Merge branch 'es/doc-worktree-guessremote-config'
[git.git] / archive-tar.c
blob4aabd566fbb8af7065ebe8fa62afe8e8e70abe04
1 /*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
4 #include "cache.h"
5 #include "config.h"
6 #include "tar.h"
7 #include "archive.h"
8 #include "object-store.h"
9 #include "streaming.h"
10 #include "run-command.h"
12 #define RECORDSIZE (512)
13 #define BLOCKSIZE (RECORDSIZE * 20)
15 static char block[BLOCKSIZE];
16 static unsigned long offset;
18 static int tar_umask = 002;
20 static int write_tar_filter_archive(const struct archiver *ar,
21 struct archiver_args *args);
24 * This is the max value that a ustar size header can specify, as it is fixed
25 * at 11 octal digits. POSIX specifies that we switch to extended headers at
26 * this size.
28 * Likewise for the mtime (which happens to use a buffer of the same size).
30 #if ULONG_MAX == 0xFFFFFFFF
31 #define USTAR_MAX_SIZE ULONG_MAX
32 #else
33 #define USTAR_MAX_SIZE 077777777777UL
34 #endif
35 #if TIME_MAX == 0xFFFFFFFF
36 #define USTAR_MAX_MTIME TIME_MAX
37 #else
38 #define USTAR_MAX_MTIME 077777777777ULL
39 #endif
41 /* writes out the whole block, but only if it is full */
42 static void write_if_needed(void)
44 if (offset == BLOCKSIZE) {
45 write_or_die(1, block, BLOCKSIZE);
46 offset = 0;
51 * queues up writes, so that all our write(2) calls write exactly one
52 * full block; pads writes to RECORDSIZE
54 static void do_write_blocked(const void *data, unsigned long size)
56 const char *buf = data;
58 if (offset) {
59 unsigned long chunk = BLOCKSIZE - offset;
60 if (size < chunk)
61 chunk = size;
62 memcpy(block + offset, buf, chunk);
63 size -= chunk;
64 offset += chunk;
65 buf += chunk;
66 write_if_needed();
68 while (size >= BLOCKSIZE) {
69 write_or_die(1, buf, BLOCKSIZE);
70 size -= BLOCKSIZE;
71 buf += BLOCKSIZE;
73 if (size) {
74 memcpy(block + offset, buf, size);
75 offset += size;
79 static void finish_record(void)
81 unsigned long tail;
82 tail = offset % RECORDSIZE;
83 if (tail) {
84 memset(block + offset, 0, RECORDSIZE - tail);
85 offset += RECORDSIZE - tail;
87 write_if_needed();
90 static void write_blocked(const void *data, unsigned long size)
92 do_write_blocked(data, size);
93 finish_record();
97 * The end of tar archives is marked by 2*512 nul bytes and after that
98 * follows the rest of the block (if any).
100 static void write_trailer(void)
102 int tail = BLOCKSIZE - offset;
103 memset(block + offset, 0, tail);
104 write_or_die(1, block, BLOCKSIZE);
105 if (tail < 2 * RECORDSIZE) {
106 memset(block, 0, offset);
107 write_or_die(1, block, BLOCKSIZE);
112 * queues up writes, so that all our write(2) calls write exactly one
113 * full block; pads writes to RECORDSIZE
115 static int stream_blocked(const struct object_id *oid)
117 struct git_istream *st;
118 enum object_type type;
119 unsigned long sz;
120 char buf[BLOCKSIZE];
121 ssize_t readlen;
123 st = open_istream(oid, &type, &sz, NULL);
124 if (!st)
125 return error(_("cannot stream blob %s"), oid_to_hex(oid));
126 for (;;) {
127 readlen = read_istream(st, buf, sizeof(buf));
128 if (readlen <= 0)
129 break;
130 do_write_blocked(buf, readlen);
132 close_istream(st);
133 if (!readlen)
134 finish_record();
135 return readlen;
139 * pax extended header records have the format "%u %s=%s\n". %u contains
140 * the size of the whole string (including the %u), the first %s is the
141 * keyword, the second one is the value. This function constructs such a
142 * string and appends it to a struct strbuf.
144 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
145 const char *value, unsigned int valuelen)
147 int len, tmp;
149 /* "%u %s=%s\n" */
150 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
151 for (tmp = len; tmp > 9; tmp /= 10)
152 len++;
154 strbuf_grow(sb, len);
155 strbuf_addf(sb, "%u %s=", len, keyword);
156 strbuf_add(sb, value, valuelen);
157 strbuf_addch(sb, '\n');
161 * Like strbuf_append_ext_header, but for numeric values.
