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db5e523fdd
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
214 lines
4.5 KiB
C
214 lines
4.5 KiB
C
#include "builtin.h"
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#include "cache.h"
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#include "object.h"
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#include "blob.h"
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#include "delta.h"
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#include "pack.h"
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#include "csum-file.h"
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static int max_depth = 10;
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static unsigned long object_count;
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static int packfd;
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static int current_depth;
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static void *lastdat;
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static unsigned long lastdatlen;
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static unsigned char lastsha1[20];
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static ssize_t yread(int fd, void *buffer, size_t length)
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{
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ssize_t ret = 0;
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while (ret < length) {
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ssize_t size = xread(fd, (char *) buffer + ret, length - ret);
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if (size < 0) {
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return size;
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}
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if (size == 0) {
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return ret;
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}
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ret += size;
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}
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return ret;
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}
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static ssize_t ywrite(int fd, void *buffer, size_t length)
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{
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ssize_t ret = 0;
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while (ret < length) {
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ssize_t size = xwrite(fd, (char *) buffer + ret, length - ret);
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if (size < 0) {
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return size;
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}
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if (size == 0) {
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return ret;
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}
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ret += size;
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}
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return ret;
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}
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static unsigned long encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
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{
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int n = 1;
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unsigned char c;
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if (type < OBJ_COMMIT || type > OBJ_DELTA)
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die("bad type %d", type);
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c = (type << 4) | (size & 15);
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size >>= 4;
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while (size) {
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*hdr++ = c | 0x80;
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c = size & 0x7f;
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size >>= 7;
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n++;
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}
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*hdr = c;
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return n;
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}
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static void write_blob (void *dat, unsigned long datlen)
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{
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z_stream s;
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void *out, *delta;
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unsigned char hdr[64];
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unsigned long hdrlen, deltalen;
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if (lastdat && current_depth < max_depth) {
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delta = diff_delta(lastdat, lastdatlen,
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dat, datlen,
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&deltalen, 0);
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} else
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delta = 0;
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memset(&s, 0, sizeof(s));
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deflateInit(&s, zlib_compression_level);
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if (delta) {
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current_depth++;
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s.next_in = delta;
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s.avail_in = deltalen;
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hdrlen = encode_header(OBJ_DELTA, deltalen, hdr);
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if (ywrite(packfd, hdr, hdrlen) != hdrlen)
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die("Can't write object header: %s", strerror(errno));
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if (ywrite(packfd, lastsha1, sizeof(lastsha1)) != sizeof(lastsha1))
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die("Can't write object base: %s", strerror(errno));
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} else {
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current_depth = 0;
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s.next_in = dat;
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s.avail_in = datlen;
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hdrlen = encode_header(OBJ_BLOB, datlen, hdr);
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if (ywrite(packfd, hdr, hdrlen) != hdrlen)
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die("Can't write object header: %s", strerror(errno));
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}
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s.avail_out = deflateBound(&s, s.avail_in);
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s.next_out = out = xmalloc(s.avail_out);
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while (deflate(&s, Z_FINISH) == Z_OK)
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/* nothing */;
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deflateEnd(&s);
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if (ywrite(packfd, out, s.total_out) != s.total_out)
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die("Failed writing compressed data %s", strerror(errno));
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free(out);
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if (delta)
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free(delta);
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}
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static void init_pack_header ()
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{
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const char* magic = "PACK";
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unsigned long version = 2;
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unsigned long zero = 0;
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version = htonl(version);
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if (ywrite(packfd, (char*)magic, 4) != 4)
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die("Can't write pack magic: %s", strerror(errno));
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if (ywrite(packfd, &version, 4) != 4)
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die("Can't write pack version: %s", strerror(errno));
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if (ywrite(packfd, &zero, 4) != 4)
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die("Can't write 0 object count: %s", strerror(errno));
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}
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static void fixup_header_footer ()
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{
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SHA_CTX c;
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char hdr[8];
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unsigned char sha1[20];
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unsigned long cnt;
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char *buf;
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size_t n;
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if (lseek(packfd, 0, SEEK_SET) != 0)
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die("Failed seeking to start: %s", strerror(errno));
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SHA1_Init(&c);
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if (yread(packfd, hdr, 8) != 8)
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die("Failed reading header: %s", strerror(errno));
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SHA1_Update(&c, hdr, 8);
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fprintf(stderr, "%lu objects\n", object_count);
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cnt = htonl(object_count);
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SHA1_Update(&c, &cnt, 4);
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if (ywrite(packfd, &cnt, 4) != 4)
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die("Failed writing object count: %s", strerror(errno));
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buf = xmalloc(128 * 1024);
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for (;;) {
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n = xread(packfd, buf, 128 * 1024);
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if (n <= 0)
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break;
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SHA1_Update(&c, buf, n);
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}
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free(buf);
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SHA1_Final(sha1, &c);
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if (ywrite(packfd, sha1, sizeof(sha1)) != sizeof(sha1))
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die("Failed writing pack checksum: %s", strerror(errno));
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}
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int main (int argc, const char **argv)
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{
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packfd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666);
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if (packfd < 0)
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die("Can't create pack file %s: %s", argv[1], strerror(errno));
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init_pack_header();
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for (;;) {
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unsigned long datlen;
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int hdrlen;
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void *dat;
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char hdr[128];
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unsigned char sha1[20];
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SHA_CTX c;
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if (yread(0, &datlen, 4) != 4)
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break;
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dat = xmalloc(datlen);
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if (yread(0, dat, datlen) != datlen)
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break;
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hdrlen = sprintf(hdr, "blob %lu", datlen) + 1;
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SHA1_Init(&c);
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SHA1_Update(&c, hdr, hdrlen);
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SHA1_Update(&c, dat, datlen);
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SHA1_Final(sha1, &c);
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write_blob(dat, datlen);
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object_count++;
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printf("%s\n", sha1_to_hex(sha1));
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fflush(stdout);
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if (lastdat)
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free(lastdat);
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lastdat = dat;
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lastdatlen = datlen;
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memcpy(lastsha1, sha1, sizeof(sha1));
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}
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fixup_header_footer();
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close(packfd);
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return 0;
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}
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