netsurf/image/image_cache.c
Vincent Sanders 230779848e metadata links stored in contents
browser uses metadata links for favicons

svn path=/trunk/netsurf/; revision=12977
2011-10-07 18:12:47 +00:00

587 lines
15 KiB
C

/*
* Copyright 2011 Vincent Sanders <vince@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include "utils/errors.h"
#include "utils/log.h"
#include "utils/config.h"
#include "utils/schedule.h"
#include "content/content_protected.h"
#include "image/image_cache.h"
/** Age of an entry within the cache
*
* type deffed away so it can be readily changed later perhaps to a
* wallclock time structure.
*/
typedef unsigned int cache_age;
/** Image cache entry
*/
struct image_cache_entry_s {
struct image_cache_entry_s *next; /* next cache entry in list */
struct image_cache_entry_s *prev; /* previous cache entry in list */
struct content *content; /** content is used as a key */
struct bitmap *bitmap; /** associated bitmap entry */
/** Conversion routine */
image_cache_convert_fn *convert;
/* Statistics for replacement algorithm */
unsigned int redraw_count; /**< number of times object has been drawn */
cache_age redraw_age; /**< Age of last redraw */
size_t bitmap_size; /**< size if storage occupied by bitmap */
cache_age bitmap_age; /**< Age of last conversion to a bitmap by cache*/
int conversion_count; /**< Number of times image has been converted */
};
/** Current state of the cache.
*
* Global state of the cache. entries "age" is determined based on a
* monotonically incrementing operation count. This avoids issues with
* using wall clock time while allowing the LRU algorithm to work
* sensibly.
*/
struct image_cache_s {
/** Cache parameters */
struct image_cache_parameters params;
/** The "age" of the current operation */
cache_age current_age;
/* The objects the cache holds */
struct image_cache_entry_s *entries;
/* Statistics for management algorithm */
/** total size of bitmaps currently allocated */
size_t total_bitmap_size;
/** Total count of bitmaps currently allocated */
int bitmap_count;
/** Maximum size of bitmaps allocated at any one time */
size_t max_bitmap_size;
/** The number of objects when maximum bitmap usage occoured */
int max_bitmap_size_count;
/** Maximum count of bitmaps allocated at any one time */
int max_bitmap_count;
/** The size of the bitmaps when the max count occoured */
size_t max_bitmap_count_size;
/** Bitmap was not available at plot time required conversion */
int miss_count;
uint64_t miss_size;
/** Bitmap was available at plot time required no conversion */
int hit_count;
uint64_t hit_size;
/** Bitmap was not available at plot time and required
* conversion which failed.
*/
int fail_count;
uint64_t fail_size;
/* Cache entry freed without ever being redrawn */
int total_unrendered;
/** Bitmap was available but never required - wasted conversions */
int specultive_miss_count;
/** Total number of additional (after the first) conversions */
int total_extra_conversions;
/** counts total number of images with more than one conversion */
int total_extra_conversions_count;
/** Bitmap with most conversions was converted this many times */
int peak_conversions;
/** Size of bitmap with most conversions */
unsigned int peak_conversions_size;
};
/** image cache state */
static struct image_cache_s *image_cache = NULL;
/** Find the cache entry for a content
*/
static struct image_cache_entry_s *image_cache__find(const struct content *c)
{
struct image_cache_entry_s *found;
found = image_cache->entries;
while ((found != NULL) && (found->content != c)) {
found = found->next;
}
return found;
}
static void image_cache_stats_bitmap_add(struct image_cache_entry_s *centry)
{
centry->bitmap_age = image_cache->current_age;
centry->conversion_count++;
image_cache->total_bitmap_size += centry->bitmap_size;
image_cache->bitmap_count++;
if (image_cache->total_bitmap_size > image_cache->max_bitmap_size) {
image_cache->max_bitmap_size = image_cache->total_bitmap_size;
