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path: root/cache.c
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-rw-r--r--cache.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/cache.c b/cache.c
index e590d7b..b701e13 100644
--- a/cache.c
+++ b/cache.c
@@ -239,105 +239,173 @@ static int process_slot(struct cache_slot *slot)
239 } 239 }
240 print_slot(slot); 240 print_slot(slot);
241 close_slot(slot); 241 close_slot(slot);
242 return 0; 242 return 0;
243 } 243 }
244 244
245 /* If the cache slot does not exist (or its key doesn't match the 245 /* If the cache slot does not exist (or its key doesn't match the
246 * current key), lets try to create a new cache slot for this 246 * current key), lets try to create a new cache slot for this
247 * request. If this fails (for whatever reason), lets just generate 247 * request. If this fails (for whatever reason), lets just generate
248 * the content without caching it and fool the caller to belive 248 * the content without caching it and fool the caller to belive
249 * everything worked out (but print a warning on stdout). 249 * everything worked out (but print a warning on stdout).
250 */ 250 */
251 251
252 close_slot(slot); 252 close_slot(slot);
253 if ((err = lock_slot(slot)) != 0) { 253 if ((err = lock_slot(slot)) != 0) {
254 cache_log("[cgit] Unable to lock slot %s: %s (%d)\n", 254 cache_log("[cgit] Unable to lock slot %s: %s (%d)\n",
255 slot->lock_name, strerror(err), err); 255 slot->lock_name, strerror(err), err);
256 slot->fn(slot->cbdata); 256 slot->fn(slot->cbdata);
257 return 0; 257 return 0;
258 } 258 }
259 259
260 if ((err = fill_slot(slot)) != 0) { 260 if ((err = fill_slot(slot)) != 0) {
261 cache_log("[cgit] Unable to fill slot %s: %s (%d)\n", 261 cache_log("[cgit] Unable to fill slot %s: %s (%d)\n",
262 slot->lock_name, strerror(err), err); 262 slot->lock_name, strerror(err), err);
263 unlock_slot(slot, 0); 263 unlock_slot(slot, 0);
264 close_lock(slot); 264 close_lock(slot);
265 slot->fn(slot->cbdata); 265 slot->fn(slot->cbdata);
266 return 0; 266 return 0;
267 } 267 }
268 // We've got a valid cache slot in the lock file, which 268 // We've got a valid cache slot in the lock file, which
269 // is about to replace the old cache slot. But if we 269 // is about to replace the old cache slot. But if we
270 // release the lockfile and then try to open the new cache 270 // release the lockfile and then try to open the new cache
271 // slot, we might get a race condition with a concurrent 271 // slot, we might get a race condition with a concurrent
272 // writer for the same cache slot (with a different key). 272 // writer for the same cache slot (with a different key).
273 // Lets avoid such a race by just printing the content of 273 // Lets avoid such a race by just printing the content of
274 // the lock file. 274 // the lock file.
275 slot->cache_fd = slot->lock_fd; 275 slot->cache_fd = slot->lock_fd;
276 unlock_slot(slot, 1); 276 unlock_slot(slot, 1);
277 err = print_slot(slot); 277 err = print_slot(slot);
278 close_slot(slot); 278 close_slot(slot);
279 return err; 279 return err;
280} 280}
281 281
282/* Print cached content to stdout, generate the content if necessary. */ 282/* Print cached content to stdout, generate the content if necessary. */
283int cache_process(int size, const char *path, const char *key, int ttl, 283int cache_process(int size, const char *path, const char *key, int ttl,
284 cache_fill_fn fn, void *cbdata) 284 cache_fill_fn fn, void *cbdata)
285{ 285{
286 unsigned long hash; 286 unsigned long hash;
287 int len, i; 287 int len, i;
288 char filename[1024]; 288 char filename[1024];
289 char lockname[1024 + 5]; /* 5 = ".lock" */ 289 char lockname[1024 + 5]; /* 5 = ".lock" */
290 struct cache_slot slot; 290 struct cache_slot slot;
291 291
292 /* If the cache is disabled, just generate the content */ 292 /* If the cache is disabled, just generate the content */
293 if (size <= 0) { 293 if (size <= 0) {
