Merge branch 'master' into lj/refs
[git/git.git] / archive-tar.c
1 /*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
4 #include <time.h>
5 #include "cache.h"
6 #include "commit.h"
7 #include "strbuf.h"
8 #include "tar.h"
9 #include "builtin.h"
10 #include "archive.h"
11
12 #define RECORDSIZE (512)
13 #define BLOCKSIZE (RECORDSIZE * 20)
14
15 static char block[BLOCKSIZE];
16 static unsigned long offset;
17
18 static time_t archive_time;
19 static int tar_umask;
20 static int verbose;
21
22 /* writes out the whole block, but only if it is full */
23 static void write_if_needed(void)
24 {
25 if (offset == BLOCKSIZE) {
26 write_or_die(1, block, BLOCKSIZE);
27 offset = 0;
28 }
29 }
30
31 /*
32 * queues up writes, so that all our write(2) calls write exactly one
33 * full block; pads writes to RECORDSIZE
34 */
35 static void write_blocked(const void *data, unsigned long size)
36 {
37 const char *buf = data;
38 unsigned long tail;
39
40 if (offset) {
41 unsigned long chunk = BLOCKSIZE - offset;
42 if (size < chunk)
43 chunk = size;
44 memcpy(block + offset, buf, chunk);
45 size -= chunk;
46 offset += chunk;
47 buf += chunk;
48 write_if_needed();
49 }
50 while (size >= BLOCKSIZE) {
51 write_or_die(1, buf, BLOCKSIZE);
52 size -= BLOCKSIZE;
53 buf += BLOCKSIZE;
54 }
55 if (size) {
56 memcpy(block + offset, buf, size);
57 offset += size;
58 }
59 tail = offset % RECORDSIZE;
60 if (tail) {
61 memset(block + offset, 0, RECORDSIZE - tail);
62 offset += RECORDSIZE - tail;
63 }
64 write_if_needed();
65 }
66
67 /*
68 * The end of tar archives is marked by 2*512 nul bytes and after that
69 * follows the rest of the block (if any).
70 */
71 static void write_trailer(void)
72 {
73 int tail = BLOCKSIZE - offset;
74 memset(block + offset, 0, tail);
75 write_or_die(1, block, BLOCKSIZE);
76 if (tail < 2 * RECORDSIZE) {
77 memset(block, 0, offset);
78 write_or_die(1, block, BLOCKSIZE);
79 }
80 }
81
82 static void strbuf_append_string(struct strbuf *sb, const char *s)
83 {
84 int slen = strlen(s);
85 int total = sb->len + slen;
86 if (total > sb->alloc) {
87 sb->buf = xrealloc(sb->buf, total);
88 sb->alloc = total;
89 }
90 memcpy(sb->buf + sb->len, s, slen);
91 sb->len = total;
92 }
93
94 /*
95 * pax extended header records have the format "%u %s=%s\n". %u contains
96 * the size of the whole string (including the %u), the first %s is the
97 * keyword, the second one is the value. This function constructs such a
98 * string and appends it to a struct strbuf.
99 */
100 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
101 const char *value, unsigned int valuelen)
102 {
103 char *p;
104 int len, total, tmp;
105
106 /* "%u %s=%s\n" */
107 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
108 for (tmp = len; tmp > 9; tmp /= 10)
109 len++;
110
111 total = sb->len + len;
112 if (total > sb->alloc) {
113 sb->buf = xrealloc(sb->buf, total);
114 sb->alloc = total;
115 }
116
117 p = sb->buf;
118 p += sprintf(p, "%u %s=", len, keyword);
119 memcpy(p, value, valuelen);
120 p += valuelen;
121 *p = '\n';
122 sb->len = total;
123 }
124
125 static unsigned int ustar_header_chksum(const struct ustar_header *header)
126 {
127 char *p = (char *)header;
128 unsigned int chksum = 0;
129 while (p < header->chksum)
130 chksum += *p++;
131 chksum += sizeof(header->chksum) * ' ';
132 p += sizeof(header->chksum);
133 while (p < (char *)header + sizeof(struct ustar_header))
134 chksum += *p++;
135 return chksum;
136 }
137
138 static int get_path_prefix(const struct strbuf *path, int maxlen)
139 {
140 int i = path->len;
141 if (i > maxlen)
142 i = maxlen;
143 do {
144 i--;
145 } while (i > 0 && path->buf[i] != '/');
146 return i;
147 }
148
149 static void write_entry(const unsigned char *sha1, struct strbuf *path,
150 unsigned int mode, void *buffer, unsigned long size)
151 {
152 struct ustar_header header;
153 struct strbuf ext_header;
154
155 memset(&header, 0, sizeof(header));
156 ext_header.buf = NULL;
157 ext_header.len = ext_header.alloc = 0;
158
159 if (!sha1) {
160 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
161 mode = 0100666;
162 strcpy(header.name, "pax_global_header");
163 } else if (!path) {
164 *header.typeflag = TYPEFLAG_EXT_HEADER;
165 mode = 0100666;
166 sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
167 } else {
168 if (verbose)
169 fprintf(stderr, "%.*s\n", path->len, path->buf);
170 if (S_ISDIR(mode)) {
171 *header.typeflag = TYPEFLAG_DIR;
172 mode = (mode | 0777) & ~tar_umask;
