xref: /aosp_15_r20/external/webrtc/rtc_base/memory_stream.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef RTC_BASE_MEMORY_STREAM_H_
12 #define RTC_BASE_MEMORY_STREAM_H_
13 
14 #include <stddef.h>
15 
16 #include "rtc_base/stream.h"
17 
18 namespace rtc {
19 
20 // MemoryStream dynamically resizes to accomodate written data.
21 
22 class MemoryStream final : public StreamInterface {
23  public:
24   MemoryStream();
25   ~MemoryStream() override;
26 
27   StreamState GetState() const override;
28   StreamResult Read(rtc::ArrayView<uint8_t> buffer,
29                     size_t& bytes_read,
30                     int& error) override;
31   StreamResult Write(rtc::ArrayView<const uint8_t> buffer,
32                      size_t& bytes_written,
33                      int& error) override;
34   void Close() override;
35   bool GetSize(size_t* size) const;
36   bool ReserveSize(size_t size);
37 
38   bool SetPosition(size_t position);
39   bool GetPosition(size_t* position) const;
40   void Rewind();
41 
GetBuffer()42   char* GetBuffer() { return buffer_; }
GetBuffer()43   const char* GetBuffer() const { return buffer_; }
44 
45   void SetData(const void* data, size_t length);
46 
47  private:
48   StreamResult DoReserve(size_t size, int* error);
49 
50   // Invariant: 0 <= seek_position <= data_length_ <= buffer_length_
51   char* buffer_ = nullptr;
52   size_t buffer_length_ = 0;
53   size_t data_length_ = 0;
54   size_t seek_position_ = 0;
55 };
56 
57 }  // namespace rtc
58 
59 #endif  // RTC_BASE_MEMORY_STREAM_H_
60