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[thirdparty/git.git] / builtin-tar-tree.c
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92747a90 1/*
ae64bbc1 2 * Copyright (c) 2005, 2006 Rene Scharfe
92747a90 3 */
731ab9cc
RS
4#include <time.h>
5#include "cache.h"
1b0c7174 6#include "tree-walk.h"
c3f92812 7#include "commit.h"
ae64bbc1
RS
8#include "strbuf.h"
9#include "tar.h"
56d1398a 10#include "builtin.h"
21754264 11#include "pkt-line.h"
731ab9cc
RS
12
13#define RECORDSIZE (512)
14#define BLOCKSIZE (RECORDSIZE * 20)
15
21754264
JH
16static const char tar_tree_usage[] =
17"git-tar-tree [--remote=<repo>] <ent> [basedir]";
731ab9cc
RS
18
19static char block[BLOCKSIZE];
20static unsigned long offset;
21
731ab9cc 22static time_t archive_time;
ce1a79b6 23static int tar_umask;
731ab9cc 24
731ab9cc 25/* tries hard to write, either succeeds or dies in the attempt */
6698060c 26static void reliable_write(const void *data, unsigned long size)
731ab9cc 27{
6698060c
RS
28 const char *buf = data;
29
731ab9cc 30 while (size > 0) {
1c15afb9 31 long ret = xwrite(1, buf, size);
731ab9cc 32 if (ret < 0) {
731ab9cc
RS
33 if (errno == EPIPE)
34 exit(0);
667bb59b 35 die("git-tar-tree: %s", strerror(errno));
731ab9cc 36 } else if (!ret) {
667bb59b 37 die("git-tar-tree: disk full?");
731ab9cc
RS
38 }
39 size -= ret;
40 buf += ret;
41 }
42}
43
44/* writes out the whole block, but only if it is full */
45static void write_if_needed(void)
46{
47 if (offset == BLOCKSIZE) {
48 reliable_write(block, BLOCKSIZE);
49 offset = 0;
50 }
51}
52
731ab9cc
RS
53/*
54 * queues up writes, so that all our write(2) calls write exactly one
55 * full block; pads writes to RECORDSIZE
56 */
6698060c 57static void write_blocked(const void *data, unsigned long size)
731ab9cc 58{
6698060c 59 const char *buf = data;
731ab9cc
RS
60 unsigned long tail;
61
62 if (offset) {
63 unsigned long chunk = BLOCKSIZE - offset;
64 if (size < chunk)
65 chunk = size;
66 memcpy(block + offset, buf, chunk);
67 size -= chunk;
68 offset += chunk;
69 buf += chunk;
70 write_if_needed();
71 }
72 while (size >= BLOCKSIZE) {
73 reliable_write(buf, BLOCKSIZE);
74 size -= BLOCKSIZE;
75 buf += BLOCKSIZE;
76 }
77 if (size) {
78 memcpy(block + offset, buf, size);
731ab9cc
RS
79 offset += size;
80 }
81 tail = offset % RECORDSIZE;
82 if (tail) {
83 memset(block + offset, 0, RECORDSIZE - tail);
84 offset += RECORDSIZE - tail;
85 }
86 write_if_needed();
87}
88
37958be7
RS
89/*
90 * The end of tar archives is marked by 2*512 nul bytes and after that
91 * follows the rest of the block (if any).
92 */
93static void write_trailer(void)
94{
95 int tail = BLOCKSIZE - offset;
96 memset(block + offset, 0, tail);
97 reliable_write(block, BLOCKSIZE);
98 if (tail < 2 * RECORDSIZE) {
99 memset(block, 0, offset);
100 reliable_write(block, BLOCKSIZE);
101 }
102}
103
cb0c6df6 104static void strbuf_append_string(struct strbuf *sb, const char *s)
731ab9cc 105{
cb0c6df6
RS
106 int slen = strlen(s);
107 int total = sb->len + slen;
108 if (total > sb->alloc) {
109 sb->buf = xrealloc(sb->buf, total);
110 sb->alloc = total;
731ab9cc 111 }
cb0c6df6
RS
112 memcpy(sb->buf + sb->len, s, slen);
113 sb->len = total;
731ab9cc
RS
114}
115
ae64bbc1
RS
116/*
117 * pax extended header records have the format "%u %s=%s\n". %u contains
118 * the size of the whole string (including the %u), the first %s is the
119 * keyword, the second one is the value. This function constructs such a
120 * string and appends it to a struct strbuf.
