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show-index.c
84 lines (80 loc) · 2.21 KB
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show-index.c
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#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];
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 = malloc(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;
}