image_cache->max_bitmap_size_count = image_cache->bitmap_count;
}
if (image_cache->bitmap_count > image_cache->max_bitmap_count) {
image_cache->max_bitmap_count = image_cache->bitmap_count;
image_cache->max_bitmap_count_size = image_cache->total_bitmap_size;
}
centry->conversion_count++;
if (centry->conversion_count == 2) {
image_cache->total_extra_conversions_count++;
}
if (centry->conversion_count > 1) {
image_cache->total_extra_conversions++;
}
if ((centry->conversion_count > image_cache->peak_conversions) ||
(centry->conversion_count == image_cache->peak_conversions &&
centry->bitmap_size > image_cache->peak_conversions_size)) {
image_cache->peak_conversions = centry->conversion_count;
image_cache->peak_conversions_size = centry->bitmap_size;
}
}
static void image_cache__link(struct image_cache_entry_s *centry)
{
centry->next = image_cache->entries;
centry->prev = NULL;
if (centry->next != NULL) {
centry->next->prev = centry;
}
image_cache->entries = centry;
}
static void image_cache__unlink(struct image_cache_entry_s *centry)
{
/* unlink entry */
if (centry->prev == NULL) {
/* first in list */
if (centry->next != NULL) {
centry->next->prev = centry->prev;
image_cache->entries = centry->next;
} else {
/* empty list */
image_cache->entries = NULL;
}
} else {
centry->prev->next = centry->next;
if (centry->next != NULL) {
centry->next->prev = centry->prev;
}
}
}
static void image_cache__free_bitmap(struct image_cache_entry_s *centry)
{
if (centry->bitmap != NULL) {
#ifdef IMAGE_CACHE_VERBOSE
LOG(("Freeing bitmap %p size %d age %d redraw count %d",
centry->bitmap,
centry->bitmap_size,
image_cache->current_age - centry->bitmap_age,
centry->redraw_count));
#endif
bitmap_destroy(centry->bitmap);
centry->bitmap = NULL;
image_cache->total_bitmap_size -= centry->bitmap_size;
image_cache->bitmap_count--;
if (centry->redraw_count == 0) {
image_cache->specultive_miss_count++;
}
}
}
/* free cache entry */
static void image_cache__free_entry(struct image_cache_entry_s *centry)
{
#ifdef IMAGE_CACHE_VERBOSE
LOG(("freeing %p ", centry));
#endif
if (centry->redraw_count == 0) {
image_cache->total_unrendered++;
}
image_cache__free_bitmap(centry);
image_cache__unlink(centry);
free(centry);
}
/** Cache cleaner */
static void image_cache__clean(struct image_cache_s *icache)
{
struct image_cache_entry_s *centry = icache->entries;
while (centry != NULL) {
if ((icache->current_age - centry->redraw_age) >
icache->params.bg_clean_time) {
/* only consider older entries, avoids active entries */
if ((icache->total_bitmap_size >
(icache->params.limit - icache->params.hysteresis)) &&
(rand() > (RAND_MAX / 2))) {
image_cache__free_bitmap(centry);
}
}
centry=centry->next;
}
}
/** Cache background scheduled callback. */
static void image_cache__background_update(void *p)
{
struct image_cache_s *icache = p;
/* increment current cache age */
icache->current_age += icache->params.bg_clean_time;
#ifdef IMAGE_CACHE_VERBOSE
LOG(("Cache age %ds", icache->current_age / 1000));
#endif
image_cache__clean(icache);
schedule((icache->params.bg_clean_time / 10),
image_cache__background_update,
icache);
}
/* exported interface documented in image_cache.h */
struct bitmap *image_cache_get_bitmap(const struct content *c)
{
struct image_cache_entry_s *centry;
centry = image_cache__find(c);
if (centry == NULL) {
return NULL;
}
if (centry->bitmap == NULL) {
if (centry->convert != NULL) {
centry->bitmap = centry->convert(centry->content);
}
if (centry->bitmap != NULL) {
image_cache_stats_bitmap_add(centry);
image_cache->miss_count++;
image_cache->miss_size += centry->bitmap_size;
} else {
image_cache->fail_count++;
image_cache->fail_size += centry->bitmap_size;
}
} else {
image_cache->hit_count++;
image_cache->hit_size += centry->bitmap_size;
}
return centry->bitmap;
}
/* exported interface documented in image_cache.h */
bool image_cache_speculate(struct content *c)
{
bool decision = false;
/* If the cache is below its target usage and the bitmap is
* small enough speculate.
