1// Copyright 2013 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_TOOLS_BALSA_SIMPLE_BUFFER_H__
6#define NET_TOOLS_BALSA_SIMPLE_BUFFER_H__
7
8#include <string>
9
10#include "base/compiler_specific.h"
11#include "net/tools/balsa/buffer_interface.h"
12
13namespace net {
14
15class SimpleBuffer : public BufferInterface {
16 public:
17  SimpleBuffer();
18  explicit SimpleBuffer(int size);
19  virtual ~SimpleBuffer();
20
21  std::string str() const;
22
23  typedef char * iterator;
24  typedef const char * const_iterator;
25
26  iterator begin() { return storage_ + read_idx_; }
27  const_iterator begin() const { return storage_ + read_idx_; }
28
29  iterator end() { return storage_ + write_idx_; }
30  const_iterator end() const { return storage_ + write_idx_; }
31
32  // The following functions all override pure virtual functions
33  // in BufferInterface. See buffer_interface.h for a description
34  // of what they do.
35  virtual int ReadableBytes() const OVERRIDE;
36  virtual int BufferSize() const OVERRIDE;
37  virtual int BytesFree() const OVERRIDE;
38
39  virtual bool Empty() const OVERRIDE;
40  virtual bool Full() const OVERRIDE;
41
42  virtual int Write(const char* bytes, int size) OVERRIDE;
43
44  virtual void GetWritablePtr(char **ptr, int* size) const OVERRIDE;
45
46  virtual void GetReadablePtr(char **ptr, int* size) const OVERRIDE;
47
48  virtual int Read(char* bytes, int size) OVERRIDE;
49
50  virtual void Clear() OVERRIDE;
51
52  // This can be an expensive operation: costing a new/delete, and copying of
53  // all existing data. Even if the existing buffer does not need to be
54  // resized, unread data may still need to be non-destructively copied to
55  // consolidate fragmented free space.
56  virtual bool Reserve(int size) OVERRIDE;
57
58  virtual void AdvanceReadablePtr(int amount_to_advance) OVERRIDE;
59
60  virtual void AdvanceWritablePtr(int amount_to_advance) OVERRIDE;
61
62  void Swap(SimpleBuffer* other) {
63    char* tmp = storage_;
64    storage_ = other->storage_;
65    other->storage_ = tmp;
66
67    int tmp_int = write_idx_;
68    write_idx_ = other->write_idx_;
69    other->write_idx_ = tmp_int;
70
71    tmp_int = read_idx_;
72    read_idx_ = other->read_idx_;
73    other->read_idx_ = tmp_int;
74
75    tmp_int = storage_size_;
76    storage_size_ = other->storage_size_;
77    other->storage_size_ = tmp_int;
78  }
79
80 protected:
81  char* storage_;
82  int write_idx_;
83  int read_idx_;
84  int storage_size_;
85
86 private:
87  //DISALLOW_COPY_AND_ASSIGN(SimpleBuffer);
88};
89
90}  // namespace net
91
92#endif  // NET_TOOLS_BALSA_SIMPLE_BUFFER_H__
93