[1af751]: cache.c Maximize Restore History

Download this file

cache.c    555 lines (497 with data), 15.6 kB

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
/*
Caching file system proxy
Copyright (C) 2004 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "cache.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <glib.h>
#include <pthread.h>
#define DEFAULT_CACHE_TIMEOUT 20
#define MAX_CACHE_SIZE 10000
#define MIN_CACHE_CLEAN_INTERVAL 5
#define CACHE_CLEAN_INTERVAL 60
struct cache {
int on;
unsigned stat_timeout;
unsigned dir_timeout;
unsigned link_timeout;
struct fuse_cache_operations *next_oper;
GHashTable *table;
pthread_mutex_t lock;
time_t last_cleaned;
};
static struct cache cache;
struct node {
struct stat stat;
time_t stat_valid;
char **dir;
time_t dir_valid;
char *link;
time_t link_valid;
time_t valid;
};
struct fuse_cache_dirhandle {
const char *path;
fuse_dirh_t h;
fuse_dirfil_t filler;
GPtrArray *dir;
};
static void free_node(gpointer node_)
{
struct node *node = (struct node *) node_;
g_strfreev(node->dir);
g_free(node);
}
static int cache_clean_entry(void *key_, struct node *node, time_t *now)
{
(void) key_;
if (*now > node->valid)
return TRUE;
else
return FALSE;
}
static void cache_clean(void)
{
time_t now = time(NULL);
if (now > cache.last_cleaned + MIN_CACHE_CLEAN_INTERVAL &&
(g_hash_table_size(cache.table) > MAX_CACHE_SIZE ||
now > cache.last_cleaned + CACHE_CLEAN_INTERVAL)) {
g_hash_table_foreach_remove(cache.table,
(GHRFunc) cache_clean_entry, &now);
cache.last_cleaned = now;
}
}
static struct node *cache_lookup(const char *path)
{
return (struct node *) g_hash_table_lookup(cache.table, path);
}
static void cache_purge(const char *path)
{
g_hash_table_remove(cache.table, path);
}
static void cache_purge_parent(const char *path)
{
const char *s = strrchr(path, '/');
if (s) {
if (s == path)
g_hash_table_remove(cache.table, "/");
else {
char *parent = g_strndup(path, s - path);
cache_purge(parent);
g_free(parent);
}
}
}
void cache_invalidate(const char *path)
{
pthread_mutex_lock(&cache.lock);
cache_purge(path);
pthread_mutex_unlock(&cache.lock);
}
static void cache_invalidate_dir(const char *path)
{
pthread_mutex_lock(&cache.lock);
cache_purge(path);
cache_purge_parent(path);
pthread_mutex_unlock(&cache.lock);
}
static int cache_del_children(const char *key, void *val_, const char *path)
{
(void) val_;
if (strncmp(key, path, strlen(path)) == 0)
return TRUE;
else
return FALSE;
}
static void cache_do_rename(const char *from, const char *to)
{
pthread_mutex_lock(&cache.lock);
g_hash_table_foreach_remove(cache.table, (GHRFunc) cache_del_children,
(char *) from);
cache_purge(from);
cache_purge(to);
cache_purge_parent(from);
cache_purge_parent(to);
pthread_mutex_unlock(&cache.lock);
}
static struct node *cache_get(const char *path)
{
struct node *node = cache_lookup(path);
if (node == NULL) {
char *pathcopy = g_strdup(path);
node = g_new0(struct node, 1);
g_hash_table_insert(cache.table, pathcopy, node);
}
return node;
}
void cache_add_attr(const char *path, const struct stat *stbuf)
{
struct node *node;
time_t now;
pthread_mutex_lock(&cache.lock);
node = cache_get(path);
now = time(NULL);
node->stat = *stbuf;
node->stat_valid = time(NULL) + cache.stat_timeout;
if (node->stat_valid > node->valid)
node->valid = node->stat_valid;
