t5100: mailinfo and mailsplit tests.
[git] / builtin-tar-tree.c
1 /*
2  * Copyright (c) 2005, 2006 Rene Scharfe
3  */
4 #include <time.h>
5 #include "cache.h"
6 #include "tree-walk.h"
7 #include "commit.h"
8 #include "strbuf.h"
9 #include "tar.h"
10 #include "builtin.h"
11 #include "pkt-line.h"
12
13 #define RECORDSIZE      (512)
14 #define BLOCKSIZE       (RECORDSIZE * 20)
15
16 static const char tar_tree_usage[] =
17 "git-tar-tree [--remote=<repo>] <ent> [basedir]";
18
19 static char block[BLOCKSIZE];
20 static unsigned long offset;
21
22 static time_t archive_time;
23
24 /* tries hard to write, either succeeds or dies in the attempt */
25 static void reliable_write(void *buf, unsigned long size)
26 {
27         while (size > 0) {
28                 long ret = xwrite(1, buf, size);
29                 if (ret < 0) {
30                         if (errno == EPIPE)
31                                 exit(0);
32                         die("git-tar-tree: %s", strerror(errno));
33                 } else if (!ret) {
34                         die("git-tar-tree: disk full?");
35                 }
36                 size -= ret;
37                 buf += ret;
38         }
39 }
40
41 /* writes out the whole block, but only if it is full */
42 static void write_if_needed(void)
43 {
44         if (offset == BLOCKSIZE) {
45                 reliable_write(block, BLOCKSIZE);
46                 offset = 0;
47         }
48 }
49
50 /* acquire the next record from the buffer; user must call write_if_needed() */
51 static char *get_record(void)
52 {
53         char *p = block + offset;
54         memset(p, 0, RECORDSIZE);
55         offset += RECORDSIZE;
56         return p;
57 }
58
59 /*
60  * The end of tar archives is marked by 1024 nul bytes and after that
61  * follows the rest of the block (if any).
62  */
63 static void write_trailer(void)
64 {
65         get_record();
66         write_if_needed();
67         get_record();
68         write_if_needed();
69         while (offset) {
70                 get_record();
71                 write_if_needed();
72         }
73 }
74
75 /*
76  * queues up writes, so that all our write(2) calls write exactly one
77  * full block; pads writes to RECORDSIZE
78  */
79 static void write_blocked(void *buf, unsigned long size)
80 {
81         unsigned long tail;
82
83         if (offset) {
84                 unsigned long chunk = BLOCKSIZE - offset;
85                 if (size < chunk)
86                         chunk = size;
87                 memcpy(block + offset, buf, chunk);
88                 size -= chunk;
89                 offset += chunk;
90                 buf += chunk;
91                 write_if_needed();
92         }
93         while (size >= BLOCKSIZE) {
94                 reliable_write(buf, BLOCKSIZE);
95                 size -= BLOCKSIZE;
96                 buf += BLOCKSIZE;
97         }
98         if (size) {
99                 memcpy(block + offset, buf, size);
100                 offset += size;
101         }
102         tail = offset % RECORDSIZE;
103         if (tail)  {
104                 memset(block + offset, 0, RECORDSIZE - tail);
105                 offset += RECORDSIZE - tail;
106         }
107         write_if_needed();
108 }
109
110 static void strbuf_append_string(struct strbuf *sb, const char *s)
111 {
112         int slen = strlen(s);
113         int total = sb->len + slen;
114         if (total > sb->alloc) {
115                 sb->buf = xrealloc(sb->buf, total);
116                 sb->alloc = total;
117         }
118         memcpy(sb->buf + sb->len, s, slen);
119         sb->len = total;
120 }
121
122 /*
123  * pax extended header records have the format "%u %s=%s\n".  %u contains
124  * the size of the whole string (including the %u), the first %s is the
125  * keyword, the second one is the value.  This function constructs such a
126  * string and appends it to a struct strbuf.
