simple random data generator for tests

Reliance on /dev/urandom produces test vectors that are, well, random.
This can cause problems impossible to track down when the data is
different from one test invokation to another.

The goal is not to have random data to test, but rather to have a
convenient way to create sets of large files with non compressible and
non deltifiable data in a reproducible way.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Nicolas Pitre 2007-04-11 13:59:51 -04:00 committed by Junio C Hamano
parent 91ecbeca48
commit 2dca1af448
3 changed files with 40 additions and 2 deletions

1
.gitignore vendored
View File

@ -149,6 +149,7 @@ test-chmtime
test-date test-date
test-delta test-delta
test-dump-cache-tree test-dump-cache-tree
test-genrandom
test-match-trees test-match-trees
common-cmds.h common-cmds.h
*.tar.gz *.tar.gz

View File

@ -932,7 +932,7 @@ endif
export NO_SVN_TESTS export NO_SVN_TESTS
test: all test-chmtime$X test: all test-chmtime$X test-genrandom$X
$(MAKE) -C t/ all $(MAKE) -C t/ all
test-date$X: test-date.c date.o ctype.o test-date$X: test-date.c date.o ctype.o
@ -953,6 +953,9 @@ test-match-trees$X: test-match-trees.o $(GITLIBS)
test-chmtime$X: test-chmtime.c test-chmtime$X: test-chmtime.c
$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $< $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $<
test-genrandom$X: test-genrandom.c
$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $<
check-sha1:: test-sha1$X check-sha1:: test-sha1$X
./test-sha1.sh ./test-sha1.sh
@ -1041,7 +1044,7 @@ dist-doc:
clean: clean:
rm -f *.o mozilla-sha1/*.o arm/*.o ppc/*.o compat/*.o xdiff/*.o \ rm -f *.o mozilla-sha1/*.o arm/*.o ppc/*.o compat/*.o xdiff/*.o \
test-chmtime$X $(LIB_FILE) $(XDIFF_LIB) test-chmtime$X test-genrandom$X $(LIB_FILE) $(XDIFF_LIB)
rm -f $(ALL_PROGRAMS) $(BUILT_INS) git$X rm -f $(ALL_PROGRAMS) $(BUILT_INS) git$X
rm -f *.spec *.pyc *.pyo */*.pyc */*.pyo common-cmds.h TAGS tags rm -f *.spec *.pyc *.pyo */*.pyc */*.pyo common-cmds.h TAGS tags
rm -rf autom4te.cache rm -rf autom4te.cache

34
test-genrandom.c Normal file
View File

@ -0,0 +1,34 @@
/*
* Simple random data generator used to create reproducible test files.
* This is inspired from POSIX.1-2001 implementation example for rand().
* Copyright (C) 2007 by Nicolas Pitre, licensed under the GPL version 2.
*/
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
unsigned long count, next = 0;
unsigned char *c;
if (argc < 2 || argc > 3) {
fprintf( stderr, "Usage: %s <seed_string> [<size>]", argv[0]);
return 1;
}
c = (unsigned char *) argv[1];
do {
next = next * 11 + *c;
} while (*c++);
count = (argc == 3) ? strtoul(argv[2], NULL, 0) : -1L;
while (count--) {
next = next * 1103515245 + 12345;
if (putchar((next >> 16) & 0xff) == EOF)
return -1;
}
return 0;
}