git/builtin/show-index.c
brian m. carlson dd15f4f457 builtin/show-index: set the algorithm for object IDs
In most cases, when we load the hash of an object into a struct
object_id, we load it using one of the oid* or *_oid_hex functions.
However, for git show-index, we read it in directly using fread.  As a
consequence, set the algorithm correctly so the objects can be used
correctly both now and in the future.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-27 16:31:39 +09:00

108 lines
2.9 KiB
C

#include "builtin.h"
#include "cache.h"
#include "pack.h"
#include "parse-options.h"
static const char *const show_index_usage[] = {
"git show-index [--object-format=<hash-algorithm>]",
NULL
};
int cmd_show_index(int argc, const char **argv, const char *prefix)
{
int i;
unsigned nr;
unsigned int version;
static unsigned int top_index[256];
unsigned hashsz;
const char *hash_name = NULL;
int hash_algo;
const struct option show_index_options[] = {
OPT_STRING(0, "object-format", &hash_name, N_("hash-algorithm"),
N_("specify the hash algorithm to use")),
OPT_END()
};
argc = parse_options(argc, argv, prefix, show_index_options, show_index_usage, 0);
if (hash_name) {
hash_algo = hash_algo_by_name(hash_name);
if (hash_algo == GIT_HASH_UNKNOWN)
die(_("Unknown hash algorithm"));
repo_set_hash_algo(the_repository, hash_algo);
}
hashsz = the_hash_algo->rawsz;
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[(GIT_MAX_RAWSZ + 4) / sizeof(unsigned int)];
if (fread(entry, 4 + hashsz, 1, stdin) != 1)
die("unable to read entry %u/%u", i, nr);
offset = ntohl(entry[0]);
printf("%u %s\n", offset, hash_to_hex((void *)(entry+1)));
}
} else {
unsigned off64_nr = 0;
struct {
struct object_id oid;
uint32_t crc;
uint32_t off;
} *entries;
ALLOC_ARRAY(entries, nr);
for (i = 0; i < nr; i++) {
if (fread(entries[i].oid.hash, hashsz, 1, stdin) != 1)
die("unable to read sha1 %u/%u", i, nr);
entries[i].oid.algo = hash_algo_by_ptr(the_hash_algo);
}
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,
oid_to_hex(&entries[i].oid),
ntohl(entries[i].crc));
}
free(entries);
}
return 0;
}