Move snapshot helpers to new file snap.[ch].
authorAndre Noll <maan@systemlinux.org>
Sat, 22 Mar 2008 13:37:09 +0000 (14:37 +0100)
committerAndre Noll <maan@systemlinux.org>
Sat, 22 Mar 2008 13:37:09 +0000 (14:37 +0100)
Makefile
dss.c
snap.c [new file with mode: 0644]
snap.h [new file with mode: 0644]
time.c
time.h

index 55f9e3c..b1ba12c 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-dss_objects := cmdline.o dss.o string.o fd.o exec.o signal.o daemon.o df.o time.o
+dss_objects := cmdline.o dss.o string.o fd.o exec.o signal.o daemon.o df.o time.o snap.o
 all: dss
 man: dss.1
 
diff --git a/dss.c b/dss.c
index 3d00b0b..4a14c4b 100644 (file)
--- a/dss.c
+++ b/dss.c
 #include "signal.h"
 #include "df.h"
 #include "time.h"
+#include "snap.h"
 
 
-struct gengetopt_args_info conf;
+static struct gengetopt_args_info conf;
 static FILE *logfile;
 static int signal_pipe;
 
@@ -45,27 +46,11 @@ struct timeval next_snapshot_time;
 pid_t pre_create_hook_pid;
 /** The pid of the post-create hook. */
 pid_t post_create_hook_pid;
-
 /* Creation time of the snapshot currently being created. */
 int64_t current_snapshot_creation_time;
 
 static char *path_to_last_complete_snapshot;
 
-enum {
-       /** We are ready to take the next snapshot. */
-       SCS_READY,
-       /** The pre-creation hook has been started. */
-       SCS_PRE_HOOK_RUNNING,
-       /** The pre-creation hook exited successfully. */
-       SCS_PRE_HOOK_SUCCESS,
-       /** The rsync process is running. */
-       SCS_RSYNC_RUNNING,
-       /** The rsync process exited successfully. */
-       SCS_RSYNC_SUCCESS,
-       /** The post-create hook has been started- */
-       SCS_POST_HOOK_RUNNING,
-};
-
 static unsigned snapshot_creation_status;
 
 
@@ -91,27 +76,6 @@ int call_command_handler(void)
 #undef COMMAND
 #undef COMMANDS
 
-/*
- * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
- * complete, being deleted: 1204565370-1204565371.being_deleted
- * incomplete, not being deleted: 1204565370-incomplete
- * incomplete, being deleted: 1204565370-incomplete.being_deleted
- */
-enum snapshot_status_flags {
-       /** The rsync process terminated successfully. */
-       SS_COMPLETE = 1,
-       /** The rm process is running to remove this snapshot. */
-       SS_BEING_DELETED = 2,
-};
-
-struct snapshot {
-       char *name;
-       int64_t creation_time;
-       int64_t completion_time;
-       enum snapshot_status_flags flags;
-       unsigned interval;
-};
-
 __printf_2_3 void dss_log(int ll, const char* fmt,...)
 {
        va_list argp;
@@ -146,279 +110,72 @@ __printf_1_2 void dss_msg(const char* fmt,...)
        va_end(argp);
 }
 
-/**
- * Return the desired number of snapshots of an interval.
- */
-unsigned num_snapshots(int interval)
-{
-       unsigned n;
-
-       assert(interval >= 0);
-
-       if (interval >= conf.num_intervals_arg)
-               return 0;
-       n = conf.num_intervals_arg - interval - 1;
-       return 1 << n;
-}
-
-/* return: Whether dirname is a snapshot directory (0: no, 1: yes) */
-int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
+/* TODO: Also consider number of inodes. */
+int disk_space_low(void)
 {
-       int i, ret;
-       char *dash, *dot, *tmp;
-       int64_t num;
+       struct disk_space ds;
+       int ret = get_disk_space(".", &ds);
 
