OLD | NEW |
---|---|
(Empty) | |
1 // Copyright (c) 2017 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 #include "platform/image-decoders/SegmentStream.h" | |
6 #include <utility> | |
7 | |
8 namespace blink { | |
9 | |
10 SegmentStream::SegmentStream() = default; | |
11 | |
12 SegmentStream::SegmentStream(SegmentStream&& rhs) | |
13 : reader_(std::move(rhs.reader_)), | |
14 position_(rhs.position_), | |
15 has_read_all_contents_(rhs.has_read_all_contents_), | |
16 is_cleared_(rhs.is_cleared_) {} | |
17 | |
18 SegmentStream::~SegmentStream() = default; | |
19 | |
20 SegmentStream& SegmentStream::operator=(SegmentStream&& rhs) { | |
21 reader_ = std::move(rhs.reader_); | |
22 position_ = rhs.position_; | |
23 has_read_all_contents_ = rhs.has_read_all_contents_; | |
24 is_cleared_ = rhs.is_cleared_; | |
25 | |
26 return *this; | |
27 } | |
28 | |
29 void SegmentStream::SetReader(WTF::RefPtr<SegmentReader> reader) { | |
30 reader_ = std::move(reader); | |
31 SetPositionState(position_); | |
32 } | |
33 | |
34 size_t SegmentStream::read(void* buffer, size_t size) { | |
35 if (is_cleared_) | |
36 return 0; | |
37 | |
38 size = std::min(size, reader_->size() - position_); | |
39 | |
40 size_t bytes_advanced = 0; | |
41 if (!buffer) { // skipping, not reading | |
42 bytes_advanced = size; | |
43 } else { | |
44 bytes_advanced = peek(buffer, size); | |
45 } | |
46 | |
47 SetPositionState(position_ + bytes_advanced); | |
48 | |
49 return bytes_advanced; | |
50 } | |
51 | |
52 size_t SegmentStream::peek(void* buffer, size_t size) const { | |
53 if (is_cleared_) | |
54 return 0; | |
55 | |
56 size = std::min(size, reader_->size() - position_); | |
57 | |
58 size_t total_bytes_peeked = 0; | |
59 char* buffer_as_char_ptr = reinterpret_cast<char*>(buffer); | |
60 while (size) { | |
61 const char* segment = nullptr; | |
62 size_t bytes_peeked = | |
63 reader_->GetSomeData(segment, position_ + total_bytes_peeked); | |
64 if (!bytes_peeked) | |
65 break; | |
66 if (bytes_peeked > size) | |
67 bytes_peeked = size; | |
68 | |
69 memcpy(buffer_as_char_ptr, segment, bytes_peeked); | |
70 buffer_as_char_ptr += bytes_peeked; | |
71 size -= bytes_peeked; | |
72 total_bytes_peeked += bytes_peeked; | |
73 } | |
74 | |
75 return total_bytes_peeked; | |
76 } | |
77 | |
78 bool SegmentStream::rewind() { | |
79 SetPositionState(0); | |
80 return true; | |
81 } | |
82 | |
83 bool SegmentStream::seek(size_t position) { | |
84 SetPositionState(position); | |
85 return true; | |
86 } | |
87 | |
88 bool SegmentStream::move(long offset) { | |
89 DCHECK_GT(offset, 0); | |
90 SetPositionState(position_ + offset); | |
91 return true; | |
92 } | |
93 | |
94 void SegmentStream::SetPositionState(size_t new_position) { | |
95 position_ = new_position; | |
96 if (reader_) { | |
97 const size_t reader_size = reader_->size(); | |
98 has_read_all_contents_ = position_ >= reader_size; | |
scroggo_chromium
2017/08/15 15:19:44
Instead of computing this value each time we chang
cblume
2017/08/15 18:03:33
Done.
| |
99 is_cleared_ = position_ > reader_size; | |
100 } else { | |
101 has_read_all_contents_ = true; | |
102 is_cleared_ = true; | |
103 } | |
104 } | |
105 | |
106 } // namespace blink | |
OLD | NEW |