binlog.c

   1 /* binlog.c - binary log implementation */
   2
   3 /* Copyright (C) 2008 Graham Barr
   4
   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.
   9
  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.
  14
  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/>.
  17  */
  18
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21 #include <fcntl.h>
  22 #include <unistd.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <dirent.h>
  26 #include <sys/resource.h>
  27 #include <sys/param.h>
  28 #include <sys/uio.h>
  29 #include <sys/stat.h>
  30 #include <stdarg.h>
  31
  32 #include "tube.h"
  33 #include "job.h"
  34 #include "binlog.h"
  35 #include "util.h"
  36
  37 /* max size we will create a log file */
  38 size_t binlog_size_limit = 10 << 20;
  39
  40 char *binlog_dir = NULL;
  41 static int binlog_index = 0;
  42 static int binlog_fd = -1;
  43 static int binlog_version = 1;
  44 static size_t bytes_written;
  45 static int lock_fd;
  46
  47 static binlog first_binlog = NULL, last_binlog = NULL;
  48
  49 static int
  50 binlog_scan_dir()
  51 {
  52     DIR *dirp;
  53     struct dirent *dp;
  54     long min = 0;
  55     long max = 0;
  56     long val;
  57     char *endptr;
  58     size_t name_len;
  59
  60     dirp = opendir(binlog_dir);
  61     if (!dirp) return 0;
  62
  63     while ((dp = readdir(dirp)) != NULL) {
  64         name_len = strlen(dp->d_name);
  65         if (name_len > 7 && !strncmp("binlog.", dp->d_name, 7)) {
  66             val = strtol(dp->d_name + 7, &endptr, 10);
  67             if (endptr && *endptr == 0) {
  68                 if (max == 0 || val > max) max = val;
  69                 if (min == 0 || val < min) min = val;
  70             }
  71         }
  72     }
  73
  74     closedir(dirp);
  75     binlog_index = (int) max;
  76     return (int) min;
  77 }
  78
  79 static void
  80 binlog_remove_first()
  81 {
  82     binlog b = first_binlog;
  83
  84     if (!b) return;
  85
  86     first_binlog = b->next;
  87     if (!first_binlog) last_binlog = NULL;
  88
  89     unlink(b->path);
  90     free(b);
  91 }
  92
  93 static binlog
  94 binlog_iref(binlog b)
  95 {
  96     if (b) b->refs++;
  97     return b;
  98 }
  99
 100 static void
 101 binlog_dref(binlog b)
 102 {
 103     if (!b) return;
 104     if (b->refs < 1) return twarnx("refs is zero for binlog: %s", b->path);
 105
 106     --b->refs;
 107     if (b->refs < 1) {
 108         while (first_binlog && first_binlog->refs == 0) binlog_remove_first();
 109     }
 110 }
 111
 112 static void
 113 binlog_warn(const char *msg, int fd, const char* path)
 114 {
 115     warnx("WARNING, %s at %s:%u.\n%s", msg, path, lseek(fd, 0, SEEK_CUR),
 116           "  Continuing with next file. You may be missing data.");
 117 }
 118
 119 static void
 120 binlog_replay(int fd, job binlog_jobs, const char *path)
 121 {
 122     struct job js;
 123     tube t;
 124     job j;
 125     char tubename[MAX_TUBE_NAME_LEN];
 126     size_t namelen;
 127     ssize_t r;
 128     int version;
 129
 130     r = read(fd, &version, sizeof(version));
 131     if (r == -1) return twarn("read()");
 132     if (r < sizeof(version)) {
 133         return binlog_warn("version record is too short", fd, path);
 134     }
 135
 136     if (version != binlog_version) {
 137         return warnx("%s: binlog version mismatch %d %d", path, version,
 138                      binlog_version);
 139     }
 140
 141     while (read(fd, &namelen, sizeof(size_t)) == sizeof(size_t)) {
 142         if (namelen > 0) {
 143             r = read(fd, tubename, namelen);
 144             if (r == -1) return twarn("read()");
 145             if (r < namelen) {
 146                 lseek(fd, SEEK_CUR, 0);
 147                 return binlog_warn("tube name is too short", fd, path);
 148             }
 149         }
 150
 151         tubename[namelen] = '\0';
 152         r = read(fd, &js, sizeof(struct job));
 153         if (r == -1) return twarn("read()");
 154         if (r < sizeof(struct job)) {
