cinelerra/cache.h

   1 #ifndef CACHE_H
   2 #define CACHE_H
   3
   4 // CICache for quickly reading data that is hard to decompress yet used
   5 // over and over.
   6
   7 // Actual caching is done in the File object
   8 // the CICache keeps files open while rendering.
   9
  10 // Since the CICache outlives EDLs it must copy every parameter given to it.
  11
  12 // Files given as arguments must outlive the cache.
  13
  14 // the cache is implemented with a lookup map which acts as storage backend
  15 // and 2 lists
  16 //  the checked_out list keeps all checked out items
  17 //  when items are checked back in, they are moved to the head of the checked_in list
  18 // age expiry is done by removing elements from the tail of the checked_in list
  19
  20 #include "arraylist.h"
  21 #include "asset.inc"
  22 #include "cache.inc"
  23 #include "condition.inc"
  24 #include "edl.inc"
  25 #include "file.inc"
  26 #include "mutex.inc"
  27 #include "pluginserver.inc"
  28 #include "preferences.inc"
  29
  30 #include <stdint.h>
  31
  32 class CICacheItem
  33 {
  34 public:
  35         CICacheItem(CICache *cache, EDL *edl, Asset_GC asset);
  36         CICacheItem(){};
  37         ~CICacheItem();
  38
  39         File *file;
  40 // Number of last get or put operation involving this object.
  41         Asset_GC asset;     // Copy of asset.  CICache should outlive EDLs.
  42         bool checked_out;
  43
  44         friend class CICache;
  45 private:
  46         Condition* item_lock;
  47         CICacheItem_plist::iterator list;
  48         CICache* cache;
  49 };
  50
  51
  52 class CICache
  53 {
  54         CICacheItem_map items;
  55         CICacheItem_plist checked_in;
  56         CICacheItem_plist checked_out;
  57
  58 public:
  59
  60         CICache(Preferences *preferences,
  61                 ArrayList<PluginServer*> *plugindb);
  62         ~CICache();
  63
  64         friend class CICacheItem;
  65
  66 // Enter a new file into the cache which is already open.
  67 // If the file doesn't exist return the arguments.
  68 // If the file exists delete the arguments and return the file which exists.
  69 //      void update(File* &file);
  70 //      void set_edl(EDL *edl);
  71
  72 // open it, lock it and add it to the cache if it isn't here already
  73 // If it's already checked out, the value of block causes it to wait
  74 // until it's checked in.
  75         File* check_out(Asset_GC asset, EDL *edl, int block = 1);
  76
  77 // unlock a file from the cache
  78         int check_in(Asset_GC asset);
  79
  80 // delete an entry from the cache
  81 // before deleting an asset, starting a new project or something
  82         int delete_entry(Asset_GC asset);
  83         int delete_entry(char *path);
  84 // Remove all entries from the cache.
  85         void remove_all();
  86
  87 // Get ID of oldest member.
  88 // Called by MWindow::age_caches.
  89         int64_t get_memory_usage();
  90
  91 // Called by age() and MWindow::age_caches
  92 // returns 1 if nothing was available to delete
  93 // 0 if successful
  94         int delete_oldest();
  95
  96 // Called by check_in() and modules.
  97 // deletes oldest assets until under the memory limit
  98         // iterations is the upper limit how much much items will be removed from the cache,
  99         // use -1 for a full aging cycle (remove items until preferences.cache_size is reached)
 100         void age(int iterations);
 101
 102
 103         int dump();
 104
 105         ArrayList<PluginServer*>* plugindb;
 106
 107         const Preferences& preferences;
 108
 109 private:
 110         int64_t get_memory_usage_unlocked();
 111
 112 // for deleting items
 113         int lock_all();
 114         int unlock_all();
 115
 116 // to prevent one from checking the same asset out before it's checked in
 117 // yet without blocking the asset trying to get checked in
 118 // use a seperate mutex for checkouts and checkins
 119         Mutex* total_lock;
 120         Condition* check_out_lock;
 121 // Copy of EDL
 122         EDL *edl;
 123 };
 124
 125 #endif
 126 /*
 127 //      Local Variables:
 128 //      mode: C++
 129 //      c-file-style: "linux"
 130 //      End:
 131 */