1 /* binlog.c - binary log implementation */
3 /* Copyright (C) 2008 Graham Barr
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #endif /* else we get int types from config.h */
32 #include <sys/resource.h>
33 #include <sys/param.h>
45 typedef struct binlog
*binlog
;
56 /* max size we will create a log file */
57 size_t binlog_size_limit
= BINLOG_SIZE_LIMIT_DEFAULT
;
60 size_t fsync_throttle_ms
= 0;
61 uint64_t last_fsync
= 0;
63 char *binlog_dir
= NULL
;
64 static int binlog_index
= 0;
65 static int binlog_version
= 5;
68 static binlog oldest_binlog
= 0,
72 static const size_t job_record_size
= offsetof(struct job
, pad
);
85 dirp
= opendir(binlog_dir
);
88 while ((dp
= readdir(dirp
)) != NULL
) {
89 name_len
= strlen(dp
->d_name
);
90 if (name_len
> 7 && !strncmp("binlog.", dp
->d_name
, 7)) {
91 val
= strtol(dp
->d_name
+ 7, &endptr
, 10);
92 if (endptr
&& *endptr
== 0) {
93 if (max
== 0 || val
> max
) max
= val
;
94 if (min
== 0 || val
< min
) min
= val
;
100 binlog_index
= (int) max
;
105 binlog_remove_oldest()
107 binlog b
= oldest_binlog
;
111 oldest_binlog
= b
->next
;
118 binlog_iref(binlog b
)
125 binlog_dref(binlog b
)
128 if (b
->refs
< 1) return twarnx("refs is zero for binlog: %s", b
->path
);
132 while (oldest_binlog
&& oldest_binlog
->refs
== 0) {
133 binlog_remove_oldest();
140 binlog_warn(int fd, const char* path, const char *msg)
142 warnx("WARNING, %s at %s:%u.\n%s", msg, path, lseek(fd, 0, SEEK_CUR),
143 " Continuing. You may be missing data.");
147 #define binlog_warn(b, fmt, args...) \
148 warnx("WARNING, " fmt " at %s:%u. %s: ", \
149 ##args, b->path, lseek(b->fd, 0, SEEK_CUR), \
150 "Continuing. You may be missing data.")
153 binlog_read_log_file(binlog b
, job binlog_jobs
)
158 char tubename
[MAX_TUBE_NAME_LEN
];
163 r
= read(b
->fd
, &version
, sizeof(version
));
164 if (r
== -1) return twarn("read()");
165 if (r
< sizeof(version
)) {
166 return binlog_warn(b
, "EOF while reading version record");
169 if (version
!= binlog_version
) {
170 return warnx("%s: binlog version mismatch %d %d", b
->path
, version
,
174 while (read(b
->fd
, &namelen
, sizeof(size_t)) == sizeof(size_t)) {
176 r
= read(b
->fd
, tubename
, namelen
);
177 if (r
== -1) return twarn("read()");
179 lseek(b
->fd
, SEEK_CUR
, 0);
180 return binlog_warn(b
, "EOF while reading tube name");
184 tubename
[namelen
] = '\0';
185 r
= read(b
->fd
, &js
, job_record_size
);
186 if (r
== -1) return twarn("read()");
187 if (r
< job_record_size
) {
188 return binlog_warn(b
, "EOF while reading job record");
195 case JOB_STATE_INVALID
:
198 binlog_dref(j
->binlog
);
203 case JOB_STATE_READY
:
204 case JOB_STATE_DELAYED
:
205 if (!j
&& namelen
> 0) {
206 t
= tube_find_or_make(tubename
);
207 j
= make_job_with_id(js
.pri
, js
.delay
, js
.ttr
, js
.body_size
,
209 j
->next
= j
->prev
= j
;
210 j
->created_at
= js
.created_at
;