*/
if ((image_cache->total_bitmap_size < image_cache->params.limit) &&
(c->size <= image_cache->params.speculative_small)) {
#ifdef IMAGE_CACHE_VERBOSE
LOG(("content size (%d) is smaller than minimum (%d)", c->size, SPECULATE_SMALL));
#endif
decision = true;
}
#ifdef IMAGE_CACHE_VERBOSE
LOG(("returning %d", decision));
#endif
return decision;
}
/* exported interface documented in image_cache.h */
struct bitmap *image_cache_find_bitmap(struct content *c)
{
struct image_cache_entry_s *centry;
centry = image_cache__find(c);
if (centry == NULL) {
return NULL;
}
return centry->bitmap;
}
/* exported interface documented in image_cache.h */
nserror
image_cache_init(const struct image_cache_parameters *image_cache_parameters)
{
image_cache = calloc(1, sizeof(struct image_cache_s));
if (image_cache == NULL) {
return NSERROR_NOMEM;
}
image_cache->params = *image_cache_parameters;
schedule((image_cache->params.bg_clean_time / 10),
image_cache__background_update,
image_cache);
LOG(("Image cache initilised with a limit of %d hysteresis of %d",
image_cache->params.limit, image_cache->params.hysteresis));
return NSERROR_OK;
}
/* exported interface documented in image_cache.h */
nserror image_cache_fini(void)
{
unsigned int op_count;
schedule_remove(image_cache__background_update, image_cache);
LOG(("Size at finish %d (in %d)",
image_cache->total_bitmap_size,
image_cache->bitmap_count));
while (image_cache->entries != NULL) {
image_cache__free_entry(image_cache->entries);
}
op_count = image_cache->hit_count +
image_cache->miss_count +
image_cache->fail_count;
LOG(("Age %ds", image_cache->current_age / 1000));
LOG(("Peak size %d (in %d)",
image_cache->max_bitmap_size,
image_cache->max_bitmap_size_count ));
LOG(("Peak image count %d (size %d)",
image_cache->max_bitmap_count,
image_cache->max_bitmap_count_size));
if (op_count > 0) {
uint64_t op_size;
op_size = image_cache->hit_size +
image_cache->miss_size +
image_cache->fail_size;
LOG(("Cache total/hit/miss/fail (counts) %d/%d/%d/%d (100%%/%d%%/%d%%/%d%%)",
op_count,
image_cache->hit_count,
image_cache->miss_count,
image_cache->fail_count,
(image_cache->hit_count * 100) / op_count,
(image_cache->miss_count * 100) / op_count,
(image_cache->fail_count * 100) / op_count));
LOG(("Cache total/hit/miss/fail (size) %d/%d/%d/%d (100%%/%d%%/%d%%/%d%%)",
op_size,
image_cache->hit_size,
image_cache->miss_size,
image_cache->fail_size,
(image_cache->hit_size * 100) / op_size,
(image_cache->miss_size * 100) / op_size,
(image_cache->fail_size * 100) / op_size));
}
LOG(("Total images never rendered: %d (includes %d that were converted)",
image_cache->total_unrendered,
image_cache->specultive_miss_count));
LOG(("Total number of excessive conversions: %d (from %d images converted more than once)",
image_cache->total_extra_conversions,
image_cache->total_extra_conversions_count));
LOG(("Bitmap of size %d had most (%d) conversions",
image_cache->peak_conversions_size,
image_cache->peak_conversions));
free(image_cache);
return NSERROR_OK;
}
/* exported interface documented in image_cache.h */
nserror image_cache_add(struct content *content,
struct bitmap *bitmap,
image_cache_convert_fn *convert)
