cairo/src/cairo-rtree.c
Chris Wilson 2a07263373 rtree: defer propagating pinned nodes until eviction.
Only during infrequent eviction do we require absolute knowledge of
which graph of nodes are in use and thus pinned. So during the common
use of querying the glyph cache, we just mark the leaf as used. Then we
need to make space for a new glyph, we move the parents of the left
nodes from the evictable list to the pinned list.
2010-05-12 20:54:49 +01:00

396 lines
10 KiB
C

/* cairo - a vector graphics library with display and print output
*
* Copyright © 2009 Chris Wilson
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Chris Wilson.
*
* Contributor(s):
* Chris Wilson <chris@chris-wilson.co.uk>
*
*/
#include "cairoint.h"
#include "cairo-error-private.h"
#include "cairo-rtree-private.h"
cairo_rtree_node_t *
_cairo_rtree_node_create (cairo_rtree_t *rtree,
cairo_rtree_node_t *parent,
int x,
int y,
int width,
int height)
{
cairo_rtree_node_t *node;
node = _cairo_freepool_alloc (&rtree->node_freepool);
if (node == NULL) {
_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
return NULL;
}
node->children[0] = NULL;
node->parent = parent;
node->owner = NULL;
node->state = CAIRO_RTREE_NODE_AVAILABLE;
node->pinned = FALSE;
node->x = x;
node->y = y;
node->width = width;
node->height = height;
cairo_list_add (&node->link, &rtree->available);
return node;
}
void
_cairo_rtree_node_destroy (cairo_rtree_t *rtree, cairo_rtree_node_t *node)
{
int i;
cairo_list_del (&node->link);
if (node->state == CAIRO_RTREE_NODE_OCCUPIED) {
if (node->owner != NULL)
*node->owner = NULL;
if (rtree->evict != NULL)
rtree->evict (node);
} else {
for (i = 0; i < 4 && node->children[i] != NULL; i++)
_cairo_rtree_node_destroy (rtree, node->children[i]);
}
_cairo_freepool_free (&rtree->node_freepool, node);
}
void
_cairo_rtree_node_collapse (cairo_rtree_t *rtree, cairo_rtree_node_t *node)
{
int i;
do {
assert (node->state == CAIRO_RTREE_NODE_DIVIDED);
for (i = 0; i < 4 && node->children[i] != NULL; i++)
if (node->children[i]->state != CAIRO_RTREE_NODE_AVAILABLE)
return;
for (i = 0; i < 4 && node->children[i] != NULL; i++)
_cairo_rtree_node_destroy (rtree, node->children[i]);
node->children[0] = NULL;
node->state = CAIRO_RTREE_NODE_AVAILABLE;
cairo_list_move (&node->link, &rtree->available);
} while ((node = node->parent) != NULL);
}
cairo_status_t
_cairo_rtree_node_insert (cairo_rtree_t *rtree,
cairo_rtree_node_t *node,
int width,
int height,
cairo_rtree_node_t **out)
{
int w, h, i;
assert (node->state == CAIRO_RTREE_NODE_AVAILABLE);
assert (node->pinned == FALSE);
if (node->width - width > rtree->min_size ||
node->height - height > rtree->min_size)
{
w = node->width - width;
h = node->height - height;
i = 0;
node->children[i] = _cairo_rtree_node_create (rtree, node,
node->x, node->y,
width, height);
if (unlikely (node->children[i] == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
i++;
if (w > rtree->min_size) {
node->children[i] = _cairo_rtree_node_create (rtree, node,
node->x + width,
node->y,
w, height);
if (unlikely (node->children[i] == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
i++;
}
if (h > rtree->min_size) {
node->children[i] = _cairo_rtree_node_create (rtree, node,
node->x,
node->y + height,
width, h);
if (unlikely (node->children[i] == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
i++;
if (w > rtree->min_size) {
node->children[i] = _cairo_rtree_node_create (rtree, node,
node->x + width,
node->y + height,
w, h);
if (unlikely (node->children[i] == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
i++;
}
}
if (i < 4)
node->children[i] = NULL;
node->state = CAIRO_RTREE_NODE_DIVIDED;
cairo_list_move (&node->link, &rtree->evictable);
node = node->children[0];
}
node->state = CAIRO_RTREE_NODE_OCCUPIED;
cairo_list_move (&node->link, &rtree->evictable);
*out = node;
return CAIRO_STATUS_SUCCESS;
}
void
_cairo_rtree_node_remove (cairo_rtree_t *rtree, cairo_rtree_node_t *node)
{
assert (node->state == CAIRO_RTREE_NODE_OCCUPIED);
assert (node->pinned == FALSE);
node->state = CAIRO_RTREE_NODE_AVAILABLE;
cairo_list_move (&node->link, &rtree->available);
_cairo_rtree_node_collapse (rtree, node->parent);
}
cairo_int_status_t
_cairo_rtree_insert (cairo_rtree_t *rtree,
int width,
int height,
cairo_rtree_node_t **out)
{
cairo_rtree_node_t *node;
