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Side by Side Diff: media/midi/midi_message_queue.cc

Issue 2431393002: Web MIDI: move MIDI message validating logic into message_util.{cc|h} (Closed)
Patch Set: Created 4 years, 2 months ago
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1 // Copyright 2013 The Chromium Authors. All rights reserved. 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 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 #include "media/midi/midi_message_queue.h" 5 #include "media/midi/midi_message_queue.h"
6 6
7 #include <algorithm> 7 #include <algorithm>
8 8
9 #include "base/logging.h" 9 #include "base/logging.h"
10 #include "media/midi/midi_message_util.h" 10 #include "media/midi/message_util.h"
11 11
12 namespace midi { 12 namespace midi {
13 namespace {
14 13
15 const uint8_t kSysEx = 0xf0; 14 using midi::kSysExByte;
yukawa 2016/10/19 20:11:20 Do we need this?
Takashi Toyoshima 2016/10/20 05:18:17 Done.
16 const uint8_t kEndOfSysEx = 0xf7; 15 using midi::kEndOfSysExByte;
yukawa 2016/10/19 20:11:20 Do we need this?
Takashi Toyoshima 2016/10/20 05:18:17 Done.
17
18 bool IsDataByte(uint8_t data) {
19 return (data & 0x80) == 0;
20 }
21
22 bool IsSystemRealTimeMessage(uint8_t data) {
23 return 0xf8 <= data;
24 }
25
26 bool IsSystemMessage(uint8_t data) {
27 return 0xf0 <= data;
28 }
29
30 } // namespace
31 16
32 MidiMessageQueue::MidiMessageQueue(bool allow_running_status) 17 MidiMessageQueue::MidiMessageQueue(bool allow_running_status)
33 : allow_running_status_(allow_running_status) {} 18 : allow_running_status_(allow_running_status) {}
34 19
35 MidiMessageQueue::~MidiMessageQueue() {} 20 MidiMessageQueue::~MidiMessageQueue() {}
36 21
37 void MidiMessageQueue::Add(const std::vector<uint8_t>& data) { 22 void MidiMessageQueue::Add(const std::vector<uint8_t>& data) {
38 queue_.insert(queue_.end(), data.begin(), data.end()); 23 queue_.insert(queue_.end(), data.begin(), data.end());
39 } 24 }
40 25
41 void MidiMessageQueue::Add(const uint8_t* data, size_t length) { 26 void MidiMessageQueue::Add(const uint8_t* data, size_t length) {
42 queue_.insert(queue_.end(), data, data + length); 27 queue_.insert(queue_.end(), data, data + length);
43 } 28 }
44 29
45 void MidiMessageQueue::Get(std::vector<uint8_t>* message) { 30 void MidiMessageQueue::Get(std::vector<uint8_t>* message) {
46 message->clear(); 31 message->clear();
47 32
48 while (true) { 33 while (true) {
49 // Check if |next_message_| is already a complete MIDI message or not. 34 // Check if |next_message_| is already a complete MIDI message or not.
50 if (!next_message_.empty()) { 35 if (!next_message_.empty()) {
51 const uint8_t status_byte = next_message_.front(); 36 const uint8_t status_byte = next_message_.front();
52 const size_t target_len = GetMidiMessageLength(status_byte); 37 const size_t target_len = GetMessageLength(status_byte);
53 if (target_len == 0) { 38 if (target_len == 0) {
54 DCHECK_EQ(kSysEx, status_byte); 39 DCHECK_EQ(kSysExByte, status_byte);
55 if (next_message_.back() == kEndOfSysEx) { 40 if (next_message_.back() == kEndOfSysExByte) {
56 // OK, this is a complete SysEx message. 41 // OK, this is a complete SysEx message.
57 std::swap(*message, next_message_); 42 std::swap(*message, next_message_);
58 DCHECK(next_message_.empty()); 43 DCHECK(next_message_.empty());
59 return; 44 return;
60 } 45 }
61 } else if (next_message_.size() == target_len) { 46 } else if (next_message_.size() == target_len) {
62 // OK, this is a complete non-SysEx message. 47 // OK, this is a complete non-SysEx message.
