| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This source code is licensed under both the BSD-style license (found in the |
| 6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| 7 | * in the COPYING file in the root directory of this source tree). |
| 8 | * You may select, at your option, one of the above-listed licenses. |
| 9 | */ |
| 10 | |
| 11 | #include "data.h" |
| 12 | |
| 13 | #include <assert.h> |
| 14 | #include <errno.h> |
| 15 | #include <stdio.h> |
| 16 | #include <string.h> |
| 17 | #include <stdlib.h> /* free() */ |
| 18 | |
| 19 | #include <sys/stat.h> |
| 20 | |
| 21 | #include <curl/curl.h> |
| 22 | |
| 23 | #include "mem.h" |
| 24 | #include "util.h" |
| 25 | #define XXH_STATIC_LINKING_ONLY |
| 26 | #include "xxhash.h" |
| 27 | |
| 28 | /** |
| 29 | * Data objects |
| 30 | */ |
| 31 | |
| 32 | #define REGRESSION_RELEASE(x) \ |
| 33 | "https://github.com/facebook/zstd/releases/download/regression-data/" x |
| 34 | |
| 35 | data_t silesia = { |
| 36 | .name = "silesia", |
| 37 | .type = data_type_dir, |
| 38 | .data = |
| 39 | { |
| 40 | .url = REGRESSION_RELEASE("silesia.tar.zst"), |
| 41 | .xxhash64 = 0x48a199f92f93e977LL, |
| 42 | }, |
| 43 | }; |
| 44 | |
| 45 | data_t silesia_tar = { |
| 46 | .name = "silesia.tar", |
| 47 | .type = data_type_file, |
| 48 | .data = |
| 49 | { |
| 50 | .url = REGRESSION_RELEASE("silesia.tar.zst"), |
| 51 | .xxhash64 = 0x48a199f92f93e977LL, |
| 52 | }, |
| 53 | }; |
| 54 | |
| 55 | data_t github = { |
| 56 | .name = "github", |
| 57 | .type = data_type_dir, |
| 58 | .data = |
| 59 | { |
| 60 | .url = REGRESSION_RELEASE("github.tar.zst"), |
| 61 | .xxhash64 = 0xa9b1b44b020df292LL, |
| 62 | }, |
| 63 | .dict = |
| 64 | { |
| 65 | .url = REGRESSION_RELEASE("github.dict.zst"), |
| 66 | .xxhash64 = 0x1eddc6f737d3cb53LL, |
| 67 | |
| 68 | }, |
| 69 | }; |
| 70 | |
| 71 | data_t github_tar = { |
| 72 | .name = "github.tar", |
| 73 | .type = data_type_file, |
| 74 | .data = |
| 75 | { |
| 76 | .url = REGRESSION_RELEASE("github.tar.zst"), |
| 77 | .xxhash64 = 0xa9b1b44b020df292LL, |
| 78 | }, |
| 79 | .dict = |
| 80 | { |
| 81 | .url = REGRESSION_RELEASE("github.dict.zst"), |
| 82 | .xxhash64 = 0x1eddc6f737d3cb53LL, |
| 83 | |
| 84 | }, |
| 85 | }; |
| 86 | |
| 87 | static data_t* g_data[] = { |
| 88 | &silesia, |
| 89 | &silesia_tar, |
| 90 | &github, |
| 91 | &github_tar, |
| 92 | NULL, |
| 93 | }; |
| 94 | |
| 95 | data_t const* const* data = (data_t const* const*)g_data; |
| 96 | |
| 97 | /** |
| 98 | * data helpers. |
| 99 | */ |
| 100 | |
| 101 | int data_has_dict(data_t const* data) { |
| 102 | return data->dict.url != NULL; |
| 103 | } |
| 104 | |
| 105 | /** |
| 106 | * data buffer helper functions (documented in header). |
| 107 | */ |
| 108 | |
| 109 | data_buffer_t data_buffer_create(size_t const capacity) { |
| 110 | data_buffer_t buffer = {}; |
| 111 | |
| 112 | buffer.data = (uint8_t*)malloc(capacity); |
| 113 | if (buffer.data == NULL) |
| 114 | return buffer; |
| 115 | buffer.capacity = capacity; |
| 116 | return buffer; |
| 117 | } |
| 118 | |
| 119 | data_buffer_t data_buffer_read(char const* filename) { |
| 120 | data_buffer_t buffer = {}; |
| 121 | |
| 122 | uint64_t const size = UTIL_getFileSize(filename); |
| 123 | if (size == UTIL_FILESIZE_UNKNOWN) { |
| 124 | fprintf(stderr, "unknown size for %s\n", filename); |
