Motown in-proc streaming framework used to implement media services.

services/media/framework/stages/stage_input.cc

Index: services/media/framework/stages/stage_input.cc
diff --git a/services/media/framework/stages/stage_input.cc b/services/media/framework/stages/stage_input.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0f5312adfd79558974f7f54d0d88f02a0f19163c
--- /dev/null
+++ b/services/media/framework/stages/stage_input.cc
@@ -0,0 +1,73 @@
+// 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 "services/media/framework/engine.h"
+#include "services/media/framework/stages/stage.h"
+#include "services/media/framework/stages/stage_input.h"
+
+namespace mojo {
+namespace media {
+
+StageInput::StageInput() :
+    upstream_stage_(nullptr),
+    output_index_(0),
+    allocator_(nullptr),
+    must_allocate_(false) {}
+
+StageInput::~StageInput() {}
+
+void StageInput::connect(Stage* upstream_stage, uint32_t output_index) {
+  DCHECK(upstream_stage);
+  DCHECK(output_index < upstream_stage->output_count());
+  DCHECK(upstream_stage_ == nullptr);
+  upstream_stage_ = upstream_stage;
+  output_index_ = output_index;
+}
+
+StageOutput& StageInput::mate() const {
+  DCHECK(upstream_stage_);
+  DCHECK(output_index_ < upstream_stage_->output_count());
+  return upstream_stage_->output(output_index_);
+}
+
+void StageInput::Prepare(Allocator* allocator, bool must_allocate) {
+  DCHECK(allocator != nullptr || must_allocate == false);
+  allocator_ = allocator;
+  must_allocate_ = must_allocate;
+}
+
+Allocator* StageInput::allocator() const {
+  DCHECK(connected());
+  DCHECK(mate().downstream_stage()->prepared());
+  return allocator_;
+}
+
+bool StageInput::must_allocate() const {
+  DCHECK(connected());
+  DCHECK(mate().downstream_stage()->prepared());
+  return must_allocate_;
+}
+
+void StageInput::SetDemand(Demand demand, Engine* engine) const {
+  DCHECK(engine);
+  DCHECK(connected());
+
+  if (mate().UpdateDemand(demand)) {
+    engine->PushToDemandBacklogUnsafe(upstream_stage());
+  }
+}
+
+bool StageInput::SupplyPacketFromOutput(PacketPtr packet) {
+  DCHECK(packet);
+  DCHECK(!packet_from_upstream_);
+  packet_from_upstream_ = std::move(packet);
+  return true;
+}
+
+LpcmStageInput* StageInput::get_lpcm() {
+  return nullptr;
+}
+
+}  // namespace media
+}  // namespace mojo