-       assert(dirname);
-       dash = strchr(dirname, '-');
-       if (!dash || !dash[1] || dash == dirname)
-               return 0;
-       for (i = 0; dirname[i] != '-'; i++)
-               if (!isdigit(dirname[i]))
-                       return 0;
-       tmp = dss_strdup(dirname);
-       tmp[i] = '\0';
-       ret = dss_atoi64(tmp, &num);
-       free(tmp);
        if (ret < 0)
-               return 0;
-       assert(num >= 0);
-       if (num > now)
-               return 0;
-       s->creation_time = num;
-       //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
-       s->interval = (long long) ((now - s->creation_time)
-               / conf.unit_interval_arg / 24 / 3600);
-       if (!strcmp(dash + 1, "incomplete")) {
-               s->completion_time = -1;
-               s->flags = 0; /* neither complete, nor being deleted */
-               goto success;
-       }
-       if (!strcmp(dash + 1, "incomplete.being_deleted")) {
-               s->completion_time = -1;
-               s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
-               goto success;
-       }
-       tmp = dash + 1;
-       dot = strchr(tmp, '.');
-       if (!dot || !dot[1] || dot == tmp)
-               return 0;
-       for (i = 0; tmp[i] != '.'; i++)
-               if (!isdigit(tmp[i]))
-                       return 0;
-       tmp = dss_strdup(dash + 1);
-       tmp[i] = '\0';
-       ret = dss_atoi64(tmp, &num);
-       free(tmp);
-       if (ret < 0)
-               return 0;
-       if (num > now)
-               return 0;
-       s->completion_time = num;
-       s->flags = SS_COMPLETE;
-       if (!strcmp(dot + 1, "being_deleted"))
-               s->flags |= SS_BEING_DELETED;
-success:
-       s->name = dss_strdup(dirname);
-       return 1;
-}
-
-int64_t get_current_time(void)
-{
-       time_t now;
-       time(&now);
-       DSS_DEBUG_LOG("now: %lli\n", (long long) now);
-       return (int64_t)now;
-}
-
-char *incomplete_name(int64_t start)
-{
-       return make_message("%lli-incomplete", (long long)start);
-}
-
-char *being_deleted_name(struct snapshot *s)
-{
-       if (s->flags & SS_COMPLETE)
-               return make_message("%lli-%lli.being_deleted",
-                       (long long)s->creation_time,
-                       (long long)s->completion_time);
-       return make_message("%lli-incomplete.being_deleted",
-               (long long)s->creation_time);
-}
-
-int complete_name(int64_t start, int64_t end, char **result)
-{
-       struct tm start_tm, end_tm;
-       time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
-       time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
-       char start_str[200], end_str[200];
-
-       if (!localtime_r(start_seconds, &start_tm))
-               return -E_LOCALTIME;
-       if (!localtime_r(end_seconds, &end_tm))
-               return -E_LOCALTIME;
-       if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm))
-               return -E_STRFTIME;
-       if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm))
-               return -E_STRFTIME;
-       *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
-               start_str, end_str);
-       return 1;
-}
-
-struct snapshot_list {
-       int64_t now;
-       unsigned num_snapshots;
-       unsigned array_size;
-       struct snapshot **snapshots;
-       /**
-        * Array of size num_intervals + 1
-        *
-        * It contains the number of snapshots in each interval. interval_count[num_intervals]
-        * is the number of snapshots which belong to any interval greater than num_intervals.
-        */
-       unsigned *interval_count;
-};
-
-#define FOR_EACH_SNAPSHOT(s, i, sl) \
-       for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
-
-#define FOR_EACH_SNAPSHOT_REVERSE(s, i, sl) \
-       for ((i) = (sl)->num_snapshots; (i) > 0 && ((s) = (sl)->snapshots[(i - 1)]); (i)--)
-
-static inline struct snapshot *oldest_snapshot(struct snapshot_list *sl)
-{
-       if (!sl->num_snapshots)
-               return NULL;
-       return sl->snapshots[0];
-}
-
-#define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
-
-static int compare_snapshots(const void *a, const void *b)
-{
-       struct snapshot *s1 = *(struct snapshot **)a;
-       struct snapshot *s2 = *(struct snapshot **)b;
-       return NUM_COMPARE(s2->creation_time, s1->creation_time);
-}
-
-/** Compute the minimum of \a a and \a b. */
-#define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
-
-int add_snapshot(const char *dirname, void *private)
-{
-       struct snapshot_list *sl = private;
-       struct snapshot s;
-       int ret = is_snapshot(dirname, sl->now, &s);
-
-       if (!ret)
-               return 1;
-       if (sl->num_snapshots >= sl->array_size) {
-               sl->array_size = 2 * sl->array_size + 1;
-               sl->snapshots = dss_realloc(sl->snapshots,
-                       sl->array_size * sizeof(struct snapshot *));
-       }
-       sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
-       *(sl->snapshots[sl->num_snapshots]) = s;
-       sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
-       sl->num_snapshots++;
-       return 1;
-}
-
-void get_snapshot_list(struct snapshot_list *sl)
-{
-       sl->now = get_current_time();
-       sl->num_snapshots = 0;
-       sl->array_size = 0;
-       sl->snapshots = NULL;
-       sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
-       for_each_subdir(add_snapshot, sl);
-       qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
-               compare_snapshots);
-}
-
-void free_snapshot_list(struct snapshot_list *sl)
-{
-       int i;
-       struct snapshot *s;
-
-       FOR_EACH_SNAPSHOT(s, i, sl) {
-               free(s->name);
-               free(s);
-       }
-       free(sl->interval_count);
-       sl->interval_count = NULL;
-       free(sl->snapshots);
-       sl->snapshots = NULL;
-       sl->num_snapshots = 0;
-}
-
-void stop_rsync_process(void)
-{
-       if (!rsync_pid || rsync_stopped)
-               return;
-       kill(SIGSTOP, rsync_pid);
-       rsync_stopped = 1;
+               return ret;
+       if (conf.min_free_mb_arg)
+               if (ds.free_mb < conf.min_free_mb_arg)
+                       return 1;
+       if (conf.min_free_percent_arg)
+               if (ds.percent_free < conf.min_free_percent_arg)
+                       return 1;
+       return 0;
 }
 