| 125 | return buffer; |
| 126 | } |
| 127 | |
| 128 | buffer.data = (uint8_t*)malloc(size); |
| 129 | if (buffer.data == NULL) { |
| 130 | fprintf(stderr, "malloc failed\n"); |
| 131 | return buffer; |
| 132 | } |
| 133 | buffer.capacity = size; |
| 134 | |
| 135 | FILE* file = fopen(filename, "rb"); |
| 136 | if (file == NULL) { |
| 137 | fprintf(stderr, "file null\n"); |
| 138 | goto err; |
| 139 | } |
| 140 | buffer.size = fread(buffer.data, 1, buffer.capacity, file); |
| 141 | fclose(file); |
| 142 | if (buffer.size != buffer.capacity) { |
| 143 | fprintf(stderr, "read %zu != %zu\n", buffer.size, buffer.capacity); |
| 144 | goto err; |
| 145 | } |
| 146 | |
| 147 | return buffer; |
| 148 | err: |
| 149 | free(buffer.data); |
| 150 | memset(&buffer, 0, sizeof(buffer)); |
| 151 | return buffer; |
| 152 | } |
| 153 | |
| 154 | data_buffer_t data_buffer_get_data(data_t const* data) { |
| 155 | data_buffer_t const kEmptyBuffer = {}; |
| 156 | |
| 157 | if (data->type != data_type_file) |
| 158 | return kEmptyBuffer; |
| 159 | |
| 160 | return data_buffer_read(data->data.path); |
| 161 | } |
| 162 | |
| 163 | data_buffer_t data_buffer_get_dict(data_t const* data) { |
| 164 | data_buffer_t const kEmptyBuffer = {}; |
| 165 | |
| 166 | if (!data_has_dict(data)) |
| 167 | return kEmptyBuffer; |
| 168 | |
| 169 | return data_buffer_read(data->dict.path); |
| 170 | } |
| 171 | |
| 172 | int data_buffer_compare(data_buffer_t buffer1, data_buffer_t buffer2) { |
| 173 | size_t const size = |
| 174 | buffer1.size < buffer2.size ? buffer1.size : buffer2.size; |
| 175 | int const cmp = memcmp(buffer1.data, buffer2.data, size); |
| 176 | if (cmp != 0) |
| 177 | return cmp; |
| 178 | if (buffer1.size < buffer2.size) |
| 179 | return -1; |
| 180 | if (buffer1.size == buffer2.size) |
| 181 | return 0; |
| 182 | assert(buffer1.size > buffer2.size); |
| 183 | return 1; |
| 184 | } |
| 185 | |
| 186 | void data_buffer_free(data_buffer_t buffer) { |
| 187 | free(buffer.data); |
| 188 | } |
| 189 | |
| 190 | /** |
| 191 | * data filenames helpers. |
| 192 | */ |
| 193 | |
| 194 | FileNamesTable* data_filenames_get(data_t const* data) |
| 195 | { |
| 196 | char const* const path = data->data.path; |
| 197 | return UTIL_createExpandedFNT(&path, 1, 0 /* followLinks */ ); |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * data buffers helpers. |
| 202 | */ |
| 203 | |
| 204 | data_buffers_t data_buffers_get(data_t const* data) { |
| 205 | data_buffers_t buffers = {.size = 0}; |
| 206 | FileNamesTable* const filenames = data_filenames_get(data); |
| 207 | if (filenames == NULL) return buffers; |
| 208 | if (filenames->tableSize == 0) { |
| 209 | UTIL_freeFileNamesTable(filenames); |
| 210 | return buffers; |
| 211 | } |
| 212 | |
| 213 | data_buffer_t* buffersPtr = |
| 214 | (data_buffer_t*)malloc(filenames->tableSize * sizeof(*buffersPtr)); |
| 215 | if (buffersPtr == NULL) { |
| 216 | UTIL_freeFileNamesTable(filenames); |
| 217 | return buffers; |
| 218 | } |
| 219 | buffers.buffers = (data_buffer_t const*)buffersPtr; |
| 220 | buffers.size = filenames->tableSize; |
| 221 | |
| 222 | for (size_t i = 0; i < filenames->tableSize; ++i) { |
| 223 | buffersPtr[i] = data_buffer_read(filenames->fileNames[i]); |
| 224 | if (buffersPtr[i].data == NULL) { |
| 225 | data_buffers_t const kEmptyBuffer = {}; |
| 226 | data_buffers_free(buffers); |