294 fn(cbdata); 294 fn(cbdata);
295 return 0; 295 return 0;
296 } 296 }
297 297
298 /* Verify input, calculate filenames */ 298 /* Verify input, calculate filenames */
299 if (!path) { 299 if (!path) {
300 cache_log("[cgit] Cache path not specified, caching is disabled\n"); 300 cache_log("[cgit] Cache path not specified, caching is disabled\n");
301 fn(cbdata); 301 fn(cbdata);
302 return 0; 302 return 0;
303 } 303 }
304 len = strlen(path); 304 len = strlen(path);
305 if (len > sizeof(filename) - 10) { /* 10 = "/01234567\0" */ 305 if (len > sizeof(filename) - 10) { /* 10 = "/01234567\0" */
306 cache_log("[cgit] Cache path too long, caching is disabled: %s\n", 306 cache_log("[cgit] Cache path too long, caching is disabled: %s\n",
307 path); 307 path);
308 fn(cbdata); 308 fn(cbdata);
309 return 0; 309 return 0;
310 } 310 }
311 if (!key) 311 if (!key)
312 key = ""; 312 key = "";
313 hash = hash_str(key) % size; 313 hash = hash_str(key) % size;
314 strcpy(filename, path); 314 strcpy(filename, path);
315 if (filename[len - 1] != '/') 315 if (filename[len - 1] != '/')
316 filename[len++] = '/'; 316 filename[len++] = '/';
317 for(i = 0; i < 8; i++) { 317 for(i = 0; i < 8; i++) {
318 sprintf(filename + len++, "%x", 318 sprintf(filename + len++, "%x",
319 (unsigned char)(hash & 0xf)); 319 (unsigned char)(hash & 0xf));
320 hash >>= 4; 320 hash >>= 4;
321 } 321 }
322 filename[len] = '\0'; 322 filename[len] = '\0';
323 strcpy(lockname, filename); 323 strcpy(lockname, filename);
324 strcpy(lockname + len, ".lock"); 324 strcpy(lockname + len, ".lock");
325 slot.fn = fn; 325 slot.fn = fn;
326 slot.cbdata = cbdata; 326 slot.cbdata = cbdata;
327 slot.ttl = ttl; 327 slot.ttl = ttl;
328 slot.cache_name = filename; 328 slot.cache_name = filename;
329 slot.lock_name = lockname; 329 slot.lock_name = lockname;
330 slot.key = key; 330 slot.key = key;
331 slot.keylen = strlen(key); 331 slot.keylen = strlen(key);
332 return process_slot(&slot); 332 return process_slot(&slot);
333} 333}
334 334
335/* Return a strftime formatted date/time
336 * NB: the result from this function is to shared memory
337 */
338char *sprintftime(const char *format, time_t time)
339{
340 static char buf[64];
341 struct tm *tm;
342
343 if (!time)
344 return NULL;
345 tm = gmtime(&time);
346 strftime(buf, sizeof(buf)-1, format, tm);
347 return buf;
348}
349
350int cache_ls(const char *path)
351{
352 DIR *dir;
353 struct dirent *ent;
354 int err = 0;
355 struct cache_slot slot;
356 char fullname[1024];
357 char *name;
358
359 if (!path) {
360 cache_log("[cgit] cache path not specified\n");
361 return -1;
362 }
363 if (strlen(path) > 1024 - 10) {
364 cache_log("[cgit] cache path too long: %s\n",
365 path);
366 return -1;
367 }
368 dir = opendir(path);
369 if (!dir) {
370 err = errno;
371 cache_log("[cgit] unable to open path %s: %s (%d)\n",
372 path, strerror(err), err);
373 return err;
374 }
375 strcpy(fullname, path);
376 name = fullname + strlen(path);
377 if (*(name - 1) != '/') {
378 *name++ = '/';
379 *name = '\0';
380 }
381 slot.cache_name = fullname;
382 while((ent = readdir(dir)) != NULL) {
383 if (strlen(ent->d_name) != 8)
384 continue;
385 strcpy(name, ent->d_name);
386 if ((err = open_slot(&slot)) != 0) {
387 cache_log("[cgit] unable to open path %s: %s (%d)\n",
388 fullname, strerror(err), err);
389 continue;
390 }
391 printf("%s %s %10lld %s\n",
392 name,
393 sprintftime("%Y-%m-%d %H:%M:%S",
394 slot.cache_st.st_mtime),
395 slot.cache_st.st_size,
396 slot.buf);
397 close_slot(&slot);
398 }
399 closedir(dir);
400 return 0;
401}
402
335/* Print a message to stdout */ 403/* Print a message to stdout */
336void cache_log(const char *format, ...) 404void cache_log(const char *format, ...)
337{ 405{
338 va_list args; 406 va_list args;
339 va_start(args, format); 407 va_start(args, format);
340 vfprintf(stderr, format, args); 408 vfprintf(stderr, format, args);
341 va_end(args); 409 va_end(args);
342} 410}
343 411