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

services/media/framework/ostream.h

+// 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.
+
+#ifndef SERVICES_MEDIA_FRAMEWORK_OSTREAM_H_
+#define SERVICES_MEDIA_FRAMEWORK_OSTREAM_H_

[jeffbrown, 2016/02/02 05:35:47]

I've started calling files like this "formatting.h"

[dalesat, 2016/02/02 21:46:39]

Done.

+
+#include <ostream>
+
+#include "services/media/framework/models/demand.h"
+#include "services/media/framework/packet.h"
+#include "services/media/framework/result.h"
+#include "services/media/framework/stream_type.h"
+
+//
+// This file declares a bunch of << operator overloads for dumping media stuff.
+// Unless you want to add new operators, it's sufficient to know that you can
+// just use the operators as expected, except that some of the overloads can
+// produce multiple lines and therefore provide their own newlines.
+//
+// These operators are intended to be called after a label has been added to
+// the stream with a trailing space. If the text generated by an operator is
+// sufficiently short, the operator may add that text with no preamble and
+// terminate it with std::endl. If the text has to be multiline, the operator
+// first adds std::endl, then the multiline text with std::endl termination.
+// Each line starts with begl in order to apply the appropriate indentation.
+// The Indenter class is provided to adjust the identation level. Operators
+// that take pointers need to handle nullptr.
+//
+
+namespace mojo {
+namespace media {
+
+inline int ostream_indent_index() {

[jeffbrown, 2016/02/02 05:35:47]

Don't need inline keyword.  And in particular, this probably should go into the
implementation file since it has static storage.

[dalesat, 2016/02/02 21:46:39]

Done.

+  static int i = std::ios_base::xalloc();
+  return i;
+}
+
+template<class charT, class traits> std::basic_ostream<charT, traits>&

[jeffbrown, 2016/02/02 05:35:47]

I think this can be specialized to ostream.

[dalesat, 2016/02/02 21:46:39]

Done.

+    begl(std::basic_ostream<charT, traits>& os) {
+  for (int i = 0; i < os.iword(ostream_indent_index()); i++) {
+    os << "    ";
+  }
+  return os;
+}
+
+inline std::ostream& indent(std::ostream& os) {
+  ++os.iword(ostream_indent_index());
+  return os;
+}
+
+inline std::ostream& outdent(std::ostream& os) {
+  --os.iword(ostream_indent_index());
+  return os;
+}
+
+// The following overloads don't add newlines.
+
+std::ostream& operator<<(std::ostream& os, Result value);
+std::ostream& operator<<(std::ostream& os, Demand value);
+std::ostream& operator<<(std::ostream& os, const PacketPtr& value);
+std::ostream& operator<<(std::ostream& os, StreamType::Scheme value);
+std::ostream& operator<<(std::ostream& os, LpcmStreamType::SampleFormat value);
+std::ostream& operator<<(
+    std::ostream& os,
+    CompressedAudioStreamType::AudioEncoding value);
+std::ostream& operator<<(
+    std::ostream& os,
+    VideoStreamType::VideoEncoding value);
+std::ostream& operator<<(std::ostream& os, VideoStreamType::VideoProfile value);
+std::ostream& operator<<(std::ostream& os, VideoStreamType::PixelFormat value);
+std::ostream& operator<<(std::ostream& os, VideoStreamType::ColorSpace value);
+std::ostream& operator<<(std::ostream& os, const BytesPtr& value);
+
+template<typename T>
+std::ostream& operator<<(std::ostream& os, Range<T> value) {
+  return os << value.min << ".." << value.max;
+}
+
+std::ostream& operator<<(std::ostream& os, Range<bool> value);
+
+// The following overloads add newlines.

[jeffbrown, 2016/02/02 05:35:47]

likely to get confusing...

[dalesat, 2016/02/02 21:46:39]

Acknowledged.

+
+std::ostream& operator<<(std::ostream& os, const StreamTypePtr& value);
+std::ostream& operator<<(std::ostream& os, const StreamTypeSetPtr& value);
+std::ostream& operator<<(std::ostream& os, const StreamTypesPtr& value);
+std::ostream& operator<<(std::ostream& os, const StreamTypeSetsPtr& value);
+
+} // namespace media
+} // namespace mojo
+
+#endif // SERVICES_MEDIA_FRAMEWORK_OSTREAM_H_