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minimum bytes for mmap windows

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This commit is contained in:
John Cupitt 2009-12-10 12:34:50 +00:00
parent 3ebc6d947f
commit 3894464e42
4 changed files with 26 additions and 33 deletions
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2
ChangeLog
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@ -4,6 +4,8 @@
- argh, im_measure() was not looping over bands correctly (thanks Peter)
- removed mmap_limit, we now always use windows ... reduces VM use hugely,
because mmap windows are freed when their regions are freed
- have a min bytes for mmap windows as well, so we don't make too many tiny
windows
26/11/09 started 7.20.3
- updated en_GB.po translation

7
TODO
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@ -1,6 +1,3 @@
WONTFIX for 7.20
================
- some of deprecated.h repeats stuff we do better in image.h, eg. addr()
should just call IM_REGION_ADDR()
@ -63,10 +60,6 @@ Actions:
how can we move them to im_affinei ?
- make a "deprecated" package too
- update the Portfiles on the mac and on the website from the macports ones
- radiance read/write needs docs
maybe have an im_format(3) page with all the built-in formats?

11
libvips/include/vips/private.h
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@ -41,10 +41,15 @@ extern "C" {
#define IM_SPARE (8)
/* Private to iofuncs: the image size above which we switch from
* mmap()-whole-image behaviour to mmap()-window, plus window margins.
/* Private to iofuncs: the minimum number of scanlines we add above and below
* the window as a margin for slop.
*/
#define IM__WINDOW_MARGIN (128)
#define IM__WINDOW_MARGIN_PIXELS (128)
/* Private to iofuncs: add at least this many bytes above and below the window.
* There's no point mapping just a few KB of a small image.
*/
#define IM__WINDOW_MARGIN_BYTES (1024 * 1024 * 10)
/* sizeof() a VIPS header on disc.
*/

39
libvips/iofuncs/window.c
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@ -33,7 +33,6 @@
*/
/*
#define DEBUG_ENVIRONMENT
#define DEBUG_TOTAL
#define DEBUG
*/
@ -74,7 +73,12 @@ int im__read_test;
/* Add this many lines above and below the mmap() window.
*/
int im__window_margin = IM__WINDOW_MARGIN;
int im__window_margin_pixels = IM__WINDOW_MARGIN_PIXELS;
/* Always map at least this many bytes. There's no point making tiny windows
* on small files.
*/
int im__window_margin_bytes = IM__WINDOW_MARGIN_BYTES;
/* Track global mmap usage.
*/
@ -219,7 +223,7 @@ im_window_set( im_window_t *window, int top, int height )
gint64 start, end, pagestart;
size_t length, pagelength;
/* Calculate start and length for our window.
/* Calculate start and length for our window.
*/
start = window->im->sizeof_header +
(gint64) IM_IMAGE_SIZEOF_LINE( window->im ) * top;
@ -347,31 +351,20 @@ im_window_t *
im_window_ref( IMAGE *im, int top, int height )
{
im_window_t *window;
#ifdef DEBUG_ENVIRONMENT
static const char *str = NULL;
#endif /*DEBUG_ENVIRONMENT*/
#ifdef DEBUG_ENVIRONMENT
if( !str ) {
if( (str = g_getenv( "IM_WINDOW_MARGIN" )) ) {
printf( "iofuncs/region.c: "
"compiled with DEBUG_ENVIRONMENT enabled\n" );
im__window_margin = atoi( str );
printf( "im_region_create: setting window margin to %d "
"from environment\n", im__window_margin );
}
else
str = "done";
}
#endif /*DEBUG_ENVIRONMENT*/
g_mutex_lock( im->sslock );
if( !(window = im_window_find( im, top, height )) ) {
/* No existing window ... make a new one.
/* No existing window ... make a new one. Ask for a larger
* window than we strictly need. There's no point making tiny
* windows.
*/
top -= im__window_margin;
height += im__window_margin * 2;
int margin = IM_MIN( im__window_margin_pixels,
im__window_margin_bytes / IM_IMAGE_SIZEOF_LINE( im ) );
top -= margin;
height += margin * 2;
top = IM_CLIP( 0, top, im->Ysize - 1 );
height = IM_CLIP( 0, height, im->Ysize - top );