0,0 → 1,621 |
/***************************************************************************/ |
/* */ |
/* ftccache.c */ |
/* */ |
/* The FreeType internal cache interface (body). */ |
/* */ |
/* Copyright 2000-2007, 2009-2011, 2013 by */ |
/* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
/* */ |
/* This file is part of the FreeType project, and may only be used, */ |
/* modified, and distributed under the terms of the FreeType project */ |
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
/* this file you indicate that you have read the license and */ |
/* understand and accept it fully. */ |
/* */ |
/***************************************************************************/ |
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#include <ft2build.h> |
#include "ftcmanag.h" |
#include FT_INTERNAL_OBJECTS_H |
#include FT_INTERNAL_DEBUG_H |
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#include "ftccback.h" |
#include "ftcerror.h" |
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#undef FT_COMPONENT |
#define FT_COMPONENT trace_cache |
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#define FTC_HASH_MAX_LOAD 2 |
#define FTC_HASH_MIN_LOAD 1 |
#define FTC_HASH_SUB_LOAD ( FTC_HASH_MAX_LOAD - FTC_HASH_MIN_LOAD ) |
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/* this one _must_ be a power of 2! */ |
#define FTC_HASH_INITIAL_SIZE 8 |
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/*************************************************************************/ |
/*************************************************************************/ |
/***** *****/ |
/***** CACHE NODE DEFINITIONS *****/ |
/***** *****/ |
/*************************************************************************/ |
/*************************************************************************/ |
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/* add a new node to the head of the manager's circular MRU list */ |
static void |
ftc_node_mru_link( FTC_Node node, |
FTC_Manager manager ) |
{ |
void *nl = &manager->nodes_list; |
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FTC_MruNode_Prepend( (FTC_MruNode*)nl, |
(FTC_MruNode)node ); |
manager->num_nodes++; |
} |
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/* remove a node from the manager's MRU list */ |
static void |
ftc_node_mru_unlink( FTC_Node node, |
FTC_Manager manager ) |
{ |
void *nl = &manager->nodes_list; |
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FTC_MruNode_Remove( (FTC_MruNode*)nl, |
(FTC_MruNode)node ); |
manager->num_nodes--; |
} |
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#ifndef FTC_INLINE |
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/* move a node to the head of the manager's MRU list */ |
static void |
ftc_node_mru_up( FTC_Node node, |
FTC_Manager manager ) |
{ |
FTC_MruNode_Up( (FTC_MruNode*)&manager->nodes_list, |
(FTC_MruNode)node ); |
} |
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/* get a top bucket for specified hash from cache, |
* body for FTC_NODE__TOP_FOR_HASH( cache, hash ) |
*/ |
FT_LOCAL_DEF( FTC_Node* ) |
ftc_get_top_node_for_hash( FTC_Cache cache, |
FT_PtrDist hash ) |
{ |
FTC_Node* pnode; |
FT_UInt idx; |
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idx = (FT_UInt)( hash & cache->mask ); |
if ( idx < cache->p ) |
idx = (FT_UInt)( hash & ( 2 * cache->mask + 1 ) ); |
pnode = cache->buckets + idx; |
return pnode; |
} |
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#endif /* !FTC_INLINE */ |
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/* Note that this function cannot fail. If we cannot re-size the |
* buckets array appropriately, we simply degrade the hash table's |
* performance! |
*/ |
static void |
ftc_cache_resize( FTC_Cache cache ) |
{ |
for (;;) |
{ |
FTC_Node node, *pnode; |
FT_UFast p = cache->p; |
FT_UFast mask = cache->mask; |
FT_UFast count = mask + p + 1; /* number of buckets */ |
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/* do we need to shrink the buckets array? */ |
if ( cache->slack < 0 ) |
{ |
FTC_Node new_list = NULL; |
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/* try to expand the buckets array _before_ splitting |
* the bucket lists |
*/ |
if ( p >= mask ) |
{ |
FT_Memory memory = cache->memory; |
FT_Error error; |
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/* if we can't expand the array, leave immediately */ |
if ( FT_RENEW_ARRAY( cache->buckets, |
( mask + 1 ) * 2, ( mask + 1 ) * 4 ) ) |
break; |
} |
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/* split a single bucket */ |
pnode = cache->buckets + p; |
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for (;;) |
{ |
node = *pnode; |
if ( node == NULL ) |
break; |
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if ( node->hash & ( mask + 1 ) ) |
{ |
*pnode = node->link; |
node->link = new_list; |
new_list = node; |
} |
else |
pnode = &node->link; |
} |
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cache->buckets[p + mask + 1] = new_list; |
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cache->slack += FTC_HASH_MAX_LOAD; |
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if ( p >= mask ) |
{ |
cache->mask = 2 * mask + 1; |
cache->p = 0; |
} |
else |
cache->p = p + 1; |
} |
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/* do we need to expand the buckets array? */ |
else if ( cache->slack > (FT_Long)count * FTC_HASH_SUB_LOAD ) |
{ |
FT_UFast old_index = p + mask; |
FTC_Node* pold; |
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if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE ) |
break; |
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if ( p == 0 ) |
{ |
FT_Memory memory = cache->memory; |
FT_Error error; |
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/* if we can't shrink the array, leave immediately */ |
if ( FT_RENEW_ARRAY( cache->buckets, |
( mask + 1 ) * 2, mask + 1 ) ) |
break; |
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cache->mask >>= 1; |
