ftcache.c

ucgui的矢量字库支持包,可以象windows一样使用truetype的字库了

        }

        manager->caches[manager->num_caches++] = cache;
      }
    }

  Exit:
    *acache = cache;
    return error;
  }


  FT_LOCAL_DEF( FT_UInt )
  FTC_Manager_FlushN( FTC_Manager  manager,
                      FT_UInt      count )
  {
    FTC_Node  first = manager->nodes_list;
    FTC_Node  node;
    FT_UInt   result;


    /* try to remove `count' nodes from the list */
    if ( first == NULL )  /* empty list! */
      return 0;

    /* go to last node - it's a circular list */
    node = FTC_NODE__PREV(first);
    for ( result = 0; result < count; )
    {
      FTC_Node  prev = FTC_NODE__PREV( node );


      /* don't touch locked nodes */
      if ( node->ref_count <= 0 )
      {
        ftc_node_destroy( node, manager );
        result++;
      }

      if ( node == first )
        break;

      node = prev;
    }
    return  result;
  }


  /* documentation is in ftcache.h */

  FT_EXPORT_DEF( void )
  FTC_Manager_RemoveFaceID( FTC_Manager  manager,
                            FTC_FaceID   face_id )
  {
    FT_UInt  nn;

    /* this will remove all FTC_SizeNode that correspond to
     * the face_id as well
     */
    FTC_MruList_RemoveSelection( &manager->faces, NULL, face_id );

    for ( nn = 0; nn < manager->num_caches; nn++ )
      FTC_Cache_RemoveFaceID( manager->caches[nn], face_id );
  }


  /* documentation is in ftcache.h */

  FT_EXPORT_DEF( void )
  FTC_Node_Unref( FTC_Node     node,
                  FTC_Manager  manager )
  {
    if ( node && (FT_UInt)node->cache_index < manager->num_caches )
      node->ref_count--;
  }


#ifdef FT_CONFIG_OPTION_OLD_INTERNALS

  FT_EXPORT_DEF( FT_Error )
  FTC_Manager_Lookup_Face( FTC_Manager  manager,
                           FTC_FaceID   face_id,
                           FT_Face     *aface )
  {
    return FTC_Manager_LookupFace( manager, face_id, aface );
  }


  FT_EXPORT( FT_Error )
  FTC_Manager_Lookup_Size( FTC_Manager  manager,
                           FTC_Font     font,
                           FT_Face     *aface,
                           FT_Size     *asize )
  {
    FTC_ScalerRec  scaler;
    FT_Error       error;
    FT_Size        size;
    FT_Face        face;


    scaler.face_id = font->face_id;
    scaler.width   = font->pix_width;
    scaler.height  = font->pix_height;
    scaler.pixel   = TRUE;
    scaler.x_res   = 0;
    scaler.y_res   = 0;

    error = FTC_Manager_LookupSize( manager, &scaler, &size );
    if ( error )
    {
      face = NULL;
      size = NULL;
    }
    else
      face = size->face;

    if ( aface )
      *aface = face;

    if ( asize )
      *asize = size;

    return error;
  }

#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */


/* END */

/***************************************************************************/
/*                                                                         */
/*  ftccache.c                                                             */
/*                                                                         */
/*    The FreeType internal cache interface (body).                        */
/*                                                                         */
/*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006 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"


#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 )
  {
    FTC_MruNode_Prepend( (FTC_MruNode*)&manager->nodes_list,
                         (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 )
  {
    FTC_MruNode_Remove( (FTC_MruNode*)&manager->nodes_list,
                        (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 );
  }

#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_UInt   p      = cache->p;
      FT_UInt   mask   = cache->mask;
      FT_UInt   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_UInt    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;
      }
      else /* the hash table is balanced */
        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;
    FT_UInt    idx;


    idx = (FT_UInt)( node0->hash & cache->mask );
    if ( idx < cache->p )
      idx = (FT_UInt)( node0->hash & ( 2 * cache->mask + 1 ) );

    pnode = cache->buckets + idx;

    for (;;)
    {
      FTC_Node  node = *pnode;


      if ( node == NULL )
      {
        FT_ERROR(( "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;
    FT_UInt    idx;


    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;

    cache->slack--;
    ftc_cache_resize( cache );
  }


  /* remove a node from the cache manager */
#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
  FT_BASE_DEF( void )
#else
  FT_LOCAL_DEF( void )
#endif
  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_ERROR(( "ftc_node_destroy: invalid node handle\n" ));
      return;
    }
#endif

    cache = manager->caches[node->cache_index];

#ifdef FT_DEBUG_ERROR
    if ( cache == NULL )
    {
      FT_ERROR(( "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_ERROR(( "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 )
    {
      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 );