| 1 | #define DISABLE_SIGN_COMPARE_WARNINGS |
| 2 | |
| 3 | #include "git-compat-util.h" |
| 4 | #include "dir.h" |
| 5 | #include "hex.h" |
| 6 | #include "repository.h" |
| 7 | #include "refs.h" |
| 8 | #include "object.h" |
| 9 | #include "commit.h" |
| 10 | #include "tag.h" |
| 11 | #include "packfile.h" |
| 12 | #include "path.h" |
| 13 | #include "object-file.h" |
| 14 | #include "odb.h" |
| 15 | #include "server-info.h" |
| 16 | #include "strbuf.h" |
| 17 | #include "tempfile.h" |
| 18 | |
| 19 | struct update_info_ctx { |
| 20 | struct repository *repo; |
| 21 | FILE *cur_fp; |
| 22 | FILE *old_fp; /* becomes NULL if it differs from cur_fp */ |
| 23 | struct strbuf cur_sb; |
| 24 | struct strbuf old_sb; |
| 25 | }; |
| 26 | |
| 27 | static void uic_mark_stale(struct update_info_ctx *uic) |
| 28 | { |
| 29 | fclose(uic->old_fp); |
| 30 | uic->old_fp = NULL; |
| 31 | } |
| 32 | |
| 33 | static int uic_is_stale(const struct update_info_ctx *uic) |
| 34 | { |
| 35 | return uic->old_fp == NULL; |
| 36 | } |
| 37 | |
| 38 | __attribute__((format (printf, 2, 3))) |
| 39 | static int uic_printf(struct update_info_ctx *uic, const char *fmt, ...) |
| 40 | { |
| 41 | va_list ap; |
| 42 | int ret = -1; |
| 43 | |
| 44 | va_start(ap, fmt); |
| 45 | |
| 46 | if (uic_is_stale(uic)) { |
| 47 | ret = vfprintf(uic->cur_fp, fmt, ap); |
| 48 | } else { |
| 49 | ssize_t r; |
| 50 | struct strbuf *cur = &uic->cur_sb; |
| 51 | struct strbuf *old = &uic->old_sb; |
| 52 | |
| 53 | strbuf_reset(cur); |
| 54 | strbuf_vinsertf(cur, 0, fmt, ap); |
| 55 | |
| 56 | strbuf_reset(old); |
| 57 | strbuf_grow(old, cur->len); |
| 58 | r = fread(old->buf, 1, cur->len, uic->old_fp); |
| 59 | if (r != cur->len || memcmp(old->buf, cur->buf, r)) |
| 60 | uic_mark_stale(uic); |
| 61 | |
| 62 | if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len) |
| 63 | ret = 0; |
| 64 | } |
| 65 | |
| 66 | va_end(ap); |
| 67 | |
| 68 | return ret; |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * Create the file "path" by writing to a temporary file and renaming |
| 73 | * it into place. The contents of the file come from "generate", which |
| 74 | * should return non-zero if it encounters an error. |
| 75 | */ |
| 76 | static int update_info_file(struct repository *r, char *path, |
| 77 | int (*generate)(struct update_info_ctx *), |
| 78 | int force) |
| 79 | { |
| 80 | char *tmp = mkpathdup("%s_XXXXXX", path); |
| 81 | struct tempfile *f = NULL; |
| 82 | int ret = -1; |
| 83 | struct update_info_ctx uic = { |
| 84 | .repo = r, |
| 85 | .cur_fp = NULL, |
| 86 | .old_fp = NULL, |
| 87 | .cur_sb = STRBUF_INIT, |
| 88 | .old_sb = STRBUF_INIT |
| 89 | }; |
| 90 | |
| 91 | safe_create_leading_directories(r, path); |
| 92 | f = mks_tempfile_m(tmp, 0666); |
| 93 | if (!f) |
| 94 | goto out; |
| 95 | uic.cur_fp = fdopen_tempfile(f, "w"); |
| 96 | if (!uic.cur_fp) |
| 97 | goto out; |
| 98 | |
| 99 | /* no problem on ENOENT and old_fp == NULL, it's stale, now */ |
| 100 | if (!force) |
| 101 | uic.old_fp = fopen_or_warn(path, "r"); |
| 102 | |
| 103 | /* |
| 104 | * uic_printf will compare incremental comparison against old_fp |
| 105 | * and mark uic as stale if needed |
| 106 | */ |
| 107 | ret = generate(&uic); |
| 108 | if (ret) |
| 109 | goto out; |
| 110 | |
| 111 | /* new file may be shorter than the old one, check here */ |
| 112 | if (!uic_is_stale(&uic)) { |
| 113 | struct stat st; |
| 114 | long new_len = ftell(uic.cur_fp); |
| 115 | int old_fd = fileno(uic.old_fp); |
| 116 | |
| 117 | if (new_len < 0) { |
| 118 | ret = -1; |
| 119 | goto out; |
| 120 | } |
| 121 | if (fstat(old_fd, &st) || (st.st_size != (size_t)new_len)) |
| 122 | uic_mark_stale(&uic); |
| 123 | } |
| 124 | |
| 125 | uic.cur_fp = NULL; |
