/***************************************************************************/ | |
/* */ | |
/* ftccache.c */ | |
/* */ | |
/* The FreeType internal cache interface (body). */ | |
/* */ | |
/* Copyright 2000-2015 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_Offset hash ) | |
{ | |
FTC_Node* pnode; | |
FT_Offset idx; | |
idx = hash & cache->mask; | |
if ( idx < cache->p ) | |
idx = 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 */ | |
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 == 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_Offset 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_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 == NULL || anode == NULL ) | |
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 == 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 */ |