-void restart_rsync_process(void)
+void dss_get_snapshot_list(struct snapshot_list *sl)
 {
-       if (!rsync_pid || !rsync_stopped)
-               return;
-       kill (SIGCONT, rsync_pid);
-       rsync_stopped = 0;
+       get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
 }
 
-/**
- * Print a log message about the exit status of a child.
- */
-void log_termination_msg(pid_t pid, int status)
-{
-       if (WIFEXITED(status))
-               DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
-                       WEXITSTATUS(status));
-       else if (WIFSIGNALED(status))
-               DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
-                       WTERMSIG(status));
-       else
-               DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
-}
-
-int wait_for_process(pid_t pid, int *status)
+void compute_next_snapshot_time(void)
 {
-       int ret;
-
-       DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
-       for (;;) {
-               fd_set rfds;
+       struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
+               tmp, diff;
+       int64_t x = 0;
+       unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
+               num_complete_snapshots = 0;
+       int i, ret;
+       struct snapshot *s = NULL;
+       struct snapshot_list sl;
 
-               FD_ZERO(&rfds);
-               FD_SET(signal_pipe, &rfds);
-               ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
-               if (ret < 0)
-                       break;
-               ret = next_signal();
-               if (!ret)
+       assert(snapshot_creation_status == SCS_READY);
+       current_snapshot_creation_time = 0;
+       dss_get_snapshot_list(&sl);
+       FOR_EACH_SNAPSHOT(s, i, &sl) {
+               if (!(s->flags & SS_COMPLETE))
                        continue;
-               if (ret == SIGCHLD) {
-                       ret = waitpid(pid, status, 0);
-                       if (ret >= 0)
-                               break;
-                       if (errno != EINTR) { /* error */
-                               ret = -ERRNO_TO_DSS_ERROR(errno);
-                               break;
-                       }
-               }
-               /* SIGINT or SIGTERM */
-               DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
-               kill(pid, SIGTERM);
+               num_complete_snapshots++;
+               x += s->completion_time - s->creation_time;
        }
-       if (ret < 0)
-               DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
-       else
-               log_termination_msg(pid, *status);
-       return ret;
+       assert(x >= 0);
+       if (num_complete_snapshots)
+               x /= num_complete_snapshots; /* avg time to create one snapshot */
+       x *= wanted; /* time to create all snapshots in interval 0 */
+       tmp.tv_sec = x;
+       tmp.tv_usec = 0;
+       ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
+       gettimeofday(&now, NULL);
+       if (ret < 0 || !s)
+               goto min_sleep;
+       tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
+       diff.tv_sec = s->completion_time;
+       diff.tv_usec = 0;
+       tv_add(&diff, &tmp, &next_snapshot_time);
+       if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
+               goto out;
+min_sleep:
+       next_snapshot_time = now;
+       next_snapshot_time.tv_sec += 60;
+out:
+       free_snapshot_list(&sl);
 }
 