121 */
122static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
123 const char *value, unsigned int valuelen)
71058b1f 124{
ae64bbc1
RS
125 char *p;
126 int len, total, tmp;
71058b1f 127
71058b1f 128 /* "%u %s=%s\n" */
ae64bbc1
RS
129 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
130 for (tmp = len; tmp > 9; tmp /= 10)
71058b1f 131 len++;
71058b1f 132
ae64bbc1
RS
133 total = sb->len + len;
134 if (total > sb->alloc) {
135 sb->buf = xrealloc(sb->buf, total);
136 sb->alloc = total;
137 }
71058b1f 138
ae64bbc1
RS
139 p = sb->buf;
140 p += sprintf(p, "%u %s=", len, keyword);
141 memcpy(p, value, valuelen);
142 p += valuelen;
143 *p = '\n';
144 sb->len = total;
145}
731ab9cc 146
ae64bbc1 147static unsigned int ustar_header_chksum(const struct ustar_header *header)
731ab9cc 148{
ae64bbc1
RS
149 char *p = (char *)header;
150 unsigned int chksum = 0;
151 while (p < header->chksum)
152 chksum += *p++;
153 chksum += sizeof(header->chksum) * ' ';
154 p += sizeof(header->chksum);
155 while (p < (char *)header + sizeof(struct ustar_header))
156 chksum += *p++;
157 return chksum;
731ab9cc
RS
158}
159
4c691724 160static int get_path_prefix(const struct strbuf *path, int maxlen)
87fec8fc 161{
4c691724
RS
162 int i = path->len;
163 if (i > maxlen)
164 i = maxlen;
17cf250a 165 do {
4c691724 166 i--;
17cf250a 167 } while (i > 0 && path->buf[i] != '/');
4c691724 168 return i;
87fec8fc
RS
169}
170
ae64bbc1
RS
171static void write_entry(const unsigned char *sha1, struct strbuf *path,
172 unsigned int mode, void *buffer, unsigned long size)
731ab9cc 173{
ae64bbc1
RS
174 struct ustar_header header;
175 struct strbuf ext_header;
176
177 memset(&header, 0, sizeof(header));
178 ext_header.buf = NULL;
179 ext_header.len = ext_header.alloc = 0;
180
181 if (!sha1) {
182 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
183 mode = 0100666;
184 strcpy(header.name, "pax_global_header");
185 } else if (!path) {
186 *header.typeflag = TYPEFLAG_EXT_HEADER;
187 mode = 0100666;
188 sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
731ab9cc 189 } else {
ae64bbc1
RS
190 if (S_ISDIR(mode)) {
191 *header.typeflag = TYPEFLAG_DIR;
ce1a79b6 192 mode = (mode | 0777) & ~tar_umask;
ae64bbc1
RS
193 } else if (S_ISLNK(mode)) {
194 *header.typeflag = TYPEFLAG_LNK;
195 mode |= 0777;
196 } else if (S_ISREG(mode)) {
197 *header.typeflag = TYPEFLAG_REG;
ce1a79b6 198 mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
ae64bbc1
RS
199 } else {
200 error("unsupported file mode: 0%o (SHA1: %s)",
201 mode, sha1_to_hex(sha1));
202 return;
203 }
204 if (path->len > sizeof(header.name)) {
4c691724
RS
205 int plen = get_path_prefix(path, sizeof(header.prefix));
206 int rest = path->len - plen - 1;
207 if (plen > 0 && rest <= sizeof(header.name)) {
208 memcpy(header.prefix, path->buf, plen);
209 memcpy(header.name, path->buf + plen + 1, rest);
210 } else {
211 sprintf(header.name, "%s.data",
212 sha1_to_hex(sha1));
213 strbuf_append_ext_header(&ext_header, "path",
214 path->buf, path->len);
215 }
ae64bbc1
RS
216 } else
217 memcpy(header.name, path->buf, path->len);
731ab9cc
RS
218 }
219
ae64bbc1
RS
220 if (S_ISLNK(mode) && buffer) {
221 if (size > sizeof(header.linkname)) {
222 sprintf(header.linkname, "see %s.paxheader",
d5776d50 223 sha1_to_hex(sha1));