211 job_insert(binlog_jobs
, j
);
214 if (js
.body_size
> j
->body_size
) {
215 warnx("job size increased from %zu to %zu", j
->body_size
,
218 binlog_dref(j
->binlog
);
220 return binlog_warn(b
, "EOF while reading job body");
222 r
= read(b
->fd
, j
->body
, js
.body_size
);
223 if (r
== -1) return twarn("read()");
224 if (r
< js
.body_size
) {
225 warnx("dropping incomplete job %llu", j
->id
);
227 binlog_dref(j
->binlog
);
229 return binlog_warn(b
, "EOF while reading job body");
236 j
->deadline_at
= js
.deadline_at
;
240 j
->timeout_ct
= js
.timeout_ct
;
241 j
->release_ct
= js
.release_ct
;
242 j
->bury_ct
= js
.bury_ct
;
243 j
->kick_ct
= js
.kick_ct
;
245 /* this is a complete record, so we can move the binlog ref */
246 if (namelen
&& js
.body_size
) {
247 binlog_dref(j
->binlog
);
248 j
->binlog
= binlog_iref(b
);
255 binlog_close(binlog b
)
258 if (b
->fd
< 0) return;
265 make_binlog(char *path
)
269 b
= (binlog
) malloc(sizeof(struct binlog
) + strlen(path
) + 1);
270 if (!b
) return twarnx("OOM"), (binlog
) 0;
271 strcpy(b
->path
, path
);
286 if (!binlog_dir
) return NULL
;
288 r
= snprintf(path
, PATH_MAX
, "%s/binlog.%d", binlog_dir
, ++binlog_index
);
289 if (r
> PATH_MAX
) return twarnx("path too long: %s", binlog_dir
), (binlog
)0;
291 return make_binlog(path
);
297 if (newest_binlog
) newest_binlog
->next
= b
;
299 if (!oldest_binlog
) oldest_binlog
= b
;
305 binlog_open(binlog log
, size_t *written
)
308 size_t bytes_written
;
310 if (written
) *written
= 0;
312 if (!binlog_iref(log
)) return;
314 fd
= open(log
->path
, O_WRONLY
| O_CREAT
, 0400);
316 if (fd
< 0) return twarn("Cannot open binlog %s", log
->path
);
318 #ifdef HAVE_POSIX_FALLOCATE
321 r
= posix_fallocate(fd
, 0, binlog_size_limit
);
326 return twarn("Cannot allocate space for binlog %s", log
->path
);
330 /* Allocate space in a slow but portable way. */
335 #define ZERO_BUF_SIZE 512
336 char buf
[ZERO_BUF_SIZE
] = {}; /* initialize to zero */
338 for (i
= 0; i
< binlog_size_limit
; i
+= w
) {
339 w
= write(fd
, &buf
, ZERO_BUF_SIZE
);
341 twarn("Cannot allocate space for binlog %s", log
->path
);
348 p
= lseek(fd
, 0, SEEK_SET
);
358 bytes_written
= write(fd
, &binlog_version
, sizeof(int));
359 if (written
) *written
= bytes_written
;
361 if (bytes_written
< sizeof(int)) {
362 twarn("Cannot write to binlog");
371 /* returns 1 on success, 0 on error. */
377 if (!current_binlog
) return 0;
379 next
= current_binlog
->next
;
383 /* assert(current_binlog->reserved == 0); */
385 binlog_close(current_binlog
);
386 current_binlog
= next
;
395 binlog_close(current_binlog
);
398 /* Returns the number of jobs successfully written (either 0 or 1).
400 If this fails, something is seriously wrong. It should never fail because of
401 a full disk. (The binlog_reserve_space_* functions, on the other hand, can
402 fail because of a full disk.)
