ref: d0ab3a0dd8f6355b3603d0fb04043a9ae867639b
dir: /libfreetype/ftccache.c/
/***************************************************************************/ /* */ /* ftccache.c */ /* */ /* The FreeType internal cache interface (body). */ /* */ /* Copyright 2000-2001, 2002 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 FT_CACHE_MANAGER_H #include FT_INTERNAL_OBJECTS_H #include FT_INTERNAL_DEBUG_H #include "ftcerror.h" #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 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_EXPORT_DEF( void ) ftc_node_done( FTC_Node node, FTC_Cache cache ) { FTC_Family family; FTC_FamilyEntry entry; entry = cache->manager->families.entries + node->fam_index; family = entry->family; /* remove from parent set table - eventually destroy the set */ if ( --family->num_nodes == 0 ) FT_LruList_Remove( cache->families, (FT_LruNode) family ); } /* 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 ) { FTC_Node first = manager->nodes_list; if ( first ) { FTC_Node last = first->mru_prev; FT_ASSERT( last->mru_next == first ); node->mru_prev = last; node->mru_next = first; last->mru_next = node; first->mru_prev = node; } else { FT_ASSERT( manager->num_nodes == 0 ); node->mru_next = node; node->mru_prev = node; } manager->nodes_list = 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 ) { FTC_Node first = manager->nodes_list; FTC_Node prev = node->mru_prev; FTC_Node next = node->mru_next; FT_ASSERT( first != NULL && manager->num_nodes > 0 ); FT_ASSERT( next->mru_prev == node ); FT_ASSERT( prev->mru_next == node ); next->mru_prev = prev; prev->mru_next = next; if ( node == first ) { /* this is the last node in the list; update its head pointer */ if ( node == next ) manager->nodes_list = NULL; else manager->nodes_list = next; } node->mru_next = NULL; node->mru_prev = NULL; manager->num_nodes--; } /* 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_Node first = manager->nodes_list; if ( node != first ) { FTC_Node prev = node->mru_prev; FTC_Node next = node->mru_next; FTC_Node last; prev->mru_next = next; next->mru_prev = prev; last = first->mru_prev; node->mru_next = first; node->mru_prev = last; first->mru_prev = node; last->mru_next = node; manager->nodes_list = node; } } /* remove a node from its cache's hash table */ static FT_Error ftc_node_hash_unlink( FTC_Node node, FTC_Cache cache ) { FT_Error error = 0; FTC_Node *pnode; FT_UInt idx, num_buckets; idx = (FT_UInt)( node->hash & cache->mask ); if ( idx < cache->p ) idx = (FT_UInt)( node->hash & ( 2 * cache->mask + 1 ) ); pnode = cache->buckets + idx; for (;;) { if ( *pnode == NULL ) { FT_ERROR(( "ftc_node_hash_unlink: unknown node!\n" )); return FT_Err_Ok; } if ( *pnode == node ) { *pnode = node->link; node->link = NULL; break; } pnode = &(*pnode)->link; } num_buckets = ( cache->p + cache->mask + 1 ); if ( ++cache->slack > (FT_Long)num_buckets * FTC_HASH_SUB_LOAD ) { FT_UInt p = cache->p; FT_UInt mask = cache->mask; FT_UInt old_index = p + mask; FTC_Node* pold; FT_ASSERT( old_index >= FTC_HASH_INITIAL_SIZE ); if ( p == 0 ) { FT_Memory memory = cache->memory; cache->mask >>= 1; p = cache->mask; if ( FT_RENEW_ARRAY( cache->buckets, ( mask + 1 ) * 2, (mask+1) ) ) { FT_ERROR(( "ftc_node_hash_unlink: couldn't shunk buckets!