From c80cd285fa4ec65eb4a029a8e5ed87dccd39c0f8 Mon Sep 17 00:00:00 2001
From: Jonathan Tron <jonathan@tron.name>
Date: Mon, 29 Nov 2010 17:39:44 +0100
Subject: [PATCH] Add Mongo::GridIO#each which yield each chunks of a file,
 allowing Rack streaming

---
 lib/mongo/gridfs/grid_io.rb | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/lib/mongo/gridfs/grid_io.rb b/lib/mongo/gridfs/grid_io.rb
index 1409b82..2d9ca36 100644
--- a/lib/mongo/gridfs/grid_io.rb
+++ b/lib/mongo/gridfs/grid_io.rb
@@ -191,6 +191,20 @@ module Mongo
       end
       id
     end
+    
+    # Read a chunk of the data from the file and yield it to the given
+    # block. It will read from the current file position.
+    #
+    # @param [Block] A block called with each chunk
+    #
+    # @return [Mongo::GridIO] self
+    def each
+      return read_all unless block_given?
+      while chunk = read(chunk_size)
+        yield chunk
+      end
+      self
+    end
 
     def inspect
       "#<GridIO _id: #{@files_id}>"