Merge branch 'master' of git://repo.or.cz/git/git-p4
[git/git.git] / archive-tar.c
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1/*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
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4#include "cache.h"
5#include "commit.h"
6#include "strbuf.h"
7#include "tar.h"
8#include "builtin.h"
9#include "archive.h"
10
11#define RECORDSIZE (512)
12#define BLOCKSIZE (RECORDSIZE * 20)
13
14static char block[BLOCKSIZE];
15static unsigned long offset;
16
17static time_t archive_time;
f08b3b0e 18static int tar_umask = 002;
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19static int verbose;
20
21/* writes out the whole block, but only if it is full */
22static void write_if_needed(void)
23{
24 if (offset == BLOCKSIZE) {
25 write_or_die(1, block, BLOCKSIZE);
26 offset = 0;
27 }
28}
29
30/*
31 * queues up writes, so that all our write(2) calls write exactly one
32 * full block; pads writes to RECORDSIZE
33 */
34static void write_blocked(const void *data, unsigned long size)
35{
36 const char *buf = data;
37 unsigned long tail;
38
39 if (offset) {
40 unsigned long chunk = BLOCKSIZE - offset;
41 if (size < chunk)
42 chunk = size;
43 memcpy(block + offset, buf, chunk);
44 size -= chunk;
45 offset += chunk;
46 buf += chunk;
47 write_if_needed();
48 }
49 while (size >= BLOCKSIZE) {
50 write_or_die(1, buf, BLOCKSIZE);
51 size -= BLOCKSIZE;
52 buf += BLOCKSIZE;
53 }
54 if (size) {
55 memcpy(block + offset, buf, size);
56 offset += size;
57 }
58 tail = offset % RECORDSIZE;
59 if (tail) {
60 memset(block + offset, 0, RECORDSIZE - tail);
61 offset += RECORDSIZE - tail;
62 }
63 write_if_needed();
64}
65
66/*
67 * The end of tar archives is marked by 2*512 nul bytes and after that
68 * follows the rest of the block (if any).
69 */
70static void write_trailer(void)
71{
72 int tail = BLOCKSIZE - offset;
73 memset(block + offset, 0, tail);
74 write_or_die(1, block, BLOCKSIZE);
75 if (tail < 2 * RECORDSIZE) {
76 memset(block, 0, offset);
77 write_or_die(1, block, BLOCKSIZE);
78 }
79}
80
81static void strbuf_append_string(struct strbuf *sb, const char *s)
82{
83 int slen = strlen(s);
84 int total = sb->len + slen;
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85 if (total + 1 > sb->alloc) {
86 sb->buf = xrealloc(sb->buf, total + 1);
87 sb->alloc = total + 1;
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88 }
89 memcpy(sb->buf + sb->len, s, slen);
90 sb->len = total;
5e6cfc80 91 sb->buf[total] = '\0';
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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 */
100static 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
125static 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
138static 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
149static 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);
302b9282 170 if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
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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
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214 sprintf(header.uid, "%07o", 0);
215 sprintf(header.gid, "%07o", 0);
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216 strlcpy(header.uname, "root", sizeof(header.uname));
217 strlcpy(header.gname, "root", sizeof(header.gname));
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218 sprintf(header.devmajor, "%07o", 0);
219 sprintf(header.devminor, "%07o", 0);
220
221 memcpy(header.magic, "ustar", 6);
222 memcpy(header.version, "00", 2);
223
224 sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
225
226 if (ext_header.len > 0) {
227 write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
228 free(ext_header.buf);
229 }
230 write_blocked(&header, sizeof(header));
231 if (S_ISREG(mode) && buffer && size > 0)
232 write_blocked(buffer, size);
233}
234
235static void write_global_extended_header(const unsigned char *sha1)
236{
237 struct strbuf ext_header;
238 ext_header.buf = NULL;
239 ext_header.len = ext_header.alloc = 0;
240 strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
241 write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
242 free(ext_header.buf);
243}
244
245static int git_tar_config(const char *var, const char *value)
246{
247 if (!strcmp(var, "tar.umask")) {
248 if (!strcmp(value, "user")) {
249 tar_umask = umask(0);
250 umask(tar_umask);
251 } else {
252 tar_umask = git_config_int(var, value);
253 }
254 return 0;
255 }
256 return git_default_config(var, value);
257}
258
259static int write_tar_entry(const unsigned char *sha1,
260 const char *base, int baselen,
261 const char *filename, unsigned mode, int stage)
262{
263 static struct strbuf path;
264 int filenamelen = strlen(filename);
265 void *buffer;
21666f1a 266 enum object_type type;
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267 unsigned long size;
268
269 if (!path.alloc) {
270 path.buf = xmalloc(PATH_MAX);
271 path.alloc = PATH_MAX;
272 path.len = path.eof = 0;
273 }
5e6cfc80 274 if (path.alloc < baselen + filenamelen + 1) {
3d74982f 275 free(path.buf);
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276 path.buf = xmalloc(baselen + filenamelen + 1);
277 path.alloc = baselen + filenamelen + 1;
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278 }
279 memcpy(path.buf, base, baselen);
280 memcpy(path.buf + baselen, filename, filenamelen);
281 path.len = baselen + filenamelen;
5e6cfc80 282 path.buf[path.len] = '\0';
302b9282 283 if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
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284 strbuf_append_string(&path, "/");
285 buffer = NULL;
286 size = 0;
287 } else {
5e6cfc80 288 buffer = convert_sha1_file(path.buf, sha1, mode, &type, &size);
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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
299int 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}