misc/libfreetype/src/cache/ftccache.c
changeset 5172 88f2e05288ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/src/cache/ftccache.c	Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,626 @@
+/***************************************************************************/
+/*                                                                         */
+/*  ftccache.c                                                             */
+/*                                                                         */
+/*    The FreeType internal cache interface (body).                        */
+/*                                                                         */
+/*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010,   */
+/*            2011 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_PtrDist  hash )
+  {
+    FTC_Node*  pnode;
+    FT_UInt    idx;
+
+
+    idx = (FT_UInt)( hash & cache->mask );
+    if ( idx < cache->p )
+      idx = (FT_UInt)( 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 */
+#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_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_PtrDist 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_PtrDist  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_PtrDist  hash,
+                    FT_Pointer  query,
+                    FTC_Node   *anode )
+  {
+    FTC_Node*  bucket;
+    FTC_Node*  pnode;
+    FTC_Node   node;
+    FT_Error   error        = FTC_Err_Ok;
+    FT_Bool    list_changed = FALSE;
+
+    FTC_Node_CompareFunc  compare = cache->clazz.node_compare;
+
+
+    if ( cache == NULL || anode == NULL )
+      return FTC_Err_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 */