4 #define RECORDSIZE (512)
5 #define BLOCKSIZE (RECORDSIZE * 20)
7 #define TYPEFLAG_AUTO '\0'
8 #define TYPEFLAG_REG '0'
9 #define TYPEFLAG_LNK '2'
10 #define TYPEFLAG_DIR '5'
11 #define TYPEFLAG_GLOBAL_HEADER 'g'
12 #define TYPEFLAG_EXT_HEADER 'x'
14 #define EXT_HEADER_PATH 1
15 #define EXT_HEADER_LINKPATH 2
17 static const char *tar_tree_usage = "tar-tree <key> [basedir]";
19 static char block[BLOCKSIZE];
20 static unsigned long offset;
22 static const char *basedir;
23 static time_t archive_time;
26 struct path_prefix *prev;
30 /* tries hard to write, either succeeds or dies in the attempt */
31 static void reliable_write(void *buf, unsigned long size)
34 long ret = write(1, buf, size);
40 die("tar-tree: %s", strerror(errno));
42 die("tar-tree: disk full?");
49 /* writes out the whole block, but only if it is full */
50 static void write_if_needed(void)
52 if (offset == BLOCKSIZE) {
53 reliable_write(block, BLOCKSIZE);
58 /* acquire the next record from the buffer; user must call write_if_needed() */
59 static char *get_record(void)
61 char *p = block + offset;
62 memset(p, 0, RECORDSIZE);
68 * The end of tar archives is marked by 1024 nul bytes and after that
69 * follows the rest of the block (if any).
71 static void write_trailer(void)
73 memset(block + offset, 0, RECORDSIZE);
76 memset(block + offset, 0, RECORDSIZE);
80 memset(block + offset, 0, BLOCKSIZE - offset);
81 reliable_write(block, BLOCKSIZE);
87 * queues up writes, so that all our write(2) calls write exactly one
88 * full block; pads writes to RECORDSIZE
90 static void write_blocked(void *buf, unsigned long size)
95 unsigned long chunk = BLOCKSIZE - offset;
98 memcpy(block + offset, buf, chunk);
104 while (size >= BLOCKSIZE) {
105 reliable_write(buf, BLOCKSIZE);
110 memcpy(block + offset, buf, size);
114 tail = offset % RECORDSIZE;
116 memset(block + offset, 0, RECORDSIZE - tail);
117 offset += RECORDSIZE - tail;
122 static void append_string(char **p, const char *s)
124 unsigned int len = strlen(s);
129 static void append_char(char **p, char c)
135 static void append_path_prefix(char **buffer, struct path_prefix *prefix)
139 append_path_prefix(buffer, prefix->prev);
140 append_string(buffer, prefix->name);
141 append_char(buffer, '/');
144 static unsigned int path_prefix_len(struct path_prefix *prefix)
148 return path_prefix_len(prefix->prev) + strlen(prefix->name) + 1;
151 static void append_path(char **p, int is_dir, const char *basepath,
152 struct path_prefix *prefix, const char *path)
155 append_string(p, basepath);
158 append_path_prefix(p, prefix);
159 append_string(p, path);
164 static unsigned int path_len(int is_dir, const char *basepath,
165 struct path_prefix *prefix, const char *path)
167 unsigned int len = 0;
169 len += strlen(basepath) + 1;
170 len += path_prefix_len(prefix) + strlen(path);
176 static void append_extended_header_prefix(char **p, unsigned int size,
179 int len = sprintf(*p, "%u %s=", size, keyword);
183 static unsigned int extended_header_len(const char *keyword,
184 unsigned int valuelen)
187 unsigned int len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
195 static void append_extended_header(char **p, const char *keyword,
196 const char *value, unsigned int len)
198 unsigned int size = extended_header_len(keyword, len);
199 append_extended_header_prefix(p, size, keyword);
200 memcpy(*p, value, len);
202 append_char(p, '\n');
205 static void write_header(const char *, char, const char *, struct path_prefix *,
206 const char *, unsigned int, void *, unsigned long);
208 /* stores a pax extended header directly in the block buffer */
209 static void write_extended_header(const char *headerfilename, int is_dir,
210 unsigned int flags, const char *basepath,
211 struct path_prefix *prefix,
212 const char *path, unsigned int namelen,
213 void *content, unsigned int contentsize)
216 unsigned int pathlen, size, linkpathlen = 0;
218 size = pathlen = extended_header_len("path", namelen);
219 if (flags & EXT_HEADER_LINKPATH) {
220 linkpathlen = extended_header_len("linkpath", contentsize);
223 if (size > RECORDSIZE)
224 die("tar-tree: extended header too big, wtf?");
225 write_header(NULL, TYPEFLAG_EXT_HEADER, NULL, NULL, headerfilename,
226 0100600, NULL, size);
229 append_extended_header_prefix(&p, pathlen, "path");
230 append_path(&p, is_dir, basepath, prefix, path);
231 append_char(&p, '\n');
232 if (flags & EXT_HEADER_LINKPATH)
233 append_extended_header(&p, "linkpath", content, contentsize);