404 If we are not using the binlog at all (!current_binlog), then we pretend to
405 have made a successful write and return 1. */
407 binlog_write_job(job j
)
410 size_t tube_namelen
, to_write
= 0;
411 struct iovec vec
[4], *vptr
;
415 if (!current_binlog
) return 1;
418 vec
[0].iov_base
= (char *) &tube_namelen
;
419 to_write
+= vec
[0].iov_len
= sizeof(size_t);
421 vec
[1].iov_base
= j
->tube
->name
;
424 vec
[2].iov_base
= (char *) j
;
425 to_write
+= vec
[2].iov_len
= job_record_size
;
427 if (j
->state
== JOB_STATE_READY
|| j
->state
== JOB_STATE_DELAYED
) {
429 tube_namelen
= strlen(j
->tube
->name
);
430 to_write
+= vec
[1].iov_len
= tube_namelen
;
432 vec
[3].iov_base
= j
->body
;
433 to_write
+= vec
[3].iov_len
= j
->body_size
;
435 } else if (j
->state
== JOB_STATE_INVALID
) {
436 if (j
->binlog
) binlog_dref(j
->binlog
);
439 return twarnx("unserializable job state: %d", j
->state
), 0;
442 if (to_write
> current_binlog
->reserved
) {
443 r
= binlog_use_next();
444 if (!r
) return twarnx("failed to use next binlog"), 0;
447 if (j
->state
&& !j
->binlog
) j
->binlog
= binlog_iref(current_binlog
);
449 while (to_write
> 0) {
450 written
= writev(current_binlog
->fd
, vec
, vcnt
);
453 if (errno
== EAGAIN
) continue;
454 if (errno
== EINTR
) continue;
457 binlog_close(current_binlog
);
463 if (to_write
> 0 && written
> 0) {
464 for (vptr
= vec
; written
>= vptr
->iov_len
; vptr
++) {
465 written
-= vptr
->iov_len
;
468 vptr
->iov_base
= (char *) vptr
->iov_base
+ written
;
469 vptr
->iov_len
-= written
;
471 current_binlog
->reserved
-= written
;
472 j
->reserved_binlog_space
-= written
;
475 now
= now_usec() / 1000; /* usec -> msec */
476 if (enable_fsync
&& now
- last_fsync
>= fsync_throttle_ms
) {
477 r
= fdatasync(current_binlog
->fd
);
478 if (r
== -1) return twarn("fdatasync"), 0;
491 /* open a new binlog with more space to reserve */
492 b
= make_next_binlog();
493 if (!b
) return twarnx("error making next binlog"), (binlog
) 0;
494 binlog_open(b
, &header
);
496 /* open failed, so we can't reserve any space */
502 b
->free
= binlog_size_limit
- header
;
508 can_move_reserved(size_t n
, binlog from
, binlog to
)
510 return from
->reserved
>= n
&& to
->free
>= n
;
514 move_reserved(size_t n
, binlog from
, binlog to
)
523 ensure_free_space(size_t n
)
527 if (newest_binlog
&& newest_binlog
->free
>= n
) return n
;
529 /* open a new binlog */
530 fb
= make_future_binlog();
531 if (!fb
) return twarnx("make_future_binlog"), 0;
537 /* Preserve some invariants immediately after any space reservation.
538 * Invariant 1: current_binlog->reserved >= n.
