Keep only one cache file loaded at a time

Each cache file is now unloaded as soon as the cache directory scan is
complete. The data is not needed anymore past that point.

src/modules/cache.c

@@ -79,28 +79,28 @@ void CacheDelete( vlc_object_t *obj, const char *dir )
     free( path );
 }
 
-/*****************************************************************************
- * LoadPluginsCache: loads the plugins cache file
- *****************************************************************************
+/**
+ * Loads a plugins cache file.
+ *
  * This function will load the plugin cache if present and valid. This cache
  * will in turn be queried by AllocateAllPlugins() to see if it needs to
  * actually load the dynamically loadable module.
  * This allows us to only fully load plugins when they are actually used.
- *****************************************************************************/
-void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
+ */
+size_t CacheLoad( vlc_object_t *p_this, const char *dir, module_cache_t ***r )
 {
     char *psz_filename;
     FILE *file;
     int i_size, i_read;
     char p_cachestring[sizeof(CACHE_STRING)];
     size_t i_cache;
-    module_cache_t **pp_cache = NULL;
     int32_t i_file_size, i_marker;
 
     assert( dir != NULL );
 
+    *r = NULL;
     if( asprintf( &psz_filename, "%s"DIR_SEP CACHE_NAME, dir ) == -1 )
-        return;
+        return 0;
 
     msg_Dbg( p_this, "loading plugins cache file %s", psz_filename );
 
@@ -110,7 +110,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
         msg_Warn( p_this, "cannot read %s (%m)",
                   psz_filename );
         free( psz_filename );
-        return;
+        return 0;
     }
     free( psz_filename );
 
@@ -121,7 +121,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
         msg_Warn( p_this, "This doesn't look like a valid plugins cache "
                   "(too short)" );
         fclose( file );
-        return;
+        return 0;
     }
 
     fseek( file, 0, SEEK_END );
@@ -130,7 +130,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
         msg_Warn( p_this, "This doesn't look like a valid plugins cache "
                   "(corrupted size)" );
         fclose( file );
-        return;
+        return 0;
     }
     fseek( file, sizeof(i_file_size), SEEK_SET );
 
@@ -142,7 +142,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
     {
         msg_Warn( p_this, "This doesn't look like a valid plugins cache" );
         fclose( file );
-        return;
+        return 0;
     }
 
 #ifdef DISTRO_VERSION
@@ -155,7 +155,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
     {
         msg_Warn( p_this, "This doesn't look like a valid plugins cache" );
         fclose( file );
-        return;
+        return 0;
     }
 #endif
 
@@ -166,7 +166,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
         msg_Warn( p_this, "This doesn't look like a valid plugins cache "
                   "(corrupted header)" );
         fclose( file );
-        return;
+        return 0;
     }
 
     /* Check header marker */
@@ -177,7 +177,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
         msg_Warn( p_this, "This doesn't look like a valid plugins cache "
                   "(corrupted header)" );
         fclose( file );
-        return;
+        return 0;
     }
 
     if (fread( &i_cache, 1, sizeof(i_cache), file ) != sizeof(i_cache) )
@@ -185,22 +185,12 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
         msg_Warn( p_this, "This doesn't look like a valid plugins cache "
                   "(file too short)" );
         fclose( file );
-        return;
+        return 0;
     }
 
-    if( i_cache )
-    {
-        size_t i_already = p_bank->i_loaded_cache;
-        pp_cache = realloc( p_bank->pp_loaded_cache,
-                            (i_already + i_cache) * sizeof(*pp_cache) );
-        if( unlikely(pp_cache == NULL) )
-            i_cache = 0; /* don't load */
-        else
-        {
-            p_bank->pp_loaded_cache = pp_cache;
-            pp_cache += i_already;
-        }
-   }
+    module_cache_t **pp_cache = malloc( i_cache * sizeof(*pp_cache) );
+    if( pp_cache == NULL )
+        i_cache = 0; /* don't load anything */
 
 #define LOAD_IMMEDIATE(a) \
     if( fread( (void *)&a, sizeof(char), sizeof(a), file ) != sizeof(a) ) goto error
@@ -301,10 +291,10 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
             LOAD_STRING( p_module->domain );
         }
     }
-    p_bank->i_loaded_cache += i_cache;
-
     fclose( file );
-    return;
+
+    *r = pp_cache;
+    return i_cache;
 
  error:
 