| 227 | UTIL_freeFileNamesTable(filenames); |
| 228 | return kEmptyBuffer; |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | UTIL_freeFileNamesTable(filenames); |
| 233 | return buffers; |
| 234 | } |
| 235 | |
| 236 | /** |
| 237 | * Frees the data buffers. |
| 238 | */ |
| 239 | void data_buffers_free(data_buffers_t buffers) { |
| 240 | free((data_buffer_t*)buffers.buffers); |
| 241 | } |
| 242 | |
| 243 | /** |
| 244 | * Initialization and download functions. |
| 245 | */ |
| 246 | |
| 247 | static char* g_data_dir = NULL; |
| 248 | |
| 249 | /* mkdir -p */ |
| 250 | static int ensure_directory_exists(char const* indir) { |
| 251 | char* const dir = strdup(indir); |
| 252 | char* end = dir; |
| 253 | int ret = 0; |
| 254 | if (dir == NULL) { |
| 255 | ret = EINVAL; |
| 256 | goto out; |
| 257 | } |
| 258 | do { |
| 259 | /* Find the next directory level. */ |
| 260 | for (++end; *end != '\0' && *end != '/'; ++end) |
| 261 | ; |
| 262 | /* End the string there, make the directory, and restore the string. */ |
| 263 | char const save = *end; |
| 264 | *end = '\0'; |
| 265 | int const isdir = UTIL_isDirectory(dir); |
| 266 | ret = mkdir(dir, S_IRWXU); |
| 267 | *end = save; |
| 268 | /* Its okay if the directory already exists. */ |
| 269 | if (ret == 0 || (errno == EEXIST && isdir)) |
| 270 | continue; |
| 271 | ret = errno; |
| 272 | fprintf(stderr, "mkdir() failed\n"); |
| 273 | goto out; |
| 274 | } while (*end != '\0'); |
| 275 | |
| 276 | ret = 0; |
| 277 | out: |
| 278 | free(dir); |
| 279 | return ret; |
| 280 | } |
| 281 | |
| 282 | /** Concatenate 3 strings into a new buffer. */ |
| 283 | static char* cat3(char const* str1, char const* str2, char const* str3) { |
| 284 | size_t const size1 = strlen(str1); |
| 285 | size_t const size2 = strlen(str2); |
| 286 | size_t const size3 = str3 == NULL ? 0 : strlen(str3); |
| 287 | size_t const size = size1 + size2 + size3 + 1; |
| 288 | char* const dst = (char*)malloc(size); |
| 289 | if (dst == NULL) |
| 290 | return NULL; |
| 291 | strcpy(dst, str1); |
| 292 | strcpy(dst + size1, str2); |
| 293 | if (str3 != NULL) |
| 294 | strcpy(dst + size1 + size2, str3); |
| 295 | assert(strlen(dst) == size1 + size2 + size3); |
| 296 | return dst; |
| 297 | } |
| 298 | |
| 299 | static char* cat2(char const* str1, char const* str2) { |
| 300 | return cat3(str1, str2, NULL); |
| 301 | } |
| 302 | |
| 303 | /** |
| 304 | * State needed by the curl callback. |
| 305 | * It takes data from curl, hashes it, and writes it to the file. |
| 306 | */ |
| 307 | typedef struct { |
| 308 | FILE* file; |
| 309 | XXH64_state_t xxhash64; |
| 310 | int error; |
| 311 | } curl_data_t; |
| 312 | |
| 313 | /** Create the curl state. */ |
| 314 | static curl_data_t curl_data_create( |
| 315 | data_resource_t const* resource, |
| 316 | data_type_t type) { |
| 317 | curl_data_t cdata = {}; |
| 318 | |
| 319 | XXH64_reset(&cdata.xxhash64, 0); |
| 320 | |
| 321 | assert(UTIL_isDirectory(g_data_dir)); |
| 322 | |
| 323 | if (type == data_type_file) { |
| 324 | /* Decompress the resource and store to the path. */ |
| 325 | char* cmd = cat3("zstd -dqfo '", resource->path, "'"); |
| 326 | if (cmd == NULL) { |
| 327 | cdata.error = ENOMEM; |
| 328 | return cdata; |
| 329 | } |
| 330 | cdata.file = popen(cmd, "w"); |
| 331 | free(cmd); |
| 332 | } else { |