cache_clean();
pthread_mutex_unlock(&cache.lock);
}
static void cache_add_dir(const char *path, char **dir)
{
struct node *node;
time_t now;
pthread_mutex_lock(&cache.lock);
node = cache_get(path);
now = time(NULL);
g_strfreev(node->dir);
node->dir = dir;
node->dir_valid = time(NULL) + cache.dir_timeout;
if (node->dir_valid > node->valid)
node->valid = node->dir_valid;
cache_clean();
pthread_mutex_unlock(&cache.lock);
}
static size_t my_strnlen(const char *s, size_t maxsize)
{
const char *p;
for (p = s; maxsize && *p; maxsize--, p++);
return p - s;
}
static void cache_add_link(const char *path, const char *link, size_t size)
{
struct node *node;
time_t now;
pthread_mutex_lock(&cache.lock);
node = cache_get(path);
now = time(NULL);
g_free(node->link);
node->link = g_strndup(link, my_strnlen(link, size-1));
node->link_valid = time(NULL) + cache.link_timeout;
if (node->link_valid > node->valid)
node->valid = node->link_valid;
cache_clean();
pthread_mutex_unlock(&cache.lock);
}
static int cache_get_attr(const char *path, struct stat *stbuf)
{
struct node *node;
int err = -EAGAIN;
pthread_mutex_lock(&cache.lock);
node = cache_lookup(path);
if (node != NULL) {
time_t now = time(NULL);
if (node->stat_valid - now >= 0) {
*stbuf = node->stat;
err = 0;
}
}
pthread_mutex_unlock(&cache.lock);
return err;
}
static int cache_getattr(const char *path, struct stat *stbuf)
{
int err = cache_get_attr(path, stbuf);
if (err) {
err = cache.next_oper->oper.getattr(path, stbuf);
if (!err)
cache_add_attr(path, stbuf);
}
return err;
}
static int cache_readlink(const char *path, char *buf, size_t size)
{
struct node *node;
int err;
pthread_mutex_lock(&cache.lock);
node = cache_lookup(path);
if (node != NULL) {
time_t now = time(NULL);
if (node->link_valid - now >= 0) {
strncpy(buf, node->link, size-1);
buf[size-1] = '\0';
pthread_mutex_unlock(&cache.lock);
return 0;
}
}
pthread_mutex_unlock(&cache.lock);
err = cache.next_oper->oper.readlink(path, buf, size);
if (!err)
cache_add_link(path, buf, size);
return err;
}
static int cache_dirfill(fuse_cache_dirh_t ch, const char *name,
const struct stat *stbuf)
{
int err = ch->filler(ch->h, name, 0, 0);
if (!err) {
g_ptr_array_add(ch->dir, g_strdup(name));
if (stbuf->st_mode & S_IFMT) {
char *fullpath =
g_strdup_printf("%s/%s", !ch->path[1] ? "" : ch->path, name);
cache_add_attr(fullpath, stbuf);
g_free(fullpath);
}
}
return err;
}
static int cache_getdir(const char *path, fuse_dirh_t h, fuse_dirfil_t filler)
{
struct fuse_cache_dirhandle ch;
int err;
char **dir;
struct node *node;
pthread_mutex_lock(&cache.lock);
node = cache_lookup(path);
if (node != NULL && node->dir != NULL) {
time_t now = time(NULL);
if (node->dir_valid - now >= 0) {
for(dir = node->dir; *dir != NULL; dir++)
filler(h, *dir, 0, 0);
pthread_mutex_unlock(&cache.lock);
return 0;
}
}
pthread_mutex_unlock(&cache.lock);
ch.path = path;
ch.h = h;
ch.filler = filler;
ch.dir = g_ptr_array_new();
err = cache.next_oper->cache_getdir(path, &ch, cache_dirfill);
g_ptr_array_add(ch.dir, NULL);
dir = (char **) ch.dir->pdata;
if (!err)
cache_add_dir(path, dir);
else
g_strfreev(dir);
g_ptr_array_free(ch.dir, FALSE);
return err;
}
static int cache_unity_dirfill(fuse_cache_dirh_t ch, const char *name,
const struct stat *stbuf)
{
(void) stbuf;
return ch->filler(ch->h, name, 0, 0);
