Emit progress event during file download

This changes allows to monitor file transfer progress

related issues spmjs#43 spmjs#57

lib/client.js

@@ -5,7 +5,7 @@ var async = require('async');
 var EventEmitter = require('events').EventEmitter;
 var Connection = require('ssh2');
 var _ = require('lodash');
-
+var progressStream = require('progress-stream');
 
 function Client(options) {
   this._options = options || {};
@@ -283,17 +283,30 @@ Client.prototype.download = function(src, dest, callback) {
       return callback(err);
     }
 
-    var sftp_readStream = sftp.createReadStream(src);
-    sftp_readStream.on('error', function(err){
-      callback(err);
-    });
-    sftp_readStream.pipe(fs.createWriteStream(dest))
-    .on('close',function(){
-      self.emit('read', src);
-      callback(null);
-    })
-    .on('error', function(err){
-      callback(err);
+    sftp.stat(src, function (err, stat) {
+      if (err) {
+        return callback(err);
+      }
+      var ps = progressStream({
+        length: stat.size,
+        time: 100
+      });
+      ps.on('progress', function (progress) {
+        self.emit('progress', progress);
+      });
+      var sftp_readStream = sftp.createReadStream(src);
+      sftp_readStream.on('error', function(err){
+        callback(err);
+      });
+      sftp_readStream.pipe(ps).pipe(fs.createWriteStream(dest))
+      .on('close',function(){
+        self.emit('read', src);
+        callback(null);
+      })
+      .on('error', function(err){
+        callback(err);
+      });
+      return self;
     });
   });
 };

package.json

@@ -12,10 +12,11 @@
     "ssh2"
   ],
   "dependencies": {
-    "ssh2": "~0.4.10",
-    "glob": "~4.0.6",
     "async": "~0.9.0",
-    "lodash": "~2.4.1"
+    "glob": "~4.0.6",
+    "lodash": "~2.4.1",
+    "progress-stream": "^1.2.0",
+    "ssh2": "~0.4.10"
   },
   "repository": {
     "type": "git",