| /**************************************************************************** |
| * |
| * ftccache.c |
| * |
| * The FreeType internal cache interface (body). |
| * |
| * Copyright (C) 2000-2024 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 "ftcmanag.h" |
| #include <freetype/internal/ftobjs.h> |
| #include <freetype/internal/ftdebug.h> |
| |
| #include "ftccback.h" |
| #include "ftcerror.h" |
| |
| #undef FT_COMPONENT |
| #define FT_COMPONENT 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_Offset hash ) |
| { |
| FT_Offset idx; |
| |
| |
| idx = hash & cache->mask; |
| if ( idx >= cache->p ) |
| idx = hash & ( cache->mask >> 1 ); |
| |
| return cache->buckets + idx; |
| } |
| |
| #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 size = cache->mask + 1; /* available size */ |
| FT_UFast half = size >> 1; |
| |
| |
| /* do we need to expand 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 == size ) |
| { |
| FT_Memory memory = cache->memory; |
| FT_Error error; |
| |
| |
| /* if we can't expand the array, leave immediately */ |
| if ( FT_QRENEW_ARRAY( cache->buckets, size, size * 2 ) ) |
| break; |
| |
| cache->mask = 2 * size - 1; |
| half = size; |
| } |
| |
| /* the bucket to split */ |
| pnode = cache->buckets + p - half; |
| |
| for (;;) |
| { |
| node = *pnode; |
| if ( !node ) |
| break; |
| |
| if ( node->hash & half ) |
| { |
| *pnode = node->link; |
| node->link = new_list; |
| new_list = node; |
| } |
| else |
| pnode = &node->link; |
| } |
| |
| cache->buckets[p] = new_list; |
| |
| cache->slack += FTC_HASH_MAX_LOAD; |
| cache->p = p + 1; |
| |
| FT_TRACE2(( "ftc_cache_resize: cache %u increased to %u hashes\n", |
| cache->index, cache->p )); |
| } |
| |
| /* do we need to shrink the buckets array? */ |
| else if ( cache->slack > (FT_Long)p * FTC_HASH_SUB_LOAD ) |
| { |
| FTC_Node old_list = cache->buckets[--p]; |
| |
| |
| if ( p < FTC_HASH_INITIAL_SIZE ) |
| break; |
| |
| if ( p == half ) |
| { |
| FT_Memory memory = cache->memory; |
| FT_Error error; |
| |
| |
| /* if we can't shrink the array, leave immediately */ |
| if ( FT_QRENEW_ARRAY( cache->buckets, size, half ) ) |
| break; |
| |
| cache->mask = half - 1; |
| } |
| |
| /* the bucket to merge */ |
| pnode = cache->buckets + p - half; |
| |
| while ( *pnode ) |
| pnode = &(*pnode)->link; |
| |
| *pnode = old_list; |
| |
| cache->slack -= FTC_HASH_MAX_LOAD; |
| cache->p = p; |
| |
| FT_TRACE2(( "ftc_cache_resize: cache %u decreased to %u hashes\n", |
| cache->index, cache->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 ) |
| { |
| FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" )); |
| return; |
| } |
| |
| if ( node == node0 ) |
| break; |
| |
| pnode = &node->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 */ |
| FT_LOCAL_DEF( void ) |
| 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 ) |
| { |
| 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 (%u)\n", |
| manager->num_nodes )); |
| #endif |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** ABSTRACT CACHE CLASS *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| FT_LOCAL_DEF( FT_Error ) |
| ftc_cache_init( FTC_Cache cache ) |
| { |
| FT_Memory memory = cache->memory; |
| FT_Error error; |
| |
| |
| cache->p = FTC_HASH_INITIAL_SIZE; |
| cache->mask = FTC_HASH_INITIAL_SIZE - 1; |
| cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; |
| |
| FT_MEM_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE ); |
| return error; |
| } |
| |
| |
| FT_LOCAL_DEF( FT_Error ) |
| FTC_Cache_Init( FTC_Cache cache ) |
| { |
| return ftc_cache_init( cache ); |
| } |
| |
| |
| FT_LOCAL_DEF( void ) |
| ftc_cache_done( FTC_Cache cache ) |
| { |
| FT_Memory memory = cache->memory; |
| |
| |
| if ( cache->buckets ) |
| { |
| FTC_Manager manager = cache->manager; |
| FT_UFast count = cache->p; |
| FT_UFast i; |
| |
| |
| for ( i = 0; i < count; i++ ) |
| { |
| FTC_Node node = cache->buckets[i], next; |
| |
| |
| 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; |
| } |
| } |
| } |
| |
| FT_FREE( cache->buckets ); |
| |
| cache->p = 0; |
| cache->mask = 0; |
| cache->slack = 0; |
| } |
| |
| |
| FT_LOCAL_DEF( void ) |
| FTC_Cache_Done( FTC_Cache cache ) |
| { |
| ftc_cache_done( cache ); |
| } |
| |
| |
| static void |
| ftc_cache_add( FTC_Cache cache, |
| FT_Offset hash, |
| FTC_Node node ) |
| { |
| node->hash = hash; |
| node->cache_index = (FT_UShort)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_Offset 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_Offset 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; |
| |
| FTC_Node_CompareFunc compare = cache->clazz.node_compare; |
| |
| |
| if ( !cache || !anode ) |
| return FT_THROW( 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 ) |
| 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 ) |
| { |
| 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 ) |
| { |
| FTC_Manager manager = cache->manager; |
| FT_UFast count = cache->p; |
| FT_UFast i; |
| |
| |
| for ( i = 0; i < count; i++ ) |
| { |
| FTC_Node* pnode = cache->buckets + i; |
| |
| |
| for (;;) |
| { |
| FTC_Node node = *pnode; |
| |
| |
| if ( !node ) |
| break; |
| |
| if ( cache->clazz.node_remove_faceid( node, face_id, cache, NULL ) ) |
| { |
| *pnode = 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++; |
| } |
| else |
| pnode = &node->link; |
| } |
| } |
| |
| ftc_cache_resize( cache ); |
| } |
| |
| |
| /* END */ |