| 333 | /* Decompress and extract the resource to the cache directory. */ |
| 334 | char* cmd = cat3("zstd -dc | tar -x -C '", g_data_dir, "'"); |
| 335 | if (cmd == NULL) { |
| 336 | cdata.error = ENOMEM; |
| 337 | return cdata; |
| 338 | } |
| 339 | cdata.file = popen(cmd, "w"); |
| 340 | free(cmd); |
| 341 | } |
| 342 | if (cdata.file == NULL) { |
| 343 | cdata.error = errno; |
| 344 | } |
| 345 | |
| 346 | return cdata; |
| 347 | } |
| 348 | |
| 349 | /** Free the curl state. */ |
| 350 | static int curl_data_free(curl_data_t cdata) { |
| 351 | return pclose(cdata.file); |
| 352 | } |
| 353 | |
| 354 | /** curl callback. Updates the hash, and writes to the file. */ |
| 355 | static size_t curl_write(void* data, size_t size, size_t count, void* ptr) { |
| 356 | curl_data_t* cdata = (curl_data_t*)ptr; |
| 357 | size_t const written = fwrite(data, size, count, cdata->file); |
| 358 | XXH64_update(&cdata->xxhash64, data, written * size); |
| 359 | return written; |
| 360 | } |
| 361 | |
| 362 | static int curl_download_resource( |
| 363 | CURL* curl, |
| 364 | data_resource_t const* resource, |
| 365 | data_type_t type) { |
| 366 | curl_data_t cdata; |
| 367 | /* Download the data. */ |
| 368 | if (curl_easy_setopt(curl, CURLOPT_URL, resource->url) != 0) |
| 369 | return EINVAL; |
| 370 | if (curl_easy_setopt(curl, CURLOPT_WRITEDATA, &cdata) != 0) |
| 371 | return EINVAL; |
| 372 | cdata = curl_data_create(resource, type); |
| 373 | if (cdata.error != 0) |
| 374 | return cdata.error; |
| 375 | int const curl_err = curl_easy_perform(curl); |
| 376 | int const close_err = curl_data_free(cdata); |
| 377 | if (curl_err) { |
| 378 | fprintf( |
| 379 | stderr, |
| 380 | "downloading '%s' for '%s' failed\n", |
| 381 | resource->url, |
| 382 | resource->path); |
| 383 | return EIO; |
| 384 | } |
| 385 | if (close_err) { |
| 386 | fprintf(stderr, "writing data to '%s' failed\n", resource->path); |
| 387 | return EIO; |
| 388 | } |
| 389 | /* check that the file exists. */ |
| 390 | if (type == data_type_file && !UTIL_isRegularFile(resource->path)) { |
| 391 | fprintf(stderr, "output file '%s' does not exist\n", resource->path); |
| 392 | return EIO; |
| 393 | } |
| 394 | if (type == data_type_dir && !UTIL_isDirectory(resource->path)) { |
| 395 | fprintf( |
| 396 | stderr, "output directory '%s' does not exist\n", resource->path); |
| 397 | return EIO; |
| 398 | } |
| 399 | /* Check that the hash matches. */ |
| 400 | if (XXH64_digest(&cdata.xxhash64) != resource->xxhash64) { |
| 401 | fprintf( |
| 402 | stderr, |
| 403 | "checksum does not match: 0x%llxLL != 0x%llxLL\n", |
| 404 | (unsigned long long)XXH64_digest(&cdata.xxhash64), |
| 405 | (unsigned long long)resource->xxhash64); |
| 406 | return EINVAL; |
| 407 | } |
| 408 | |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | /** Download a single data object. */ |
| 413 | static int curl_download_datum(CURL* curl, data_t const* data) { |
| 414 | int ret; |
| 415 | ret = curl_download_resource(curl, &data->data, data->type); |
| 416 | if (ret != 0) |
| 417 | return ret; |
| 418 | if (data_has_dict(data)) { |
| 419 | ret = curl_download_resource(curl, &data->dict, data_type_file); |
| 420 | if (ret != 0) |
| 421 | return ret; |
| 422 | } |
| 423 | return ret; |
| 424 | } |
| 425 | |
| 426 | /** Download all the data. */ |
| 427 | static int curl_download_data(data_t const* const* data) { |
