net/spdy/spdy_pinnable_buffer_piece.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_SPDY_SPDY_PINNABLE_BUFFER_PIECE_H_
   6 #define NET_SPDY_SPDY_PINNABLE_BUFFER_PIECE_H_
   7
   8 #include <memory>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/strings/string_piece.h"
  12 #include "net/base/net_export.h"
  13
  14 namespace net {
  15
  16 class SpdyPrefixedBufferReader;
  17
  18 // Helper class of SpdyPrefixedBufferReader.
  19 // Represents a piece of consumed buffer which may (or may not) own its
  20 // underlying storage. Users may "pin" the buffer at a later time to ensure
  21 // a SpdyPinnableBufferPiece owns and retains storage of the buffer.
  22 struct NET_EXPORT_PRIVATE SpdyPinnableBufferPiece {
  23  public:
  24   SpdyPinnableBufferPiece();
  25   ~SpdyPinnableBufferPiece();
  26
  27   const char * buffer() const {
  28     return buffer_;
  29   }
  30
  31   size_t length() const {
  32     return length_;
  33   }
  34
  35   operator base::StringPiece() const {
  36     return base::StringPiece(buffer_, length_);
  37   }
  38
  39   // Allocates and copies the buffer to internal storage.
  40   void Pin();
  41
  42   bool IsPinned() const { return storage_ != nullptr; }
  43
  44   // Swaps buffers, including internal storage, with |other|.
  45   void Swap(SpdyPinnableBufferPiece* other);
  46
  47  private:
  48   friend class SpdyPrefixedBufferReader;
  49
  50   const char * buffer_;
  51   size_t length_;
  52   // Null iff |buffer_| isn't pinned.
  53   scoped_ptr<char[]> storage_;
  54 };
  55
  56 }  // namespace net
  57
  58 #endif  // NET_SPDY_SPDY_PINNABLE_BUFFER_PIECE_H_