63 std::swap(*message, next_message_); 48 std::swap(*message, next_message_);
64 DCHECK(next_message_.empty()); 49 DCHECK(next_message_.empty());
65 if (allow_running_status_ && !IsSystemMessage(status_byte)) { 50 if (allow_running_status_ && !IsSystemMessage(status_byte)) {
66 // Speculatively keep the status byte in case of running status. 51 // Speculatively keep the status byte in case of running status.
67 // If this assumption is not true, |next_message_| will be cleared 52 // If this assumption is not true, |next_message_| will be cleared
68 // anyway. Note that system common messages should reset the 53 // anyway. Note that system common messages should reset the
(...skipping 14 matching lines...) Expand all
83 // "System Real Time Messages" prior to |next_message_| so that each message 68 // "System Real Time Messages" prior to |next_message_| so that each message
84 // can be clearly separated as a complete MIDI message. 69 // can be clearly separated as a complete MIDI message.
85 const uint8_t next = queue_.front(); 70 const uint8_t next = queue_.front();
86 if (IsSystemRealTimeMessage(next)) { 71 if (IsSystemRealTimeMessage(next)) {
87 message->push_back(next); 72 message->push_back(next);
88 queue_.pop_front(); 73 queue_.pop_front();
89 return; 74 return;
90 } 75 }
91 76
92 if (next_message_.empty()) { 77 if (next_message_.empty()) {
93 const size_t target_len = GetMidiMessageLength(next); 78 const size_t target_len = GetMessageLength(next);
94 // If |target_len| is zero, it means either |next| is not a valid status 79 // If |target_len| is zero, it means either |next| is not a valid status
95 // byte or |next| is a valid status byte but the message length is 80 // byte or |next| is a valid status byte but the message length is
96 // unpredictable. For the latter case, only SysEx can be accepted. 81 // unpredictable. For the latter case, only SysEx can be accepted.
97 if (target_len > 0 || next == kSysEx) { 82 if (target_len > 0 || next == kSysExByte) {
98 next_message_.push_back(next); 83 next_message_.push_back(next);
99 } 84 }
100 // Consume |next| always, since if |next| isn't status byte, which means 85 // Consume |next| always, since if |next| isn't status byte, which means
101 // that |next| is just corrupted data, or a data byte followed by 86 // that |next| is just corrupted data, or a data byte followed by
102 // reserved message, which we are unable to understand and deal with 87 // reserved message, which we are unable to understand and deal with
103 // anyway. 88 // anyway.
104 queue_.pop_front(); 89 queue_.pop_front();
105 continue; 90 continue;
106 } 91 }
107 92
108 const uint8_t status_byte = next_message_.front(); 93 const uint8_t status_byte = next_message_.front();
109 94
110 // If we receive a new non-data byte before completing the pending message, 95 // If we receive a new non-data byte before completing the pending message,
111 // drop the pending message and respin the loop to re-evaluate |next|. 96 // drop the pending message and respin the loop to re-evaluate |next|.
112 // This also clears the running status byte speculatively added above, as 97 // This also clears the running status byte speculatively added above, as
113 // well as any broken incomplete messages. 98 // well as any broken incomplete messages.
114 if (!IsDataByte(next) && !(status_byte == kSysEx && next == kEndOfSysEx)) { 99 if (!IsDataByte(next) &&
100 !(status_byte == kSysExByte && next == kEndOfSysExByte)) {
115 next_message_.clear(); 101 next_message_.clear();
116 continue; 102 continue;
117 } 103 }
118 104
119 // OK to consume this byte. 105 // OK to consume this byte.
120 next_message_.push_back(next); 106 next_message_.push_back(next);
121 queue_.pop_front(); 107 queue_.pop_front();
122 } 108 }
123 } 109 }
124 110
125 } // namespace midi 111 } // namespace midi
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