Revert 237558 "Use MIDIMessageQueue/IsValidWebMIDIData for MIDI ..."

trunk/src/content/browser/renderer_host/media/midi_host.cc

Index: trunk/src/content/browser/renderer_host/media/midi_host.cc
===================================================================
--- trunk/src/content/browser/renderer_host/media/midi_host.cc	(revision 237659)
+++ trunk/src/content/browser/renderer_host/media/midi_host.cc	(working copy)
@@ -16,41 +16,26 @@
 #include "content/public/browser/media_observer.h"
 #include "content/public/browser/user_metrics.h"
 #include "media/midi/midi_manager.h"
-#include "media/midi/midi_message_queue.h"
-#include "media/midi/midi_message_util.h"
 
 using media::MIDIManager;
 using media::MIDIPortInfoList;
 
-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.
+static 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.
+static const size_t kAcknowledgementThresholdBytes = 1024 * 1024;  // 1 MB.
 
-const uint8 kSysExMessage = 0xf0;
-const uint8 kEndOfSysExMessage = 0xf7;
+static const uint8 kSysExMessage = 0xf0;
 
-bool IsDataByte(uint8 data) {
-  return (data & 0x80) == 0;
-}
+namespace content {
 
-bool IsSystemRealTimeMessage(uint8 data) {
-  return 0xf8 <= data && data <= 0xff;
-}
-
-}  // namespace
-
 MIDIHost::MIDIHost(int renderer_process_id, media::MIDIManager* midi_manager)
     : renderer_process_id_(renderer_process_id),
-      has_sys_ex_permission_(false),
       midi_manager_(midi_manager),
       sent_bytes_in_flight_(0),
       bytes_sent_since_last_acknowledgement_(0) {
@@ -90,12 +75,6 @@
     if (success) {
       input_ports = midi_manager_->input_ports();
       output_ports = midi_manager_->output_ports();
-      received_messages_queues_.clear();
-      received_messages_queues_.resize(input_ports.size());
-      // 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_);
     }
   }
 
@@ -115,26 +94,32 @@
   if (data.empty())
     return;
 
-  // Blink running in a renderer checks permission to raise a SecurityError
-  // in JavaScript. The actual permission check for security purposes
-  // happens here in the browser process.
-  if (!has_sys_ex_permission_ &&
-      (std::find(data.begin(), data.end(), kSysExMessage) != data.end())) {
-    RecordAction(UserMetricsAction("BadMessageTerminate_MIDI"));
-    BadMessageReceived();
+  base::AutoLock auto_lock(in_flight_lock_);
+
+  // Sanity check that we won't send too much.
+  if (sent_bytes_in_flight_ > kMaxInFlightBytes ||
+      data.size() > kMaxInFlightBytes ||
+      data.size() + sent_bytes_in_flight_ > kMaxInFlightBytes)
     return;
+
+  if (data[0] >= kSysExMessage) {
+    // Blink running in a renderer checks permission to raise a SecurityError in
+    // JavaScript. The actual permission check for security perposes happens
+    // here in the browser process.
+    if (!ChildProcessSecurityPolicyImpl::GetInstance()->CanSendMIDISysExMessage(
+        renderer_process_id_)) {
+      RecordAction(UserMetricsAction("BadMessageTerminate_MIDI"));
+      BadMessageReceived();
+      return;
+    }
   }
 
-  if (!IsValidWebMIDIData(data))
-    return;
+  midi_manager_->DispatchSendMIDIData(
+      this,
+      port,
+      data,
+      timestamp);
 
-  base::AutoLock auto_lock(in_flight_lock_);
-  // Sanity check that we won't send too much data.
-  // TODO(yukawa): Consider to send an error event back to the renderer
-  // after some future discussion in W3C.
-  if (data.size() + sent_bytes_in_flight_ > kMaxInFlightBytes)
-    return;
-  midi_manager_->DispatchSendMIDIData(this, port, data, timestamp);
   sent_bytes_in_flight_ += data.size();
 }
 
@@ -145,29 +130,20 @@
     double timestamp) {
   TRACE_EVENT0("midi", "MIDIHost::ReceiveMIDIData");
 
-  if (received_messages_queues_.size() <= port)
-    return;
-
-  // Lazy initialization
-  if (received_messages_queues_[port] == NULL)
-    received_messages_queues_[port] = new media::MIDIMessageQueue(true);
-
-  received_messages_queues_[port]->Add(data, length);
-  std::vector<uint8> message;
-  while (true) {
-    received_messages_queues_[port]->Get(&message);
-    if (message.empty())
-      break;
-
-    // MIDI devices may send a system exclusive messages even if the renderer
-    // doesn't have a permission to receive it. Don't kill the renderer as
-    // OnSendData() does.
-    if (message[0] == kSysExMessage && !has_sys_ex_permission_)
-      continue;
-
-    // Send to the renderer.
-    Send(new MIDIMsg_DataReceived(port, message, timestamp));
+  // Check a process security policy to receive a system exclusive message.
+  if (length > 0 && data[0] >= kSysExMessage) {
+    if (!ChildProcessSecurityPolicyImpl::GetInstance()->CanSendMIDISysExMessage(
+        renderer_process_id_)) {
+      // MIDI devices may send a system exclusive messages even if the renderer
+      // doesn't have a permission to receive it. Don't kill the renderer as
+      // OnSendData() does.
+      return;
+    }
   }
+
+  // Send to the renderer.
+  std::vector<uint8> v(data, data + length);
+  Send(new MIDIMsg_DataReceived(port, v, timestamp));
 }
 
 void MIDIHost::AccumulateMIDIBytesSent(size_t n) {
@@ -189,37 +165,4 @@
   }
 }
 
-// static
-bool MIDIHost::IsValidWebMIDIData(const std::vector<uint8>& data) {
-  bool in_sysex = false;
-  size_t waiting_data_length = 0;
-  for (size_t i = 0; i < data.size(); ++i) {
-    const uint8 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] == kEndOfSysExMessage)
-        in_sysex = false;
-      else if (!IsDataByte(current))
-        return false;  // Error: |current| should have been data byte.
-      continue;  // Found data byte as expected.
-    }
-    if (current == kSysExMessage) {
-      in_sysex = true;
-      continue;  // Found SysEX
-    }
-    waiting_data_length = media::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