Implement WebSocketDeflater.

net/websockets/websocket_deflater.h

+// Copyright (c) 2013 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_WEBSOCKETS_WEBSOCKET_DEFLATER_H_
+#define NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+
+typedef struct z_stream_s z_stream;

[Adam Rice, 2013/08/29 12:04:33]

z_stream_s has C linkage so this is actually a different type than is defined in
zlib.h. I think it compiles because the C++ compiler fails to notice that it is
a different type, and the linker doesn't care because it doesn't have any
methods or constructors to link. You could wrap this statement in extern "C" { }
but I would prefer to leave that detail out of the header file.

One solution would be to forward declare

private:
  struct ZlibStream;

in the header file and then trivially define

struct WebSocketDeflater::ZlibStream {
  z_stream s;
};

in the implementation. That means writing stream_->s. where you currently just
write stream_, but it is probably not too bad.

[yhirano, 2013/08/30 06:20:35]

Thanks, including zlib.h solves the problem.

+
+namespace net {
+
+class IOBufferWithSize;
+
+class WebSocketDeflater {
+ public:
+  enum ContextTakeOverMode {
+    DO_NOT_TAKE_OVER_CONTEXT,
+    TAKE_OVER_CONTEXT,
+  };
+
+  // |window_bits| must be between 8 and 15 (both inclusive).
+  WebSocketDeflater(int window_bits, ContextTakeOverMode mode);
+  ~WebSocketDeflater();
+
+  // Adds bytes to |stream_|.
+  // Returns true if there is no error and false otherwise.
+  bool AddBytes(const char* data, size_t size);
+
+  // Flushes and returns deflated result.
+  // Returns null if there is an error.
+  scoped_refptr<IOBufferWithSize> Finish();
+
+ private:
+  void Reset();
+
+  scoped_ptr<z_stream> stream_;
+  ContextTakeOverMode mode_;
+  std::vector<char> buffer_;
+  bool are_bytes_added_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebSocketDeflater);
+};
+
+}  // namespace net
+
+#endif  // NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_