}
static int cache_unity_getdir(const char *path, fuse_dirh_t h,
fuse_dirfil_t filler)
{
struct fuse_cache_dirhandle ch;
ch.h = h;
ch.filler = filler;
return cache.next_oper->cache_getdir(path, &ch, cache_unity_dirfill);
}
static int cache_mknod(const char *path, mode_t mode, dev_t rdev)
{
int err = cache.next_oper->oper.mknod(path, mode, rdev);
if (!err)
cache_invalidate_dir(path);
return err;
}
static int cache_mkdir(const char *path, mode_t mode)
{
int err = cache.next_oper->oper.mkdir(path, mode);
if (!err)
cache_invalidate_dir(path);
return err;
}
static int cache_unlink(const char *path)
{
int err = cache.next_oper->oper.unlink(path);
if (!err)
cache_invalidate_dir(path);
return err;
}
static int cache_rmdir(const char *path)
{
int err = cache.next_oper->oper.rmdir(path);
if (!err)
cache_invalidate_dir(path);
return err;
}
static int cache_symlink(const char *from, const char *to)
{
int err = cache.next_oper->oper.symlink(from, to);
if (!err)
cache_invalidate_dir(to);
return err;
}
static int cache_rename(const char *from, const char *to)
{
int err = cache.next_oper->oper.rename(from, to);
if (!err)
cache_do_rename(from, to);
return err;
}
static int cache_link(const char *from, const char *to)
{
int err = cache.next_oper->oper.link(from, to);
if (!err) {
cache_invalidate(from);
cache_invalidate_dir(to);
}
return err;
}
static int cache_chmod(const char *path, mode_t mode)
{
int err = cache.next_oper->oper.chmod(path, mode);
if (!err)
cache_invalidate(path);
return err;
}
static int cache_chown(const char *path, uid_t uid, gid_t gid)
{
int err = cache.next_oper->oper.chown(path, uid, gid);
if (!err)
cache_invalidate(path);
return err;
}
static int cache_truncate(const char *path, off_t size)
{
int err = cache.next_oper->oper.truncate(path, size);
if (!err)
cache_invalidate(path);
return err;
}
static int cache_utime(const char *path, struct utimbuf *buf)
{
int err = cache.next_oper->oper.utime(path, buf);
if (!err)
cache_invalidate(path);
return err;
}
static int cache_write(const char *path, const char *buf, size_t size,
off_t offset, struct fuse_file_info *fi)
{
int res = cache.next_oper->oper.write(path, buf, size, offset, fi);
if (res >= 0)
cache_invalidate(path);
return res;
}
#if FUSE_VERSION >= 25
static int cache_create(const char *path, mode_t mode,
struct fuse_file_info *fi)
{
int err = cache.next_oper->oper.create(path, mode, fi);
if (!err)
cache_invalidate_dir(path);
return err;
}
static int cache_ftruncate(const char *path, off_t size,
struct fuse_file_info *fi)
{
int err = cache.next_oper->oper.ftruncate(path, size, fi);
if (!err)
cache_invalidate(path);
return err;
}
static int cache_fgetattr(const char *path, struct stat *stbuf,
struct fuse_file_info *fi)
{
int err = cache_get_attr(path, stbuf);
if (err) {
err = cache.next_oper->oper.fgetattr(path, stbuf, fi);
if (!err)
cache_add_attr(path, stbuf);
}
return err;
}
#endif
static void cache_unity_fill(struct fuse_cache_operations *oper,
struct fuse_operations *cache_oper)
{
#if FUSE_VERSION >= 23
cache_oper->init = oper->oper.init;
#endif
cache_oper->getattr = oper->oper.getattr;
cache_oper->readlink = oper->oper.readlink;
cache_oper->getdir = cache_unity_getdir;
cache_oper->mknod = oper->oper.mknod;
cache_oper->mkdir = oper->oper.mkdir;
cache_oper->symlink = oper->oper.symlink;
