Implements RTP header dumping.

chrome/browser/media/webrtc_rtp_dump_handler.cc

Index: chrome/browser/media/webrtc_rtp_dump_handler.cc
diff --git a/chrome/browser/media/webrtc_rtp_dump_handler.cc b/chrome/browser/media/webrtc_rtp_dump_handler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ed8947f4857b5922a2cb8ec3aca4609e9c1d9b68
--- /dev/null
+++ b/chrome/browser/media/webrtc_rtp_dump_handler.cc
@@ -0,0 +1,282 @@
+// Copyright 2014 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 "chrome/browser/media/webrtc_rtp_dump_handler.h"
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/time/time.h"
+#include "chrome/browser/media/webrtc_rtp_dump_writer.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace {
+
+// |path| must be a copy of FilePath, not a reference.

[Henrik Grunell, 2014/05/15 14:36:34]

Explain why not a reference in the comment.

[jiayl, 2014/05/15 23:06:22]

I was wrong. It doesn't need to be a copy.

+void DeleteFileHelper(base::FilePath path) {
+  base::DeleteFile(path, false);
+}
+
+static const size_t kMaxOngoingRtpDumpsAllowed = 5;
+
+// The browser process wide total number of ongoing (i.e. started and not
+// released) RTP dumps. Incoming and outgoing in one WebRtcDumpHandler are
+// counted as one dump.
+// Must be accessed on the browser IO thread.
+static size_t g_ongoing_rtp_dumps = 0;
+
+void FireGenericDoneCallback(
+    const WebRtcRtpDumpHandler::GenericDoneCallback& callback,
+    bool success,
+    const std::string& error_message) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(!callback.is_null());
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(callback, success, error_message));
+}
+
+}  // namespace
+
+// static
+bool WebRtcRtpDumpHandler::TypeContainsIncoming(PacketType type) {
+  return type == PACKET_TYPE_INCOMING_ONLY || type == PACKET_TYPE_BOTH;
+}
+
+// static
+bool WebRtcRtpDumpHandler::TypeContainsOutgoing(PacketType type) {
+  return type == PACKET_TYPE_OUTGOING_ONLY || type == PACKET_TYPE_BOTH;
+}
+
+WebRtcRtpDumpHandler::WebRtcRtpDumpHandler(const base::FilePath& dump_dir)
+    : dump_dir_(dump_dir),

[Henrik Grunell, 2014/05/15 14:36:34]

Is |dump_dir_| ever checked to be existing? This should be done.

[jiayl, 2014/05/15 23:06:22]

it's stated in the header file that the caller must ensure the dir exists.

+      incoming_state_(STATE_NONE),
+      outgoing_state_(STATE_NONE) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+}
+
+WebRtcRtpDumpHandler::~WebRtcRtpDumpHandler() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (incoming_state_ != STATE_NONE && !incoming_dump_path_.empty()) {
+    BrowserThread::PostTask(BrowserThread::FILE,

[Henrik Grunell, 2014/05/15 14:36:34]

How is it guaranteed that the writer stops writing before the file is deleted?
Looks like that could happen.

[jiayl, 2014/05/15 23:06:22]

Fixed. Reset the writer first will guarantee that.

+                            FROM_HERE,
+                            base::Bind(&DeleteFileHelper, incoming_dump_path_));
+  }
+
+  if (outgoing_state_ != STATE_NONE && !outgoing_dump_path_.empty()) {
+    BrowserThread::PostTask(BrowserThread::FILE,
+                            FROM_HERE,
+                            base::Bind(&DeleteFileHelper, outgoing_dump_path_));
+  }
+
+  if (dump_writer_)
+    --g_ongoing_rtp_dumps;
+}
+
+bool WebRtcRtpDumpHandler::StartDump(PacketType type,
+                                     std::string* error_message) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  bool succeeded = false;
+
+  if (TypeContainsIncoming(type) && incoming_state_ == STATE_NONE) {
+    incoming_state_ = STATE_STARTED;
+    succeeded = true;

[Henrik Grunell, 2014/05/15 14:36:34]

I think this should only succeed if both types could be started.