cairo_list_foreach_entry (node, cairo_rtree_node_t,
&rtree->available, link)
{
if (node->width >= width && node->height >= height)
return _cairo_rtree_node_insert (rtree, node, width, height, out);
}
return CAIRO_INT_STATUS_UNSUPPORTED;
}
static uint32_t
hars_petruska_f54_1_random (void)
{
#define rol(x,k) ((x << k) | (x >> (32-k)))
static uint32_t x;
return x = (x ^ rol (x, 5) ^ rol (x, 24)) + 0x37798849;
#undef rol
}
cairo_int_status_t
_cairo_rtree_evict_random (cairo_rtree_t *rtree,
int width,
int height,
cairo_rtree_node_t **out)
{
cairo_rtree_node_t *node, *next;
int i, cnt;
/* propagate pinned from children to root */
cairo_list_foreach_entry_safe (node, next, cairo_rtree_node_t,
&rtree->pinned, link)
{
if (node->parent != NULL)
_cairo_rtree_pin (rtree, node->parent);
}
cnt = 0;
cairo_list_foreach_entry (node, cairo_rtree_node_t,
&rtree->evictable, link)
{
if (node->width >= width && node->height >= height)
cnt++;
}
if (cnt == 0)
return CAIRO_INT_STATUS_UNSUPPORTED;
cnt = hars_petruska_f54_1_random () % cnt;
cairo_list_foreach_entry (node, cairo_rtree_node_t,
&rtree->evictable, link)
{
if (node->width >= width && node->height >= height && cnt-- == 0) {
if (node->state == CAIRO_RTREE_NODE_OCCUPIED) {
if (node->owner != NULL)
*node->owner = NULL;
if (rtree->evict != NULL)
rtree->evict (node);
} else {
for (i = 0; i < 4 && node->children[i] != NULL; i++)
_cairo_rtree_node_destroy (rtree, node->children[i]);
node->children[0] = NULL;
}
node->state = CAIRO_RTREE_NODE_AVAILABLE;
cairo_list_move (&node->link, &rtree->available);
*out = node;
return CAIRO_STATUS_SUCCESS;
}
}
return CAIRO_INT_STATUS_UNSUPPORTED;
}
void
_cairo_rtree_unpin (cairo_rtree_t *rtree)
{
cairo_rtree_node_t *node, *next;
cairo_list_t can_collapse;
if (cairo_list_is_empty (&rtree->pinned))
return;
cairo_list_init (&can_collapse);
cairo_list_foreach_entry_safe (node, next,
cairo_rtree_node_t,
&rtree->pinned,
link)
{
node->pinned = FALSE;
if (node->state == CAIRO_RTREE_NODE_OCCUPIED && node->owner == NULL) {
cairo_bool_t all_available;
int i;
node->state = CAIRO_RTREE_NODE_AVAILABLE;
cairo_list_move (&node->link, &rtree->available);
all_available = TRUE;
node = node->parent;
for (i = 0; i < 4 && node->children[i] != NULL && all_available; i++)
all_available &= node->children[i]->state == CAIRO_RTREE_NODE_AVAILABLE;
if (all_available) {
cairo_list_move (&node->link, &can_collapse);
for (i = 0; i < 4 && node->children[i] != NULL; i++)
cairo_list_del (&node->children[i]->link);
}
}
else
{
cairo_list_move (&node->link, &rtree->evictable);
}
}
cairo_list_foreach_entry_safe (node, next,
cairo_rtree_node_t,
&can_collapse,
link)
{
_cairo_rtree_node_collapse (rtree, node);
}
}
void
_cairo_rtree_init (cairo_rtree_t *rtree,
int width,
int height,
int min_size,
int node_size,
void (*evict) (void *node))
{
rtree->evict = evict;
assert (node_size >= (int) sizeof (cairo_rtree_node_t));
_cairo_freepool_init (&rtree->node_freepool, node_size);
cairo_list_init (&rtree->available);
cairo_list_init (&rtree->pinned);
cairo_list_init (&rtree->evictable);
rtree->min_size = min_size;
memset (&rtree->root, 0, sizeof (rtree->root));
rtree->root.width = width;
rtree->root.height = height;
rtree->root.state = CAIRO_RTREE_NODE_AVAILABLE;
cairo_list_add (&rtree->root.link, &rtree->available);
}
void
_cairo_rtree_reset (cairo_rtree_t *rtree)
{
int i;
if (rtree->root.state == CAIRO_RTREE_NODE_OCCUPIED) {
if (rtree->root.owner != NULL)
*rtree->root.owner = NULL;
if (rtree->evict != NULL)
rtree->evict (&rtree->root);
} else {
for (i = 0; i < 4 && rtree->root.children[i] != NULL; i++)
_cairo_rtree_node_destroy (rtree, rtree->root.children[i]);
rtree->root.children[0] = NULL;
}
cairo_list_init (&rtree->available);
cairo_list_init (&rtree->evictable);
cairo_list_init (&rtree->pinned);
rtree->root.state = CAIRO_RTREE_NODE_AVAILABLE;
rtree->root.pinned = FALSE;
cairo_list_add (&rtree->root.link, &rtree->available);
}
void
_cairo_rtree_fini (cairo_rtree_t *rtree)
{
int i;
if (rtree->root.state == CAIRO_RTREE_NODE_OCCUPIED) {
if (rtree->root.owner != NULL)
*rtree->root.owner = NULL;
if (rtree->evict != NULL)
rtree->evict (&rtree->root);
} else {
for (i = 0; i < 4 && rtree->root.children[i] != NULL; i++)
_cairo_rtree_node_destroy (rtree, rtree->root.children[i]);
}
_cairo_freepool_fini (&rtree->node_freepool);
}