cache_oper->unlink = oper->oper.unlink;
cache_oper->rmdir = oper->oper.rmdir;
cache_oper->rename = oper->oper.rename;
cache_oper->link = oper->oper.link;
cache_oper->chmod = oper->oper.chmod;
cache_oper->chown = oper->oper.chown;
cache_oper->truncate = oper->oper.truncate;
cache_oper->utime = oper->oper.utime;
cache_oper->open = oper->oper.open;
cache_oper->read = oper->oper.read;
cache_oper->write = oper->oper.write;
cache_oper->flush = oper->oper.flush;
cache_oper->release = oper->oper.release;
cache_oper->fsync = oper->oper.fsync;
cache_oper->statfs = oper->oper.statfs;
cache_oper->setxattr = oper->oper.setxattr;
cache_oper->getxattr = oper->oper.getxattr;
cache_oper->listxattr = oper->oper.listxattr;
cache_oper->removexattr = oper->oper.removexattr;
#if FUSE_VERSION >= 25
cache_oper->create = oper->oper.create;
cache_oper->ftruncate = oper->oper.ftruncate;
cache_oper->fgetattr = oper->oper.fgetattr;
#endif
}
struct fuse_operations *cache_init(struct fuse_cache_operations *oper)
{
static struct fuse_operations cache_oper;
cache.next_oper = oper;
cache_unity_fill(oper, &cache_oper);
if (cache.on) {
cache_oper.getattr = oper->oper.getattr ? cache_getattr : NULL;
cache_oper.readlink = oper->oper.readlink ? cache_readlink : NULL;
cache_oper.getdir = oper->cache_getdir ? cache_getdir : NULL;
cache_oper.mknod = oper->oper.mknod ? cache_mknod : NULL;
cache_oper.mkdir = oper->oper.mkdir ? cache_mkdir : NULL;
cache_oper.symlink = oper->oper.symlink ? cache_symlink : NULL;
cache_oper.unlink = oper->oper.unlink ? cache_unlink : NULL;
cache_oper.rmdir = oper->oper.rmdir ? cache_rmdir : NULL;
cache_oper.rename = oper->oper.rename ? cache_rename : NULL;
cache_oper.link = oper->oper.link ? cache_link : NULL;
cache_oper.chmod = oper->oper.chmod ? cache_chmod : NULL;
cache_oper.chown = oper->oper.chown ? cache_chown : NULL;
cache_oper.truncate = oper->oper.truncate ? cache_truncate : NULL;
cache_oper.utime = oper->oper.utime ? cache_utime : NULL;
cache_oper.write = oper->oper.write ? cache_write : NULL;
#if FUSE_VERSION >= 25
cache_oper.create = oper->oper.create ? cache_create : NULL;
cache_oper.ftruncate = oper->oper.ftruncate ? cache_ftruncate : NULL;
cache_oper.fgetattr = oper->oper.fgetattr ? cache_fgetattr : NULL;
#endif
pthread_mutex_init(&cache.lock, NULL);
cache.table = g_hash_table_new_full(g_str_hash, g_str_equal, g_free,
free_node);
if (cache.table == NULL) {
fprintf(stderr, "failed to create cache\n");
return NULL;
}
}
return &cache_oper;
}
static const struct fuse_opt cache_opts[] = {
{ "cache=yes", offsetof(struct cache, on), 1 },
{ "cache=no", offsetof(struct cache, on), 0 },
{ "cache_timeout=%u", offsetof(struct cache, stat_timeout), 0 },
{ "cache_timeout=%u", offsetof(struct cache, dir_timeout), 0 },
{ "cache_timeout=%u", offsetof(struct cache, link_timeout), 0 },
{ "cache_stat_timeout=%u", offsetof(struct cache, stat_timeout), 0 },
{ "cache_dir_timeout=%u", offsetof(struct cache, dir_timeout), 0 },
{ "cache_link_timeout=%u", offsetof(struct cache, link_timeout), 0 },
FUSE_OPT_END
};
int cache_parse_options(struct fuse_args *args)
{
cache.stat_timeout = DEFAULT_CACHE_TIMEOUT;
cache.dir_timeout = DEFAULT_CACHE_TIMEOUT;
cache.link_timeout = DEFAULT_CACHE_TIMEOUT;
cache.on = 1;
return fuse_opt_parse(args, &cache, cache_opts, NULL);
}