[jiayl, 2014/05/15 23:06:22]

Done.

+  }
+  if (TypeContainsOutgoing(type) && outgoing_state_ == STATE_NONE) {
+    outgoing_state_ = STATE_STARTED;
+    succeeded = true;
+  }
+
+  if (!dump_writer_ && g_ongoing_rtp_dumps >= kMaxOngoingRtpDumpsAllowed) {

[Henrik Grunell, 2014/05/15 14:36:34]

Do this check before the state checks above.

[jiayl, 2014/05/15 23:06:22]

Done.

+    *error_message = "Max RTP dump limit reached.";
+    DVLOG(2) << *error_message;
+    return false;
+  }
+
+  if (!succeeded) {
+    *error_message = "RTP dump already started.";
+    return false;
+  }
+
+  DVLOG(2) << "Start RTP dumping: type = " << type;
+
+  if (!dump_writer_) {
+    ++g_ongoing_rtp_dumps;
+
+    static const char kRecvDumpFilePrefix[] = "rtpdump_recv_";
+    static const char kSendDumpFilePrefix[] = "rtpdump_send_";
+    static const char kDumpFileExtension[] = ".gz";
+    static const size_t kMaxDumpSize = 5 * 1024 * 1024;  // 5MB
+
+    std::string dump_id = base::DoubleToString(base::Time::Now().ToDoubleT());
+    incoming_dump_path_ =
+        dump_dir_.AppendASCII(std::string(kRecvDumpFilePrefix) + dump_id)
+            .AddExtension(kDumpFileExtension);
+
+    outgoing_dump_path_ =
+        dump_dir_.AppendASCII(std::string(kSendDumpFilePrefix) + dump_id)
+            .AddExtension(kDumpFileExtension);
+
+    // WebRtcRtpDumpWriter does not support changing the dump path after it's
+    // created. So we assign both incoming and outgoing dump path even if only
+    // one type of dumping has been started.
+    dump_writer_.reset(new WebRtcRtpDumpWriter(
+        incoming_dump_path_,
+        outgoing_dump_path_,
+        kMaxDumpSize,
+        base::Bind(&WebRtcRtpDumpHandler::OnMaxDumpSizeReached,
+                   base::Unretained(this))));
+  }
+
+  return true;
+}
+
+void WebRtcRtpDumpHandler::StopDump(PacketType type,
+                                    const GenericDoneCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  bool stop_incoming = false;
+  bool stop_outgoing = false;
+  if (TypeContainsIncoming(type) && incoming_state_ == STATE_STARTED) {
+    incoming_state_ = STATE_STOPPING;
+    stop_incoming = true;
+  }
+
+  if (TypeContainsOutgoing(type) && outgoing_state_ == STATE_STARTED) {
+    outgoing_state_ = STATE_STOPPING;
+    stop_outgoing = true;
+  }
+
+  if (!stop_incoming && !stop_outgoing) {
+    if (!callback.is_null()) {
+      FireGenericDoneCallback(
+          callback, false, "RTP dump not started or already stopped.");
+    }
+    return;
+  }
+
+  DVLOG(2) << "Stopping RTP dumping: type = " << type;
+
+  if (stop_incoming) {
+    dump_writer_->EndDump(

[Henrik Grunell, 2014/05/15 14:36:34]

Can the EndDump be changed so that it's called once only? The logic gets a bit
complicated when only one callback to the LHH must be ensured.

[jiayl, 2014/05/15 23:06:22]

Done.

+        true,
+        base::Bind(&WebRtcRtpDumpHandler::OnDumpEnded,
+                   base::Unretained(this),

[Henrik Grunell, 2014/05/15 14:36:34]

Why is unretained safe? (Comment on this at all places used or a general comment
on top.)

[jiayl, 2014/05/15 23:06:22]

Done.

