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Diffstat (limited to 'src/cache/ftccache.c')
| -rw-r--r-- | src/cache/ftccache.c | 626 |
1 files changed, 626 insertions, 0 deletions
diff --git a/src/cache/ftccache.c b/src/cache/ftccache.c new file mode 100644 index 0000000..f01c403 --- /dev/null +++ b/src/cache/ftccache.c @@ -0,0 +1,626 @@ +/***************************************************************************/ +/* */ +/* ftccache.c */ +/* */ +/* The FreeType internal cache interface (body). */ +/* */ +/* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, */ +/* 2011 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. */ +/* */ +/***************************************************************************/ + + +#include <ft2build.h> +#include "ftcmanag.h" +#include FT_INTERNAL_OBJECTS_H +#include FT_INTERNAL_DEBUG_H + +#include "ftccback.h" +#include "ftcerror.h" + +#undef FT_COMPONENT +#define FT_COMPONENT trace_cache + + +#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 ) + + /* this one _must_ be a power of 2! */ +#define FTC_HASH_INITIAL_SIZE 8 + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** CACHE NODE DEFINITIONS *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + /* 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; + + + FTC_MruNode_Prepend( (FTC_MruNode*)nl, + (FTC_MruNode)node ); + manager->num_nodes++; + } + + + /* 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; + + + FTC_MruNode_Remove( (FTC_MruNode*)nl, + (FTC_MruNode)node ); + manager->num_nodes--; + } + + +#ifndef FTC_INLINE + + /* 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 ); + } + + + /* 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; + + + idx = (FT_UInt)( hash & cache->mask ); + if ( idx < cache->p ) + idx = (FT_UInt)( hash & ( 2 * cache->mask + 1 ) ); + pnode = cache->buckets + idx; + return pnode; + } + +#endif /* !FTC_INLINE */ + + + /* 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 */ + + + /* do we need to shrink the buckets array? */ + if ( cache->slack < 0 ) + { + FTC_Node new_list = NULL; + + + /* try to expand the buckets array _before_ splitting + * the bucket lists + */ + if ( p >= mask ) + { + FT_Memory memory = cache->memory; + FT_Error error; + + + /* if we can't expand the array, leave immediately */ + if ( FT_RENEW_ARRAY( cache->buckets, + ( mask + 1 ) * 2, ( mask + 1 ) * 4 ) ) + break; + } + + /* split a single bucket */ + pnode = cache->buckets + p; + + for (;;) + { + node = *pnode; + if ( node == NULL ) + break; + + if ( node->hash & ( mask + 1 ) ) + { + *pnode = node->link; + node->link = new_list; + new_list = node; + } + else + pnode = &node->link; + } + + cache->buckets[p + mask + 1] = new_list; + + cache->slack += FTC_HASH_MAX_LOAD; + + if ( p >= mask ) + { + cache->mask = 2 * mask + 1; + cache->p = 0; + } + else + cache->p = p + 1; + } + + /* 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; + + + if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE ) + break; + + if ( p == 0 ) + { + FT_Memory memory = cache->memory; + FT_Error error; + + + /* if we can't shrink the array, leave immediately */ + if ( FT_RENEW_ARRAY( cache->buckets, + ( mask + 1 ) * 2, mask + 1 ) ) + break; + + cache->mask >>= 1; + p = cache->mask; + } + else + p--; + + pnode = cache->buckets + p; + while ( *pnode ) + pnode = &(*pnode)->link; + + pold = cache->buckets + old_index; + *pnode = *pold; + *pold = NULL; + + cache->slack -= FTC_HASH_MAX_LOAD; + cache->p = p; + } + + /* otherwise, the hash table is balanced */ + else + break; + } + } + + + /* 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 ); + + + for (;;) + { + FTC_Node node = *pnode; + + + if ( node == NULL ) + { + FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" )); + return; + } + + if ( node == node0 ) + break; + + pnode = &(*pnode)->link; + } + + *pnode = node0->link; + node0->link = NULL; + + cache->slack++; + ftc_cache_resize( cache ); + } + + + /* 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 ); + + + node->link = *pnode; + *pnode = node; + + cache->slack--; + ftc_cache_resize( cache ); + } + + + /* remove a node from the cache manager */ +#ifdef FT_CONFIG_OPTION_OLD_INTERNALS + FT_BASE_DEF( void ) +#else + FT_LOCAL_DEF( void ) +#endif + ftc_node_destroy( FTC_Node node, + FTC_Manager manager ) + { + FTC_Cache cache; + + +#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 + + cache = manager->caches[node->cache_index]; + +#ifdef FT_DEBUG_ERROR + if ( cache == NULL ) + { + FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); + return; + } +#endif + + manager->cur_weight -= cache->clazz.node_weight( node, cache ); + + /* remove node from mru list */ + ftc_node_mru_unlink( node, manager ); + + /* remove node from cache's hash table */ + ftc_node_hash_unlink( node, cache ); + + /* now finalize it */ + cache->clazz.node_free( node, cache ); + +#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 + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** ABSTRACT CACHE CLASS *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + + FT_LOCAL_DEF( FT_Error ) + FTC_Cache_Init( FTC_Cache cache ) + { + return ftc_cache_init( cache ); + } + + + FT_LOCAL_DEF( FT_Error ) + ftc_cache_init( FTC_Cache cache ) + { + FT_Memory memory = cache->memory; + FT_Error error; + + + cache->p = 0; + cache->mask = FTC_HASH_INITIAL_SIZE - 1; + cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; + + (void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 ); + return error; + } + + + static void + FTC_Cache_Clear( FTC_Cache cache ) + { + if ( cache && cache->buckets ) + { + FTC_Manager manager = cache->manager; + FT_UFast i; + FT_UFast count; + + + count = cache->p + cache->mask + 1; + + for ( i = 0; i < count; i++ ) + { + FTC_Node *pnode = cache->buckets + i, next, node = *pnode; + + + while ( node ) + { + next = node->link; + node->link = NULL; + + /* remove node from mru list */ + ftc_node_mru_unlink( node, manager ); + + /* now finalize it */ + manager->cur_weight -= cache->clazz.node_weight( node, cache ); + + cache->clazz.node_free( node, cache ); + node = next; + } + cache->buckets[i] = NULL; + } + ftc_cache_resize( cache ); + } + } + + + FT_LOCAL_DEF( void ) + ftc_cache_done( FTC_Cache cache ) + { + if ( cache->memory ) + { + FT_Memory memory = cache->memory; + + + FTC_Cache_Clear( cache ); + + FT_FREE( cache->buckets ); + cache->mask = 0; + cache->p = 0; + cache->slack = 0; + + cache->memory = NULL; + } + } + + + FT_LOCAL_DEF( void ) + FTC_Cache_Done( FTC_Cache cache ) + { + ftc_cache_done( cache ); + } + + + 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; + + ftc_node_hash_link( node, cache ); + ftc_node_mru_link( node, cache->manager ); + + { + FTC_Manager manager = cache->manager; + + + manager->cur_weight += cache->clazz.node_weight( node, cache ); + + if ( manager->cur_weight >= manager->max_weight ) + { + node->ref_count++; + FTC_Manager_Compress( manager ); + node->ref_count--; + } + } + } + + + 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; + + + /* + * 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. + */ + + FTC_CACHE_TRYLOOP( cache ) + { + error = cache->clazz.node_new( &node, query, cache ); + } + FTC_CACHE_TRYLOOP_END( NULL ); + + 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 ); + } + + *anode = node; + return error; + } + + +#ifndef FTC_INLINE + + 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 = FTC_Err_Ok; + FT_Bool list_changed = FALSE; + + FTC_Node_CompareFunc compare = cache->clazz.node_compare; + + + if ( cache == NULL || anode == NULL ) + return FTC_Err_Invalid_Argument; + + /* Go to the `top' node of the list sharing same masked hash */ + bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); + + /* 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; + + if ( node->hash == hash && + compare( node, query, cache, &list_changed ) ) + break; + + pnode = &node->link; + } + + if ( list_changed ) + { + /* Update bucket by modified linked list */ + bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); + + /* 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); + } + } + + /* Reorder the list to move the found node to the `top' */ + if ( node != *bucket ) + { + *pnode = node->link; + node->link = *bucket; + *bucket = node; + } + + /* move to head of MRU list */ + { + FTC_Manager manager = cache->manager; + + + if ( node != manager->nodes_list ) + ftc_node_mru_up( node, manager ); + } + *anode = node; + + return error; + + NewNode: + return FTC_Cache_NewNode( cache, hash, query, anode ); + } + +#endif /* !FTC_INLINE */ + + + 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; + + + count = cache->p + cache->mask + 1; + for ( i = 0; i < count; i++ ) + { + FTC_Node* bucket = cache->buckets + i; + FTC_Node* pnode = bucket; + + + for ( ;; ) + { + FTC_Node node = *pnode; + FT_Bool list_changed = FALSE; + + + if ( node == NULL ) + break; + + if ( cache->clazz.node_remove_faceid( node, face_id, + cache, &list_changed ) ) + { + *pnode = node->link; + node->link = frees; + frees = node; + } + else + pnode = &node->link; + } + } + + /* remove all nodes in the free list */ + while ( frees ) + { + FTC_Node node; + + + node = frees; + frees = node->link; + + manager->cur_weight -= cache->clazz.node_weight( node, cache ); + ftc_node_mru_unlink( node, manager ); + + cache->clazz.node_free( node, cache ); + + cache->slack++; + } + + ftc_cache_resize( cache ); + } + + +/* END */ |