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1 // Copyright 2014 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef MEDIA_FORMATS_COMMON_OFFSET_BYTE_QUEUE_H_ | 5 #ifndef MEDIA_FORMATS_COMMON_OFFSET_BYTE_QUEUE_H_ |
6 #define MEDIA_FORMATS_COMMON_OFFSET_BYTE_QUEUE_H_ | 6 #define MEDIA_FORMATS_COMMON_OFFSET_BYTE_QUEUE_H_ |
7 | 7 |
8 #include "base/basictypes.h" | |
9 #include "media/base/byte_queue.h" | 8 #include "media/base/byte_queue.h" |
10 #include "media/base/media_export.h" | 9 #include "media/base/media_export.h" |
11 | 10 |
12 namespace media { | 11 namespace media { |
13 | 12 |
14 // A wrapper around a ByteQueue which maintains a notion of a | 13 // A wrapper around a ByteQueue which maintains a notion of a |
15 // monotonically-increasing offset. All buffer access is done by passing these | 14 // monotonically-increasing offset. All buffer access is done by passing these |
16 // offsets into this class, going some way towards preventing the proliferation | 15 // offsets into this class, going some way towards preventing the proliferation |
17 // of many different meanings of "offset", "head", etc. | 16 // of many different meanings of "offset", "head", etc. |
18 class MEDIA_EXPORT OffsetByteQueue { | 17 class MEDIA_EXPORT OffsetByteQueue { |
19 public: | 18 public: |
20 OffsetByteQueue(); | 19 OffsetByteQueue(); |
21 ~OffsetByteQueue(); | 20 ~OffsetByteQueue(); |
22 | 21 |
23 // These work like their underlying ByteQueue counterparts. | 22 // These work like their underlying ByteQueue counterparts. |
24 void Reset(); | 23 void Reset(); |
25 void Push(const uint8* buf, int size); | 24 void Push(const uint8_t* buf, int size); |
26 void Peek(const uint8** buf, int* size); | 25 void Peek(const uint8_t** buf, int* size); |
27 void Pop(int count); | 26 void Pop(int count); |
28 | 27 |
29 // Sets |buf| to point at the first buffered byte corresponding to |offset|, | 28 // Sets |buf| to point at the first buffered byte corresponding to |offset|, |
30 // and |size| to the number of bytes available starting from that offset. | 29 // and |size| to the number of bytes available starting from that offset. |
31 // | 30 // |
32 // It is an error if the offset is before the current head. It's not an error | 31 // It is an error if the offset is before the current head. It's not an error |
33 // if the current offset is beyond tail(), but you will of course get back | 32 // if the current offset is beyond tail(), but you will of course get back |
34 // a null |buf| and a |size| of zero. | 33 // a null |buf| and a |size| of zero. |
35 void PeekAt(int64 offset, const uint8** buf, int* size); | 34 void PeekAt(int64_t offset, const uint8_t** buf, int* size); |
36 | 35 |
37 // Marks the bytes up to (but not including) |max_offset| as ready for | 36 // Marks the bytes up to (but not including) |max_offset| as ready for |
38 // deletion. This is relatively inexpensive, but will not necessarily reduce | 37 // deletion. This is relatively inexpensive, but will not necessarily reduce |
39 // the resident buffer size right away (or ever). | 38 // the resident buffer size right away (or ever). |
40 // | 39 // |
41 // Returns true if the full range of bytes were successfully trimmed, | 40 // Returns true if the full range of bytes were successfully trimmed, |
42 // including the case where |max_offset| is less than the current head. | 41 // including the case where |max_offset| is less than the current head. |
43 // Returns false if |max_offset| > tail() (although all bytes currently | 42 // Returns false if |max_offset| > tail() (although all bytes currently |
44 // buffered are still cleared). | 43 // buffered are still cleared). |
45 bool Trim(int64 max_offset); | 44 bool Trim(int64_t max_offset); |
46 | 45 |
47 // The head and tail positions, in terms of the file's absolute offsets. | 46 // The head and tail positions, in terms of the file's absolute offsets. |
48 // tail() is an exclusive bound. | 47 // tail() is an exclusive bound. |
49 int64 head() { return head_; } | 48 int64_t head() { return head_; } |
50 int64 tail() { return head_ + size_; } | 49 int64_t tail() { return head_ + size_; } |
51 | 50 |
52 private: | 51 private: |
53 // Synchronize |buf_| and |size_| with |queue_|. | 52 // Synchronize |buf_| and |size_| with |queue_|. |
54 void Sync(); | 53 void Sync(); |
55 | 54 |
56 ByteQueue queue_; | 55 ByteQueue queue_; |
57 const uint8* buf_; | 56 const uint8_t* buf_; |
58 int size_; | 57 int size_; |
59 int64 head_; | 58 int64_t head_; |
60 | 59 |
61 DISALLOW_COPY_AND_ASSIGN(OffsetByteQueue); | 60 DISALLOW_COPY_AND_ASSIGN(OffsetByteQueue); |
62 }; | 61 }; |
63 | 62 |
64 } // namespace media | 63 } // namespace media |
65 | 64 |
66 #endif // MEDIA_FORMATS_COMMON_OFFSET_BYTE_QUEUE_H_ | 65 #endif // MEDIA_FORMATS_COMMON_OFFSET_BYTE_QUEUE_H_ |
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