fdo-mirrors/cairo
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/cairo/cairo.git synced 2026-06-19 01:58:39 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

script: Don't hash the entire image.

Browse source 
The reuse hit rate is very small, and most images are quickly
distinguished in the first few bytes... Though perhaps not for video as
in the swfdec-youtube case...
This commit is contained in:
Chris Wilson 2010-04-03 14:48:36 +01:00
parent a85c6c1e36
commit b9f7a4b526
1 changed files with 24 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

35
util/cairo-script/cairo-script-operators.c
View file

@ -126,19 +126,17 @@ _csi_proxy_destroy (void *closure)
cairo_script_interpreter_destroy (ctx);
}
static unsigned long
_csi_blob_hash (const uint8_t *bytes, int len)
static void
_csi_blob_hash (csi_blob_t *blob, const uint32_t *data, int len)
{
unsigned long hash = blob->hash;
/* very simple! */
unsigned long hash = 5381;
unsigned long *data = (unsigned long *) bytes;
len /= sizeof (unsigned long);
while (len--) {
unsigned long c = *data++;
hash *= 33;
hash ^= c;
}
return hash;
blob->hash = hash;
}
static csi_boolean_t
@ -152,10 +150,6 @@ _csi_blob_equal (const csi_list_t *link, void *data)
if (A->len != B->len)
return FALSE;
if (A->hash == 0)
A->hash = _csi_blob_hash (A->bytes, A->len);
if (B->hash == 0)
B->hash = _csi_blob_hash (B->bytes, B->len);
if (A->hash != B->hash)
return FALSE;
@ -165,7 +159,7 @@ _csi_blob_equal (const csi_list_t *link, void *data)
static void
_csi_blob_init (csi_blob_t *blob, uint8_t *bytes, int len)
{
blob->hash = 0;
blob->hash = 5381;
blob->len = len;
blob->bytes = bytes;
}
@ -1760,6 +1754,7 @@ _ft_create_for_source (csi_t *ctx,
/* check for an existing FT_Face (kept alive by the font cache) */
/* XXX index/flags */
_csi_blob_init (&tmpl, (uint8_t *) source->string, source->len);
_csi_blob_hash (&tmpl, (uint32_t *) source->string, source->len / sizeof (uint32_t));
link = _csi_list_find (ctx->_faces, _csi_blob_equal, &tmpl);
if (link) {
if (--source->base.ref == 0)
@ -1869,6 +1864,7 @@ _ft_create_for_pattern (csi_t *ctx,
void *bytes;
_csi_blob_init (&tmpl, (uint8_t *) string->string, string->len);
_csi_blob_hash (&tmpl, (uint32_t *) string->string, string->len / sizeof (uint32_t));
link = _csi_list_find (ctx->_faces, _csi_blob_equal, &tmpl);
if (link) {
if (--string->base.ref == 0)
@ -3082,6 +3078,22 @@ _image_tag_done (void *closure)
cairo_script_interpreter_destroy (ctx);
}
static void
_image_hash (csi_blob_t *blob,
cairo_surface_t *surface)
{
uint32_t value;
value = cairo_image_surface_get_width (surface);
_csi_blob_hash (blob, &value, 1);
value = cairo_image_surface_get_height (surface);
_csi_blob_hash (blob, &value, 1);
value = cairo_image_surface_get_format (surface);
_csi_blob_hash (blob, &value, 1);
}
static cairo_surface_t *
_image_cached (csi_t *ctx, cairo_surface_t *surface)
{
@ -3097,6 +3109,7 @@ _image_cached (csi_t *ctx, cairo_surface_t *surface)
stride = cairo_image_surface_get_stride (surface);
height = cairo_image_surface_get_height (surface);
_csi_blob_init (&tmpl, data, stride * height);
_image_hash (&tmpl, surface);
link = _csi_list_find (ctx->_images, _csi_blob_equal, &tmpl);
if (link) {
cairo_surface_destroy (surface);