p = cache->mask; |
} |
else |
p--; |
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pnode = cache->buckets + p; |
while ( *pnode ) |
pnode = &(*pnode)->link; |
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pold = cache->buckets + old_index; |
*pnode = *pold; |
*pold = NULL; |
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cache->slack -= FTC_HASH_MAX_LOAD; |
cache->p = p; |
} |
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/* otherwise, the hash table is balanced */ |
else |
break; |
} |
} |
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/* remove a node from its cache's hash table */ |
static void |
ftc_node_hash_unlink( FTC_Node node0, |
FTC_Cache cache ) |
{ |
FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node0->hash ); |
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for (;;) |
{ |
FTC_Node node = *pnode; |
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if ( node == NULL ) |
{ |
FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" )); |
return; |
} |
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if ( node == node0 ) |
break; |
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pnode = &(*pnode)->link; |
} |
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*pnode = node0->link; |
node0->link = NULL; |
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cache->slack++; |
ftc_cache_resize( cache ); |
} |
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/* add a node to the `top' of its cache's hash table */ |
static void |
ftc_node_hash_link( FTC_Node node, |
FTC_Cache cache ) |
{ |
FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node->hash ); |
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node->link = *pnode; |
*pnode = node; |
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cache->slack--; |
ftc_cache_resize( cache ); |
} |
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/* remove a node from the cache manager */ |
FT_LOCAL_DEF( void ) |
ftc_node_destroy( FTC_Node node, |
FTC_Manager manager ) |
{ |
FTC_Cache cache; |
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#ifdef FT_DEBUG_ERROR |
/* find node's cache */ |
if ( node->cache_index >= manager->num_caches ) |
{ |
FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); |
return; |
} |
#endif |
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cache = manager->caches[node->cache_index]; |
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#ifdef FT_DEBUG_ERROR |
if ( cache == NULL ) |
{ |
FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); |
return; |
} |
#endif |
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manager->cur_weight -= cache->clazz.node_weight( node, cache ); |
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/* remove node from mru list */ |
ftc_node_mru_unlink( node, manager ); |
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/* remove node from cache's hash table */ |
ftc_node_hash_unlink( node, cache ); |
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/* now finalize it */ |
cache->clazz.node_free( node, cache ); |
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#if 0 |
/* check, just in case of general corruption :-) */ |
if ( manager->num_nodes == 0 ) |
FT_TRACE0(( "ftc_node_destroy: invalid cache node count (%d)\n", |
manager->num_nodes )); |
#endif |
} |
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/*************************************************************************/ |
/*************************************************************************/ |
/***** *****/ |
/***** ABSTRACT CACHE CLASS *****/ |
/***** *****/ |
/*************************************************************************/ |
/*************************************************************************/ |
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FT_LOCAL_DEF( FT_Error ) |
FTC_Cache_Init( FTC_Cache cache ) |
{ |
return ftc_cache_init( cache ); |
} |
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FT_LOCAL_DEF( FT_Error ) |
ftc_cache_init( FTC_Cache cache ) |
{ |
FT_Memory memory = cache->memory; |
FT_Error error; |
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cache->p = 0; |
cache->mask = FTC_HASH_INITIAL_SIZE - 1; |
cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; |
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(void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 ); |
return error; |
} |
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static void |
FTC_Cache_Clear( FTC_Cache cache ) |
{ |
if ( cache && cache->buckets ) |
{ |
FTC_Manager manager = cache->manager; |
FT_UFast i; |
FT_UFast count; |
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count = cache->p + cache->mask + 1; |
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for ( i = 0; i < count; i++ ) |
{ |
FTC_Node *pnode = cache->buckets + i, next, node = *pnode; |
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while ( node ) |
{ |
next = node->link; |
node->link = NULL; |
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/* remove node from mru list */ |
ftc_node_mru_unlink( node, manager ); |
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/* now finalize it */ |
manager->cur_weight -= cache->clazz.node_weight( node, cache ); |
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cache->clazz.node_free( node, cache ); |
node = next; |
} |
cache->buckets[i] = NULL; |
} |
ftc_cache_resize( cache ); |
} |
} |
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FT_LOCAL_DEF( void ) |
ftc_cache_done( FTC_Cache cache ) |
{ |
if ( cache->memory ) |
{ |
FT_Memory memory = cache->memory; |
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FTC_Cache_Clear( cache ); |
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FT_FREE( cache->buckets ); |
cache->mask = 0; |
cache->p = 0; |
cache->slack = 0; |
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cache->memory = NULL; |
} |
} |
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FT_LOCAL_DEF( void ) |