163 static void strbuf_append_ext_header_uint(struct strbuf *sb,
164 const char *keyword,
165 uintmax_t value)
167 char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
168 int len;
170 len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
171 strbuf_append_ext_header(sb, keyword, buf, len);
174 static unsigned int ustar_header_chksum(const struct ustar_header *header)
176 const unsigned char *p = (const unsigned char *)header;
177 unsigned int chksum = 0;
178 while (p < (const unsigned char *)header->chksum)
179 chksum += *p++;
180 chksum += sizeof(header->chksum) * ' ';
181 p += sizeof(header->chksum);
182 while (p < (const unsigned char *)header + sizeof(struct ustar_header))
183 chksum += *p++;
184 return chksum;
187 static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
189 size_t i = pathlen;
190 if (i > 1 && path[i - 1] == '/')
191 i--;
192 if (i > maxlen)
193 i = maxlen;
194 do {
195 i--;
196 } while (i > 0 && path[i] != '/');
197 return i;
200 static void prepare_header(struct archiver_args *args,
201 struct ustar_header *header,
202 unsigned int mode, unsigned long size)
204 xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
205 xsnprintf(header->size, sizeof(header->size), "%011"PRIoMAX , S_ISREG(mode) ? (uintmax_t)size : (uintmax_t)0);
206 xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
208 xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
209 xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
210 strlcpy(header->uname, "root", sizeof(header->uname));
211 strlcpy(header->gname, "root", sizeof(header->gname));
212 xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
213 xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
215 memcpy(header->magic, "ustar", 6);
216 memcpy(header->version, "00", 2);
218 xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
221 static void write_extended_header(struct archiver_args *args,
222 const struct object_id *oid,
223 const void *buffer, unsigned long size)
225 struct ustar_header header;
226 unsigned int mode;
227 memset(&header, 0, sizeof(header));
228 *header.typeflag = TYPEFLAG_EXT_HEADER;
229 mode = 0100666;
230 xsnprintf(header.name, sizeof(header.name), "%s.paxheader", oid_to_hex(oid));
231 prepare_header(args, &header, mode, size);
232 write_blocked(&header, sizeof(header));
233 write_blocked(buffer, size);
236 static int write_tar_entry(struct archiver_args *args,
237 const struct object_id *oid,
238 const char *path, size_t pathlen,
239 unsigned int mode)
241 struct ustar_header header;
242 struct strbuf ext_header = STRBUF_INIT;
243 unsigned int old_mode = mode;
244 unsigned long size, size_in_header;
245 void *buffer;
246 int err = 0;
248 memset(&header, 0, sizeof(header));
250 if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
251 *header.typeflag = TYPEFLAG_DIR;
252 mode = (mode | 0777) & ~tar_umask;
253 } else if (S_ISLNK(mode)) {
254 *header.typeflag = TYPEFLAG_LNK;
255 mode |= 0777;
256 } else if (S_ISREG(mode)) {
257 *header.typeflag = TYPEFLAG_REG;
258 mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
259 } else {
260 return error(_("unsupported file mode: 0%o (SHA1: %s)"),
261 mode, oid_to_hex(oid));
263 if (pathlen > sizeof(header.name)) {
264 size_t plen = get_path_prefix(path, pathlen,
265 sizeof(header.prefix));
266 size_t rest = pathlen - plen - 1;
267 if (plen > 0 && rest <= sizeof(header.name)) {
268 memcpy(header.prefix, path, plen);
269 memcpy(header.name, path + plen + 1, rest);
270 } else {
271 xsnprintf(header.name, sizeof(header.name), "%s.data",
272 oid_to_hex(oid));
273 strbuf_append_ext_header(&ext_header, "path",
274 path, pathlen);
276 } else
277 memcpy(header.name, path, pathlen);
279 if (S_ISREG(mode) && !args->convert &&
280 oid_object_info(args->repo, oid, &size) == OBJ_BLOB &&
281 size > big_file_threshold)
282 buffer = NULL;
283 else if (S_ISLNK(mode) || S_ISREG(mode)) {
284 enum object_type type;
285 buffer = object_file_to_archive(args, path, oid, old_mode, &type, &size);
286 if (!buffer)
287 return error(_("cannot read %s"), oid_to_hex(oid));
288 } else {
289 buffer = NULL;
290 size = 0;
293 if (S_ISLNK(mode)) {
294 if (size > sizeof(header.linkname)) {
295 xsnprintf(header.linkname, sizeof(header.linkname),
296 "see %s.paxheader", oid_to_hex(oid));
297 strbuf_append_ext_header(&ext_header, "linkpath",
298 buffer, size);
299 } else
300 memcpy(header.linkname, buffer, size);
303 size_in_header = size;
304 if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
305 size_in_header = 0;
306 strbuf_append_ext_header_uint(&ext_header, "size", size);
309 prepare_header(args, &header, mode, size_in_header);
