git/test-delta.c
Nicolas Pitre 38fd0721d0 diff-delta: allow reusing of the reference buffer index
When a reference buffer is used multiple times then its index can be
computed only once and reused multiple times.  This patch adds an extra
pointer to a pointer argument (from_index) to diff_delta() for this.

If from_index is NULL then everything is like before.

If from_index is non NULL and *from_index is NULL then the index is
created and its location stored to *from_index.  In this case the caller
has the responsibility to free the memory pointed to by *from_index.

If from_index and *from_index are non NULL then the index is reused as
is.

This currently saves about 10% of CPU time to repack the git archive.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-01 21:53:22 -08:00

84 lines
1.8 KiB
C

/*
* test-delta.c: test code to exercise diff-delta.c and patch-delta.c
*
* (C) 2005 Nicolas Pitre <nico@cam.org>
*
* This code is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include "delta.h"
static const char usage[] =
"test-delta (-d|-p) <from_file> <data_file> <out_file>";
int main(int argc, char *argv[])
{
int fd;
struct stat st;
void *from_buf, *data_buf, *out_buf;
unsigned long from_size, data_size, out_size;
if (argc != 5 || (strcmp(argv[1], "-d") && strcmp(argv[1], "-p"))) {
fprintf(stderr, "Usage: %s\n", usage);
return 1;
}
fd = open(argv[2], O_RDONLY);
if (fd < 0 || fstat(fd, &st)) {
perror(argv[2]);
return 1;
}
from_size = st.st_size;
from_buf = mmap(NULL, from_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (from_buf == MAP_FAILED) {
perror(argv[2]);
close(fd);
return 1;
}
close(fd);
fd = open(argv[3], O_RDONLY);
if (fd < 0 || fstat(fd, &st)) {
perror(argv[3]);
return 1;
}
data_size = st.st_size;
data_buf = mmap(NULL, data_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (data_buf == MAP_FAILED) {
perror(argv[3]);
close(fd);
return 1;
}
close(fd);
if (argv[1][1] == 'd')
out_buf = diff_delta(from_buf, from_size,
data_buf, data_size,
&out_size, 0);
else
out_buf = patch_delta(from_buf, from_size,
data_buf, data_size,
&out_size);
if (!out_buf) {
fprintf(stderr, "delta operation failed (returned NULL)\n");
return 1;
}
fd = open (argv[4], O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (fd < 0 || write(fd, out_buf, out_size) != out_size) {
perror(argv[4]);
return 1;
}
return 0;
}