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 #include "version.h"
  37
  38 /* max size we will create a log file */
  39 size_t binlog_size_limit = 10 << 20;
  40
  41 char *binlog_dir = NULL;
  42 static int binlog_index = 0;
  43 static int binlog_fd = -1;
  44 static int binlog_version = 1;
  45 static size_t bytes_written;
  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_replay(int fd, job binlog_jobs)
 114 {
 115     struct job js;
 116     tube t;
 117     job j;
 118     char tubename[MAX_TUBE_NAME_LEN];
 119     size_t namelen;
 120     int version;
 121
 122     if (read(fd, &version, sizeof(version)) < sizeof(version)) {
 123         return twarn("read()");
 124     }
 125     if (version != binlog_version) {
 126         return twarnx("binlog version mismatch %d %d", version, binlog_version);
 127     }
 128
 129     while (read(fd, &namelen, sizeof(size_t)) == sizeof(size_t)) {
 130         if (namelen > 0 && read(fd, tubename, namelen) != namelen) {
 131             return twarnx("oops %x %d", namelen, (int)lseek(fd, SEEK_CUR, 0));
 132         }
 133
 134         tubename[namelen] = '\0';
 135         if (read(fd, &js, sizeof(struct job)) != sizeof(struct job)) {
 136             return twarn("read()");
 137         }
 138
 139         j = job_find(js.id);
 140         switch (js.state) {
 141         case JOB_STATE_INVALID:
 142             if (j) {
 143                 job_remove(j);
 144                 binlog_dref(j->binlog);
 145                 job_free(j);
 146                 j = NULL;
 147             }
 148             break;
 149         case JOB_STATE_READY:
 150         case JOB_STATE_DELAYED:
 151             if (!j) {
 152                 t = tube_find_or_make(tubename);
 153                 j = make_job_with_id(js.pri, js.delay, js.ttr, js.body_size,
 154                                      t, js.id);
 155                 j->next = j->prev = j;
 156                 j->creation = js.creation;
 157                 job_insert(binlog_jobs, j);
 158                 if (read(fd, j->body, js.body_size) < js.body_size) {
 159                     twarn("read()");
 160                     return;
 161                 }
 162             }
 163             break;
 164         }
 165         if (j) {
 166             j->state = js.state;
 167             j->deadline = js.deadline;
 168             j->pri = js.pri;
 169             j->delay = js.delay;
 170             j->ttr = js.ttr;
 171             j->timeout_ct = js.timeout_ct;
 172             j->release_ct = js.release_ct;
 173             j->bury_ct = js.bury_ct;
 174             j->kick_ct = js.kick_ct;
 175
 176             /* this is a complete record, so we can move the binlog ref */
 177             if (namelen && js.body_size) {
 178                 binlog_dref(j->binlog);
 179                 j->binlog = binlog_iref(last_binlog);
 180             }
 181         }
 182     }
 183 }
 184
 185 void
 186 binlog_close()
 187 {
 188     if (binlog_fd < 0) return;
 189     close(binlog_fd);
 190     binlog_dref(last_binlog);
 191     binlog_fd = -1;
 192 }
 193
 194 static binlog
 195 add_binlog(char *path)
 196 {
 197     binlog b;
 198
 199     b = (binlog)malloc(sizeof(struct binlog) + strlen(path) + 1);
 200     if (!b) return twarnx("OOM"), NULL;
 201     strcpy(b->path, path);
 202     b->refs = 0;
 203     b->next = NULL;
 204     if (last_binlog) last_binlog->next = b;
 205     last_binlog = b;
 206     if (!first_binlog) first_binlog = b;
 207
 208     return b;
 209 }
 210
 211 static int
 212 binlog_open()
 213 {
 214     char path[PATH_MAX];
 215     binlog b;
 216     int fd, r;
 217
 218     if (!binlog_dir) return -1;
 219     r = snprintf(path, PATH_MAX, "%s/binlog.%d", binlog_dir, ++binlog_index);
 220     if (r > PATH_MAX) return twarnx("path too long: %s", binlog_dir), -1;
 221
 222     if (!binlog_iref(add_binlog(path))) return -1;
 223     fd = open(path, O_WRONLY | O_CREAT, 0400);
 224
 225     if (fd < 0) {
 226         twarn("Cannot open binlog %s", path);
