Merge branch 'bw/submodule-helper-usage-fix'
[git/git.git] / tmp-objdir.c
CommitLineData
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1#include "cache.h"
2#include "tmp-objdir.h"
3#include "dir.h"
4#include "sigchain.h"
5#include "string-list.h"
6#include "strbuf.h"
7#include "argv-array.h"
aae2ae4f 8#include "quote.h"
0d4a1321 9#include "object-store.h"
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10
11struct tmp_objdir {
12 struct strbuf path;
13 struct argv_array env;
14};
15
16/*
17 * Allow only one tmp_objdir at a time in a running process, which simplifies
18 * our signal/atexit cleanup routines. It's doubtful callers will ever need
19 * more than one, and we can expand later if so. You can have many such
20 * tmp_objdirs simultaneously in many processes, of course.
21 */
22static struct tmp_objdir *the_tmp_objdir;
23
24static void tmp_objdir_free(struct tmp_objdir *t)
25{
26 strbuf_release(&t->path);
27 argv_array_clear(&t->env);
28 free(t);
29}
30
31static int tmp_objdir_destroy_1(struct tmp_objdir *t, int on_signal)
32{
33 int err;
34
35 if (!t)
36 return 0;
37
38 if (t == the_tmp_objdir)
39 the_tmp_objdir = NULL;
40
41 /*
42 * This may use malloc via strbuf_grow(), but we should
43 * have pre-grown t->path sufficiently so that this
44 * doesn't happen in practice.
45 */
46 err = remove_dir_recursively(&t->path, 0);
47
48 /*
49 * When we are cleaning up due to a signal, we won't bother
50 * freeing memory; it may cause a deadlock if the signal
51 * arrived while libc's allocator lock is held.
52 */
53 if (!on_signal)
54 tmp_objdir_free(t);
55 return err;
56}
57
58int tmp_objdir_destroy(struct tmp_objdir *t)
59{
60 return tmp_objdir_destroy_1(t, 0);
61}
62
63static void remove_tmp_objdir(void)
64{
65 tmp_objdir_destroy(the_tmp_objdir);
66}
67
68static void remove_tmp_objdir_on_signal(int signo)
69{
70 tmp_objdir_destroy_1(the_tmp_objdir, 1);
71 sigchain_pop(signo);
72 raise(signo);
73}
74
75/*
76 * These env_* functions are for setting up the child environment; the
77 * "replace" variant overrides the value of any existing variable with that
78 * "key". The "append" variant puts our new value at the end of a list,
79 * separated by PATH_SEP (which is what separate values in
80 * GIT_ALTERNATE_OBJECT_DIRECTORIES).
81 */
82static void env_append(struct argv_array *env, const char *key, const char *val)
83{
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84 struct strbuf quoted = STRBUF_INIT;
85 const char *old;
2564d994 86
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87 /*
88 * Avoid quoting if it's not necessary, for maximum compatibility
89 * with older parsers which don't understand the quoting.
90 */
91 if (*val == '"' || strchr(val, PATH_SEP)) {
92 strbuf_addch(&quoted, '"');
93 quote_c_style(val, &quoted, NULL, 1);
94 strbuf_addch(&quoted, '"');
95 val = quoted.buf;
96 }
97
98 old = getenv(key);
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99 if (!old)
100 argv_array_pushf(env, "%s=%s", key, val);
101 else
102 argv_array_pushf(env, "%s=%s%c%s", key, old, PATH_SEP, val);
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103
104 strbuf_release(&quoted);
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105}
106
107static void env_replace(struct argv_array *env, const char *key, const char *val)
108{
109 argv_array_pushf(env, "%s=%s", key, val);
110}
111
112static int setup_tmp_objdir(const char *root)
113{
114 char *path;
115 int ret = 0;
116
117 path = xstrfmt("%s/pack", root);
118 ret = mkdir(path, 0777);
119 free(path);
120
121 return ret;
122}
123
124struct tmp_objdir *tmp_objdir_create(void)
125{
126 static int installed_handlers;
127 struct tmp_objdir *t;
128
129 if (the_tmp_objdir)
033abf97 130 BUG("only one tmp_objdir can be used at a time");
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131
132 t = xmalloc(sizeof(*t));
133 strbuf_init(&t->path, 0);
134 argv_array_init(&t->env);
135
136 strbuf_addf(&t->path, "%s/incoming-XXXXXX", get_object_directory());
137
138 /*
139 * Grow the strbuf beyond any filename we expect to be placed in it.
140 * If tmp_objdir_destroy() is called by a signal handler, then
141 * we should be able to use the strbuf to remove files without
142 * having to call malloc.