ae64bbc1
RS
224 strbuf_append_ext_header(&ext_header, "linkpath",
225 buffer, size);
226 } else
227 memcpy(header.linkname, buffer, size);
d5776d50
RS
228 }
229
ae64bbc1
RS
230 sprintf(header.mode, "%07o", mode & 07777);
231 sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
232 sprintf(header.mtime, "%011lo", archive_time);
731ab9cc
RS
233
234 /* XXX: should we provide more meaningful info here? */
ae64bbc1
RS
235 sprintf(header.uid, "%07o", 0);
236 sprintf(header.gid, "%07o", 0);
817151e6
PE
237 strlcpy(header.uname, "git", sizeof(header.uname));
238 strlcpy(header.gname, "git", sizeof(header.gname));
ae64bbc1
RS
239 sprintf(header.devmajor, "%07o", 0);
240 sprintf(header.devminor, "%07o", 0);
731ab9cc 241
ae64bbc1
RS
242 memcpy(header.magic, "ustar", 6);
243 memcpy(header.version, "00", 2);
731ab9cc 244
ae64bbc1 245 sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
731ab9cc 246
ae64bbc1
RS
247 if (ext_header.len > 0) {
248 write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
249 free(ext_header.buf);
250 }
251 write_blocked(&header, sizeof(header));
252 if (S_ISREG(mode) && buffer && size > 0)
253 write_blocked(buffer, size);
254}
731ab9cc 255
bf0f910d 256static void write_global_extended_header(const unsigned char *sha1)
87fec8fc 257{
ae64bbc1
RS
258 struct strbuf ext_header;
259 ext_header.buf = NULL;
260 ext_header.len = ext_header.alloc = 0;
261 strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
262 write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
263 free(ext_header.buf);
731ab9cc
RS
264}
265
cb0c6df6 266static void traverse_tree(struct tree_desc *tree, struct strbuf *path)
731ab9cc 267{
cb0c6df6 268 int pathlen = path->len;
4c068a98 269 struct name_entry entry;
731ab9cc 270
4c068a98 271 while (tree_entry(tree, &entry)) {
731ab9cc
RS
272 void *eltbuf;
273 char elttype[20];
274 unsigned long eltsize;
5207234a 275
4c068a98 276 eltbuf = read_sha1_file(entry.sha1, elttype, &eltsize);
731ab9cc 277 if (!eltbuf)
4c068a98 278 die("cannot read %s", sha1_to_hex(entry.sha1));
cb0c6df6
RS
279
280 path->len = pathlen;
4c068a98
LT
281 strbuf_append_string(path, entry.path);
282 if (S_ISDIR(entry.mode))
cb0c6df6
RS
283 strbuf_append_string(path, "/");
284
4c068a98 285 write_entry(entry.sha1, path, entry.mode, eltbuf, eltsize);
cb0c6df6 286
4c068a98 287 if (S_ISDIR(entry.mode)) {
7ec57556
LT
288 struct tree_desc subtree;
289 subtree.buf = eltbuf;
290 subtree.size = eltsize;
cb0c6df6 291 traverse_tree(&subtree, path);
731ab9cc
RS
292 }
293 free(eltbuf);
294 }
295}
296
ce1a79b6
WT
297int git_tar_config(const char *var, const char *value)
298{
299 if (!strcmp(var, "tar.umask")) {
300 if (!strcmp(value, "user")) {
301 tar_umask = umask(0);
302 umask(tar_umask);
303 } else {
304 tar_umask = git_config_int(var, value);
305 }
306 return 0;
307 }
308 return git_default_config(var, value);
309}
310
1af0d112 311static int generate_tar(int argc, const char **argv, char** envp)
731ab9cc 312{
2c6df2d5 313 unsigned char sha1[20], tree_sha1[20];
c3f92812 314 struct commit *commit;
7ec57556 315 struct tree_desc tree;
cb0c6df6
RS
316 struct strbuf current_path;
317
318 current_path.buf = xmalloc(PATH_MAX);
319 current_path.alloc = PATH_MAX;
320 current_path.len = current_path.eof = 0;
731ab9cc 321
