Motown: Use new TimelineTransform and related definitions

services/media/common/timeline_control_site.cc

Index: services/media/common/timeline_control_site.cc
diff --git a/services/media/common/timeline_control_site.cc b/services/media/common/timeline_control_site.cc
new file mode 100644
index 0000000000000000000000000000000000000000..26dc07f214a603745aca3408e5bdd86c77683d93
--- /dev/null
+++ b/services/media/common/timeline_control_site.cc
@@ -0,0 +1,193 @@
+// Copyright 2016 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 "base/bind.h"
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "mojo/services/media/common/cpp/timeline.h"
+#include "services/media/common/timeline_control_site.h"
+
+namespace mojo {
+namespace media {
+
+// For checking preconditions when handling mojo requests.
+// Checks the condition, and, if it's false, resets and calls return.
+#define RCHECK(condition)                                         \
+  if (!(condition)) {                                             \
+    LOG(ERROR) << "request precondition failed: " #condition "."; \
+    ResetUnsafe();                                                \
+    return;                                                       \
+  }
+
+TimelineControlSite::TimelineControlSite()
+    : control_site_binding_(this), consumer_binding_(this) {
+  task_runner_ = base::MessageLoop::current()->task_runner();
+  DCHECK(task_runner_);
+
+  base::AutoLock lock(lock_);
+  ClearPendingTimelineFunctionUnsafe(false);
+
+  status_publisher_.SetCallbackRunner(
+      [this](const GetStatusCallback& callback, uint64_t version) {
+        MediaTimelineControlSiteStatusPtr status;
+        {
+          base::AutoLock lock(lock_);
+          status = MediaTimelineControlSiteStatus::New();
+          status->timeline_transform =
+              TimelineTransform::From(current_timeline_function_);
+          status->end_of_stream = false; // TODO(dalesat): Provide this.
+        }
+        callback.Run(version, status.Pass());
+      });
+}
+
+TimelineControlSite::~TimelineControlSite() {}
+
+void TimelineControlSite::Bind(
+    InterfaceRequest<MediaTimelineControlSite> request) {
+  if (control_site_binding_.is_bound()) {
+    control_site_binding_.Close();
+  }
+
+  control_site_binding_.Bind(request.Pass());
+}
+
+void TimelineControlSite::Reset() {
+  if (control_site_binding_.is_bound()) {
+    control_site_binding_.Close();
+  }
+
+  if (consumer_binding_.is_bound()) {
+    consumer_binding_.Close();
+  }
+
+  {
+    base::AutoLock lock(lock_);
+    current_timeline_function_ = TimelineFunction();
+    ClearPendingTimelineFunctionUnsafe(false);
+    generation_ = 1;
+  }
+
+  status_publisher_.SendUpdates();
+}
+
+void TimelineControlSite::SnapshotCurrentFunction(int64_t reference_time,
+                                                  TimelineFunction* out,
+                                                  uint32_t* generation) {
+  DCHECK(out);
+  base::AutoLock lock(lock_);
+  ApplyPendingChangesUnsafe(reference_time);
+  *out = current_timeline_function_;
+  if (generation) {
+    *generation = generation_;
+  }
+}
+
+void TimelineControlSite::GetStatus(uint64_t version_last_seen,
+                                    const GetStatusCallback& callback) {
+  status_publisher_.Get(version_last_seen, callback);
+}
+
+void TimelineControlSite::GetTimelineConsumer(
+    InterfaceRequest<TimelineConsumer> timeline_consumer) {
+  if (consumer_binding_.is_bound()) {
+    consumer_binding_.Close();
+  }
+
+  consumer_binding_.Bind(timeline_consumer.Pass());
+}
+
+void TimelineControlSite::SetTimelineTransform(
+    int64_t subject_time,
+    uint32_t reference_delta,
+    uint32_t subject_delta,
+    int64_t effective_reference_time,
+    int64_t effective_subject_time,
+    const SetTimelineTransformCallback& callback) {
+  base::AutoLock lock(lock_);
+
+  // At most one of the effective times must be specified.
+  RCHECK(effective_reference_time == kUnspecifiedTime ||
+         effective_subject_time == kUnspecifiedTime);
+  // effective_subject_time can only be used if we're progressing already.
+  RCHECK(effective_subject_time == kUnspecifiedTime ||
+         current_timeline_function_.subject_delta() != 0);
+  RCHECK(reference_delta != 0);
+
+  if (effective_subject_time != kUnspecifiedTime) {
+    // Infer effective_reference_time from effective_subject_time.
+    effective_reference_time =
+        current_timeline_function_.ApplyInverse(effective_subject_time);
+
+    if (subject_time == kUnspecifiedTime) {
+      // Infer subject_time from effective_subject_time.
+      subject_time = effective_subject_time;
+    }
+  } else {
+    if (effective_reference_time == kUnspecifiedTime) {
+      // Neither effective time was specified. Effective time is now.
+      effective_reference_time = Timeline::local_now();
+    }
+
+    if (subject_time == kUnspecifiedTime) {
+      // Infer subject_time from effective_reference_time.
+      subject_time = current_timeline_function_(effective_reference_time);
+    }
+  }
+
+  // Eject any previous pending change.
+  ClearPendingTimelineFunctionUnsafe(false);
+
+  // Queue up the new pending change.
+  pending_timeline_function_ = TimelineFunction(
+      effective_reference_time, subject_time, reference_delta, subject_delta);
+
+  set_timeline_transform_callback_ = callback;
+}
+
+void TimelineControlSite::ApplyPendingChangesUnsafe(int64_t reference_time) {
+  lock_.AssertAcquired();
+
+  if (!TimelineFunctionPendingUnsafe() ||
+      pending_timeline_function_.reference_time() > reference_time) {
+    return;
+  }
+
+  current_timeline_function_ = pending_timeline_function_;
+  ClearPendingTimelineFunctionUnsafe(true);
+
+  ++generation_;
+
+  task_runner_->PostTask(
+      FROM_HERE, base::Bind(&MojoPublisher<GetStatusCallback>::SendUpdates,
+                            base::Unretained(&status_publisher_)));
+}
+
+void TimelineControlSite::ClearPendingTimelineFunctionUnsafe(bool completed) {
+  lock_.AssertAcquired();
+
+  pending_timeline_function_ =
+      TimelineFunction(kUnspecifiedTime, kUnspecifiedTime, 1, 0);
+  if (!set_timeline_transform_callback_.is_null()) {
+    task_runner_->PostTask(
+        FROM_HERE, base::Bind(&TimelineControlSite::RunCallback,
+                              set_timeline_transform_callback_, completed));
+    set_timeline_transform_callback_.reset();
+  }
+}
+
+void TimelineControlSite::ResetUnsafe() {
+  lock_.AssertAcquired();
+  task_runner_->PostTask(FROM_HERE, base::Bind(&TimelineControlSite::Reset,
+                                               base::Unretained(this)));
+}
+
+// static
+void TimelineControlSite::RunCallback(SetTimelineTransformCallback callback,
+                                      bool completed) {
+  callback.Run(completed);
+}
+
+}  // namespace media
+}  // namespace mojo