311 if (ext_header.len > 0) {
312 write_extended_header(args, oid, ext_header.buf,
313 ext_header.len);
315 strbuf_release(&ext_header);
316 write_blocked(&header, sizeof(header));
317 if (S_ISREG(mode) && size > 0) {
318 if (buffer)
319 write_blocked(buffer, size);
320 else
321 err = stream_blocked(oid);
323 free(buffer);
324 return err;
327 static void write_global_extended_header(struct archiver_args *args)
329 const unsigned char *sha1 = args->commit_sha1;
330 struct strbuf ext_header = STRBUF_INIT;
331 struct ustar_header header;
332 unsigned int mode;
334 if (sha1)
335 strbuf_append_ext_header(&ext_header, "comment",
336 sha1_to_hex(sha1), 40);
337 if (args->time > USTAR_MAX_MTIME) {
338 strbuf_append_ext_header_uint(&ext_header, "mtime",
339 args->time);
340 args->time = USTAR_MAX_MTIME;
343 if (!ext_header.len)
344 return;
346 memset(&header, 0, sizeof(header));
347 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
348 mode = 0100666;
349 xsnprintf(header.name, sizeof(header.name), "pax_global_header");
350 prepare_header(args, &header, mode, ext_header.len);
351 write_blocked(&header, sizeof(header));
352 write_blocked(ext_header.buf, ext_header.len);
353 strbuf_release(&ext_header);
356 static struct archiver **tar_filters;
357 static int nr_tar_filters;
358 static int alloc_tar_filters;
360 static struct archiver *find_tar_filter(const char *name, int len)
362 int i;
363 for (i = 0; i < nr_tar_filters; i++) {
364 struct archiver *ar = tar_filters[i];
365 if (!strncmp(ar->name, name, len) && !ar->name[len])
366 return ar;
368 return NULL;
371 static int tar_filter_config(const char *var, const char *value, void *data)
373 struct archiver *ar;
374 const char *name;
375 const char *type;
376 int namelen;
378 if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
379 return 0;
381 ar = find_tar_filter(name, namelen);
382 if (!ar) {
383 ar = xcalloc(1, sizeof(*ar));
384 ar->name = xmemdupz(name, namelen);
385 ar->write_archive = write_tar_filter_archive;
386 ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
387 ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
388 tar_filters[nr_tar_filters++] = ar;
391 if (!strcmp(type, "command")) {
392 if (!value)
393 return config_error_nonbool(var);
394 free(ar->data);
395 ar->data = xstrdup(value);
396 return 0;
398 if (!strcmp(type, "remote")) {
399 if (git_config_bool(var, value))
400 ar->flags |= ARCHIVER_REMOTE;
401 else
402 ar->flags &= ~ARCHIVER_REMOTE;
403 return 0;
406 return 0;
409 static int git_tar_config(const char *var, const char *value, void *cb)
411 if (!strcmp(var, "tar.umask")) {
412 if (value && !strcmp(value, "user")) {
413 tar_umask = umask(0);
414 umask(tar_umask);
415 } else {
416 tar_umask = git_config_int(var, value);
418 return 0;
421 return tar_filter_config(var, value, cb);
424 static int write_tar_archive(const struct archiver *ar,
425 struct archiver_args *args)
427 int err = 0;
429 write_global_extended_header(args);
430 err = write_archive_entries(args, write_tar_entry);
431 if (!err)
432 write_trailer();
433 return err;
436 static int write_tar_filter_archive(const struct archiver *ar,
437 struct archiver_args *args)
439 struct strbuf cmd = STRBUF_INIT;
440 struct child_process filter = CHILD_PROCESS_INIT;
441 const char *argv[2];
442 int r;
444 if (!ar->data)
445 BUG("tar-filter archiver called with no filter defined");
447 strbuf_addstr(&cmd, ar->data);
448 if (args->compression_level >= 0)
449 strbuf_addf(&cmd, " -%d", args->compression_level);
451 argv[0] = cmd.buf;
452 argv[1] = NULL;
453 filter.argv = argv;
454 filter.use_shell = 1;
455 filter.in = -1;
457 if (start_command(&filter) < 0)
458 die_errno(_("unable to start '%s' filter"), argv[0]);
459 close(1);
460 if (dup2(filter.in, 1) < 0)
461 die_errno(_("unable to redirect descriptor"));
462 close(filter.in);
464 r = write_tar_archive(ar, args);
466 close(1);
467 if (finish_command(&filter) != 0)
468 die(_("'%s' filter reported error"), argv[0]);
470 strbuf_release(&cmd);
471 return r;
474 static struct archiver tar_archiver = {
475 "tar",
476 write_tar_archive,
477 ARCHIVER_REMOTE
480 void init_tar_archiver(void)
482 int i;
483 register_archiver(&tar_archiver);
485 tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
486 tar_filter_config("tar.tgz.remote", "true", NULL);
487 tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
488 tar_filter_config("tar.tar.gz.remote", "true", NULL);
489 git_config(git_tar_config, NULL);
490 for (i = 0; i < nr_tar_filters; i++) {
491 /* omit any filters that never had a command configured */
492 if (tar_filters[i]->data)
493 register_archiver(tar_filters[i]);