143 */
144 strbuf_grow(&t->path, 1024);
145
146 if (!mkdtemp(t->path.buf)) {
147 /* free, not destroy, as we never touched the filesystem */
148 tmp_objdir_free(t);
149 return NULL;
150 }
151
152 the_tmp_objdir = t;
153 if (!installed_handlers) {
154 atexit(remove_tmp_objdir);
155 sigchain_push_common(remove_tmp_objdir_on_signal);
156 installed_handlers++;
157 }
158
159 if (setup_tmp_objdir(t->path.buf)) {
160 tmp_objdir_destroy(t);
161 return NULL;
162 }
163
164 env_append(&t->env, ALTERNATE_DB_ENVIRONMENT,
165 absolute_path(get_object_directory()));
166 env_replace(&t->env, DB_ENVIRONMENT, absolute_path(t->path.buf));
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167 env_replace(&t->env, GIT_QUARANTINE_ENVIRONMENT,
168 absolute_path(t->path.buf));
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169
170 return t;
171}
172
173/*
174 * Make sure we copy packfiles and their associated metafiles in the correct
175 * order. All of these ends_with checks are slightly expensive to do in
176 * the midst of a sorting routine, but in practice it shouldn't matter.
177 * We will have a relatively small number of packfiles to order, and loose
178 * objects exit early in the first line.
179 */
180static int pack_copy_priority(const char *name)
181{
182 if (!starts_with(name, "pack"))
183 return 0;
184 if (ends_with(name, ".keep"))
185 return 1;
186 if (ends_with(name, ".pack"))
187 return 2;
188 if (ends_with(name, ".idx"))
189 return 3;
190 return 4;
191}
192
193static int pack_copy_cmp(const char *a, const char *b)
194{
195 return pack_copy_priority(a) - pack_copy_priority(b);
196}
197
198static int read_dir_paths(struct string_list *out, const char *path)
199{
200 DIR *dh;
201 struct dirent *de;
202
203 dh = opendir(path);
204 if (!dh)
205 return -1;
206
207 while ((de = readdir(dh)))
62fe0eb4 208 if (de->d_name[0] != '.')
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209 string_list_append(out, de->d_name);
210
211 closedir(dh);
212 return 0;
213}
214
215static int migrate_paths(struct strbuf *src, struct strbuf *dst);
216
217static int migrate_one(struct strbuf *src, struct strbuf *dst)
218{
219 struct stat st;
220
221 if (stat(src->buf, &st) < 0)
222 return -1;
223 if (S_ISDIR(st.st_mode)) {
224 if (!mkdir(dst->buf, 0777)) {
225 if (adjust_shared_perm(dst->buf))
226 return -1;
227 } else if (errno != EEXIST)
228 return -1;
229 return migrate_paths(src, dst);
230 }
231 return finalize_object_file(src->buf, dst->buf);
232}
233
234static int migrate_paths(struct strbuf *src, struct strbuf *dst)
235{
236 size_t src_len = src->len, dst_len = dst->len;
237 struct string_list paths = STRING_LIST_INIT_DUP;
238 int i;
239 int ret = 0;
240
241 if (read_dir_paths(&paths, src->buf) < 0)
242 return -1;
243 paths.cmp = pack_copy_cmp;
244 string_list_sort(&paths);
245
246 for (i = 0; i < paths.nr; i++) {
247 const char *name = paths.items[i].string;
248
249 strbuf_addf(src, "/%s", name);
250 strbuf_addf(dst, "/%s", name);
251
252 ret |= migrate_one(src, dst);
253
254 strbuf_setlen(src, src_len);
255 strbuf_setlen(dst, dst_len);
256 }
257
258 string_list_clear(&paths, 0);
259 return ret;
260}
261
262int tmp_objdir_migrate(struct tmp_objdir *t)
263{
264 struct strbuf src = STRBUF_INIT, dst = STRBUF_INIT;
265 int ret;
266
267 if (!t)
268 return 0;
269
270 strbuf_addbuf(&src, &t->path);
271 strbuf_addstr(&dst, get_object_directory());
272
273 ret = migrate_paths(&src, &dst);
274
275 strbuf_release(&src);
276 strbuf_release(&dst);
277
278 tmp_objdir_destroy(t);
279 return ret;
280}
281
282const char **tmp_objdir_env(const struct tmp_objdir *t)
283{
284 if (!t)
285 return NULL;
286 return t->env.argv;
287}
288
289void tmp_objdir_add_as_alternate(const struct tmp_objdir *t)
290{
291 add_to_alternates_memory(t->path.buf);
292}