godot/thirdparty/freetype/src/cache/ftccache.h

/****************************************************************************
 *
 * ftccache.h
 *
 *   FreeType internal cache interface (specification).
 *
 * Copyright (C) 2000-2023 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.
 *
 */


#ifndef FTCCACHE_H_
#define FTCCACHE_H_

#include <freetype/internal/compiler-macros.h>
#include "ftcmru.h"

FT_BEGIN_HEADER

#define FTC_FACE_ID_HASH( i ) …

  /* handle to cache object */
  FTC_Cache;

  /* handle to cache class */
  FTC_CacheClass;


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                   CACHE NODE DEFINITIONS                      *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /**************************************************************************
   *
   * Each cache controls one or more cache nodes.  Each node is part of
   * the global_lru list of the manager.  Its `data' field however is used
   * as a reference count for now.
   *
   * A node can be anything, depending on the type of information held by
   * the cache.  It can be an individual glyph image, a set of bitmaps
   * glyphs for a given size, some metrics, etc.
   *
   */

  /* structure size should be 20 bytes on 32-bits machines */
  FTC_NodeRec;


#define FTC_NODE( x ) …
#define FTC_NODE_P( x ) …

#define FTC_NODE_NEXT( x ) …
#define FTC_NODE_PREV( x ) …

  /* address the hash table entries */
#ifdef FTC_INLINE
#define FTC_NODE_TOP_FOR_HASH( cache, hash ) …
#else
  FT_LOCAL( FTC_Node* )
  ftc_get_top_node_for_hash( FTC_Cache  cache,
                             FT_Offset  hash );
#define FTC_NODE_TOP_FOR_HASH …
#endif


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       CACHE DEFINITIONS                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /* initialize a new cache node */
  FTC_Node_NewFunc;

  FTC_Node_WeightFunc;

  /* compare a node to a given key pair */
  FTC_Node_CompareFunc;


  FTC_Node_FreeFunc;

  FTC_Cache_InitFunc;

  FTC_Cache_DoneFunc;


  FTC_CacheClassRec;


  /* each cache really implements a hash table to manage its nodes    */
  /* the number of the table entries (buckets) can change dynamically */
  /* each bucket contains a linked lists of nodes for a given hash    */
  FTC_CacheRec;


#define FTC_CACHE( x ) …
#define FTC_CACHE_P( x ) …


  /* default cache initialize */
  FT_LOCAL( FT_Error )
  FTC_Cache_Init( FTC_Cache  cache );

  /* default cache finalizer */
  FT_LOCAL( void )
  FTC_Cache_Done( FTC_Cache  cache );

  /* Call this function to look up the cache.  If no corresponding
   * node is found, a new one is automatically created.  This function
   * is capable of flushing the cache adequately to make room for the
   * new cache object.
   */

#ifndef FTC_INLINE
  FT_LOCAL( FT_Error )
  FTC_Cache_Lookup( FTC_Cache   cache,
                    FT_Offset   hash,
                    FT_Pointer  query,
                    FTC_Node   *anode );
#endif

  FT_LOCAL( FT_Error )
  FTC_Cache_NewNode( FTC_Cache   cache,
                     FT_Offset   hash,
                     FT_Pointer  query,
                     FTC_Node   *anode );

  /* Remove all nodes that relate to a given face_id.  This is useful
   * when un-installing fonts.  Note that if a cache node relates to
   * the face_id but is locked (i.e., has `ref_count > 0'), the node
   * will _not_ be destroyed, but its internal face_id reference will
   * be modified.
   *
   * The final result will be that the node will never come back
   * in further lookup requests, and will be flushed on demand from
   * the cache normally when its reference count reaches 0.
   */
  FT_LOCAL( void )
  FTC_Cache_RemoveFaceID( FTC_Cache   cache,
                          FTC_FaceID  face_id );


#ifdef FTC_INLINE

#define FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ) …

#else /* !FTC_INLINE */

#define FTC_CACHE_LOOKUP_CMP …

#endif /* !FTC_INLINE */


  /*
   * This macro, together with FTC_CACHE_TRYLOOP_END, defines a retry
   * loop to flush the cache repeatedly in case of memory overflows.
   *
   * It is used when creating a new cache node, or within a lookup
   * that needs to allocate data (e.g. the sbit cache lookup).
   *
   * Example:
   *
   * {
   *   FTC_CACHE_TRYLOOP( cache )
   *     error = load_data( ... );
   *   FTC_CACHE_TRYLOOP_END()
   * }
   *
   */
#define FTC_CACHE_TRYLOOP( cache ) …


#define FTC_CACHE_TRYLOOP_END( list_changed ) …

 /* */

FT_END_HEADER


#endif /* FTCCACHE_H_ */


/* END */