2 * Copyright (c) 2005, 2006 Rene Scharfe
13 #define RECORDSIZE (512)
14 #define BLOCKSIZE (RECORDSIZE * 20)
16 static const char tar_tree_usage[] =
17 "git-tar-tree [--remote=<repo>] <ent> [basedir]";
19 static char block[BLOCKSIZE];
20 static unsigned long offset;
22 static time_t archive_time;
24 /* tries hard to write, either succeeds or dies in the attempt */
25 static void reliable_write(void *buf, unsigned long size)
28 long ret = xwrite(1, buf, size);
32 die("git-tar-tree: %s", strerror(errno));
34 die("git-tar-tree: disk full?");
41 /* writes out the whole block, but only if it is full */
42 static void write_if_needed(void)
44 if (offset == BLOCKSIZE) {
45 reliable_write(block, BLOCKSIZE);
51 * queues up writes, so that all our write(2) calls write exactly one
52 * full block; pads writes to RECORDSIZE
54 static void write_blocked(void *buf, unsigned long size)
59 unsigned long chunk = BLOCKSIZE - offset;
62 memcpy(block + offset, buf, chunk);
68 while (size >= BLOCKSIZE) {
69 reliable_write(buf, BLOCKSIZE);
74 memcpy(block + offset, buf, size);
77 tail = offset % RECORDSIZE;
79 memset(block + offset, 0, RECORDSIZE - tail);
80 offset += RECORDSIZE - tail;
86 * The end of tar archives is marked by 2*512 nul bytes and after that
87 * follows the rest of the block (if any).
89 static void write_trailer(void)
91 int tail = BLOCKSIZE - offset;
92 memset(block + offset, 0, tail);
93 reliable_write(block, BLOCKSIZE);
94 if (tail < 2 * RECORDSIZE) {
95 memset(block, 0, offset);
96 reliable_write(block, BLOCKSIZE);
100 static void strbuf_append_string(struct strbuf *sb, const char *s)
102 int slen = strlen(s);
103 int total = sb->len + slen;
104 if (total > sb->alloc) {
105 sb->buf = xrealloc(sb->buf, total);
108 memcpy(sb->buf + sb->len, s, slen);
113 * pax extended header records have the format "%u %s=%s\n". %u contains
114 * the size of the whole string (including the %u), the first %s is the
115 * keyword, the second one is the value. This function constructs such a
116 * string and appends it to a struct strbuf.
118 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
119 const char *value, unsigned int valuelen)
125 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
126 for (tmp = len; tmp > 9; tmp /= 10)
129 total = sb->len + len;
130 if (total > sb->alloc) {
131 sb->buf = xrealloc(sb->buf, total);
136 p += sprintf(p, "%u %s=", len, keyword);
137 memcpy(p, value, valuelen);
143 static unsigned int ustar_header_chksum(const struct ustar_header *header)
145 char *p = (char *)header;
146 unsigned int chksum = 0;
147 while (p < header->chksum)
149 chksum += sizeof(header->chksum) * ' ';
150 p += sizeof(header->chksum);
151 while (p < (char *)header + sizeof(struct ustar_header))
156 static int get_path_prefix(const struct strbuf *path, int maxlen)
163 } while (i > 0 && path->buf[i] != '/');
167 static void write_entry(const unsigned char *sha1, struct strbuf *path,
168 unsigned int mode, void *buffer, unsigned long size)
170 struct ustar_header header;
171 struct strbuf ext_header;
173 memset(&header, 0, sizeof(header));
174 ext_header.buf = NULL;
175 ext_header.len = ext_header.alloc = 0;
178 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
180 strcpy(header.name, "pax_global_header");
182 *header.typeflag = TYPEFLAG_EXT_HEADER;
184 sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
187 *header.typeflag = TYPEFLAG_DIR;
189 } else if (S_ISLNK(mode)) {
190 *header.typeflag = TYPEFLAG_LNK;
192 } else if (S_ISREG(mode)) {
193 *header.typeflag = TYPEFLAG_REG;
194 mode |= (mode & 0100) ? 0777 : 0666;
196 error("unsupported file mode: 0%o (SHA1: %s)",
197 mode, sha1_to_hex(sha1));
200 if (path->len > sizeof(header.name)) {
201 int plen = get_path_prefix(path, sizeof(header.prefix));
202 int rest = path->len - plen - 1;
203 if (plen > 0 && rest <= sizeof(header.name)) {
204 memcpy(header.prefix, path->buf, plen);
205 memcpy(header.name, path->buf + plen + 1, rest);
207 sprintf(header.name, "%s.data",
209 strbuf_append_ext_header(&ext_header, "path",
210 path->buf, path->len);
213 memcpy(header.name, path->buf, path->len);
216 if (S_ISLNK(mode) && buffer) {
217 if (size > sizeof(header.linkname)) {
218 sprintf(header.linkname, "see %s.paxheader",
220 strbuf_append_ext_header(&ext_header, "linkpath",
223 memcpy(header.linkname, buffer, size);
226 sprintf(header.mode, "%07o", mode & 07777);