53228a5f 322 setup_git_directory();
ce1a79b6 323 git_config(git_tar_config);
53228a5f 324
731ab9cc
RS
325 switch (argc) {
326 case 3:
cb0c6df6
RS
327 strbuf_append_string(&current_path, argv[2]);
328 strbuf_append_string(&current_path, "/");
731ab9cc
RS
329 /* FALLTHROUGH */
330 case 2:
31fff305
DL
331 if (get_sha1(argv[1], sha1))
332 die("Not a valid object name %s", argv[1]);
731ab9cc
RS
333 break;
334 default:
335 usage(tar_tree_usage);
336 }
337
473d404b 338 commit = lookup_commit_reference_gently(sha1, 1);
c3f92812
DB
339 if (commit) {
340 write_global_extended_header(commit->object.sha1);
341 archive_time = commit->date;
cb0c6df6
RS
342 } else
343 archive_time = time(NULL);
344
8e440259 345 tree.buf = read_object_with_reference(sha1, tree_type, &tree.size,
2c6df2d5 346 tree_sha1);
7ec57556 347 if (!tree.buf)
db413479
RS
348 die("not a reference to a tag, commit or tree object: %s",
349 sha1_to_hex(sha1));
cb0c6df6
RS
350
351 if (current_path.len > 0)
352 write_entry(tree_sha1, &current_path, 040777, NULL, 0);
353 traverse_tree(&tree, &current_path);
731ab9cc 354 write_trailer();
cb0c6df6 355 free(current_path.buf);
731ab9cc
RS
356 return 0;
357}
21754264
JH
358
359static const char *exec = "git-upload-tar";
360
361static int remote_tar(int argc, const char **argv)
362{
363 int fd[2], ret, len;
364 pid_t pid;
365 char buf[1024];
366 char *url;
367
368 if (argc < 3 || 4 < argc)
369 usage(tar_tree_usage);
370
371 /* --remote=<repo> */
372 url = strdup(argv[1]+9);
373 pid = git_connect(fd, url, exec);
374 if (pid < 0)
375 return 1;
376
377 packet_write(fd[1], "want %s\n", argv[2]);
378 if (argv[3])
379 packet_write(fd[1], "base %s\n", argv[3]);
380 packet_flush(fd[1]);
381
382 len = packet_read_line(fd[0], buf, sizeof(buf));
383 if (!len)
384 die("git-tar-tree: expected ACK/NAK, got EOF");
385 if (buf[len-1] == '\n')
386 buf[--len] = 0;
387 if (strcmp(buf, "ACK")) {
388 if (5 < len && !strncmp(buf, "NACK ", 5))
389 die("git-tar-tree: NACK %s", buf + 5);
390 die("git-tar-tree: protocol error");
391 }
392 /* expect a flush */
393 len = packet_read_line(fd[0], buf, sizeof(buf));
394 if (len)
395 die("git-tar-tree: expected a flush");
396
397 /* Now, start reading from fd[0] and spit it out to stdout */
398 ret = copy_fd(fd[0], 1);
399 close(fd[0]);
400
401 ret |= finish_connect(pid);
402 return !!ret;
403}
404
405int cmd_tar_tree(int argc, const char **argv, char **envp)
406{
407 if (argc < 2)
408 usage(tar_tree_usage);
409 if (!strncmp("--remote=", argv[1], 9))
410 return remote_tar(argc, argv);
1af0d112 411 return generate_tar(argc, argv, envp);
21754264 412}
52ba03cb
RS
413
414/* ustar header + extended global header content */
415#define HEADERSIZE (2 * RECORDSIZE)
416
417int cmd_get_tar_commit_id(int argc, const char **argv, char **envp)
418{
419 char buffer[HEADERSIZE];
420 struct ustar_header *header = (struct ustar_header *)buffer;
421 char *content = buffer + RECORDSIZE;
422 ssize_t n;
423
424 n = xread(0, buffer, HEADERSIZE);
425 if (n < HEADERSIZE)
426 die("git-get-tar-commit-id: read error");
427 if (header->typeflag[0] != 'g')
428 return 1;
429 if (memcmp(content, "52 comment=", 11))
430 return 1;
431
432 n = xwrite(1, content + 11, 41);
433 if (n < 41)
434 die("git-get-tar-commit-id: write error");
435
436 return 0;
437}