[net] Change order of RequestPriority to natural: higher > lower

net/spdy/spdy_io_buffer.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_SPDY_SPDY_IO_BUFFER_H_
 #define NET_SPDY_SPDY_IO_BUFFER_H_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_export.h"
 #include "net/spdy/spdy_stream.h"
 
 namespace net {
 
 // A class for managing SPDY IO buffers.  These buffers need to be prioritized
 // so that the SpdySession sends them in the right order.  Further, they need
 // to track the SpdyStream which they are associated with so that incremental
 // completion of the IO can notify the appropriate stream of completion.
 class NET_EXPORT_PRIVATE SpdyIOBuffer {
  public:
   // Constructor
   // |buffer| is the actual data buffer.
   // |size| is the size of the data buffer.
-  // |priority| is the priority of this buffer.  Lower numbers are higher
-  //            priority.
+  // |priority| is the priority of this buffer.
   // |stream| is a pointer to the stream which is managing this buffer.
   SpdyIOBuffer(IOBuffer* buffer, int size, int priority, SpdyStream* stream);

[Ryan Hamilton, 2012/04/23 22:51:05]

Can you make |priority| a RequestPriority?  It looks like
SpdySession::QueueFrame is construction SpdyIOBuffers with RequestPriority so I
hope this would be an easy change.

[szym, 2012/04/24 00:19:31]

I considered that. The only doubt was caused by the unit test which creates
SpdyIOBuffer with priorities 0..100. Would using undefined enum values be ok?

[Ryan Hamilton, 2012/04/24 00:42:11]

Hm.  I think I would be inclined to change the class to use RequestPriority, and
change the test to only create NUM_PRIORITIES priorities.  I fear that having a
class with SPDY in the name that takes an int priority but whose value is not a
SPDY priority, is just asking for problems :>  (You updated the comment, which
is awesome, but I'm still afraid I'd do the wrong thing in the future).  Work
for you?

[szym, 2012/04/24 00:47:58]

Yup. I'm on it.

   SpdyIOBuffer();
   ~SpdyIOBuffer();
 
   // Accessors.
   DrainableIOBuffer* buffer() const { return buffer_; }
   size_t size() const { return buffer_->size(); }
   void release();
   int priority() const { return priority_; }
   const scoped_refptr<SpdyStream>& stream() const { return stream_; }
 
   // Comparison operator to support sorting.
   bool operator<(const SpdyIOBuffer& other) const {
     if (priority_ != other.priority_)
-      return priority_ > other.priority_;
+      return priority_ < other.priority_;
     return position_ > other.position_;
   }
 
  private:
   scoped_refptr<DrainableIOBuffer> buffer_;
   int priority_;
   uint64 position_;
   scoped_refptr<SpdyStream> stream_;
   static uint64 order_;  // Maintains a FIFO order for equal priorities.
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_IO_BUFFER_H_