\n" )); goto Exit; } } 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; } Exit: return error; } /* add a node to the "top" of its cache's hash table */ static FT_Error ftc_node_hash_link( FTC_Node node, FTC_Cache cache ) { FTC_Node *pnode; FT_UInt idx; FT_Error error = 0; idx = (FT_UInt)( node->hash & cache->mask ); if ( idx < cache->p ) idx = (FT_UInt)( node->hash & (2 * cache->mask + 1 ) ); pnode = cache->buckets + idx; node->link = *pnode; *pnode = node; if ( --cache->slack < 0 ) { FT_UInt p = cache->p; FT_UInt mask = cache->mask; FTC_Node new_list; /* split a single bucket */ new_list = NULL; 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 ) { FT_Memory memory = cache->memory; if ( FT_RENEW_ARRAY( cache->buckets, ( mask + 1 ) * 2, ( mask + 1 ) * 4 ) ) { FT_ERROR(( "ftc_node_hash_link: couldn't expand buckets!\n" )); goto Exit; } cache->mask = 2 * mask + 1; cache->p = 0; } else cache->p = p + 1; } Exit: return error; } /* remove a node from the cache manager */ FT_EXPORT_DEF( void ) ftc_node_destroy( FTC_Node node, FTC_Manager manager ) { FT_Memory memory = manager->library->memory; FTC_Cache cache; FTC_FamilyEntry entry; FTC_Cache_Class clazz; #ifdef FT_DEBUG_ERROR /* find node's cache */ if ( node->fam_index >= manager->families.count ) { FT_ERROR(( "ftc_node_destroy: invalid node handle\n" )); return; } #endif entry = manager->families.entries + node->fam_index; cache = entry->cache; #ifdef FT_DEBUG_ERROR if ( cache == NULL ) { FT_ERROR(( "ftc_node_destroy: invalid node handle\n" )); return; } #endif clazz = cache->clazz; manager->cur_weight -= 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 */ if ( clazz->node_done ) clazz->node_done( node, cache ); FT_FREE( node ); /* check, just in case of general corruption :-) */ if ( manager->num_nodes == 0 ) FT_ERROR(( "ftc_node_destroy: invalid cache node count! = %d\n", manager->num_nodes )); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** CACHE FAMILY DEFINITIONS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_EXPORT_DEF( FT_Error ) ftc_family_init( FTC_Family family, FTC_Query query, FTC_Cache cache ) { FT_Error error; FTC_Manager manager = cache->manager; FT_Memory memory = manager->library->memory; FTC_FamilyEntry entry; family->cache = cache; family->num_nodes = 0; /* now add to manager's family table */ error = ftc_family_table_alloc( &manager->families, memory, &entry ); if ( !error ) { entry->cache = cache; entry->family = family; family->fam_index = entry->index; query->family = family; /* save family in query */ } return error; } FT_EXPORT_DEF( void ) ftc_family_done( FTC_Family family ) { FTC_Manager manager = family->cache->manager; /* remove from manager's family table */ ftc_family_table_free( &manager->families, family->fam_index ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** ABSTRACT CACHE CLASS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_EXPORT_DEF( FT_Error ) ftc_cache_init( FTC_Cache cache ) { FT_Memory memory = cache->memory; FTC_Cache_Class clazz = cache->clazz; FT_Error error; cache->p = 0; cache->mask = FTC_HASH_INITIAL_SIZE - 1; cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; if ( FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 ) ) goto Exit; /* now, initialize the lru list of families for this cache */ if ( clazz->family_size > 0 ) { FT_LruList_ClassRec* lru_class = &cache->family_class; lru_class->list_size = sizeof( FT_LruListRec ); lru_class->list_init = NULL; lru_class->list_done = NULL; lru_class->node_size = clazz->family_size; lru_class->node_init = (FT_LruNode_InitFunc) clazz->family_init; lru_class->node_done = (FT_LruNode_DoneFunc) clazz->family_done; lru_class->node_flush = (FT_LruNode_FlushFunc) NULL; lru_class->node_compare = (FT_LruNode_CompareFunc)clazz->family_compare; error = FT_LruList_New( (FT_LruList_Class) lru_class, 0, /* max items == 0 => unbounded list */ cache, memory, &cache->families ); if ( error ) FT_FREE( cache->buckets ); } Exit: return error; } FT_EXPORT_DEF( void ) ftc_cache_clear( FTC_Cache cache ) { if ( cache ) { FT_Memory memory = cache->memory; FTC_Cache_Class clazz = cache->clazz; FTC_Manager manager = cache->manager; FT_UFast i; FT_UInt 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 -= clazz->node_weight( node, cache ); if ( clazz->node_done ) clazz->node_done( node, cache ); FT_FREE( node ); node = next; } cache->buckets[i] = NULL; } cache->p = 0; /* destroy the families */ if ( cache->families ) FT_LruList_Reset( cache->families ); } } FT_EXPORT_DEF( void ) ftc_cache_done( FTC_Cache cache ) { if ( cache ) { FT_Memory memory = cache->memory; ftc_cache_clear( cache ); FT_FREE( cache->buckets ); cache->mask = 0; cache->slack = 0; if ( cache->families ) { FT_LruList_Destroy( cache->families ); cache->families = NULL; } } } /* Look up a node in "top" of its cache's hash table. */ /* If not found, create a new node. */ /* */ FT_EXPORT_DEF( FT_Error ) ftc_cache_lookup( FTC_Cache cache, FTC_Query query, FTC_Node *anode ) { FT_Error error = FT_Err_Ok; FT_LruNode lru; if ( !cache || !query || !anode ) return FTC_Err_Invalid_Argument; *anode = NULL; query->hash = 0; query->family = NULL; /* XXX: we break encapsulation for the sake of speed! */ { /* first of all, find the relevant family */ FT_LruList list = cache->families; FT_LruNode fam, *pfam; FT_LruNode_CompareFunc compare = list->clazz->node_compare; pfam = &list->nodes; for (;;) { fam = *pfam; if ( fam == NULL ) { error = FT_LruList_Lookup( list, query, &lru ); if ( error ) goto Exit; goto Skip; } if ( compare( fam, query, list->data ) ) break; pfam = &fam->next; } FT_ASSERT( fam != NULL ); /* move to top of list when needed */ if ( fam != list->nodes ) { *pfam = fam->next; fam->next = list->nodes; list->nodes = fam; } lru = fam; Skip: ; } { FTC_Family family = (FTC_Family) lru; FT_UFast hash = query->hash; FTC_Node* bucket; FT_UInt idx; idx = hash & cache->mask; if ( idx < cache->p ) idx = hash & ( cache->mask * 2 + 1 ); bucket = cache->buckets + idx; if ( query->family != family || family->fam_index >= cache->manager->families.size ) { FT_ERROR(( "ftc_cache_lookup: invalid query (bad 'family' field)\n" )); return FTC_Err_Invalid_Argument; } if ( *bucket ) { FTC_Node* pnode = bucket; FTC_Node_CompareFunc compare = cache->clazz->node_compare; for ( ;; ) { FTC_Node node; node = *pnode; if ( node == NULL ) break; if ( node->hash == hash && (FT_UInt)node->fam_index == family->fam_index && compare( node, query, cache ) ) { /* move to head of bucket list */ if ( pnode != bucket ) { *pnode = node->link; node->link = *bucket; *bucket = node; } /* move to head of MRU list */ if ( node != cache->manager->nodes_list ) ftc_node_mru_up( node, cache->manager ); *anode = node; goto Exit; } pnode = &node->link; } } /* didn't find a node, create a new one */ { FTC_Cache_Class clazz = cache->clazz; FTC_Manager manager = cache->manager; FT_Memory memory = cache->memory; FTC_Node node; if ( FT_ALLOC( node, clazz->node_size ) ) goto Exit; node->fam_index = (FT_UShort) family->fam_index; node->hash = query->hash; node->ref_count = 0; error = clazz->node_init( node, query, cache ); if ( error ) { FT_FREE( node ); goto Exit; } error = ftc_node_hash_link( node, cache ); if ( error ) { clazz->node_done( node, cache ); FT_FREE( node ); goto Exit; } ftc_node_mru_link( node, cache->manager ); cache->manager->cur_weight += clazz->node_weight( node, cache ); /* now try to compress the node pool when necessary */ if ( manager->cur_weight >= manager->max_weight ) { node->ref_count++; FTC_Manager_Compress( manager ); node->ref_count--; } *anode = node; } } Exit: return error; } /* END */