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

content/browser/media/midi_host.cc

 // Copyright (c) 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 "content/browser/media/midi_host.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
-#include "base/metrics/histogram_macros.h"
 #include "base/process/process.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/common/media/midi_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/user_metrics.h"
+#include "media/midi/message_util.h"
 #include "media/midi/midi_manager.h"
 #include "media/midi/midi_message_queue.h"
-#include "media/midi/midi_message_util.h"
 
 namespace content {
 namespace {
 
 // The total number of bytes which we're allowed to send to the OS
 // before knowing that they have been successfully sent.
 const size_t kMaxInFlightBytes = 10 * 1024 * 1024;  // 10 MB.
 
 // We keep track of the number of bytes successfully sent to
 // the hardware.  Every once in a while we report back to the renderer
 // the number of bytes sent since the last report. This threshold determines
 // how many bytes will be sent before reporting back to the renderer.
 const size_t kAcknowledgementThresholdBytes = 1024 * 1024;  // 1 MB.
 
-bool IsDataByte(uint8_t data) {
-  return (data & 0x80) == 0;
-}
-
-bool IsSystemRealTimeMessage(uint8_t data) {
-  return 0xf8 <= data && data <= 0xff;
-}
-
 }  // namespace
 
+using midi::IsDataByte;
+using midi::IsSystemRealTimeMessage;
+using midi::IsValidWebMIDIData;
+using midi::MidiPortInfo;
 using midi::kSysExByte;
 using midi::kEndOfSysExByte;
 using midi::mojom::Result;
 
 MidiHost::MidiHost(int renderer_process_id,
                    midi::MidiManager* midi_manager)
     : BrowserMessageFilter(MidiMsgStart),
       renderer_process_id_(renderer_process_id),
       has_sys_ex_permission_(false),
       is_session_requested_(false),
@@ skipping 91 matching lines @@
   DCHECK(is_session_requested_);
   if (result == Result::OK) {
     // ChildSecurityPolicy is set just before OnStartSession by
     // MidiDispatcherHost. So we can safely cache the policy.
     has_sys_ex_permission_ = ChildProcessSecurityPolicyImpl::GetInstance()->
         CanSendMidiSysExMessage(renderer_process_id_);
   }
   Send(new MidiMsg_SessionStarted(result));
 }
 
-void MidiHost::AddInputPort(const midi::MidiPortInfo& info) {
+void MidiHost::AddInputPort(const MidiPortInfo& info) {
   base::AutoLock auto_lock(messages_queues_lock_);
   // MidiMessageQueue is created later in ReceiveMidiData().
   received_messages_queues_.push_back(nullptr);
   Send(new MidiMsg_AddInputPort(info));
 }
 
-void MidiHost::AddOutputPort(const midi::MidiPortInfo& info) {
+void MidiHost::AddOutputPort(const MidiPortInfo& info) {
   base::AutoLock auto_lock(output_port_count_lock_);
   output_port_count_++;
   Send(new MidiMsg_AddOutputPort(info));
 }
 
 void MidiHost::SetInputPortState(uint32_t port,
                                  midi::MidiPortState state) {
   Send(new MidiMsg_SetInputPortState(port, state));
 }
 
@@ skipping 50 matching lines @@
     Send(new MidiMsg_AcknowledgeSentData(
         bytes_sent_since_last_acknowledgement_));
     bytes_sent_since_last_acknowledgement_ = 0;
   }
 }
 
 void MidiHost::Detach() {
   midi_manager_ = nullptr;
 }
 
-// static
-bool MidiHost::IsValidWebMIDIData(const std::vector<uint8_t>& data) {
-  bool in_sysex = false;
-  size_t sysex_start_offset = 0;
-  size_t waiting_data_length = 0;
-  for (size_t i = 0; i < data.size(); ++i) {
-    const uint8_t current = data[i];
-    if (IsSystemRealTimeMessage(current))
-      continue;  // Real time message can be placed at any point.
-    if (waiting_data_length > 0) {
-      if (!IsDataByte(current))
-        return false;  // Error: |current| should have been data byte.
-      --waiting_data_length;
-      continue;  // Found data byte as expected.
-    }
-    if (in_sysex) {
-      if (data[i] == kEndOfSysExByte) {
-        in_sysex = false;
-        UMA_HISTOGRAM_COUNTS("Media.Midi.SysExMessageSizeUpTo1MB",
-                             i - sysex_start_offset + 1);
-      } else if (!IsDataByte(current)) {
-        return false;  // Error: |current| should have been data byte.
-      }
-      continue;  // Found data byte as expected.
-    }
-    if (current == kSysExByte) {
-      in_sysex = true;
-      sysex_start_offset = i;
-      continue;  // Found SysEX
-    }
-    waiting_data_length = midi::GetMidiMessageLength(current);
-    if (waiting_data_length == 0)
-      return false;  // Error: |current| should have been a valid status byte.
-    --waiting_data_length;  // Found status byte
-  }
-  return waiting_data_length == 0 && !in_sysex;
-}
-
 }  // namespace content