127  */
128 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
129                                      const char *value, unsigned int valuelen)
130 {
131         char *p;
132         int len, total, tmp;
133
134         /* "%u %s=%s\n" */
135         len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
136         for (tmp = len; tmp > 9; tmp /= 10)
137                 len++;
138
139         total = sb->len + len;
140         if (total > sb->alloc) {
141                 sb->buf = xrealloc(sb->buf, total);
142                 sb->alloc = total;
143         }
144
145         p = sb->buf;
146         p += sprintf(p, "%u %s=", len, keyword);
147         memcpy(p, value, valuelen);
148         p += valuelen;
149         *p = '\n';
150         sb->len = total;
151 }
152
153 static unsigned int ustar_header_chksum(const struct ustar_header *header)
154 {
155         char *p = (char *)header;
156         unsigned int chksum = 0;
157         while (p < header->chksum)
158                 chksum += *p++;
159         chksum += sizeof(header->chksum) * ' ';
160         p += sizeof(header->chksum);
161         while (p < (char *)header + sizeof(struct ustar_header))
162                 chksum += *p++;
163         return chksum;
164 }
165
166 static int get_path_prefix(const struct strbuf *path, int maxlen)
167 {
168         int i = path->len;
169         if (i > maxlen)
170                 i = maxlen;
171         do {
172                 i--;
173         } while (i > 0 && path->buf[i] != '/');
174         return i;
175 }
176
177 static void write_entry(const unsigned char *sha1, struct strbuf *path,
178                         unsigned int mode, void *buffer, unsigned long size)
179 {
180         struct ustar_header header;
181         struct strbuf ext_header;
182
183         memset(&header, 0, sizeof(header));
184         ext_header.buf = NULL;
185         ext_header.len = ext_header.alloc = 0;
186
187         if (!sha1) {
188                 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
189                 mode = 0100666;
190                 strcpy(header.name, "pax_global_header");
191         } else if (!path) {
192                 *header.typeflag = TYPEFLAG_EXT_HEADER;
193                 mode = 0100666;
194                 sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
195         } else {
196                 if (S_ISDIR(mode)) {
197                         *header.typeflag = TYPEFLAG_DIR;
198                         mode |= 0777;
199                 } else if (S_ISLNK(mode)) {
200                         *header.typeflag = TYPEFLAG_LNK;
201                         mode |= 0777;
202                 } else if (S_ISREG(mode)) {
203                         *header.typeflag = TYPEFLAG_REG;
204                         mode |= (mode & 0100) ? 0777 : 0666;
205                 } else {
206                         error("unsupported file mode: 0%o (SHA1: %s)",
207                               mode, sha1_to_hex(sha1));
208                         return;
209                 }
210                 if (path->len > sizeof(header.name)) {
211                         int plen = get_path_prefix(path, sizeof(header.prefix));
212                         int rest = path->len - plen - 1;
213                         if (plen > 0 && rest <= sizeof(header.name)) {
214                                 memcpy(header.prefix, path->buf, plen);
215                                 memcpy(header.name, path->buf + plen + 1, rest);
216                         } else {
217                                 sprintf(header.name, "%s.data",
218                                         sha1_to_hex(sha1));
219                                 strbuf_append_ext_header(&ext_header, "path",
220                                                          path->buf, path->len);
221                         }
222                 } else
223                         memcpy(header.name, path->buf, path->len);
224         }
225
226         if (S_ISLNK(mode) && buffer) {
227                 if (size > sizeof(header.linkname)) {
228                         sprintf(header.linkname, "see %s.paxheader",
229                                 sha1_to_hex(sha1));
230                         strbuf_append_ext_header(&ext_header, "linkpath",
231                                                  buffer, size);
232                 } else
233                         memcpy(header.linkname, buffer, size);
234         }
235
236         sprintf(header.mode, "%07o", mode & 07777);
237         sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
238         sprintf(header.mtime, "%011lo", archive_time);
239
240         /* XXX: should we provide more meaningful info here? */
241         sprintf(header.uid, "%07o", 0);
242         sprintf(header.gid, "%07o", 0);
243         safe_strncpy(header.uname, "git", sizeof(header.uname));
244         safe_strncpy(header.gname, "git", sizeof(header.gname));
245         sprintf(header.devmajor, "%07o", 0);
246         sprintf(header.devminor, "%07o", 0);
247
248         memcpy(header.magic, "ustar", 6);
249         memcpy(header.version, "00", 2);
250
251         sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
252
253         if (ext_header.len > 0) {
254                 write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
255                 free(ext_header.buf);
256         }
257         write_blocked(&header, sizeof(header));
258         if (S_ISREG(mode) && buffer && size > 0)
259                 write_blocked(buffer, size);
260 }
261
262 static void write_global_extended_header(const unsigned char *sha1)
263 {
264         struct strbuf ext_header;
265         ext_header.buf = NULL;
266         ext_header.len = ext_header.alloc = 0;
