[PATCH] Kill a bunch of pointer sign warnings for gcc4
[git/git.git] / tar-tree.c
1 /*
2 * Copyright (c) 2005 Rene Scharfe
3 */
4 #include <time.h>
5 #include "cache.h"
6
7 #define RECORDSIZE (512)
8 #define BLOCKSIZE (RECORDSIZE * 20)
9
10 #define TYPEFLAG_AUTO '\0'
11 #define TYPEFLAG_REG '0'
12 #define TYPEFLAG_LNK '2'
13 #define TYPEFLAG_DIR '5'
14 #define TYPEFLAG_GLOBAL_HEADER 'g'
15 #define TYPEFLAG_EXT_HEADER 'x'
16
17 #define EXT_HEADER_PATH 1
18 #define EXT_HEADER_LINKPATH 2
19
20 static const char *tar_tree_usage = "tar-tree <key> [basedir]";
21
22 static char block[BLOCKSIZE];
23 static unsigned long offset;
24
25 static const char *basedir;
26 static time_t archive_time;
27
28 struct path_prefix {
29 struct path_prefix *prev;
30 const char *name;
31 };
32
33 /* tries hard to write, either succeeds or dies in the attempt */
34 static void reliable_write(void *buf, unsigned long size)
35 {
36 while (size > 0) {
37 long ret = write(1, buf, size);
38 if (ret < 0) {
39 if (errno == EAGAIN)
40 continue;
41 if (errno == EPIPE)
42 exit(0);
43 die("tar-tree: %s", strerror(errno));
44 } else if (!ret) {
45 die("tar-tree: disk full?");
46 }
47 size -= ret;
48 buf += ret;
49 }
50 }
51
52 /* writes out the whole block, but only if it is full */
53 static void write_if_needed(void)
54 {
55 if (offset == BLOCKSIZE) {
56 reliable_write(block, BLOCKSIZE);
57 offset = 0;
58 }
59 }
60
61 /* acquire the next record from the buffer; user must call write_if_needed() */
62 static char *get_record(void)
63 {
64 char *p = block + offset;
65 memset(p, 0, RECORDSIZE);
66 offset += RECORDSIZE;
67 return p;
68 }
69
70 /*
71 * The end of tar archives is marked by 1024 nul bytes and after that
72 * follows the rest of the block (if any).
73 */
74 static void write_trailer(void)
75 {
76 memset(block + offset, 0, RECORDSIZE);
77 offset += RECORDSIZE;
78 write_if_needed();
79 memset(block + offset, 0, RECORDSIZE);
80 offset += RECORDSIZE;
81 write_if_needed();
82 if (offset) {
83 memset(block + offset, 0, BLOCKSIZE - offset);
84 reliable_write(block, BLOCKSIZE);
85 offset = 0;
86 }
87 }
88
89 /*
90 * queues up writes, so that all our write(2) calls write exactly one
91 * full block; pads writes to RECORDSIZE
92 */
93 static void write_blocked(void *buf, unsigned long size)
94 {
95 unsigned long tail;
96
97 if (offset) {
98 unsigned long chunk = BLOCKSIZE - offset;
99 if (size < chunk)
100 chunk = size;
101 memcpy(block + offset, buf, chunk);
102 size -= chunk;
103 offset += chunk;
104 buf += chunk;
105 write_if_needed();
106 }
107 while (size >= BLOCKSIZE) {
108 reliable_write(buf, BLOCKSIZE);
109 size -= BLOCKSIZE;
110 buf += BLOCKSIZE;
111 }
112 if (size) {
113 memcpy(block + offset, buf, size);
114 buf += size;
115 offset += size;
116 }
117 tail = offset % RECORDSIZE;
118 if (tail) {
119 memset(block + offset, 0, RECORDSIZE - tail);
120 offset += RECORDSIZE - tail;
121 }
122 write_if_needed();
123 }
124
125 static void append_string(char **p, const char *s)
126 {
127 unsigned int len = strlen(s);
128 memcpy(*p, s, len);
129 *p += len;
130 }
131
132 static void append_char(char **p, char c)
133 {
134 **p = c;
135 *p += 1;
136 }
137
138 static void append_path_prefix(char **buffer, struct path_prefix *prefix)
139 {
140 if (!prefix)
141 return;
142 append_path_prefix(buffer, prefix->prev);
143 append_string(buffer, prefix->name);
144 append_char(buffer, '/');
145 }
146
147 static unsigned int path_prefix_len(struct path_prefix *prefix)
148 {
149 if (!prefix)
150 return 0;
151 return path_prefix_len(prefix->prev) + strlen(prefix->name) + 1;
152 }
153
154 static void append_path(char **p, int is_dir, const char *basepath,
155 struct path_prefix *prefix, const char *path)
156 {
157 if (basepath) {
158 append_string(p, basepath);
159 append_char(p, '/');
160 }
161 append_path_prefix(p, prefix);
162 append_string(p, path);
163 if (is_dir)
164 append_char(p, '/');
165 }
166
