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![brian m. carlson](/assets/img/avatar_default.png)
show-index is capable of reading any possible index file whether or not the index is inside a repository. However, because our index files lack metadata about the hash algorithm in use, it's not possible to autodetect the algorithm that a particular index file is using. In order to allow us to read index files of any algorithm, let's set up the .git directory gently so that we default to the algorithm for the current repository, and add an --object-format option to allow users to override this setting and continue to run show-index outside of a repository altogether. Let's also document this new option so that people can find it and use it. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
#include "builtin.h"
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#include "cache.h"
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#include "pack.h"
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#include "parse-options.h"
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static const char *const show_index_usage[] = {
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"git show-index [--object-format=<hash-algorithm>]",
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NULL
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};
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int cmd_show_index(int argc, const char **argv, const char *prefix)
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{
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int i;
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unsigned nr;
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unsigned int version;
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static unsigned int top_index[256];
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unsigned hashsz;
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const char *hash_name = NULL;
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int hash_algo;
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const struct option show_index_options[] = {
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OPT_STRING(0, "object-format", &hash_name, N_("hash-algorithm"),
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N_("specify the hash algorithm to use")),
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OPT_END()
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};
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argc = parse_options(argc, argv, prefix, show_index_options, show_index_usage, 0);
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if (hash_name) {
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hash_algo = hash_algo_by_name(hash_name);
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if (hash_algo == GIT_HASH_UNKNOWN)
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die(_("Unknown hash algorithm"));
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repo_set_hash_algo(the_repository, hash_algo);
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}
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hashsz = the_hash_algo->rawsz;
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if (fread(top_index, 2 * 4, 1, stdin) != 1)
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die("unable to read header");
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if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
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version = ntohl(top_index[1]);
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if (version < 2 || version > 2)
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die("unknown index version");
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if (fread(top_index, 256 * 4, 1, stdin) != 1)
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die("unable to read index");
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} else {
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version = 1;
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if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
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die("unable to read index");
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}
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nr = 0;
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for (i = 0; i < 256; i++) {
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unsigned n = ntohl(top_index[i]);
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if (n < nr)
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die("corrupt index file");
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nr = n;
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}
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if (version == 1) {
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for (i = 0; i < nr; i++) {
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unsigned int offset, entry[(GIT_MAX_RAWSZ + 4) / sizeof(unsigned int)];
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if (fread(entry, 4 + hashsz, 1, stdin) != 1)
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die("unable to read entry %u/%u", i, nr);
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offset = ntohl(entry[0]);
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printf("%u %s\n", offset, hash_to_hex((void *)(entry+1)));
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}
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} else {
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unsigned off64_nr = 0;
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struct {
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struct object_id oid;
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uint32_t crc;
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uint32_t off;
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} *entries;
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ALLOC_ARRAY(entries, nr);
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for (i = 0; i < nr; i++)
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if (fread(entries[i].oid.hash, hashsz, 1, stdin) != 1)
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die("unable to read sha1 %u/%u", i, nr);
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for (i = 0; i < nr; i++)
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if (fread(&entries[i].crc, 4, 1, stdin) != 1)
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die("unable to read crc %u/%u", i, nr);
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for (i = 0; i < nr; i++)
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if (fread(&entries[i].off, 4, 1, stdin) != 1)
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die("unable to read 32b offset %u/%u", i, nr);
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for (i = 0; i < nr; i++) {
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uint64_t offset;
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uint32_t off = ntohl(entries[i].off);
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if (!(off & 0x80000000)) {
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offset = off;
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} else {
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uint32_t off64[2];
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if ((off & 0x7fffffff) != off64_nr)
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die("inconsistent 64b offset index");
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if (fread(off64, 8, 1, stdin) != 1)
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die("unable to read 64b offset %u", off64_nr);
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offset = (((uint64_t)ntohl(off64[0])) << 32) |
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ntohl(off64[1]);
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off64_nr++;
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}
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printf("%" PRIuMAX " %s (%08"PRIx32")\n",
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(uintmax_t) offset,
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oid_to_hex(&entries[i].oid),
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ntohl(entries[i].crc));
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}
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free(entries);
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}
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return 0;
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}
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