267         strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
268         write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
269         free(ext_header.buf);
270 }
271
272 static void traverse_tree(struct tree_desc *tree, struct strbuf *path)
273 {
274         int pathlen = path->len;
275         struct name_entry entry;
276
277         while (tree_entry(tree, &entry)) {
278                 void *eltbuf;
279                 char elttype[20];
280                 unsigned long eltsize;
281
282                 eltbuf = read_sha1_file(entry.sha1, elttype, &eltsize);
283                 if (!eltbuf)
284                         die("cannot read %s", sha1_to_hex(entry.sha1));
285
286                 path->len = pathlen;
287                 strbuf_append_string(path, entry.path);
288                 if (S_ISDIR(entry.mode))
289                         strbuf_append_string(path, "/");
290
291                 write_entry(entry.sha1, path, entry.mode, eltbuf, eltsize);
292
293                 if (S_ISDIR(entry.mode)) {
294                         struct tree_desc subtree;
295                         subtree.buf = eltbuf;
296                         subtree.size = eltsize;
297                         traverse_tree(&subtree, path);
298                 }
299                 free(eltbuf);
300         }
301 }
302
303 static int generate_tar(int argc, const char **argv, char** envp)
304 {
305         unsigned char sha1[20], tree_sha1[20];
306         struct commit *commit;
307         struct tree_desc tree;
308         struct strbuf current_path;
309
310         current_path.buf = xmalloc(PATH_MAX);
311         current_path.alloc = PATH_MAX;
312         current_path.len = current_path.eof = 0;
313
314         setup_git_directory();
315         git_config(git_default_config);
316
317         switch (argc) {
318         case 3:
319                 strbuf_append_string(&current_path, argv[2]);
320                 strbuf_append_string(&current_path, "/");
321                 /* FALLTHROUGH */
322         case 2:
323                 if (get_sha1(argv[1], sha1))
324                         die("Not a valid object name %s", argv[1]);
325                 break;
326         default:
327                 usage(tar_tree_usage);
328         }
329
330         commit = lookup_commit_reference_gently(sha1, 1);
331         if (commit) {
332                 write_global_extended_header(commit->object.sha1);
333                 archive_time = commit->date;
334         } else
335                 archive_time = time(NULL);
336
337         tree.buf = read_object_with_reference(sha1, tree_type, &tree.size,
338                                               tree_sha1);
339         if (!tree.buf)
340                 die("not a reference to a tag, commit or tree object: %s",
341                     sha1_to_hex(sha1));
342
343         if (current_path.len > 0)
344                 write_entry(tree_sha1, &current_path, 040777, NULL, 0);
345         traverse_tree(&tree, &current_path);
346         write_trailer();
347         free(current_path.buf);
348         return 0;
349 }
350
351 static const char *exec = "git-upload-tar";
352
353 static int remote_tar(int argc, const char **argv)
354 {
355         int fd[2], ret, len;
356         pid_t pid;
357         char buf[1024];
358         char *url;
359
360         if (argc < 3 || 4 < argc)
361                 usage(tar_tree_usage);
362
363         /* --remote=<repo> */
364         url = strdup(argv[1]+9);
365         pid = git_connect(fd, url, exec);
366         if (pid < 0)
367                 return 1;
368
369         packet_write(fd[1], "want %s\n", argv[2]);
370         if (argv[3])
371                 packet_write(fd[1], "base %s\n", argv[3]);
372         packet_flush(fd[1]);
373
374         len = packet_read_line(fd[0], buf, sizeof(buf));
375         if (!len)
376                 die("git-tar-tree: expected ACK/NAK, got EOF");
377         if (buf[len-1] == '\n')
378                 buf[--len] = 0;
379         if (strcmp(buf, "ACK")) {
380                 if (5 < len && !strncmp(buf, "NACK ", 5))
381                         die("git-tar-tree: NACK %s", buf + 5);
382                 die("git-tar-tree: protocol error");
383         }
384         /* expect a flush */
385         len = packet_read_line(fd[0], buf, sizeof(buf));
386         if (len)
387                 die("git-tar-tree: expected a flush");
388
389         /* Now, start reading from fd[0] and spit it out to stdout */
390         ret = copy_fd(fd[0], 1);
391         close(fd[0]);
392
393         ret |= finish_connect(pid);
394         return !!ret;
395 }
396
397 int cmd_tar_tree(int argc, const char **argv, char **envp)
398 {
399         if (argc < 2)
400                 usage(tar_tree_usage);
401         if (!strncmp("--remote=", argv[1], 9))
402                 return remote_tar(argc, argv);
403         return generate_tar(argc, argv, envp);
404 }
405
406 /* ustar header + extended global header content */
407 #define HEADERSIZE (2 * RECORDSIZE)
408
409 int cmd_get_tar_commit_id(int argc, const char **argv, char **envp)
410 {
411         char buffer[HEADERSIZE];
412         struct ustar_header *header = (struct ustar_header *)buffer;
413         char *content = buffer + RECORDSIZE;
414         ssize_t n;
415
416         n = xread(0, buffer, HEADERSIZE);
417         if (n < HEADERSIZE)
418                 die("git-get-tar-commit-id: read error");
419         if (header->typeflag[0] != 'g')
420                 return 1;
421         if (memcmp(content, "52 comment=", 11))
422                 return 1;
423
424         n = xwrite(1, content + 11, 41);
425         if (n < 41)
426                 die("git-get-tar-commit-id: write error");
427
428         return 0;
429 }