Motown: Remove LPCM optimizations, fix prepare, add flush, add ActiveMultistreamSink model/stage

services/media/framework/graph.cc

Index: services/media/framework/graph.cc
diff --git a/services/media/framework/graph.cc b/services/media/framework/graph.cc
new file mode 100644
index 0000000000000000000000000000000000000000..794985d2823bc0fea7e534dd5e2d34070237fa07
--- /dev/null
+++ b/services/media/framework/graph.cc
@@ -0,0 +1,219 @@
+// 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/graph.h"
+
+namespace mojo {
+namespace media {
+
+Graph::Graph() {
+  update_function_ = [this](Stage* stage) {
+    engine_.RequestUpdate(stage);
+  };
+}
+
+Graph::~Graph() {
+  Reset();
+}
+
+void Graph::RemovePart(PartRef part) {
+  DCHECK(part.valid());
+
+  Stage* stage = part.stage_;
+
+  size_t input_count = stage->input_count();
+  for (size_t input_index = 0; input_index < input_count; input_index++) {
+    if (stage->input(input_index).connected()) {
+      DisconnectInput(InputRef(stage, input_index));
+    }
+  }
+
+  size_t output_count = stage->output_count();
+  for (size_t output_index = 0; output_index < output_count; output_index++) {
+    if (stage->output(output_index).connected()) {
+      DisconnectOutput(OutputRef(stage, output_index));
+    }
+  }
+
+  stage->SetUpdateCallback(nullptr);
+
+  sources_.remove(stage);
+  sinks_.remove(stage);
+  stages_.remove(stage);
+
+  delete stage;
+}
+
+PartRef Graph::Connect(const OutputRef& output, const InputRef& input) {
+  DCHECK(output.valid());
+  DCHECK(input.valid());
+
+  if (output.connected()) {
+    DisconnectOutput(output);
+  }
+  if (input.connected()) {
+    DisconnectInput(input);
+  }
+
+  output.actual().Connect(input);
+  input.actual().Connect(output);
+
+  return input.part();
+}
+
+PartRef Graph::ConnectParts(
+    PartRef upstream_part,
+    PartRef downstream_part) {
+  DCHECK(upstream_part.valid());
+  DCHECK(downstream_part.valid());
+  Connect(upstream_part.output(), downstream_part.input());
+  return downstream_part;
+}
+
+PartRef Graph::ConnectOutputToPart(
+    const OutputRef& output,
+    PartRef downstream_part) {
+  DCHECK(output.valid());
+  DCHECK(downstream_part.valid());
+  Connect(output, downstream_part.input());
+  return downstream_part;
+}
+
+PartRef Graph::ConnectPartToInput(
+    PartRef upstream_part,
+    const InputRef& input) {
+  DCHECK(upstream_part.valid());
+  DCHECK(input.valid());
+  Connect(upstream_part.output(), input);
+  return input.part();
+}
+
+void Graph::DisconnectOutput(const OutputRef& output) {
+  DCHECK(output.valid());
+
+  if (!output.connected()) {
+    return;
+  }
+
+  Input& mate = output.mate().actual();
+
+  if (mate.prepared()) {
+    CHECK(false) << "attempt to disconnect prepared output";
+    return;
+  }
+
+  mate.Disconnect();
+  output.actual().Disconnect();
+}
+
+void Graph::DisconnectInput(const InputRef& input) {
+  DCHECK(input.valid());
+
+  if (!input.connected()) {
+    return;
+  }
+
+  Output& mate = input.mate().actual();
+
+  if (input.actual().prepared()) {
+    CHECK(false) << "attempt to disconnect prepared input";
+    return;
+  }
+
+  mate.Disconnect();
+  input.actual().Disconnect();
+}
+
+void Graph::RemovePartsConnectedToPart(PartRef part) {
+  DCHECK(part.valid());
+
+  std::deque<PartRef> to_remove { part };
+
+  while (!to_remove.empty()) {
+    PartRef part = to_remove.front();
+    to_remove.pop_front();
+
+    for (size_t i = 0; i < part.input_count(); ++i) {
+      to_remove.push_back(part.input(i).part());
+    }
+
+    for (size_t i = 0; i < part.output_count(); ++i) {
+      to_remove.push_back(part.output(i).part());
+    }
+
+    RemovePart(part);
+  }
+}
+
+void Graph::RemovePartsConnectedToOutput(const OutputRef& output) {
+  DCHECK(output.valid());
+
+  if (!output.connected()) {
+    return;
+  }
+
+  PartRef downstream_part = output.mate().part();
+  DisconnectOutput(output);
+  RemovePartsConnectedToPart(downstream_part);
+}
+
+void Graph::RemovePartsConnectedToInput(const InputRef& input) {
+  DCHECK(input.valid());
+
+  if (!input.connected()) {
+    return;
+  }
+
+  PartRef upstream_part = input.mate().part();
+  DisconnectInput(input);
+  RemovePartsConnectedToPart(upstream_part);
+}
+
+void Graph::Reset() {
+  sources_.clear();
+  sinks_.clear();
+  while (!stages_.empty()) {
+    Stage* stage = stages_.front();
+    stages_.pop_front();
+    delete stage;
+  }
+}
+
+void Graph::Prepare() {
+  for (Stage* sink : sinks_) {
+    for (size_t i = 0; i < sink->input_count(); ++i) {
+      engine_.PrepareInput(InputRef(sink, i));
+    }
+  }
+}
+
+void Graph::PrepareInput(const InputRef& input) {
+  DCHECK(input.valid());
+  engine_.PrepareInput(input);
+}
+
+void Graph::PrimeSinks() {
+  for (Stage* sink : sinks_) {
+    sink->Prime();
+  }
+}
+
+PartRef Graph::Add(Stage* stage) {
+  stages_.push_back(stage);
+
+  if (stage->input_count() == 0) {
+    sources_.push_back(stage);
+  }
+
+  if (stage->output_count() == 0) {
+    sinks_.push_back(stage);
+  }
+
+  stage->SetUpdateCallback(update_function_);
+
+  return PartRef(stage);
+}
+
+}  // namespace media
+}  // namespace mojo