+
 int remove_snapshot(struct snapshot *s)
 {
        int fds[3] = {0, 0, 0};
@@ -430,7 +187,6 @@ int remove_snapshot(struct snapshot *s)
        if (ret < 0)
                goto out;
        DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
-       stop_rsync_process();
        ret = dss_exec(&rm_pid, argv[0], argv, fds);
 out:
        free(new_name);
@@ -448,7 +204,7 @@ int remove_redundant_snapshot(struct snapshot_list *sl)
 
        DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
        for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
-               unsigned keep = num_snapshots(interval);
+               unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
                unsigned num = sl->interval_count[interval];
                struct snapshot *victim = NULL, *prev = NULL;
                int64_t score = LONG_MAX;
@@ -521,119 +277,16 @@ int remove_outdated_snapshot(struct snapshot_list *sl)
        return 0;
 }
 
-int handle_rm_exit(int status)
-{
-       rm_pid = 0;
-       if (!WIFEXITED(status))
-               return -E_INVOLUNTARY_EXIT;
-       if (WEXITSTATUS(status))
-               return -E_BAD_EXIT_CODE;
-       return 1;
-}
-
-int wait_for_rm_process(void)
-{
-       int status, ret = wait_for_process(rm_pid, &status);
-
-       if (ret < 0)
-               return ret;
-       return handle_rm_exit(status);
-}
-
-void kill_process(pid_t pid)
+int remove_oldest_snapshot(struct snapshot_list *sl)
 {
-       if (!pid)
-               return;
-       DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
-       kill(pid, SIGTERM);
-}
+       struct snapshot *s = get_oldest_snapshot(sl);
 
-int check_config(void)
-{
-       if (conf.unit_interval_arg <= 0) {
-               DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
-               return -E_INVALID_NUMBER;
-       }
-       DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
-       if (conf.num_intervals_arg <= 0) {
-               DSS_ERROR_LOG("bad number of intervals  %i\n", conf.num_intervals_arg);
-               return -E_INVALID_NUMBER;
-       }
-       DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
-       return 1;
-}
-
-/* exits on errors */
-void parse_config_file(int override)
-{
-       int ret;
-       char *config_file;
-       struct stat statbuf;
-       char *old_logfile_arg = NULL;
-       int old_daemon_given = 0;
-
-       if (conf.config_file_given)
-               config_file = dss_strdup(conf.config_file_arg);
-       else {
-               char *home = get_homedir();
-               config_file = make_message("%s/.dssrc", home);
-               free(home);
-       }
-       if (override) { /* SIGHUP */
-               if (conf.logfile_given)
-                       old_logfile_arg = dss_strdup(conf.logfile_arg);
-               old_daemon_given = conf.daemon_given;
-       }
-
-       ret = stat(config_file, &statbuf);
-       if (ret && conf.config_file_given) {
-               ret = -ERRNO_TO_DSS_ERROR(errno);
-               DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
-               goto out;
-       }
-       if (!ret) {
-               struct cmdline_parser_params params = {
-                       .override = override,
-                       .initialize = 0,
-                       .check_required = 1,
-                       .check_ambiguity = 0
-               };
-               cmdline_parser_config_file(config_file, &conf, &params);
-       }
-       ret = check_config();
-       if (ret < 0)
-               goto out;
-       if (override) {
-               /* don't change daemon mode on SIGHUP */
-               conf.daemon_given = old_daemon_given;
-               close_log(logfile);
-               logfile = NULL;
-               if (conf.logfile_given)
-                       free(old_logfile_arg);
-               else if (conf.daemon_given) { /* re-use old logfile */
-                       conf.logfile_arg = old_logfile_arg;
-                       conf.logfile_given = 1;
-               }
-       }
-       if (conf.logfile_given) {
-               logfile = open_log(conf.logfile_arg);
-               log_welcome(conf.loglevel_arg);
-       }
-       DSS_EMERG_LOG("loglevel: %d\n", conf.loglevel_arg);
-//     cmdline_parser_dump(logfile? logfile : stdout, &conf);
-       ret = dss_chdir(conf.dest_dir_arg);
-out:
-       free(config_file);
-       if (ret >= 0)
-               return;
-       DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
-       exit(EXIT_FAILURE);
-}
-
-void handle_sighup(void)
-{
-       DSS_NOTICE_LOG("SIGHUP\n");
-       parse_config_file(1);
+       if (!s) /* no snapshot found */
+               return 0;
+       DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
+       if (s->creation_time == current_snapshot_creation_time)
+               return 0; /* do not remove the snapshot currently being created */
+       return remove_snapshot(s);
 }
 
 int rename_incomplete_snapshot(int64_t start)
@@ -655,191 +308,191 @@ int rename_incomplete_snapshot(int64_t start)
        return ret;
 }
 