| 126 | |
| 127 | if (uic_is_stale(&uic)) { |
| 128 | if (adjust_shared_perm(r, get_tempfile_path(f)) < 0) |
| 129 | goto out; |
| 130 | if (rename_tempfile(&f, path) < 0) |
| 131 | goto out; |
| 132 | } else { |
| 133 | delete_tempfile(&f); |
| 134 | } |
| 135 | ret = 0; |
| 136 | |
| 137 | out: |
| 138 | if (ret) { |
| 139 | error_errno("unable to update %s", path); |
| 140 | if (f) |
| 141 | delete_tempfile(&f); |
| 142 | } |
| 143 | free(tmp); |
| 144 | if (uic.old_fp) |
| 145 | fclose(uic.old_fp); |
| 146 | strbuf_release(&uic.old_sb); |
| 147 | strbuf_release(&uic.cur_sb); |
| 148 | return ret; |
| 149 | } |
| 150 | |
| 151 | static int add_info_ref(const struct reference *ref, void *cb_data) |
| 152 | { |
| 153 | struct update_info_ctx *uic = cb_data; |
| 154 | struct object *o = parse_object(uic->repo, ref->oid); |
| 155 | if (!o) |
| 156 | return -1; |
| 157 | |
| 158 | if (uic_printf(uic, "%s %s\n", oid_to_hex(ref->oid), ref->name) < 0) |
| 159 | return -1; |
| 160 | |
| 161 | if (o->type == OBJ_TAG) { |
| 162 | o = deref_tag(uic->repo, o, ref->name, 0); |
| 163 | if (o) |
| 164 | if (uic_printf(uic, "%s %s^{}\n", |
| 165 | oid_to_hex(&o->oid), ref->name) < 0) |
| 166 | return -1; |
| 167 | } |
| 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | static int generate_info_refs(struct update_info_ctx *uic) |
| 172 | { |
| 173 | return refs_for_each_ref(get_main_ref_store(uic->repo), |
| 174 | add_info_ref, uic); |
| 175 | } |
| 176 | |
| 177 | static int update_info_refs(struct repository *r, int force) |
| 178 | { |
| 179 | char *path = repo_git_path(r, "info/refs"); |
| 180 | int ret = update_info_file(r, path, generate_info_refs, force); |
| 181 | free(path); |
| 182 | return ret; |
| 183 | } |
| 184 | |
| 185 | /* packs */ |
| 186 | static struct pack_info { |
| 187 | struct packed_git *p; |
| 188 | int old_num; |
| 189 | int new_num; |
| 190 | } **info; |
| 191 | static int num_pack; |
| 192 | |
| 193 | static struct pack_info *find_pack_by_name(const char *name) |
| 194 | { |
| 195 | int i; |
| 196 | for (i = 0; i < num_pack; i++) { |
| 197 | struct packed_git *p = info[i]->p; |
| 198 | if (!strcmp(pack_basename(p), name)) |
| 199 | return info[i]; |
| 200 | } |
| 201 | return NULL; |
| 202 | } |
| 203 | |
| 204 | /* Returns non-zero when we detect that the info in the |
| 205 | * old file is useless. |
| 206 | */ |
| 207 | static int parse_pack_def(const char *packname, int old_cnt) |
| 208 | { |
| 209 | struct pack_info *i = find_pack_by_name(packname); |
| 210 | if (i) { |
| 211 | i->old_num = old_cnt; |
| 212 | return 0; |
| 213 | } |
| 214 | else { |
| 215 | /* The file describes a pack that is no longer here */ |
| 216 | return 1; |
| 217 | } |
| 218 | } |
| 219 | |
| 220 | /* Returns non-zero when we detect that the info in the |
| 221 | * old file is useless. |
| 222 | */ |
| 223 | static int read_pack_info_file(const char *infofile) |
| 224 | { |
| 225 | FILE *fp; |
| 226 | struct strbuf line = STRBUF_INIT; |
| 227 | int old_cnt = 0; |
| 228 | int stale = 1; |
| 229 | |
| 230 | fp = fopen_or_warn(infofile, "r"); |
| 231 | if (!fp) |
| 232 | return 1; /* nonexistent is not an error. */ |
| 233 | |
| 234 | while (strbuf_getline(&line, fp) != EOF) { |
| 235 | const char *arg; |
| 236 | |
| 237 | if (!line.len) |
| 238 | continue; |
| 239 | |
| 240 | if (skip_prefix(line.buf, "P ", &arg)) { |
| 241 | /* P name */ |
| 242 | if (parse_pack_def(arg, old_cnt++)) |
| 243 | goto out_stale; |
| 244 | } else if (line.buf[0] == 'D') { |
| 245 | /* we used to emit D but that was misguided. */ |
| 246 | goto out_stale; |
| 247 | } else if (line.buf[0] == 'T') { |
| 248 | /* we used to emit T but nobody uses it. */ |
| 249 | goto out_stale; |
