Revision 55672a39b4e0f82e6f997879724ea37ca7e0d765 authored by Junio C Hamano on 09 May 2016, 18:36:09 UTC, committed by Junio C Hamano on 09 May 2016, 19:32:42 UTC
We never used the "letters" form since we came up with "test_seq" to
replace use of non-portable "seq" in our test script, which we
introduced it at d17cf5f3 (tests: Introduce test_seq, 2012-08-04).

We use this helper to either iterate for N times (i.e. the values on
the lines do not even matter), or just to get N distinct strings
(i.e. the values on the lines themselves do not really matter, but
we care that they are different from each other and reproducible).

Stop promising that we may allow using "letters"; this would open an
easier reimplementation that does not rely on $PERL, if somebody
later wants to.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 7654286
Raw File
show-index.c
#include "cache.h"
#include "pack.h"

static const char show_index_usage[] =
"git show-index < <packed archive index>";

int main(int argc, char **argv)
{
	int i;
	unsigned nr;
	unsigned int version;
	static unsigned int top_index[256];

	git_setup_gettext();

	if (argc != 1)
		usage(show_index_usage);
	if (fread(top_index, 2 * 4, 1, stdin) != 1)
		die("unable to read header");
	if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
		version = ntohl(top_index[1]);
		if (version < 2 || version > 2)
			die("unknown index version");
		if (fread(top_index, 256 * 4, 1, stdin) != 1)
			die("unable to read index");
	} else {
		version = 1;
		if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
			die("unable to read index");
	}
	nr = 0;
	for (i = 0; i < 256; i++) {
		unsigned n = ntohl(top_index[i]);
		if (n < nr)
			die("corrupt index file");
		nr = n;
	}
	if (version == 1) {
		for (i = 0; i < nr; i++) {
			unsigned int offset, entry[6];

			if (fread(entry, 4 + 20, 1, stdin) != 1)
				die("unable to read entry %u/%u", i, nr);
			offset = ntohl(entry[0]);
			printf("%u %s\n", offset, sha1_to_hex((void *)(entry+1)));
		}
	} else {
		unsigned off64_nr = 0;
		struct {
			unsigned char sha1[20];
			uint32_t crc;
			uint32_t off;
		} *entries = xmalloc(nr * sizeof(entries[0]));
		for (i = 0; i < nr; i++)
			if (fread(entries[i].sha1, 20, 1, stdin) != 1)
				die("unable to read sha1 %u/%u", i, nr);
		for (i = 0; i < nr; i++)
			if (fread(&entries[i].crc, 4, 1, stdin) != 1)
				die("unable to read crc %u/%u", i, nr);
		for (i = 0; i < nr; i++)
			if (fread(&entries[i].off, 4, 1, stdin) != 1)
				die("unable to read 32b offset %u/%u", i, nr);
		for (i = 0; i < nr; i++) {
			uint64_t offset;
			uint32_t off = ntohl(entries[i].off);
			if (!(off & 0x80000000)) {
				offset = off;
			} else {
				uint32_t off64[2];
				if ((off & 0x7fffffff) != off64_nr)
					die("inconsistent 64b offset index");
				if (fread(off64, 8, 1, stdin) != 1)
					die("unable to read 64b offset %u", off64_nr);
				offset = (((uint64_t)ntohl(off64[0])) << 32) |
						     ntohl(off64[1]);
				off64_nr++;
			}
			printf("%" PRIuMAX " %s (%08"PRIx32")\n",
			       (uintmax_t) offset,
			       sha1_to_hex(entries[i].sha1),
			       ntohl(entries[i].crc));
		}
		free(entries);
	}
	return 0;
}
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