-void compute_next_snapshot_time(void)
+int try_to_free_disk_space(int low_disk_space)
 {
-       struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
-               tmp, diff;
-       int64_t x = 0;
-       unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
-       int i, ret;
-       struct snapshot *s = NULL;
+       int ret;
        struct snapshot_list sl;
 
-       assert(snapshot_creation_status == SCS_READY);
-       current_snapshot_creation_time = 0;
-       get_snapshot_list(&sl);
-       FOR_EACH_SNAPSHOT(s, i, &sl) {
-               if (!(s->flags & SS_COMPLETE))
-                       continue;
-               num_complete_snapshots++;
-               x += s->completion_time - s->creation_time;
-       }
-       assert(x >= 0);
-       if (num_complete_snapshots)
-               x /= num_complete_snapshots; /* avg time to create one snapshot */
-       x *= wanted; /* time to create all snapshots in interval 0 */
-       tmp.tv_sec = x;
-       tmp.tv_usec = 0;
-       ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
-       gettimeofday(&now, NULL);
-       if (ret < 0 || !s)
-               goto min_sleep;
-       tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
-       diff.tv_sec = s->completion_time;
-       diff.tv_usec = 0;
-       tv_add(&diff, &tmp, &next_snapshot_time);
-       if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
+       dss_get_snapshot_list(&sl);
+       ret = remove_outdated_snapshot(&sl);
+       if (ret) /* error, or we are removing something */
                goto out;
-min_sleep:
-       next_snapshot_time = now;
-       next_snapshot_time.tv_sec += 60;
+       /* no outdated snapshot */
+       ret = remove_redundant_snapshot(&sl);
+       if (ret)
+               goto out;
+       ret = 0;
+       if (!low_disk_space)
+               goto out;
+       DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
+       ret = remove_oldest_snapshot(&sl);
+       if (ret)
+               goto out;
+       DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
+       ret= -ENOSPC;
 out:
        free_snapshot_list(&sl);
+       return ret;
 }
 
-int handle_rsync_exit(int status)
+int pre_create_hook(void)
 {
-       int es, ret;
+       int ret, fds[3] = {0, 0, 0};
 
-       if (!WIFEXITED(status)) {
-               DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
-               ret = -E_INVOLUNTARY_EXIT;
-               snapshot_creation_status = SCS_READY;
-               compute_next_snapshot_time();
-               goto out;
+       if (!conf.pre_create_hook_given) {
+               snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
+               return 0;
        }
-       es = WEXITSTATUS(status);
-       if (es != 0 && es != 23 && es != 24) {
-               DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
-               ret = -E_BAD_EXIT_CODE;
+       DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
+       ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
+               conf.pre_create_hook_arg, fds);
+       if (ret < 0)
+               return ret;
+       snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
+       return ret;
+}
+
+int post_create_hook(void)
+{
+       int ret, fds[3] = {0, 0, 0};
+       char *cmd;
+
+       if (!conf.post_create_hook_given) {
                snapshot_creation_status = SCS_READY;
                compute_next_snapshot_time();
-               goto out;
+               return 0;
        }
-       ret = rename_incomplete_snapshot(current_snapshot_creation_time);
+       cmd = make_message("%s %s", conf.post_create_hook_arg,
+               path_to_last_complete_snapshot);
+       DSS_NOTICE_LOG("executing %s\n", cmd);
+       ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
+       free(cmd);
        if (ret < 0)
-               goto out;
-       snapshot_creation_status = SCS_RSYNC_SUCCESS;
-out:
-       rsync_pid = 0;
-       rsync_stopped = 0;
+               return ret;
+       snapshot_creation_status = SCS_POST_HOOK_RUNNING;
        return ret;
 }
 
