Web MIDI: move MIDI message validating logic into message_util.{cc|h}

media/midi/midi_message_queue.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/midi/midi_message_queue.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
-#include "media/midi/midi_message_util.h"
+#include "media/midi/message_util.h"
 
 namespace midi {
-namespace {
-
-const uint8_t kSysEx = 0xf0;
-const uint8_t kEndOfSysEx = 0xf7;
-
-bool IsDataByte(uint8_t data) {
-  return (data & 0x80) == 0;
-}
-
-bool IsSystemRealTimeMessage(uint8_t data) {
-  return 0xf8 <= data;
-}
-
-bool IsSystemMessage(uint8_t data) {
-  return 0xf0 <= data;
-}
-
-}  // namespace
 
 MidiMessageQueue::MidiMessageQueue(bool allow_running_status)
     : allow_running_status_(allow_running_status) {}
 
 MidiMessageQueue::~MidiMessageQueue() {}
 
 void MidiMessageQueue::Add(const std::vector<uint8_t>& data) {
   queue_.insert(queue_.end(), data.begin(), data.end());
 }
 
 void MidiMessageQueue::Add(const uint8_t* data, size_t length) {
   queue_.insert(queue_.end(), data, data + length);
 }
 
 void MidiMessageQueue::Get(std::vector<uint8_t>* message) {
   message->clear();
 
   while (true) {
     // Check if |next_message_| is already a complete MIDI message or not.
     if (!next_message_.empty()) {
       const uint8_t status_byte = next_message_.front();
-      const size_t target_len = GetMidiMessageLength(status_byte);
+      const size_t target_len = GetMessageLength(status_byte);
       if (target_len == 0) {
-        DCHECK_EQ(kSysEx, status_byte);
-        if (next_message_.back() == kEndOfSysEx) {
-           // OK, this is a complete SysEx message.
-           std::swap(*message, next_message_);
-           DCHECK(next_message_.empty());
+        DCHECK_EQ(kSysExByte, status_byte);
+        if (next_message_.back() == kEndOfSysExByte) {
+          // OK, this is a complete SysEx message.
+          std::swap(*message, next_message_);
+          DCHECK(next_message_.empty());
           return;
         }
       } else if (next_message_.size() == target_len) {
         // OK, this is a complete non-SysEx message.
         std::swap(*message, next_message_);
         DCHECK(next_message_.empty());
         if (allow_running_status_ && !IsSystemMessage(status_byte)) {
           // Speculatively keep the status byte in case of running status.
           // If this assumption is not true, |next_message_| will be cleared
           // anyway.  Note that system common messages should reset the
@@ skipping 14 matching lines @@
     // "System Real Time Messages" prior to |next_message_| so that each message
     // can be clearly separated as a complete MIDI message.
     const uint8_t next = queue_.front();
     if (IsSystemRealTimeMessage(next)) {
       message->push_back(next);
       queue_.pop_front();
       return;
     }
 
     if (next_message_.empty()) {
-      const size_t target_len = GetMidiMessageLength(next);
+      const size_t target_len = GetMessageLength(next);
       // If |target_len| is zero, it means either |next| is not a valid status
       // byte or |next| is a valid status byte but the message length is
       // unpredictable.  For the latter case, only SysEx can be accepted.
-      if (target_len > 0 || next == kSysEx) {
+      if (target_len > 0 || next == kSysExByte) {
         next_message_.push_back(next);
       }
       // Consume |next| always, since if |next| isn't status byte, which means
       // that |next| is just corrupted data, or a data byte followed by
       // reserved message, which we are unable to understand and deal with
       // anyway.
       queue_.pop_front();
       continue;
     }
 
     const uint8_t status_byte = next_message_.front();
 
     // If we receive a new non-data byte before completing the pending message,
     // drop the pending message and respin the loop to re-evaluate |next|.
     // This also clears the running status byte speculatively added above, as
     // well as any broken incomplete messages.
-    if (!IsDataByte(next) && !(status_byte == kSysEx && next == kEndOfSysEx)) {
+    if (!IsDataByte(next) &&
+        !(status_byte == kSysExByte && next == kEndOfSysExByte)) {
       next_message_.clear();
       continue;
     }
 
     // OK to consume this byte.
     next_message_.push_back(next);
     queue_.pop_front();
   }
 }
 
 }  // namespace midi