227 sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
228 sprintf(header.mtime, "%011lo", archive_time);
230 /* XXX: should we provide more meaningful info here? */
231 sprintf(header.uid, "%07o", 0);
232 sprintf(header.gid, "%07o", 0);
233 safe_strncpy(header.uname, "git", sizeof(header.uname));
234 safe_strncpy(header.gname, "git", sizeof(header.gname));
235 sprintf(header.devmajor, "%07o", 0);
236 sprintf(header.devminor, "%07o", 0);
238 memcpy(header.magic, "ustar", 6);
239 memcpy(header.version, "00", 2);
241 sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
243 if (ext_header.len > 0) {
244 write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
245 free(ext_header.buf);
247 write_blocked(&header, sizeof(header));
248 if (S_ISREG(mode) && buffer && size > 0)
249 write_blocked(buffer, size);
252 static void write_global_extended_header(const unsigned char *sha1)
254 struct strbuf ext_header;
255 ext_header.buf = NULL;
256 ext_header.len = ext_header.alloc = 0;
257 strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
258 write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
259 free(ext_header.buf);
262 static void traverse_tree(struct tree_desc *tree, struct strbuf *path)
264 int pathlen = path->len;
265 struct name_entry entry;
267 while (tree_entry(tree, &entry)) {
270 unsigned long eltsize;
272 eltbuf = read_sha1_file(entry.sha1, elttype, &eltsize);
274 die("cannot read %s", sha1_to_hex(entry.sha1));
277 strbuf_append_string(path, entry.path);
278 if (S_ISDIR(entry.mode))
279 strbuf_append_string(path, "/");
281 write_entry(entry.sha1, path, entry.mode, eltbuf, eltsize);
283 if (S_ISDIR(entry.mode)) {
284 struct tree_desc subtree;
285 subtree.buf = eltbuf;
286 subtree.size = eltsize;
287 traverse_tree(&subtree, path);
293 static int generate_tar(int argc, const char **argv, char** envp)
295 unsigned char sha1[20], tree_sha1[20];
296 struct commit *commit;
297 struct tree_desc tree;
298 struct strbuf current_path;
300 current_path.buf = xmalloc(PATH_MAX);
301 current_path.alloc = PATH_MAX;
302 current_path.len = current_path.eof = 0;
304 setup_git_directory();
305 git_config(git_default_config);
309 strbuf_append_string(¤t_path, argv[2]);
310 strbuf_append_string(¤t_path, "/");
313 if (get_sha1(argv[1], sha1))
314 die("Not a valid object name %s", argv[1]);
317 usage(tar_tree_usage);
320 commit = lookup_commit_reference_gently(sha1, 1);
322 write_global_extended_header(commit->object.sha1);
323 archive_time = commit->date;
325 archive_time = time(NULL);
327 tree.buf = read_object_with_reference(sha1, tree_type, &tree.size,
330 die("not a reference to a tag, commit or tree object: %s",
333 if (current_path.len > 0)
334 write_entry(tree_sha1, ¤t_path, 040777, NULL, 0);
335 traverse_tree(&tree, ¤t_path);
337 free(current_path.buf);
341 static const char *exec = "git-upload-tar";
343 static int remote_tar(int argc, const char **argv)
350 if (argc < 3 || 4 < argc)
351 usage(tar_tree_usage);
353 /* --remote=<repo> */
354 url = strdup(argv[1]+9);
355 pid = git_connect(fd, url, exec);
359 packet_write(fd[1], "want %s\n", argv[2]);
361 packet_write(fd[1], "base %s\n", argv[3]);
364 len = packet_read_line(fd[0], buf, sizeof(buf));
366 die("git-tar-tree: expected ACK/NAK, got EOF");
367 if (buf[len-1] == '\n')
369 if (strcmp(buf, "ACK")) {
370 if (5 < len && !strncmp(buf, "NACK ", 5))
371 die("git-tar-tree: NACK %s", buf + 5);
372 die("git-tar-tree: protocol error");
375 len = packet_read_line(fd[0], buf, sizeof(buf));
377 die("git-tar-tree: expected a flush");
379 /* Now, start reading from fd[0] and spit it out to stdout */
380 ret = copy_fd(fd[0], 1);
383 ret |= finish_connect(pid);
387 int cmd_tar_tree(int argc, const char **argv, char **envp)
390 usage(tar_tree_usage);
391 if (!strncmp("--remote=", argv[1], 9))
392 return remote_tar(argc, argv);
393 return generate_tar(argc, argv, envp);
396 /* ustar header + extended global header content */
397 #define HEADERSIZE (2 * RECORDSIZE)
399 int cmd_get_tar_commit_id(int argc, const char **argv, char **envp)
401 char buffer[HEADERSIZE];
402 struct ustar_header *header = (struct ustar_header *)buffer;
403 char *content = buffer + RECORDSIZE;
406 n = xread(0, buffer, HEADERSIZE);
408 die("git-get-tar-commit-id: read error");
409 if (header->typeflag[0] != 'g')
411 if (memcmp(content, "52 comment=", 11))
414 n = xwrite(1, content + 11, 41);
416 die("git-get-tar-commit-id: write error");