Add the copresence DirectiveHandler.

components/copresence/handlers/audio/audio_directive_list.cc

Index: components/copresence/handlers/audio/audio_directive_list.cc
diff --git a/components/copresence/handlers/audio/audio_directive_list.cc b/components/copresence/handlers/audio/audio_directive_list.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f590c392fbaf69a1a3e367705665745d75ba6c7e
--- /dev/null
+++ b/components/copresence/handlers/audio/audio_directive_list.cc
@@ -0,0 +1,146 @@
+// 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 "components/copresence/handlers/audio/audio_directive_list.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/strings/string_util.h"
+#include "media/base/audio_bus.h"
+
+namespace {
+
+// UrlSafe is defined as:
+// '/' represented by a '_' and '+' represented by a '-'
+// TODO(rkc): Move this processing to the whispernet wrapper.
+std::string FromUrlSafe(std::string token) {
+  base::ReplaceChars(token, "-", "+", &token);
+  base::ReplaceChars(token, "_", "/", &token);
+  return token;
+}
+
+const int kSampleExpiryTimeMs = 60 * 60 * 1000;  // 60 minutes.
+const int kMaxSamples = 10000;
+
+}  // namespace
+
+namespace copresence {
+
+// Public methods.
+
+AudioDirective::AudioDirective() {
+}
+
+AudioDirective::AudioDirective(const std::string& op_id, base::Time end_time)
+    : op_id(op_id), end_time(end_time) {
+}
+
+AudioDirective::AudioDirective(const std::string& token,
+                               const std::string& op_id,
+                               base::Time end_time)
+    : token(token), op_id(op_id), end_time(end_time) {
+}
+
+AudioDirective::AudioDirective(
+    const std::string& token,
+    const std::string& op_id,
+    base::Time end_time,
+    const scoped_refptr<media::AudioBusRefCounted>& samples)
+    : token(token), op_id(op_id), end_time(end_time), samples(samples) {
+}
+
+AudioDirective::~AudioDirective() {
+}
+
+AudioDirectiveList::AudioDirectiveList(
+    const EncodeTokenCallback& encode_token_callback,
+    const base::Closure& token_added_callback)
+    : encode_token_callback_(encode_token_callback),
+      token_added_callback_(token_added_callback),
+      samples_cache_(base::TimeDelta::FromMilliseconds(kSampleExpiryTimeMs),
+                     kMaxSamples) {
+}
+
+AudioDirectiveList::~AudioDirectiveList() {
+}
+
+void AudioDirectiveList::AddTransmitDirective(const std::string& token,
+                                              const std::string& op_id,
+                                              base::TimeDelta ttl) {
+  std::string valid_token = FromUrlSafe(token);
+  base::Time end_time = base::Time::Now() + ttl;
+
+  if (samples_cache_.HasKey(valid_token)) {
+    active_transmit_tokens_.push(AudioDirective(
+        valid_token, op_id, end_time, samples_cache_.GetValue(valid_token)));
+    return;
+  }
+
+  // If an encode request for this token has been sent, don't send it again.
+  if (pending_transmit_tokens_.find(valid_token) !=
+      pending_transmit_tokens_.end()) {
+    return;
+  }
+
+  pending_transmit_tokens_[valid_token] =
+      AudioDirective(valid_token, op_id, end_time);
+  // All whispernet callbacks will be cleared before we are destructed, so
+  // unretained is safe to use here.
+  encode_token_callback_.Run(
+      valid_token,
+      base::Bind(&AudioDirectiveList::OnTokenEncoded, base::Unretained(this)));
+}
+
+void AudioDirectiveList::AddReceiveDirective(const std::string& op_id,
+                                             base::TimeDelta ttl) {
+  active_receive_tokens_.push(AudioDirective(op_id, base::Time::Now() + ttl));
+}
+
+scoped_ptr<AudioDirective> AudioDirectiveList::GetNextTransmit() {
+  return GetNextFromList(&active_transmit_tokens_);
+}
+
+scoped_ptr<AudioDirective> AudioDirectiveList::GetNextReceive() {
+  return GetNextFromList(&active_receive_tokens_);
+}
+
+scoped_ptr<AudioDirective> AudioDirectiveList::GetNextFromList(
+    AudioDirectiveQueue* list) {
+  CHECK(list);
+
+  // Checks if we have any valid tokens at all (since the top of the list is
+  // always pointing to the token with the latest expiry time). If we don't
+  // have any valid tokens left, clear the list.
+  while (!list->empty() && list->top().end_time < base::Time::Now()) {

[xiyuan, 2014/07/29 00:22:26]

Can we do:

if (!list->empty() && list->top().end_time < base::Time::Now()) {
  AudioDirectiveQueue empty;
  list->swap(empty);
}

[rkc, 2014/07/29 00:33:36]

Done.

+    while (!list->empty())
+      list->pop();
+  }
+
+  if (list->empty())
+    return make_scoped_ptr<AudioDirective>(NULL);
+
+  return make_scoped_ptr(new AudioDirective(list->top()));
+}
+
+void AudioDirectiveList::OnTokenEncoded(
+    const std::string& token,
+    const scoped_refptr<media::AudioBusRefCounted>& samples) {
+  // We shouldn't re-encode a token if it's already in the cache.
+  DCHECK(!samples_cache_.HasKey(token));
+  DVLOG(3) << "Token: " << token << " encoded.";
+  samples_cache_.Add(token, samples);
+
+  // Copy the samples into its corresponding directive object and move
+  // that object into the active queue. TODO(rkc): The actual directive without
+  // the samples is small, but we should find a better way to move around
+  // the samples vector.
+  pending_transmit_tokens_[token].samples = samples;
+  active_transmit_tokens_.push(pending_transmit_tokens_[token]);
+  pending_transmit_tokens_.erase(token);
+
+  if (!token_added_callback_.is_null())
+    token_added_callback_.Run();
+}
+
+}  // namespace copresence