167 static unsigned int path_len(int is_dir, const char *basepath,
168 struct path_prefix *prefix, const char *path)
169 {
170 unsigned int len = 0;
171 if (basepath)
172 len += strlen(basepath) + 1;
173 len += path_prefix_len(prefix) + strlen(path);
174 if (is_dir)
175 len++;
176 return len;
177 }
178
179 static void append_extended_header_prefix(char **p, unsigned int size,
180 const char *keyword)
181 {
182 int len = sprintf(*p, "%u %s=", size, keyword);
183 *p += len;
184 }
185
186 static unsigned int extended_header_len(const char *keyword,
187 unsigned int valuelen)
188 {
189 /* "%u %s=%s\n" */
190 unsigned int len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
191 if (len > 9)
192 len++;
193 if (len > 99)
194 len++;
195 return len;
196 }
197
198 static void append_extended_header(char **p, const char *keyword,
199 const char *value, unsigned int len)
200 {
201 unsigned int size = extended_header_len(keyword, len);
202 append_extended_header_prefix(p, size, keyword);
203 memcpy(*p, value, len);
204 *p += len;
205 append_char(p, '\n');
206 }
207
208 static void write_header(const unsigned char *, char, const char *, struct path_prefix *,
209 const char *, unsigned int, void *, unsigned long);
210
211 /* stores a pax extended header directly in the block buffer */
212 static void write_extended_header(const char *headerfilename, int is_dir,
213 unsigned int flags, const char *basepath,
214 struct path_prefix *prefix,
215 const char *path, unsigned int namelen,
216 void *content, unsigned int contentsize)
217 {
218 char *buffer, *p;
219 unsigned int pathlen, size, linkpathlen = 0;
220
221 size = pathlen = extended_header_len("path", namelen);
222 if (flags & EXT_HEADER_LINKPATH) {
223 linkpathlen = extended_header_len("linkpath", contentsize);
224 size += linkpathlen;
225 }
226 write_header(NULL, TYPEFLAG_EXT_HEADER, NULL, NULL, headerfilename,
227 0100600, NULL, size);
228
229 buffer = p = malloc(size);
230 if (!buffer)
231 die("git-tar-tree: %s", strerror(errno));
232 append_extended_header_prefix(&p, pathlen, "path");
233 append_path(&p, is_dir, basepath, prefix, path);
234 append_char(&p, '\n');
235 if (flags & EXT_HEADER_LINKPATH)
236 append_extended_header(&p, "linkpath", content, contentsize);
237 write_blocked(buffer, size);
238 free(buffer);
239 }
240
241 static void write_global_extended_header(const unsigned char *sha1)
242 {
243 char *p;
244 unsigned int size;
245
246 size = extended_header_len("comment", 40);
247 write_header(NULL, TYPEFLAG_GLOBAL_HEADER, NULL, NULL,
248 "pax_global_header", 0100600, NULL, size);
249
250 p = get_record();
251 append_extended_header(&p, "comment", sha1_to_hex(sha1), 40);
252 write_if_needed();
253 }
254
255 /* stores a ustar header directly in the block buffer */
256 static void write_header(const unsigned char *sha1, char typeflag, const char *basepath,
257 struct path_prefix *prefix, const char *path,
258 unsigned int mode, void *buffer, unsigned long size)
259 {
260 unsigned int namelen;
261 char *header = NULL;
262 unsigned int checksum = 0;
263 int i;
264 unsigned int ext_header = 0;
265
266 if (typeflag == TYPEFLAG_AUTO) {
267 if (S_ISDIR(mode))
268 typeflag = TYPEFLAG_DIR;
269 else if (S_ISLNK(mode))
270 typeflag = TYPEFLAG_LNK;
271 else
272 typeflag = TYPEFLAG_REG;
273 }
274
275 namelen = path_len(S_ISDIR(mode), basepath, prefix, path);
276 if (namelen > 100)
277 ext_header |= EXT_HEADER_PATH;
278 if (typeflag == TYPEFLAG_LNK && size > 100)
279 ext_header |= EXT_HEADER_LINKPATH;
280
281 /* the extended header must be written before the normal one */
282 if (ext_header) {
283 char headerfilename[51];
284 sprintf(headerfilename, "%s.paxheader", sha1_to_hex(sha1));
285 write_extended_header(headerfilename, S_ISDIR(mode),
286 ext_header, basepath, prefix, path,
287 namelen, buffer, size);
288 }
289
290 header = get_record();
291
292 if (ext_header) {
293 sprintf(header, "%s.data", sha1_to_hex(sha1));
294 } else {
295 char *p = header;