| 428 | if (curl_global_init(CURL_GLOBAL_ALL) != 0) |
| 429 | return EFAULT; |
| 430 | |
| 431 | curl_data_t cdata = {}; |
| 432 | CURL* curl = curl_easy_init(); |
| 433 | int err = EFAULT; |
| 434 | |
| 435 | if (curl == NULL) |
| 436 | return EFAULT; |
| 437 | |
| 438 | if (curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L) != 0) |
| 439 | goto out; |
| 440 | if (curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L) != 0) |
| 441 | goto out; |
| 442 | if (curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_write) != 0) |
| 443 | goto out; |
| 444 | |
| 445 | assert(data != NULL); |
| 446 | for (; *data != NULL; ++data) { |
| 447 | if (curl_download_datum(curl, *data) != 0) |
| 448 | goto out; |
| 449 | } |
| 450 | |
| 451 | err = 0; |
| 452 | out: |
| 453 | curl_easy_cleanup(curl); |
| 454 | curl_global_cleanup(); |
| 455 | return err; |
| 456 | } |
| 457 | |
| 458 | /** Fill the path member variable of the data objects. */ |
| 459 | static int data_create_paths(data_t* const* data, char const* dir) { |
| 460 | size_t const dirlen = strlen(dir); |
| 461 | assert(data != NULL); |
| 462 | for (; *data != NULL; ++data) { |
| 463 | data_t* const datum = *data; |
| 464 | datum->data.path = cat3(dir, "/", datum->name); |
| 465 | if (datum->data.path == NULL) |
| 466 | return ENOMEM; |
| 467 | if (data_has_dict(datum)) { |
| 468 | datum->dict.path = cat2(datum->data.path, ".dict"); |
| 469 | if (datum->dict.path == NULL) |
| 470 | return ENOMEM; |
| 471 | } |
| 472 | } |
| 473 | return 0; |
| 474 | } |
| 475 | |
| 476 | /** Free the path member variable of the data objects. */ |
| 477 | static void data_free_paths(data_t* const* data) { |
| 478 | assert(data != NULL); |
| 479 | for (; *data != NULL; ++data) { |
| 480 | data_t* datum = *data; |
| 481 | free((void*)datum->data.path); |
| 482 | free((void*)datum->dict.path); |
| 483 | datum->data.path = NULL; |
| 484 | datum->dict.path = NULL; |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | static char const kStampName[] = "STAMP"; |
| 489 | |
| 490 | static void xxh_update_le(XXH64_state_t* state, uint64_t data) { |
| 491 | if (!MEM_isLittleEndian()) |
| 492 | data = MEM_swap64(data); |
| 493 | XXH64_update(state, &data, sizeof(data)); |
| 494 | } |
| 495 | |
| 496 | /** Hash the data to create the stamp. */ |
| 497 | static uint64_t stamp_hash(data_t const* const* data) { |
| 498 | XXH64_state_t state; |
| 499 | |
| 500 | XXH64_reset(&state, 0); |
| 501 | assert(data != NULL); |
| 502 | for (; *data != NULL; ++data) { |
| 503 | data_t const* datum = *data; |
| 504 | /* We don't care about the URL that we fetch from. */ |
| 505 | /* The path is derived from the name. */ |
| 506 | XXH64_update(&state, datum->name, strlen(datum->name)); |
| 507 | xxh_update_le(&state, datum->data.xxhash64); |
| 508 | xxh_update_le(&state, datum->dict.xxhash64); |
| 509 | xxh_update_le(&state, datum->type); |
| 510 | } |
| 511 | return XXH64_digest(&state); |
| 512 | } |
| 513 | |
| 514 | /** Check if the stamp matches the stamp in the cache directory. */ |
| 515 | static int stamp_check(char const* dir, data_t const* const* data) { |
| 516 | char* stamp = cat3(dir, "/", kStampName); |
| 517 | uint64_t const expected = stamp_hash(data); |
| 518 | XXH64_canonical_t actual; |
| 519 | FILE* stampfile = NULL; |
| 520 | int matches = 0; |
| 521 | |
| 522 | if (stamp == NULL) |
