+++ /dev/null
-/***************************************************************************/
-/* */
-/* ftlru.h */
-/* */
-/* Simple LRU list-cache (specification). */
-/* */
-/* Copyright 2000-2001 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. */
-/* */
-/***************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* An LRU is a list that cannot hold more than a certain number of */
- /* elements (`max_elements'). All elements on the list are sorted in */
- /* least-recently-used order, i.e., the `oldest' element is at the tail */
- /* of the list. */
- /* */
- /* When doing a lookup (either through `Lookup()' or `Lookup_Node()'), */
- /* the list is searched for an element with the corresponding key. If */
- /* it is found, the element is moved to the head of the list and is */
- /* returned. */
- /* */
- /* If no corresponding element is found, the lookup routine will try to */
- /* obtain a new element with the relevant key. If the list is already */
- /* full, the oldest element from the list is discarded and replaced by a */
- /* new one; a new element is added to the list otherwise. */
- /* */
- /* Note that it is possible to pre-allocate the element list nodes. */
- /* This is handy if `max_elements' is sufficiently small, as it saves */
- /* allocations/releases during the lookup process. */
- /* */
- /*************************************************************************/
-
-
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
- /********* *********/
- /********* WARNING, THIS IS BETA CODE. *********/
- /********* *********/
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
-
-
-#ifndef __FTLRU_H__
-#define __FTLRU_H__
-
-
-#include <ft2build.h>
-#include FT_FREETYPE_H
-
-
-FT_BEGIN_HEADER
-
-
- /* generic key type */
- typedef FT_Pointer FT_LruKey;
-
-
- /* an lru node -- root.data points to the element */
- typedef struct FT_LruNodeRec_
- {
- FT_ListNodeRec root;
- FT_LruKey key;
-
- } FT_LruNodeRec, *FT_LruNode;
-
-
- /* forward declaration */
- typedef struct FT_LruRec_* FT_Lru;
-
-
- /* LRU class */
- typedef struct FT_Lru_Class_
- {
- FT_UInt lru_size; /* object size in bytes */
-
- /* this method is used to initialize a new list element node */
- FT_Error
- (*init_element)( FT_Lru lru,
- FT_LruNode node );
-
- /* this method is used to finalize a given list element node */
- void
- (*done_element)( FT_Lru lru,
- FT_LruNode node );
-
- /* If defined, this method is called when the list if full */
- /* during the lookup process -- it is used to change the contents */
- /* of a list element node, instead of calling `done_element()', */
- /* then `init_element'. Set it to 0 for default behaviour. */
- FT_Error
- (*flush_element)( FT_Lru lru,
- FT_LruNode node,
- FT_LruKey new_key );
-
- /* If defined, this method is used to compare a list element node */
- /* with a given key during a lookup. If set to 0, the `key' */
- /* fields will be directly compared instead. */
- FT_Bool
- (*compare_element)( FT_LruNode node,
- FT_LruKey key );
-
- } FT_Lru_Class;
-
-
- /* A selector is used to indicate whether a given list element node */
- /* is part of a selection for FT_Lru_Remove_Selection(). The function */
- /* must return true (i.e., non-null) to indicate that the node is part */
- /* of it. */
- typedef FT_Bool
- (*FT_Lru_Selector)( FT_Lru lru,
- FT_LruNode node,
- FT_Pointer data );
-
-
- typedef struct FT_LruRec_
- {
- FT_Lru_Class* clazz;
- FT_UInt max_elements;
- FT_UInt num_elements;
- FT_ListRec elements;
- FT_Memory memory;
- FT_Pointer user_data;
-
- /* the following fields are only meaningful for static lru containers */
- FT_ListRec free_nodes;
- FT_LruNode nodes;
-
- } FT_LruRec;
-
-
- FT_EXPORT( FT_Error )
- FT_Lru_New( const FT_Lru_Class* clazz,
- FT_UInt max_elements,
- FT_Pointer user_data,
- FT_Memory memory,
- FT_Bool pre_alloc,
- FT_Lru *anlru );
-
- FT_EXPORT( void )
- FT_Lru_Reset( FT_Lru lru );
-
- FT_EXPORT( void )
- FT_Lru_Done ( FT_Lru lru );
-
- FT_EXPORT( FT_Error )
- FT_Lru_Lookup_Node( FT_Lru lru,
- FT_LruKey key,
- FT_LruNode *anode );
-
- FT_EXPORT( FT_Error )
- FT_Lru_Lookup( FT_Lru lru,
- FT_LruKey key,
- FT_Pointer *anobject );
-
- FT_EXPORT( void )
- FT_Lru_Remove_Node( FT_Lru lru,
- FT_LruNode node );
-
- FT_EXPORT( void )
- FT_Lru_Remove_Selection( FT_Lru lru,
- FT_Lru_Selector selector,
- FT_Pointer data );
-
-
-FT_END_HEADER
-
-#endif /* __FTLRU_H__ */
-
-
-/* END */
projects / rrdtool.git / blobdiff