FTC_Cache_Done( FTC_Cache cache ) |
{ |
ftc_cache_done( cache ); |
} |
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static void |
ftc_cache_add( FTC_Cache cache, |
FT_PtrDist hash, |
FTC_Node node ) |
{ |
node->hash = hash; |
node->cache_index = (FT_UInt16)cache->index; |
node->ref_count = 0; |
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ftc_node_hash_link( node, cache ); |
ftc_node_mru_link( node, cache->manager ); |
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{ |
FTC_Manager manager = cache->manager; |
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manager->cur_weight += cache->clazz.node_weight( node, cache ); |
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if ( manager->cur_weight >= manager->max_weight ) |
{ |
node->ref_count++; |
FTC_Manager_Compress( manager ); |
node->ref_count--; |
} |
} |
} |
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FT_LOCAL_DEF( FT_Error ) |
FTC_Cache_NewNode( FTC_Cache cache, |
FT_PtrDist hash, |
FT_Pointer query, |
FTC_Node *anode ) |
{ |
FT_Error error; |
FTC_Node node; |
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/* |
* We use the FTC_CACHE_TRYLOOP macros to support out-of-memory |
* errors (OOM) correctly, i.e., by flushing the cache progressively |
* in order to make more room. |
*/ |
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FTC_CACHE_TRYLOOP( cache ) |
{ |
error = cache->clazz.node_new( &node, query, cache ); |
} |
FTC_CACHE_TRYLOOP_END( NULL ); |
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if ( error ) |
node = NULL; |
else |
{ |
/* don't assume that the cache has the same number of buckets, since |
* our allocation request might have triggered global cache flushing |
*/ |
ftc_cache_add( cache, hash, node ); |
} |
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*anode = node; |
return error; |
} |
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#ifndef FTC_INLINE |
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FT_LOCAL_DEF( FT_Error ) |
FTC_Cache_Lookup( FTC_Cache cache, |
FT_PtrDist hash, |
FT_Pointer query, |
FTC_Node *anode ) |
{ |
FTC_Node* bucket; |
FTC_Node* pnode; |
FTC_Node node; |
FT_Error error = FT_Err_Ok; |
FT_Bool list_changed = FALSE; |
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FTC_Node_CompareFunc compare = cache->clazz.node_compare; |
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if ( cache == NULL || anode == NULL ) |
return FT_THROW( Invalid_Argument ); |
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/* Go to the `top' node of the list sharing same masked hash */ |
bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); |
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/* Lookup a node with exactly same hash and queried properties. */ |
/* NOTE: _nodcomp() may change the linked list to reduce memory. */ |
for (;;) |
{ |
node = *pnode; |
if ( node == NULL ) |
goto NewNode; |
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if ( node->hash == hash && |
compare( node, query, cache, &list_changed ) ) |
break; |
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pnode = &node->link; |
} |
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if ( list_changed ) |
{ |
/* Update bucket by modified linked list */ |
bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); |
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/* Update pnode by modified linked list */ |
while ( *pnode != node ) |
{ |
if ( *pnode == NULL ) |
{ |
FT_ERROR(( "FTC_Cache_Lookup: oops!!! node missing\n" )); |
goto NewNode; |
} |
else |
pnode = &((*pnode)->link); |
} |
} |
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/* Reorder the list to move the found node to the `top' */ |
if ( node != *bucket ) |
{ |
*pnode = node->link; |
node->link = *bucket; |
*bucket = node; |
} |
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/* move to head of MRU list */ |
{ |
FTC_Manager manager = cache->manager; |
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if ( node != manager->nodes_list ) |
ftc_node_mru_up( node, manager ); |
} |
*anode = node; |
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return error; |
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NewNode: |
return FTC_Cache_NewNode( cache, hash, query, anode ); |
} |
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#endif /* !FTC_INLINE */ |
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FT_LOCAL_DEF( void ) |
FTC_Cache_RemoveFaceID( FTC_Cache cache, |
FTC_FaceID face_id ) |
{ |
FT_UFast i, count; |
FTC_Manager manager = cache->manager; |
FTC_Node frees = NULL; |
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count = cache->p + cache->mask + 1; |
for ( i = 0; i < count; i++ ) |
{ |
FTC_Node* bucket = cache->buckets + i; |
FTC_Node* pnode = bucket; |
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for ( ;; ) |
{ |
FTC_Node node = *pnode; |
FT_Bool list_changed = FALSE; |
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if ( node == NULL ) |
break; |
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if ( cache->clazz.node_remove_faceid( node, face_id, |
cache, &list_changed ) ) |
{ |
*pnode = node->link; |
node->link = frees; |
frees = node; |
} |
else |
pnode = &node->link; |
} |
} |
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/* remove all nodes in the free list */ |
while ( frees ) |
{ |
FTC_Node node; |
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node = frees; |
frees = node->link; |
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manager->cur_weight -= cache->clazz.node_weight( node, cache ); |
ftc_node_mru_unlink( node, manager ); |
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cache->clazz.node_free( node, cache ); |
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cache->slack++; |
} |
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ftc_cache_resize( cache ); |
} |
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/* END */ |