src/kits/media/ChunkCache.h

   1 /*
   2  * Copyright 2009, Axel Dörfler, axeld@pinc-software.de.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _CHUNK_CACHE_H
   6 #define _CHUNK_CACHE_H
   7
   8
   9 #include <Locker.h>
  10 #include <MediaDefs.h>
  11 #include <RealtimeAlloc.h>
  12 #include <queue>
  13 #include <deque>
  14
  15 #include "ReaderPlugin.h"
  16
  17
  18 namespace BPrivate {
  19 namespace media {
  20
  21 // Limit to 10 entries, we might want to instead limit to a length of time
  22 #define CACHE_MAX_ENTRIES 10
  23
  24 struct chunk_buffer {
  25         void*                   buffer;
  26         size_t                  size;
  27         size_t                  capacity;
  28         media_header    header;
  29         status_t                status;
  30 };
  31
  32 typedef std::queue<chunk_buffer*> ChunkQueue;
  33 typedef std::deque<chunk_buffer*> ChunkList;
  34
  35 class ChunkCache : public BLocker {
  36 public:
  37                                                                 ChunkCache(sem_id waitSem, size_t maxBytes);
  38                                                                 ~ChunkCache();
  39
  40                         status_t                        InitCheck() const;
  41
  42                         void                            MakeEmpty();
  43                         bool                            SpaceLeft() const;
  44
  45                         chunk_buffer*           NextChunk(Reader* reader, void* cookie);
  46                         void                            RecycleChunk(chunk_buffer* chunk);
  47                         bool                            ReadNextChunk(Reader* reader, void* cookie);
  48
  49 private:
  50                         rtm_pool*                       fRealTimePool;
  51                         sem_id                          fWaitSem;
  52                         size_t                          fMaxBytes;
  53                         ChunkQueue                      fChunkCache;
  54                         ChunkList                       fUnusedChunks;
  55 };
  56
  57
  58 }       // namespace media
  59 }       // namespace BPrivate
  60
  61 using namespace BPrivate::media;
  62
  63 #endif  // _CHUNK_CACHE_H