173 } else if (S_ISLNK(mode)) {
174 *header.typeflag = TYPEFLAG_LNK;
175 mode |= 0777;
176 } else if (S_ISREG(mode)) {
177 *header.typeflag = TYPEFLAG_REG;
178 mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
179 } else {
180 error("unsupported file mode: 0%o (SHA1: %s)",
181 mode, sha1_to_hex(sha1));
182 return;
183 }
184 if (path->len > sizeof(header.name)) {
185 int plen = get_path_prefix(path, sizeof(header.prefix));
186 int rest = path->len - plen - 1;
187 if (plen > 0 && rest <= sizeof(header.name)) {
188 memcpy(header.prefix, path->buf, plen);
189 memcpy(header.name, path->buf + plen + 1, rest);
190 } else {
191 sprintf(header.name, "%s.data",
192 sha1_to_hex(sha1));
193 strbuf_append_ext_header(&ext_header, "path",
194 path->buf, path->len);
195 }
196 } else
197 memcpy(header.name, path->buf, path->len);
198 }
199
200 if (S_ISLNK(mode) && buffer) {
201 if (size > sizeof(header.linkname)) {
202 sprintf(header.linkname, "see %s.paxheader",
203 sha1_to_hex(sha1));
204 strbuf_append_ext_header(&ext_header, "linkpath",
205 buffer, size);
206 } else
207 memcpy(header.linkname, buffer, size);
208 }
209
210 sprintf(header.mode, "%07o", mode & 07777);
211 sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
212 sprintf(header.mtime, "%011lo", archive_time);
213
214 /* XXX: should we provide more meaningful info here? */
215 sprintf(header.uid, "%07o", 0);
216 sprintf(header.gid, "%07o", 0);
217 strlcpy(header.uname, "git", sizeof(header.uname));
218 strlcpy(header.gname, "git", sizeof(header.gname));
219 sprintf(header.devmajor, "%07o", 0);
220 sprintf(header.devminor, "%07o", 0);
221
222 memcpy(header.magic, "ustar", 6);
223 memcpy(header.version, "00", 2);
224
225 sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
226
227 if (ext_header.len > 0) {
228 write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
229 free(ext_header.buf);
230 }
231 write_blocked(&header, sizeof(header));
232 if (S_ISREG(mode) && buffer && size > 0)
233 write_blocked(buffer, size);
234 }
235
236 static void write_global_extended_header(const unsigned char *sha1)
237 {
238 struct strbuf ext_header;
239 ext_header.buf = NULL;
240 ext_header.len = ext_header.alloc = 0;
241 strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
242 write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
243 free(ext_header.buf);
244 }
245
246 static int git_tar_config(const char *var, const char *value)
247 {
248 if (!strcmp(var, "tar.umask")) {
249 if (!strcmp(value, "user")) {
250 tar_umask = umask(0);
251 umask(tar_umask);
252 } else {
253 tar_umask = git_config_int(var, value);
254 }
255 return 0;
256 }
257 return git_default_config(var, value);
258 }
259
260 static int write_tar_entry(const unsigned char *sha1,
261 const char *base, int baselen,
262 const char *filename, unsigned mode, int stage)
263 {
264 static struct strbuf path;
265 int filenamelen = strlen(filename);
266 void *buffer;
267 char type[20];
268 unsigned long size;
269
270 if (!path.alloc) {
271 path.buf = xmalloc(PATH_MAX);
272 path.alloc = PATH_MAX;
273 path.len = path.eof = 0;
274 }
275 if (path.alloc < baselen + filenamelen) {
276 free(path.buf);
277 path.buf = xmalloc(baselen + filenamelen);
278 path.alloc = baselen + filenamelen;
279 }
280 memcpy(path.buf, base, baselen);
281 memcpy(path.buf + baselen, filename, filenamelen);
282 path.len = baselen + filenamelen;
283 if (S_ISDIR(mode)) {
284 strbuf_append_string(&path, "/");
285 buffer = NULL;
286 size = 0;
287 } else {
288 buffer = read_sha1_file(sha1, type, &size);
289 if (!buffer)
290 die("cannot read %s", sha1_to_hex(sha1));
291 }
292
293 write_entry(sha1, &path, mode, buffer, size);
294 free(buffer);
295
296 return READ_TREE_RECURSIVE;
297 }
298
299 int write_tar_archive(struct archiver_args *args)
300 {
301 int plen = args->base ? strlen(args->base) : 0;
302
303 git_config(git_tar_config);
304
305 archive_time = args->time;
306 verbose = args->verbose;
307
308 if (args->commit_sha1)
309 write_global_extended_header(args->commit_sha1);
310
311 if (args->base && plen > 0 && args->base[plen - 1] == '/') {
312 char *base = xstrdup(args->base);
313 int baselen = strlen(base);
314
315 while (baselen > 0 && base[baselen - 1] == '/')
316 base[--baselen] = '\0';
317 write_tar_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
318 free(base);
319 }
320 read_tree_recursive(args->tree, args->base, plen, 0,
321 args->pathspec, write_tar_entry);
322 write_trailer();
323
324 return 0;
325 }