539 * Invariant 2: current_binlog->reserved is congruent to n (mod z), where z
540 * is the size of a delete record in the binlog. */
542 maintain_invariant(size_t n
)
544 size_t reserved_later
, remainder
, complement
, z
, r
;
546 /* In this function, reserved bytes are conserved (they are neither created
547 * nor destroyed). We just move them around to preserve the invariant. We
548 * might have to create new free space (i.e. allocate a new binlog file),
552 /* This is a loop, but it's guaranteed to run at most once. The proof is
553 * left as an exercise for the reader. */
554 while (current_binlog
->reserved
< n
) {
555 size_t to_move
= current_binlog
->reserved
;
557 r
= ensure_free_space(to_move
);
559 twarnx("ensure_free_space");
560 if (newest_binlog
->reserved
>= n
) {
561 newest_binlog
->reserved
-= n
;
563 twarnx("failed to unreserve %zd bytes", n
); /* can't happen */
568 move_reserved(to_move
, current_binlog
, newest_binlog
);
575 z
= sizeof(size_t) + job_record_size
;
576 reserved_later
= current_binlog
->reserved
- n
;
577 remainder
= reserved_later
% z
;
578 if (remainder
== 0) return n
;
579 complement
= z
- remainder
;
580 if (can_move_reserved(complement
, newest_binlog
, current_binlog
)) {
581 move_reserved(complement
, newest_binlog
, current_binlog
);
585 r
= ensure_free_space(remainder
);
586 if (r
!= remainder
) {
587 twarnx("ensure_free_space");
588 if (newest_binlog
->reserved
>= n
) {
589 newest_binlog
->reserved
-= n
;
591 twarnx("failed to unreserve %zd bytes", n
); /* can't happen */
595 move_reserved(remainder
, current_binlog
, newest_binlog
);
600 /* Returns the number of bytes successfully reserved: either 0 or n. */
602 binlog_reserve_space(size_t n
)
606 /* This return value must be nonzero but is otherwise ignored. */
607 if (!current_binlog
) return 1;
609 if (current_binlog
->free
>= n
) {
610 current_binlog
->free
-= n
;
611 current_binlog
->reserved
+= n
;
612 return maintain_invariant(n
);
615 r
= ensure_free_space(n
);
616 if (r
!= n
) return twarnx("ensure_free_space"), 0;
618 newest_binlog
->free
-= n
;
619 newest_binlog
->reserved
+= n
;
620 return maintain_invariant(n
);
623 /* Returns the number of bytes reserved. */
625 binlog_reserve_space_put(job j
)
629 /* reserve space for the initial job record */
631 z
+= strlen(j
->tube
->name
);
632 z
+= job_record_size
;
635 /* plus space for a delete to come later */
637 z
+= job_record_size
;
639 return binlog_reserve_space(z
);
643 binlog_reserve_space_update(job j
)
648 z
+= job_record_size
;
649 return binlog_reserve_space(z
);
659 r
= snprintf(path
, PATH_MAX
, "%s/lock", binlog_dir
);
660 if (r
> PATH_MAX
) return twarnx("path too long: %s", binlog_dir
), 0;
662 lock_fd
= open(path
, O_WRONLY
|O_CREAT
, 0600);
663 if (lock_fd
== -1) return twarn("open"), 0;
665 lock
.l_type
= F_WRLCK
;
666 lock
.l_whence
= SEEK_SET
;
669 r
= fcntl(lock_fd
, F_SETLK
, &lock
);
670 if (r
) return twarn("fcntl"), 0;
676 binlog_init(job binlog_jobs
)
678 int binlog_index_min
;
685 if (!binlog_dir
) return;
687 /* Recover any jobs in old binlogs */
689 if (stat(binlog_dir
, &sbuf
) < 0) {
690 if (mkdir(binlog_dir
, 0700) < 0) return twarn("%s", binlog_dir
);
691 } else if (!(sbuf
.st_mode
& S_IFDIR
)) {
692 twarnx("%s", binlog_dir
);
696 binlog_index_min
= binlog_scan_dir();
698 if (binlog_index_min
) {
699 for (idx
= binlog_index_min
; idx
<= binlog_index
; idx
++) {
700 r
= snprintf(path
, PATH_MAX
, "%s/binlog.%d", binlog_dir
, idx
);
701 if (r
> PATH_MAX
) return twarnx("path too long: %s", binlog_dir
);
703 fd
= open(path
, O_RDONLY
);
708 b
= binlog_iref(add_binlog(make_binlog(path
)));
710 binlog_read_log_file(b
, binlog_jobs
);
720 /* Set up for writing out new jobs */
721 n
= ensure_free_space(1);
722 if (!n
) return twarnx("error making first writable binlog");
724 current_binlog
= newest_binlog
;
728 binlog_oldest_index()
730 if (!oldest_binlog
) return "0";
732 return strrchr(oldest_binlog
->path
, '.') + 1;
736 binlog_current_index()
738 if (!newest_binlog
) return "0";
740 return strrchr(newest_binlog
->path
, '.') + 1;