components/copresence/handlers/audio/audio_directive_list.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_COPRESENCE_HANDLERS_AUDIO_AUDIO_DIRECTIVE_LIST_H_
   6 #define COMPONENTS_COPRESENCE_HANDLERS_AUDIO_AUDIO_DIRECTIVE_LIST_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback_forward.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/time/default_tick_clock.h"
  15 #include "base/time/time.h"
  16 #include "components/copresence/handlers/audio/tick_clock_ref_counted.h"
  17 #include "components/copresence/proto/data.pb.h"
  18
  19 namespace media {
  20 class AudioBusRefCounted;
  21 }
  22
  23 namespace copresence {
  24
  25 class TickClockRefCounted;
  26
  27 struct AudioDirective final {
  28   // Default ctor, required by the priority queue.
  29   AudioDirective();
  30   AudioDirective(const std::string& op_id,
  31                  base::TimeTicks end_time,
  32                  const Directive& server_directive);
  33
  34   std::string op_id;
  35
  36   // We're currently using TimeTicks to track time. This may not work for cases
  37   // where your machine suspends. See crbug.com/426136
  38   base::TimeTicks end_time;
  39
  40   Directive server_directive;
  41 };
  42
  43 // This class maintains a list of active audio directives. It fetches the audio
  44 // samples associated with a audio transmit directives and expires directives
  45 // that have outlived their TTL.
  46 // TODO(rkc): Once we implement more token technologies, move reusable code
  47 // from here to a base class and inherit various XxxxDirectiveList
  48 // classes from it.
  49 class AudioDirectiveList final {
  50  public:
  51   explicit AudioDirectiveList(const scoped_refptr<TickClockRefCounted>& clock =
  52       make_scoped_refptr(new TickClockRefCounted(new base::DefaultTickClock)));
  53   ~AudioDirectiveList();
  54
  55   void AddDirective(const std::string& op_id, const Directive& directive);
  56   void RemoveDirective(const std::string& op_id);
  57
  58   scoped_ptr<AudioDirective> GetActiveDirective();
  59
  60   const std::vector<AudioDirective>& directives() const;
  61
  62  private:
  63   // Comparator for comparing end_times on audio tokens.
  64   class LatestFirstComparator {
  65    public:
  66     // This will sort our queue with the 'latest' time being the top.
  67     bool operator()(const AudioDirective& left,
  68                     const AudioDirective& right) const {
  69       return left.end_time < right.end_time;
  70     }
  71   };
  72
  73   std::vector<AudioDirective>::iterator FindDirectiveByOpId(
  74       const std::string& op_id);
  75
  76   // This vector will be organized as a heap with the latest time as the first
  77   // element. Only currently active directives will exist in this list.
  78   std::vector<AudioDirective> active_directives_;
  79
  80   scoped_refptr<TickClockRefCounted> clock_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(AudioDirectiveList);
  83 };
  84
  85 }  // namespace copresence
  86
  87 #endif  // COMPONENTS_COPRESENCE_HANDLERS_AUDIO_AUDIO_DIRECTIVE_LIST_H_