296 append_path(&p, S_ISDIR(mode), basepath, prefix, path);
297 }
298
299 if (typeflag == TYPEFLAG_LNK) {
300 if (ext_header & EXT_HEADER_LINKPATH) {
301 sprintf(&header[157], "see %s.paxheader",
302 sha1_to_hex(sha1));
303 } else {
304 if (buffer)
305 strncpy(&header[157], buffer, size);
306 }
307 }
308
309 if (S_ISDIR(mode))
310 mode |= 0755; /* GIT doesn't store permissions of dirs */
311 if (S_ISLNK(mode))
312 mode |= 0777; /* ... nor of symlinks */
313 sprintf(&header[100], "%07o", mode & 07777);
314
315 /* XXX: should we provide more meaningful info here? */
316 sprintf(&header[108], "%07o", 0); /* uid */
317 sprintf(&header[116], "%07o", 0); /* gid */
318 strncpy(&header[265], "git", 31); /* uname */
319 strncpy(&header[297], "git", 31); /* gname */
320
321 if (S_ISDIR(mode) || S_ISLNK(mode))
322 size = 0;
323 sprintf(&header[124], "%011lo", size);
324 sprintf(&header[136], "%011lo", archive_time);
325
326 header[156] = typeflag;
327
328 memcpy(&header[257], "ustar", 6);
329 memcpy(&header[263], "00", 2);
330
331 printf(&header[329], "%07o", 0); /* devmajor */
332 printf(&header[337], "%07o", 0); /* devminor */
333
334 memset(&header[148], ' ', 8);
335 for (i = 0; i < RECORDSIZE; i++)
336 checksum += header[i];
337 sprintf(&header[148], "%07o", checksum & 0x1fffff);
338
339 write_if_needed();
340 }
341
342 static void traverse_tree(void *buffer, unsigned long size,
343 struct path_prefix *prefix)
344 {
345 struct path_prefix this_prefix;
346 this_prefix.prev = prefix;
347
348 while (size) {
349 int namelen = strlen(buffer)+1;
350 void *eltbuf;
351 char elttype[20];
352 unsigned long eltsize;
353 unsigned char *sha1 = buffer + namelen;
354 char *path = strchr(buffer, ' ') + 1;
355 unsigned int mode;
356
357 if (size < namelen + 20 || sscanf(buffer, "%o", &mode) != 1)
358 die("corrupt 'tree' file");
359 buffer = sha1 + 20;
360 size -= namelen + 20;
361
362 eltbuf = read_sha1_file(sha1, elttype, &eltsize);
363 if (!eltbuf)
364 die("cannot read %s", sha1_to_hex(sha1));
365 write_header(sha1, TYPEFLAG_AUTO, basedir, prefix, path,
366 mode, eltbuf, eltsize);
367 if (!strcmp(elttype, "tree")) {
368 this_prefix.name = path;
369 traverse_tree(eltbuf, eltsize, &this_prefix);
370 } else if (!strcmp(elttype, "blob") && !S_ISLNK(mode)) {
371 write_blocked(eltbuf, eltsize);
372 }
373 free(eltbuf);
374 }
375 }
376
377 /* get commit time from committer line of commit object */
378 time_t commit_time(void * buffer, unsigned long size)
379 {
380 time_t result = 0;
381 char *p = buffer;
382
383 while (size > 0) {
384 char *endp = memchr(p, '\n', size);
385 if (!endp || endp == p)
386 break;
387 *endp = '\0';
388 if (endp - p > 10 && !memcmp(p, "committer ", 10)) {
389 char *nump = strrchr(p, '>');
390 if (!nump)
391 break;
392 nump++;
393 result = strtoul(nump, &endp, 10);
394 if (*endp != ' ')
395 result = 0;
396 break;
397 }
398 size -= endp - p - 1;
399 p = endp + 1;
400 }
401 return result;
402 }
403
404 int main(int argc, char **argv)
405 {
406 unsigned char sha1[20];
407 unsigned char commit_sha1[20];
408 void *buffer;
409 unsigned long size;
410
411 switch (argc) {
412 case 3:
413 basedir = argv[2];
414 /* FALLTHROUGH */
415 case 2:
416 if (get_sha1(argv[1], sha1) < 0)
417 usage(tar_tree_usage);
418 break;
419 default:
420 usage(tar_tree_usage);
421 }
422
423 buffer = read_object_with_reference(sha1, "commit", &size, commit_sha1);
424 if (buffer) {
425 write_global_extended_header(commit_sha1);
426 archive_time = commit_time(buffer, size);
427 free(buffer);
428 }
429 buffer = read_object_with_reference(sha1, "tree", &size, NULL);
430 if (!buffer)
431 die("not a reference to a tag, commit or tree object: %s",
432 sha1_to_hex(sha1));
433 if (!archive_time)
434 archive_time = time(NULL);
435 if (basedir)
436 write_header("0", TYPEFLAG_DIR, NULL, NULL, basedir, 040755,
437 NULL, 0);
438 traverse_tree(buffer, size, NULL);
439 free(buffer);
440 write_trailer();
441 return 0;
442 }