 155           return binlog_warn("job record is too short", fd, path);
 156         }
 157
 158         j = job_find(js.id);
 159         switch (js.state) {
 160         case JOB_STATE_INVALID:
 161             if (j) {
 162                 job_remove(j);
 163                 binlog_dref(j->binlog);
 164                 job_free(j);
 165                 j = NULL;
 166             }
 167             break;
 168         case JOB_STATE_READY:
 169         case JOB_STATE_DELAYED:
 170             if (!j) {
 171                 t = tube_find_or_make(tubename);
 172                 j = make_job_with_id(js.pri, js.delay, js.ttr, js.body_size,
 173                                      t, js.id);
 174                 j->next = j->prev = j;
 175                 j->creation = js.creation;
 176                 job_insert(binlog_jobs, j);
 177                 r = read(fd, j->body, js.body_size);
 178                 if (r == -1) return twarn("read()");
 179                 if (r < js.body_size) {
 180                     warnx("dropping incomplete job %llu", j->id);
 181                     job_remove(j);
 182                     binlog_dref(j->binlog);
 183                     job_free(j);
 184                     return binlog_warn("job body is too short", fd, path);
 185                 }
 186             }
 187             break;
 188         }
 189         if (j) {
 190             j->state = js.state;
 191             j->deadline = js.deadline;
 192             j->pri = js.pri;
 193             j->delay = js.delay;
 194             j->ttr = js.ttr;
 195             j->timeout_ct = js.timeout_ct;
 196             j->release_ct = js.release_ct;
 197             j->bury_ct = js.bury_ct;
 198             j->kick_ct = js.kick_ct;
 199
 200             /* this is a complete record, so we can move the binlog ref */
 201             if (namelen && js.body_size) {
 202                 binlog_dref(j->binlog);
 203                 j->binlog = binlog_iref(last_binlog);
 204             }
 205         }
 206     }
 207 }
 208
 209 void
 210 binlog_close()
 211 {
 212     if (binlog_fd < 0) return;
 213     close(binlog_fd);
 214     binlog_dref(last_binlog);
 215     binlog_fd = -1;
 216 }
 217
 218 static binlog
 219 add_binlog(char *path)
 220 {
 221     binlog b;
 222
 223     b = (binlog)malloc(sizeof(struct binlog) + strlen(path) + 1);
 224     if (!b) return twarnx("OOM"), NULL;
 225     strcpy(b->path, path);
 226     b->refs = 0;
 227     b->next = NULL;
 228     if (last_binlog) last_binlog->next = b;
 229     last_binlog = b;
 230     if (!first_binlog) first_binlog = b;
 231
 232     return b;
 233 }
 234
 235 static int
 236 binlog_open()
 237 {
 238     char path[PATH_MAX];
 239     binlog b;
 240     int fd, r;
 241
 242     if (!binlog_dir) return -1;
 243     r = snprintf(path, PATH_MAX, "%s/binlog.%d", binlog_dir, ++binlog_index);
 244     if (r > PATH_MAX) return twarnx("path too long: %s", binlog_dir), -1;
 245
 246     if (!binlog_iref(add_binlog(path))) return -1;
 247     fd = open(path, O_WRONLY | O_CREAT, 0400);
 248
 249     if (fd < 0) {
 250         twarn("Cannot open binlog %s", path);
 251         return -1;
 252     }
 253
 254
 255     bytes_written = write(fd, &binlog_version, sizeof(int));
 256
 257     if (bytes_written < sizeof(int)) {
 258         twarn("Cannot write to binlog");
 259         close(fd);
 260         binlog_dref(last_binlog);
 261         return -1;
 262     }
 263
 264     return fd;
 265 }
 266
 267 static void
 268 binlog_open_next()
 269 {
 270     if (binlog_fd < 0) return;
 271     close(binlog_fd);
 272     binlog_dref(last_binlog);
 273     binlog_fd = binlog_open();
 274 }
 275
 276 void
 277 binlog_write_job(job j)
 278 {
 279     size_t tube_namelen, to_write;
 280     struct iovec vec[4], *vptr;
 281     int vcnt = 3;
 282
 283     if (binlog_fd < 0) return;
 284     tube_namelen = 0;
 285
 286     vec[0].iov_base = (char *) &tube_namelen;
 287     vec[0].iov_len = sizeof(size_t);
 288     to_write = sizeof(size_t);
 289
 290     vec[1].iov_base = j->tube->name;