| 523 | goto out; |
| 524 | if (!UTIL_isRegularFile(stamp)) { |
| 525 | fprintf(stderr, "stamp does not exist: recreating the data cache\n"); |
| 526 | goto out; |
| 527 | } |
| 528 | |
| 529 | stampfile = fopen(stamp, "rb"); |
| 530 | if (stampfile == NULL) { |
| 531 | fprintf(stderr, "could not open stamp: recreating the data cache\n"); |
| 532 | goto out; |
| 533 | } |
| 534 | |
| 535 | size_t b; |
| 536 | if ((b = fread(&actual, sizeof(actual), 1, stampfile)) != 1) { |
| 537 | fprintf(stderr, "invalid stamp: recreating the data cache\n"); |
| 538 | goto out; |
| 539 | } |
| 540 | |
| 541 | matches = (expected == XXH64_hashFromCanonical(&actual)); |
| 542 | if (matches) |
| 543 | fprintf(stderr, "stamp matches: reusing the cached data\n"); |
| 544 | else |
| 545 | fprintf(stderr, "stamp does not match: recreating the data cache\n"); |
| 546 | |
| 547 | out: |
| 548 | free(stamp); |
| 549 | if (stampfile != NULL) |
| 550 | fclose(stampfile); |
| 551 | return matches; |
| 552 | } |
| 553 | |
| 554 | /** On success write a new stamp, on failure delete the old stamp. */ |
| 555 | static int |
| 556 | stamp_write(char const* dir, data_t const* const* data, int const data_err) { |
| 557 | char* stamp = cat3(dir, "/", kStampName); |
| 558 | FILE* stampfile = NULL; |
| 559 | int err = EIO; |
| 560 | |
| 561 | if (stamp == NULL) |
| 562 | return ENOMEM; |
| 563 | |
| 564 | if (data_err != 0) { |
| 565 | err = data_err; |
| 566 | goto out; |
| 567 | } |
| 568 | XXH64_canonical_t hash; |
| 569 | |
| 570 | XXH64_canonicalFromHash(&hash, stamp_hash(data)); |
| 571 | |
| 572 | stampfile = fopen(stamp, "wb"); |
| 573 | if (stampfile == NULL) |
| 574 | goto out; |
| 575 | if (fwrite(&hash, sizeof(hash), 1, stampfile) != 1) |
| 576 | goto out; |
| 577 | err = 0; |
| 578 | fprintf(stderr, "stamped new data cache\n"); |
| 579 | out: |
| 580 | if (err != 0) |
| 581 | /* Ignore errors. */ |
| 582 | unlink(stamp); |
| 583 | free(stamp); |
| 584 | if (stampfile != NULL) |
| 585 | fclose(stampfile); |
| 586 | return err; |
| 587 | } |
| 588 | |
| 589 | int data_init(char const* dir) { |
| 590 | int err; |
| 591 | |
| 592 | if (dir == NULL) |
| 593 | return EINVAL; |
| 594 | |
| 595 | /* This must be first to simplify logic. */ |
| 596 | err = ensure_directory_exists(dir); |
| 597 | if (err != 0) |
| 598 | return err; |
| 599 | |
| 600 | /* Save the cache directory. */ |
| 601 | g_data_dir = strdup(dir); |
| 602 | if (g_data_dir == NULL) |
| 603 | return ENOMEM; |
| 604 | |
| 605 | err = data_create_paths(g_data, dir); |
| 606 | if (err != 0) |
| 607 | return err; |
| 608 | |
| 609 | /* If the stamp matches then we are good to go. |
| 610 | * This must be called before any modifications to the data cache. |
| 611 | * After this point, we MUST call stamp_write() to update the STAMP, |
| 612 | * since we've updated the data cache. |
| 613 | */ |
| 614 | if (stamp_check(dir, data)) |
| 615 | return 0; |
| 616 | |
| 617 | err = curl_download_data(data); |
| 618 | if (err != 0) |
| 619 | goto out; |
| 620 | |
| 621 | out: |
| 622 | /* This must be last, since it must know if data_init() succeeded. */ |
| 623 | stamp_write(dir, data, err); |
| 624 | return err; |
| 625 | } |
| 626 | |
| 627 | void data_finish(void) { |
| 628 | data_free_paths(g_data); |
| 629 | free(g_data_dir); |
| 630 | g_data_dir = NULL; |
| 631 | } |