@@ -312,7 +302,7 @@ void CacheLoad( vlc_object_t *p_this, module_bank_t *p_bank, const char *dir )
 
     /* TODO: cleanup */
     fclose( file );
-    return;
+    return 0;
 }
 
 

src/modules/modules.c

@@ -103,8 +103,8 @@ void module_InitBank( vlc_object_t *p_this )
     {
         p_bank = calloc (1, sizeof(*p_bank));
         p_bank->i_usage = 1;
-        p_bank->i_cache = p_bank->i_loaded_cache = 0;
-        p_bank->pp_cache = p_bank->pp_loaded_cache = NULL;
+        p_bank->i_cache = 0;
+        p_bank->pp_cache = NULL;
         p_bank->head = NULL;
 
         /* Everything worked, attach the object */
@@ -164,18 +164,6 @@ void module_EndBank( vlc_object_t *p_this, bool b_plugins )
     vlc_mutex_unlock( &module_lock );
 
 #ifdef HAVE_DYNAMIC_PLUGINS
-    while( p_bank->i_loaded_cache-- )
-    {
-        if( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] )
-        {
-            if( unlikely( p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->p_module != NULL ) )
-                DeleteModule( p_bank,
-                    p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->p_module );
-            free( p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->path );
-            free( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] );
-        }
-    }
-    free( p_bank->pp_loaded_cache );
     while( p_bank->i_cache-- )
     {
         free( p_bank->pp_cache[p_bank->i_cache]->path );
@@ -868,28 +856,48 @@ static void AllocateAllPlugins( vlc_object_t *p_this, module_bank_t *p_bank )
 static void AllocatePluginPath( vlc_object_t *p_this, module_bank_t *p_bank,
                                 const char *path, cache_mode_t mode )
 {
+    module_cache_t **cache;
+    size_t count = 0;
     size_t offset = p_module_bank->i_cache;
 
     switch( mode )
     {
         case CACHE_USE:
-            CacheLoad( p_this, p_module_bank, path );
+            count = CacheLoad( p_this, path, &cache );
             break;
         case CACHE_RESET:
             CacheDelete( p_this, path );
             break;
-        default:
+        case CACHE_IGNORE:
             msg_Dbg( p_this, "ignoring plugins cache file" );
     }
 
     msg_Dbg( p_this, "recursively browsing `%s'", path );
 
+    /* TODO: pass as argument, remove this hack */
+    p_bank->pp_loaded_cache = cache;
+    p_bank->i_loaded_cache = count;
     /* Don't go deeper than 5 subdirectories */
     AllocatePluginDir( p_this, p_bank, path, 5, mode );
 
-    if( mode != CACHE_IGNORE )
-        CacheSave( p_this, path, p_module_bank->pp_cache + offset,
-                   p_module_bank->i_cache - offset );
+    switch( mode )
+    {
+        case CACHE_USE:
+            for( size_t i = 0; i < count; i++ )
+                if( likely(cache[i] != NULL) )
+                {
+                    if( cache[i]->p_module != NULL )
+                       DeleteModule( p_bank, cache[i]->p_module );
+                    free( cache[i]->path );
+                    free( cache[i] );
+                }
+            free( cache );
+        case CACHE_RESET:
+            CacheSave( p_this, path, p_bank->pp_cache + offset,
+                       p_bank->i_cache - offset );
+        case CACHE_IGNORE:
+            break;
+    }
 }
 
 /*****************************************************************************

src/modules/modules.h

@@ -150,7 +150,7 @@ void module_Unload (module_handle_t);
 /* Plugins cache */
 void   CacheMerge (vlc_object_t *, module_t *, module_t *);
 void   CacheDelete(vlc_object_t *, const char *);
-void   CacheLoad  (vlc_object_t *, module_bank_t *, const char *);
+size_t CacheLoad  (vlc_object_t *, const char *, module_cache_t ***);
 void   CacheSave  (vlc_object_t *, const char *, module_cache_t *const *, size_t);
 module_t * CacheFind (module_bank_t *, const char *, time_t, off_t);