closes #3990

[arvados.git] / apps / workbench / app / controllers / collections_controller.rb

diff --git a/apps/workbench/app/controllers/collections_controller.rb b/apps/workbench/app/controllers/collections_controller.rb
index 9882fa6a34a38f97e6615804038d107290604e4a..3c6c9d7a8571842ce55fc594b7242e8ce5d193b8 100644 (file)
--- a/apps/workbench/app/controllers/collections_controller.rb
+++ b/apps/workbench/app/controllers/collections_controller.rb
@@ -150,11 +150,29 @@ class CollectionsController < ApplicationController
     elsif params[:file].nil? or not coll.manifest.has_file?(params[:file])
       return render_not_found
     end
+
     opts = params.merge(arvados_api_token: usable_token)
+
+    # Handle Range requests. Currently we support only 'bytes=0-....'
+    if request.headers.include? 'HTTP_RANGE'
+      if m = /^bytes=0-(\d+)/.match(request.headers['HTTP_RANGE'])
+        opts[:maxbytes] = m[1]
+        size = params[:size] || '*'
+        self.response.status = 206
+        self.response.headers['Content-Range'] = "bytes 0-#{m[1]}/#{size}"
+      end
+    end
+
     ext = File.extname(params[:file])
     self.response.headers['Content-Type'] =
       Rack::Mime::MIME_TYPES[ext] || 'application/octet-stream'
-    self.response.headers['Content-Length'] = params[:size] if params[:size]
+    if params[:size]
+      size = params[:size].to_i
+      if opts[:maxbytes]
+        size = [size, opts[:maxbytes].to_i].min
+      end
+      self.response.headers['Content-Length'] = size.to_s
+    end
     self.response.headers['Content-Disposition'] = params[:disposition] if params[:disposition]
     begin
       file_enumerator(opts).each do |bytes|
@@ -305,12 +323,19 @@ class CollectionsController < ApplicationController
       env['ARVADOS_API_TOKEN'] = @opts[:arvados_api_token]
       env['ARVADOS_API_HOST_INSECURE'] = "true" if Rails.configuration.arvados_insecure_https
 
-      IO.popen([env, 'arv-get', "#{@opts[:uuid]}/#{@opts[:file]}"],
-               'rb') do |io|
-        while buf = io.read(2**16)
-          yield buf
+      bytesleft = @opts[:maxbytes].andand.to_i || 2**16
+      io = IO.popen([env, 'arv-get', "#{@opts[:uuid]}/#{@opts[:file]}"], 'rb')
+      while bytesleft > 0 && (buf = io.read([bytesleft, 2**16].min)) != nil
+        # shrink the bytesleft count, if we were given a maximum byte
+        # count to read
+        if @opts.include? :maxbytes
+          bytesleft = bytesleft - buf.length
         end
+        yield buf
       end
+      io.close
+      # "If ios is opened by IO.popen, close sets $?."
+      # http://www.ruby-doc.org/core-2.1.3/IO.html#method-i-close
       Rails.logger.warn("#{@opts[:uuid]}/#{@opts[:file]}: #{$?}") if $? != 0
     end
   end