 227         return -1;
 228     }
 229
 230
 231     bytes_written = write(fd, &binlog_version, sizeof(int));
 232
 233     if (bytes_written < sizeof(int)) {
 234         twarn("Cannot write to binlog");
 235         close(fd);
 236         binlog_dref(last_binlog);
 237         return -1;
 238     }
 239
 240     return fd;
 241 }
 242
 243 static void
 244 binlog_open_next()
 245 {
 246     if (binlog_fd < 0) return;
 247     close(binlog_fd);
 248     binlog_dref(last_binlog);
 249     binlog_fd = binlog_open();
 250 }
 251
 252 void
 253 binlog_write_job(job j)
 254 {
 255     size_t tube_namelen, to_write;
 256     struct iovec vec[4], *vptr;
 257     int vcnt = 3;
 258
 259     if (binlog_fd < 0) return;
 260     tube_namelen = 0;
 261
 262     vec[0].iov_base = (char *) &tube_namelen;
 263     vec[0].iov_len = sizeof(size_t);
 264     to_write = sizeof(size_t);
 265
 266     vec[1].iov_base = j->tube->name;
 267     vec[1].iov_len = 0;
 268
 269     /* we could save some bytes in the binlog file by only saving some parts of
 270      * the job struct */
 271     vec[2].iov_base = (char *) j;
 272     vec[2].iov_len = sizeof(struct job);
 273     to_write += sizeof(struct job);
 274
 275     if (j->state == JOB_STATE_READY || j->state == JOB_STATE_DELAYED) {
 276         if (!j->binlog) {
 277             tube_namelen = strlen(j->tube->name);
 278             vec[1].iov_len = tube_namelen;
 279             to_write += tube_namelen;
 280             vcnt = 4;
 281             vec[3].iov_base = j->body;
 282             vec[3].iov_len = j->body_size;
 283             to_write += j->body_size;
 284         }
 285     } else if (j->state == JOB_STATE_INVALID) {
 286         if (j->binlog) binlog_dref(j->binlog);
 287         j->binlog = NULL;
 288     } else {
 289         return twarnx("unserializable job state: %d", j->state);
 290     }
 291
 292     if ((bytes_written + to_write) > binlog_size_limit) binlog_open_next();
 293     if (binlog_fd < 0) return;
 294
 295     if (j->state && !j->binlog) j->binlog = binlog_iref(last_binlog);
 296
 297     while (to_write > 0) {
 298         size_t written = writev(binlog_fd, vec, vcnt);
 299
 300         if (written < 0) {
 301             twarn("Cannot write to binlog");
 302             binlog_close();
 303             return;
 304         }
 305
 306         bytes_written += written;
 307         to_write -= written;
 308         if (to_write > 0 && written > 0) {
 309             for (vptr = vec; written >= vptr->iov_len; vptr++) {
 310                 written -= vptr->iov_len;
 311                 vptr->iov_len = 0;
 312             }
 313             vptr->iov_base = (char *) vptr->iov_base + written;
 314             vptr->iov_len -= written;
 315         }
 316     }
 317 }
 318
 319
 320 void
 321 binlog_read(job binlog_jobs)
 322 {
 323     int binlog_index_min;
 324     struct stat sbuf;
 325     int fd, idx, r;
 326     char path[PATH_MAX];
 327     binlog b;
 328
 329     if (!binlog_dir) return;
 330
 331     if (stat(binlog_dir, &sbuf) < 0) {
 332         if (mkdir(binlog_dir, 0700) < 0) return twarn("%s", binlog_dir);
 333     } else if (!(sbuf.st_mode & S_IFDIR)) {
 334         twarnx("%s", binlog_dir);
 335         return;
 336     }
 337
 338     binlog_index_min = binlog_scan_dir();
 339
 340     if (binlog_index_min) {
 341         for (idx = binlog_index_min; idx <= binlog_index; idx++) {
 342             r = snprintf(path, PATH_MAX, "%s/binlog.%d", binlog_dir, idx);
 343             if (r > PATH_MAX) return twarnx("path too long: %s", binlog_dir);
 344
 345             fd = open(path, O_RDONLY);
 346
 347             if (fd < 0) {
 348                 twarn("%s", path);
 349             } else {
 350                 b = binlog_iref(add_binlog(path));
 351                 binlog_replay(fd, binlog_jobs);
 352                 close(fd);
 353                 binlog_dref(b);
 354             }
 355         }
 356
 357     }
 358 }
 359
 360 void
 361 binlog_init()
 362 {
 363     binlog_fd = binlog_open();
 364 }
 365