    "type": "MIT",
-    "url" : "http://github.com/fent/node-ytdl-core/raw/master/LICENSE"
-  }]
+  "licenses": [
+    {
+      "type": "MIT",
+      "url": "http://github.com/fent/node-ytdl-core/raw/master/LICENSE"
+    }
+  ]
 }