+                   stop_outgoing ? GenericDoneCallback() : callback,
+                   true));
+  }
+
+  if (stop_outgoing) {
+    dump_writer_->EndDump(false,
+                          base::Bind(&WebRtcRtpDumpHandler::OnDumpEnded,
+                                     base::Unretained(this),
+                                     callback,
+                                     false));
+  }
+
+  return;
+}
+
+WebRtcRtpDumpHandler::ReleasedDumps WebRtcRtpDumpHandler::ReleaseDumps() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  ReleasedDumps result;
+
+  // All types of dumps must have been stopped, or one stopped and the other not
+  // started.
+  if (incoming_state_ == STATE_STARTED || incoming_state_ == STATE_STOPPING ||
+      outgoing_state_ == STATE_STARTED || outgoing_state_ == STATE_STOPPING ||
+      (incoming_state_ == STATE_NONE && outgoing_state_ == STATE_NONE)) {
+    DVLOG(2) << "ReleaseDumps called in invalid state: incoming_state = "
+             << incoming_state_ << ", outgoing_state = " << outgoing_state_;
+    return result;
+  }
+
+  if (incoming_state_ == STATE_STOPPED) {
+    DVLOG(2) << "Incoming RTP dumps released: " << incoming_dump_path_.value();
+
+    incoming_state_ = STATE_NONE;
+    result.incoming_dump_path = incoming_dump_path_;
+  }
+
+  if (outgoing_state_ == STATE_STOPPED) {
+    DVLOG(2) << "Outgoing RTP dumps released: " << outgoing_dump_path_.value();
+
+    outgoing_state_ = STATE_NONE;
+    result.outgoing_dump_path = outgoing_dump_path_;
+  }
+  return result;
+}
+
+void WebRtcRtpDumpHandler::OnRtpPacket(const uint8* packet_header,
+                                       size_t header_length,
+                                       size_t packet_length,
+                                       bool incoming) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if ((incoming && incoming_state_ != STATE_STARTED) ||
+      (!incoming && outgoing_state_ != STATE_STARTED))
+    return;
+
+  dump_writer_->WriteRtpPacket(
+      packet_header, header_length, packet_length, incoming);
+}
+
+void WebRtcRtpDumpHandler::SetDumpWriterForTesting(
+    scoped_ptr<WebRtcRtpDumpWriter> writer) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  dump_writer_ = writer.Pass();
+  g_ongoing_rtp_dumps++;
+
+  incoming_dump_path_ = dump_dir_.AppendASCII("recv");
+  outgoing_dump_path_ = dump_dir_.AppendASCII("send");
+}
+
+void WebRtcRtpDumpHandler::OnMaxDumpSizeReached() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  StopDump(PACKET_TYPE_BOTH, GenericDoneCallback());
+}
+
+void WebRtcRtpDumpHandler::OnDumpEnded(const GenericDoneCallback& callback,
+                                       bool incoming,
+                                       bool succeeded) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (incoming) {
+    DCHECK_EQ(STATE_STOPPING, incoming_state_);
+    incoming_state_ = STATE_STOPPED;
+  } else {
+    DCHECK_EQ(STATE_STOPPING, outgoing_state_);
+    outgoing_state_ = STATE_STOPPED;
+  }
+
+  if (!succeeded) {
+    base::FilePath* dump =
+        incoming ? &incoming_dump_path_ : &outgoing_dump_path_;
+
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE, base::Bind(&DeleteFileHelper, *dump));
+
+    DVLOG(2) << "Deleted invalid dump " << dump->value();
+    dump->clear();
+  }
+
+  if (!callback.is_null())
+    callback.Run(true, "");
+
+  // Release the writer when it's no longer needed.
+  if (incoming_state_ != STATE_STOPPING && outgoing_state_ != STATE_STOPPING &&
+      incoming_state_ != STATE_STARTED && outgoing_state_ != STATE_STARTED) {
+    dump_writer_.reset();
+    g_ongoing_rtp_dumps--;
+  }
+}