+/*---------- defer and backlog files ----------*/
+
+static void open_defer(void) {
+ struct stat stab;
+
+ if (defer) return;
+
+ defer= fopen(path_defer, "a+");
+ if (!defer) sysfatal("could not open defer file %s", path_defer);
+
+ /* truncate away any half-written records */
+
+ xfstat_isreg(fileno(defer), &stab, "newly opened defer file");
+
+ if (stab.st_size > LONG_MAX)
+ die("defer file %s size is far too large", path_defer);
+
+ if (!stab.st_size)
+ return;
+
+ long orgsize= stab.st_size;
+ long truncto= stab.st_size;
+ for (;;) {
+ if (!truncto) break; /* was only (if anything) one half-truncated record */
+ if (fseek(defer, truncto-1, SEEK_SET) < 0)
+ sysdie("seek in defer file %s while truncating partial", path_defer);
+
+ r= getc(defer);
+ if (r==EOF) {
+ if (ferror(defer))
+ sysdie("failed read from defer file %s", path_defer);
+ else
+ die("defer file %s shrank while we were checking it!", path_defer);
+ }
+ if (r=='\n') break;
+ truncto--;
+ }
+
+ if (stab.st_size != truncto) {
+ warn("truncating half-record at end of defer file %s -"
+ " shrinking by %ld bytes from %ld to %ld",
+ path_defer, orgsize - truncto, orgsize, truncto);
+
+ if (fflush(defer))
+ sysfatal("could not flush defer file %s", path_defer);
+ if (ftruncate(fileno(defer), truncto))
+ sysdie("could not truncate defer file %s", path_defer);
+
+ } else {
+ info("continuing existing defer file %s (%ld bytes)",
+ path_defer, orgsize);
+ }
+ if (fseek(defer, truncto, SEEK_SET))
+ sysdie("could not seek to new end of defer file %s", path_defer);
+}
+
+static void close_defer(void) {
+ if (!defer)
+ return;
+
+ xfstat(fileno(defer), &stab, "defer file");
+
+ if (fclose(defer)) sysfatal("could not close defer file %s", path_defer);
+ defer= 0;
+
+ char *backlog= xasprintf("%s_backlog_%lu.%lu", feedfile,
+ (unsigned long)now.tv_sec,
+ (unsigned long)stab.st_ino);
+ if (link(path_defer, path_backlog))
+ sysfatal("could not install defer file %s as backlog file %s",
+ path_defer, backlog);
+ if (unlink(path_defer))
+ sysdie("could not unlink old defer link %s to backlog file %s",
+ path_defer, backlog);
+
+ if (backlog_nextscan_periods < 0 ||
+ backlog_nextscan_periods > backlog_retry_minperiods + 1)
+ backlog_nextscan_periods= backlog_retry_minperiods + 1;
+}
+
+static void poll_backlog_file(void) {
+ if (backlog_nextscan_periods < 0) return;
+ if (backlog_nextscan_periods-- > 0) return;
+ search_backlog_file();
+}
+
+static int search_backlog_file(void) {
+ /* returns non-0 iff there are any backlog files */
+
+ glob_t gl;
+ int r;
+ struct stat stab;
+ const char *oldest_path=0;
+ time_t oldest_mtime, now;
+
+ if (backlog_input_file) return 3;
+
+ try_again:
+
+ r= glob(globpat_backlog, GLOB_ERR|GLOB_MARK|GLOB_NOSORT, 0, &gl);
+
+ switch (r) {
+ case GLOB_ABORTED:
+ sysdie("failed to expand backlog pattern %s", globpat_backlog);
+ case GLOB_NOSPACE:
+ die("out of memory expanding backlog pattern %s", globpat_backlog);
+ case 0:
+ for (i=0; i<gl.gl_pathc; i++) {
+ const char *path= gl.gl_pathv[i];
+
+ if (strchr(path,'#') || strchr(path,'~')) {
+ debug("backlog file search skipping %s", path);
+ continue;
+ }
+ r= stat(path, &stab);
+ if (r) {
+ syswarn("failed to stat backlog file %s", path);
+ continue;
+ }
+ if (!S_ISREG(stab.st_mode)) {
+ warn("backlog file %s is not a plain file (or link to one)", path);
+ continue;
+ }
+ if (!oldest_path || stab.st_mtime < oldest_mtime) {
+ oldest_path= path;
+ oldest_mtime= stab.st_mtime;
+ }
+ }
+ case GLOB_NOMATCH: /* fall through */
+ break;
+ default:
+ sysdie("glob expansion of backlog pattern %s gave unexpected"
+ " nonzero (error?) return value %d", globpat_backlog, r);
+ }
+
+ globfree(&gl);
+
+ if (!oldest_path) {
+ debug("backlog scan: none");
+ backlog_nextscan_periods= backlog_spontaneous_rescan_periods;
+ return 0;
+ }
+
+ now= time(); if (now==-1) sysdie("time(2) failed");
+ double age= difftime(now, oldest_mtime);
+ long age_deficiency= (backlog_retry_minperiods * PERIOD_SECONDS) - age;
+
+ if (age_deficiency <= 0) {
+ debug("backlog scan: found age=%f deficiency=%ld oldest=%s",
+ age, age_deficiency, oldest_path);
+
+ backlog_input_file= open_input_file();
+ if (!backlog_input_file) {
+ warn("backlog file %s vanished as we opened it", backlog_input_file);
+ goto try_again;
+ }
+ inputfile_tailing_start(backlog_input_file);
+ backlog_nextscan_periods= -1;
+ return 1;
+ }
+
+ backlog_nextscan_periods= age_deficiency / PERIOD_SECONDS;
+
+ if (backlog_spontaneous_rescan_periods >= 0 &&
+ backlog_nextscan_periods > backlog_spontaneous_rescan_periods)
+ backlog_nextscan_periods= backlog_spontaneous_rescan_periods;
+
+ debug("backlog scan: young age=%f deficiency=%ld nextscan=%d oldest=%s",
+ age, age_deficiency, backlog_nextscan_periods, oldest_path);
+ return 2;
+}
+
~ian / inn-innduct.git / blobdiff