{
struct image_cache_entry_s *centry;
/* bump the cache age by a ms to ensure multiple items are not
* added at exactly the same time
*/
image_cache->current_age++;
centry = image_cache__find(content);
if (centry == NULL) {
/* new cache entry, content not previously added */
centry = calloc(1, sizeof(struct image_cache_entry_s));
if (centry == NULL) {
return NSERROR_NOMEM;
}
image_cache__link(centry);
centry->content = content;
centry->bitmap_size = content->width * content->height * 4;
}
LOG(("centry %p, content %p, bitmap %p", centry, content, bitmap));
centry->convert = convert;
/* set bitmap entry if one is passed, free extant one if present */
if (bitmap != NULL) {
if (centry->bitmap != NULL) {
bitmap_destroy(centry->bitmap);
} else {
image_cache_stats_bitmap_add(centry);
}
centry->bitmap = bitmap;
} else {
/* no bitmap, check to see if we should speculatively convert */
if ((centry->convert != NULL) &&
(image_cache_speculate(content) == true)) {
centry->bitmap = centry->convert(centry->content);
if (centry->bitmap != NULL) {
image_cache_stats_bitmap_add(centry);
} else {
image_cache->fail_count++;
}
}
}
return NSERROR_OK;
}
/* exported interface documented in image_cache.h */
nserror image_cache_remove(struct content *content)
{
struct image_cache_entry_s *centry;
/* get the cache entry */
centry = image_cache__find(content);
if (centry == NULL) {
LOG(("Could not find cache entry for content (%p)", content));
return NSERROR_NOT_FOUND;
}
image_cache__free_entry(centry);
return NSERROR_OK;
}
/* exported interface documented in image_cache.h */
bool image_cache_redraw(struct content *c,
struct content_redraw_data *data,
const struct rect *clip,
const struct redraw_context *ctx)
{
bitmap_flags_t flags = BITMAPF_NONE;
struct image_cache_entry_s *centry;
/* get the cache entry */
centry = image_cache__find(c);
if (centry == NULL) {
LOG(("Could not find cache entry for content (%p)", c));
return NULL;
}
if (centry->bitmap == NULL) {
if (centry->convert != NULL) {
centry->bitmap = centry->convert(centry->content);
}
if (centry->bitmap != NULL) {
image_cache_stats_bitmap_add(centry);
image_cache->miss_count++;
image_cache->miss_size += centry->bitmap_size;
} else {
image_cache->fail_count++;
image_cache->fail_size += centry->bitmap_size;
return false;
}
} else {
image_cache->hit_count++;
image_cache->hit_size += centry->bitmap_size;
}
/* update statistics */
centry->redraw_count++;
centry->redraw_age = image_cache->current_age;
/* do the plot */
if (data->repeat_x)
flags |= BITMAPF_REPEAT_X;
if (data->repeat_y)
flags |= BITMAPF_REPEAT_Y;
return ctx->plot->bitmap(data->x, data->y, data->width, data->height,
centry->bitmap, data->background_colour, flags);
}
void image_cache_destroy(struct content *content)
{
struct image_cache_entry_s *centry;
/* get the cache entry */
centry = image_cache__find(content);
if (centry == NULL) {
LOG(("Could not find cache entry for content (%p)", content));
} else {
image_cache__free_entry(centry);
}
}
void *image_cache_get_internal(const struct content *c, void *context)
{
return image_cache_get_bitmap(c);
}
content_type image_cache_content_type(void)
{
return CONTENT_IMAGE;
}