| 250 | } else { |
| 251 | error("unrecognized: %s", line.buf); |
| 252 | } |
| 253 | } |
| 254 | stale = 0; |
| 255 | |
| 256 | out_stale: |
| 257 | strbuf_release(&line); |
| 258 | fclose(fp); |
| 259 | return stale; |
| 260 | } |
| 261 | |
| 262 | static int compare_info(const void *a_, const void *b_) |
| 263 | { |
| 264 | struct pack_info *const *a = a_; |
| 265 | struct pack_info *const *b = b_; |
| 266 | |
| 267 | if (0 <= (*a)->old_num && 0 <= (*b)->old_num) |
| 268 | /* Keep the order in the original */ |
| 269 | return (*a)->old_num - (*b)->old_num; |
| 270 | else if (0 <= (*a)->old_num) |
| 271 | /* Only A existed in the original so B is obviously newer */ |
| 272 | return -1; |
| 273 | else if (0 <= (*b)->old_num) |
| 274 | /* The other way around. */ |
| 275 | return 1; |
| 276 | |
| 277 | /* then it does not matter but at least keep the comparison stable */ |
| 278 | if ((*a)->p == (*b)->p) |
| 279 | return 0; |
| 280 | else if ((*a)->p < (*b)->p) |
| 281 | return -1; |
| 282 | else |
| 283 | return 1; |
| 284 | } |
| 285 | |
| 286 | static void init_pack_info(struct repository *r, const char *infofile, int force) |
| 287 | { |
| 288 | struct packed_git *p; |
| 289 | int stale; |
| 290 | int i; |
| 291 | size_t alloc = 0; |
| 292 | |
| 293 | repo_for_each_pack(r, p) { |
| 294 | /* we ignore things on alternate path since they are |
| 295 | * not available to the pullers in general. |
| 296 | */ |
| 297 | if (!p->pack_local || !file_exists(p->pack_name)) |
| 298 | continue; |
| 299 | |
| 300 | i = num_pack++; |
| 301 | ALLOC_GROW(info, num_pack, alloc); |
| 302 | CALLOC_ARRAY(info[i], 1); |
| 303 | info[i]->p = p; |
| 304 | info[i]->old_num = -1; |
| 305 | } |
| 306 | |
| 307 | if (infofile && !force) |
| 308 | stale = read_pack_info_file(infofile); |
| 309 | else |
| 310 | stale = 1; |
| 311 | |
| 312 | for (i = 0; i < num_pack; i++) |
| 313 | if (stale) |
| 314 | info[i]->old_num = -1; |
| 315 | |
| 316 | /* renumber them */ |
| 317 | QSORT(info, num_pack, compare_info); |
| 318 | for (i = 0; i < num_pack; i++) |
| 319 | info[i]->new_num = i; |
| 320 | } |
| 321 | |
| 322 | static void free_pack_info(void) |
| 323 | { |
| 324 | int i; |
| 325 | for (i = 0; i < num_pack; i++) |
| 326 | free(info[i]); |
| 327 | free(info); |
| 328 | } |
| 329 | |
| 330 | static int write_pack_info_file(struct update_info_ctx *uic) |
| 331 | { |
| 332 | int i; |
| 333 | for (i = 0; i < num_pack; i++) { |
| 334 | if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0) |
| 335 | return -1; |
| 336 | } |
| 337 | if (uic_printf(uic, "\n") < 0) |
| 338 | return -1; |
| 339 | return 0; |
| 340 | } |
| 341 | |
| 342 | static int update_info_packs(struct repository *r, int force) |
| 343 | { |
| 344 | char *infofile = mkpathdup("%s/info/packs", |
| 345 | repo_get_object_directory(r)); |
| 346 | int ret; |
| 347 | |
| 348 | init_pack_info(r, infofile, force); |
| 349 | ret = update_info_file(r, infofile, write_pack_info_file, force); |
| 350 | free_pack_info(); |
| 351 | free(infofile); |
| 352 | return ret; |
| 353 | } |
| 354 | |
| 355 | /* public */ |
| 356 | int update_server_info(struct repository *r, int force) |
| 357 | { |
| 358 | /* We would add more dumb-server support files later, |
| 359 | * including index of available pack files and their |
| 360 | * intended audiences. |
| 361 | */ |
| 362 | int errs = 0; |
| 363 | char *path; |
| 364 | |
| 365 | errs = errs | update_info_refs(r, force); |
| 366 | errs = errs | update_info_packs(r, force); |
| 367 | |
| 368 | /* remove leftover rev-cache file if there is any */ |
| 369 | path = repo_git_path(r, "info/rev-cache"); |
| 370 | unlink_or_warn(path); |
| 371 | free(path); |
| 372 | |
| 373 | return errs; |
| 374 | } |