 291     vec[1].iov_len = 0;
 292
 293     /* we could save some bytes in the binlog file by only saving some parts of
 294      * the job struct */
 295     vec[2].iov_base = (char *) j;
 296     vec[2].iov_len = sizeof(struct job);
 297     to_write += sizeof(struct job);
 298
 299     if (j->state == JOB_STATE_READY || j->state == JOB_STATE_DELAYED) {
 300         if (!j->binlog) {
 301             tube_namelen = strlen(j->tube->name);
 302             vec[1].iov_len = tube_namelen;
 303             to_write += tube_namelen;
 304             vcnt = 4;
 305             vec[3].iov_base = j->body;
 306             vec[3].iov_len = j->body_size;
 307             to_write += j->body_size;
 308         }
 309     } else if (j->state == JOB_STATE_INVALID) {
 310         if (j->binlog) binlog_dref(j->binlog);
 311         j->binlog = NULL;
 312     } else {
 313         return twarnx("unserializable job state: %d", j->state);
 314     }
 315
 316     if ((bytes_written + to_write) > binlog_size_limit) binlog_open_next();
 317     if (binlog_fd < 0) return;
 318
 319     if (j->state && !j->binlog) j->binlog = binlog_iref(last_binlog);
 320
 321     while (to_write > 0) {
 322         size_t written = writev(binlog_fd, vec, vcnt);
 323
 324         if (written < 0) {
 325             twarn("Cannot write to binlog");
 326             binlog_close();
 327             return;
 328         }
 329
 330         bytes_written += written;
 331         to_write -= written;
 332         if (to_write > 0 && written > 0) {
 333             for (vptr = vec; written >= vptr->iov_len; vptr++) {
 334                 written -= vptr->iov_len;
 335                 vptr->iov_len = 0;
 336             }
 337             vptr->iov_base = (char *) vptr->iov_base + written;
 338             vptr->iov_len -= written;
 339         }
 340     }
 341 }
 342
 343
 344 void
 345 binlog_read(job binlog_jobs)
 346 {
 347     int binlog_index_min;
 348     struct stat sbuf;
 349     int fd, idx, r;
 350     char path[PATH_MAX];
 351     binlog b;
 352
 353     if (!binlog_dir) return;
 354
 355     if (stat(binlog_dir, &sbuf) < 0) {
 356         if (mkdir(binlog_dir, 0700) < 0) return twarn("%s", binlog_dir);
 357     } else if (!(sbuf.st_mode & S_IFDIR)) {
 358         twarnx("%s", binlog_dir);
 359         return;
 360     }
 361
 362     binlog_index_min = binlog_scan_dir();
 363
 364     if (binlog_index_min) {
 365         for (idx = binlog_index_min; idx <= binlog_index; idx++) {
 366             r = snprintf(path, PATH_MAX, "%s/binlog.%d", binlog_dir, idx);
 367             if (r > PATH_MAX) return twarnx("path too long: %s", binlog_dir);
 368
 369             fd = open(path, O_RDONLY);
 370
 371             if (fd < 0) {
 372                 twarn("%s", path);
 373             } else {
 374                 b = binlog_iref(add_binlog(path));
 375                 binlog_replay(fd, binlog_jobs, path);
 376                 close(fd);
 377                 binlog_dref(b);
 378             }
 379         }
 380
 381     }
 382 }
 383
 384 int
 385 binlog_lock()
 386 {
 387     int r;
 388     struct flock lock;
 389     char path[PATH_MAX];
 390
 391     r = snprintf(path, PATH_MAX, "%s/lock", binlog_dir);
 392     if (r > PATH_MAX) return twarnx("path too long: %s", binlog_dir), 0;
 393
 394     lock_fd = open(path, O_WRONLY|O_CREAT, 0600);
 395     if (lock_fd == -1) return twarn("open"), 0;
 396
 397     lock.l_type = F_WRLCK;
 398     lock.l_whence = SEEK_SET;
 399     lock.l_start = 0;
 400     lock.l_len = 0;
 401     r = fcntl(lock_fd, F_SETLK, &lock);
 402     if (r) return twarn("fcntl"), 0;
 403
 404     return 1;
 405 }
 406
 407 void
 408 binlog_init()
 409 {
 410     binlog_fd = binlog_open();
 411 }
 412
 413 const char *
 414 binlog_oldest_index()
 415 {
 416     if (!first_binlog) return "0";
 417
 418     return strrchr(first_binlog->path, '.') + 1;
 419 }
 420
 421 const char *
 422 binlog_current_index()
 423 {
 424     if (!last_binlog) return "0";
 425
 426     return strrchr(last_binlog->path, '.') + 1;
 427 }