237 static void write_global_extended_header(const char *sha1)
242 size = extended_header_len("comment", 40);
243 write_header(NULL, TYPEFLAG_GLOBAL_HEADER, NULL, NULL,
244 "pax_global_header", 0100600, NULL, size);
247 append_extended_header(&p, "comment", sha1_to_hex(sha1), 40);
251 /* stores a ustar header directly in the block buffer */
252 static void write_header(const char *sha1, char typeflag, const char *basepath,
253 struct path_prefix *prefix, const char *path,
254 unsigned int mode, void *buffer, unsigned long size)
256 unsigned int namelen;
258 unsigned int checksum = 0;
260 unsigned int ext_header = 0;
262 if (typeflag == TYPEFLAG_AUTO) {
264 typeflag = TYPEFLAG_DIR;
265 else if (S_ISLNK(mode))
266 typeflag = TYPEFLAG_LNK;
268 typeflag = TYPEFLAG_REG;
271 namelen = path_len(S_ISDIR(mode), basepath, prefix, path);
273 die("tar-tree: name too log of object %s\n", sha1_to_hex(sha1));
274 else if (namelen > 100)
275 ext_header |= EXT_HEADER_PATH;
276 if (typeflag == TYPEFLAG_LNK && size > 100)
277 ext_header |= EXT_HEADER_LINKPATH;
279 /* the extended header must be written before the normal one */
281 char headerfilename[51];
282 sprintf(headerfilename, "%s.paxheader", sha1_to_hex(sha1));
283 write_extended_header(headerfilename, S_ISDIR(mode),
284 ext_header, basepath, prefix, path,
285 namelen, buffer, size);
288 header = get_record();
291 sprintf(header, "%s.data", sha1_to_hex(sha1));
294 append_path(&p, S_ISDIR(mode), basepath, prefix, path);
297 if (typeflag == TYPEFLAG_LNK) {
298 if (ext_header & EXT_HEADER_LINKPATH) {
299 sprintf(&header[157], "see %s.paxheader",
303 strncpy(&header[157], buffer, size);
308 mode |= 0755; /* GIT doesn't store permissions of dirs */
310 mode |= 0777; /* ... nor of symlinks */
311 sprintf(&header[100], "%07o", mode & 07777);
313 /* XXX: should we provide more meaningful info here? */
314 sprintf(&header[108], "%07o", 0); /* uid */
315 sprintf(&header[116], "%07o", 0); /* gid */
316 strncpy(&header[265], "git", 31); /* uname */
317 strncpy(&header[297], "git", 31); /* gname */
319 if (S_ISDIR(mode) || S_ISLNK(mode))
321 sprintf(&header[124], "%011lo", size);
322 sprintf(&header[136], "%011lo", archive_time);
324 header[156] = typeflag;
326 memcpy(&header[257], "ustar", 6);
327 memcpy(&header[263], "00", 2);
329 printf(&header[329], "%07o", 0); /* devmajor */
330 printf(&header[337], "%07o", 0); /* devminor */
332 memset(&header[148], ' ', 8);
333 for (i = 0; i < RECORDSIZE; i++)
334 checksum += header[i];
335 sprintf(&header[148], "%07o", checksum & 0x1fffff);
340 static void traverse_tree(void *buffer, unsigned long size,
341 struct path_prefix *prefix)
343 struct path_prefix this_prefix;
344 this_prefix.prev = prefix;
347 int namelen = strlen(buffer)+1;
350 unsigned long eltsize;
351 unsigned char *sha1 = buffer + namelen;
352 char *path = strchr(buffer, ' ') + 1;
355 if (size < namelen + 20 || sscanf(buffer, "%o", &mode) != 1)
356 die("corrupt 'tree' file");
358 size -= namelen + 20;
360 eltbuf = read_sha1_file(sha1, elttype, &eltsize);
362 die("cannot read %s", sha1_to_hex(sha1));
363 write_header(sha1, TYPEFLAG_AUTO, basedir, prefix, path,
364 mode, eltbuf, eltsize);
365 if (!strcmp(elttype, "tree")) {
366 this_prefix.name = path;
367 traverse_tree(eltbuf, eltsize, &this_prefix);
368 } else if (!strcmp(elttype, "blob") && !S_ISLNK(mode)) {
369 write_blocked(eltbuf, eltsize);
375 /* get commit time from committer line of commit object */
376 time_t commit_time(void * buffer, unsigned long size)
382 char *endp = memchr(p, '\n', size);
383 if (!endp || endp == p)
386 if (endp - p > 10 && !memcmp(p, "committer ", 10)) {
387 char *nump = strrchr(p, '>');
391 result = strtoul(nump, &endp, 10);
396 size -= endp - p - 1;
402 int main(int argc, char **argv)
404 unsigned char sha1[20];
405 unsigned char commit_sha1[20];
414 if (get_sha1(argv[1], sha1) < 0)
415 usage(tar_tree_usage);
418 usage(tar_tree_usage);
421 sha1_file_directory = getenv(DB_ENVIRONMENT);
422 if (!sha1_file_directory)
423 sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
425 buffer = read_object_with_reference(sha1, "commit", &size, commit_sha1);
427 write_global_extended_header(commit_sha1);
428 archive_time = commit_time(buffer, size);
431 buffer = read_object_with_reference(sha1, "tree", &size, NULL);
433 die("not a reference to a tag, commit or tree object: %s",
436 archive_time = time(NULL);
438 write_header("0", TYPEFLAG_DIR, NULL, NULL, basedir, 040755,
440 traverse_tree(buffer, size, NULL);