1/*
2 * libjingle
3 * Copyright 2004-2010, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#ifndef TALK_BASE_BUFFER_H_
29#define TALK_BASE_BUFFER_H_
30
31#include <cstring>
32
33#include "talk/base/scoped_ptr.h"
34
35namespace talk_base {
36
37// Basic buffer class, can be grown and shrunk dynamically.
38// Unlike std::string/vector, does not initialize data when expanding capacity.
39class Buffer {
40 public:
41  Buffer() {
42    Construct(NULL, 0, 0);
43  }
44  Buffer(const void* data, size_t length) {
45    Construct(data, length, length);
46  }
47  Buffer(const void* data, size_t length, size_t capacity) {
48    Construct(data, length, capacity);
49  }
50  Buffer(const Buffer& buf) {
51    Construct(buf.data(), buf.length(), buf.length());
52  }
53
54  const char* data() const { return data_.get(); }
55  char* data() { return data_.get(); }
56  // TODO: should this be size(), like STL?
57  size_t length() const { return length_; }
58  size_t capacity() const { return capacity_; }
59
60  Buffer& operator=(const Buffer& buf) {
61    if (&buf != this) {
62      Construct(buf.data(), buf.length(), buf.length());
63    }
64    return *this;
65  }
66  bool operator==(const Buffer& buf) const {
67    return (length_ == buf.length() &&
68            memcmp(data_.get(), buf.data(), length_) == 0);
69  }
70  bool operator!=(const Buffer& buf) const {
71    return !operator==(buf);
72  }
73
74  void SetData(const void* data, size_t length) {
75    ASSERT(data != NULL || length == 0);
76    SetLength(length);
77    memcpy(data_.get(), data, length);
78  }
79  void AppendData(const void* data, size_t length) {
80    ASSERT(data != NULL || length == 0);
81    size_t old_length = length_;
82    SetLength(length_ + length);
83    memcpy(data_.get() + old_length, data, length);
84  }
85  void SetLength(size_t length) {
86    SetCapacity(length);
87    length_ = length;
88  }
89  void SetCapacity(size_t capacity) {
90    if (capacity > capacity_) {
91      talk_base::scoped_array<char> data(new char[capacity]);
92      memcpy(data.get(), data_.get(), length_);
93      data_.swap(data);
94      capacity_ = capacity;
95    }
96  }
97
98  void TransferTo(Buffer* buf) {
99    ASSERT(buf != NULL);
100    buf->data_.reset(data_.release());
101    buf->length_ = length_;
102    buf->capacity_ = capacity_;
103    Construct(NULL, 0, 0);
104  }
105
106 protected:
107  void Construct(const void* data, size_t length, size_t capacity) {
108    data_.reset(new char[capacity_ = capacity]);
109    SetData(data, length);
110  }
111
112  scoped_array<char> data_;
113  size_t length_;
114  size_t capacity_;
115};
116
117}  // namespace talk_base
118
119#endif  // TALK_BASE_BUFFER_H_
120