-__malloc char *name_of_newest_complete_snapshot(void)
+void kill_process(pid_t pid)
 {
-       struct snapshot_list sl;
-       struct snapshot *s;
-       int i;
-       char *name = NULL;
-
-       get_snapshot_list(&sl);
+       if (!pid)
+               return;
+       DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
+       kill(pid, SIGTERM);
+}
 
-       FOR_EACH_SNAPSHOT_REVERSE(s, i, &sl) {
-               if (s->flags != SS_COMPLETE) /* incomplete or being deleted */
-                       continue;
-               name = dss_strdup(s->name);
-               break;
-       }
-       free_snapshot_list(&sl);
-       return name;
+void stop_rsync_process(void)
+{
+       if (!rsync_pid || rsync_stopped)
+               return;
+       kill(SIGSTOP, rsync_pid);
+       rsync_stopped = 1;
 }
 
-void create_rsync_argv(char ***argv, int64_t *num)
+void restart_rsync_process(void)
 {
-       char *logname, *newest = name_of_newest_complete_snapshot();
-       int i = 0, j;
+       if (!rsync_pid || !rsync_stopped)
+               return;
+       kill (SIGCONT, rsync_pid);
+       rsync_stopped = 0;
+}
 
-       *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
-       (*argv)[i++] = dss_strdup("rsync");
-       (*argv)[i++] = dss_strdup("-aq");
-       (*argv)[i++] = dss_strdup("--delete");
-       for (j = 0; j < conf.rsync_option_given; j++)
-               (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
-       if (newest) {
-               DSS_INFO_LOG("using %s as reference snapshot\n", newest);
-               (*argv)[i++] = make_message("--link-dest=../%s", newest);
-               free(newest);
-       } else
-               DSS_INFO_LOG("no previous snapshot found\n");
-       if (conf.exclude_patterns_given) {
-               (*argv)[i++] = dss_strdup("--exclude-from");
-               (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
 
-       }
-       logname = dss_logname();
-       if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
-               (*argv)[i++] = dss_strdup(conf.source_dir_arg);
+/**
+ * Print a log message about the exit status of a child.
+ */
+void log_termination_msg(pid_t pid, int status)
+{
+       if (WIFEXITED(status))
+               DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
+                       WEXITSTATUS(status));
+       else if (WIFSIGNALED(status))
+               DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
+                       WTERMSIG(status));
        else
-               (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
-                       conf.remote_user_arg : logname,
-                       conf.remote_host_arg, conf.source_dir_arg);
-       free(logname);
-       *num = get_current_time();
-       (*argv)[i++] = incomplete_name(*num);
-       (*argv)[i++] = NULL;
-       for (j = 0; j < i; j++)
-               DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
+               DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 }
 
-void free_rsync_argv(char **argv)
+int wait_for_process(pid_t pid, int *status)
 {
-       int i;
-       for (i = 0; argv[i]; i++)
-               free(argv[i]);
-       free(argv);
-}
+       int ret;
 
-int pre_create_hook(void)
-{
-       int ret, fds[3] = {0, 0, 0};
+       DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
+       for (;;) {
+               fd_set rfds;
 
-       if (!conf.pre_create_hook_given) {
-               snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
-               return 0;
+               FD_ZERO(&rfds);
+               FD_SET(signal_pipe, &rfds);
+               ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
+               if (ret < 0)
+                       break;
+               ret = next_signal();
+               if (!ret)
+                       continue;
+               if (ret == SIGCHLD) {
+                       ret = waitpid(pid, status, 0);
+                       if (ret >= 0)
+                               break;
+                       if (errno != EINTR) { /* error */
+                               ret = -ERRNO_TO_DSS_ERROR(errno);
+                               break;
+                       }
+               }
+               /* SIGINT or SIGTERM */
+               DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
+               kill(pid, SIGTERM);
        }
-       DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
-       ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
-               conf.pre_create_hook_arg, fds);
        if (ret < 0)
-               return ret;
-       snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
+               DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
+       else
+               log_termination_msg(pid, *status);
        return ret;
 }
+int handle_rm_exit(int status)
+{
+       rm_pid = 0;
+       if (!WIFEXITED(status))
+               return -E_INVOLUNTARY_EXIT;
+       if (WEXITSTATUS(status))
+               return -E_BAD_EXIT_CODE;
+       return 1;
+}
 
-int post_create_hook(void)
+int wait_for_rm_process(void)
 {
-       int ret, fds[3] = {0, 0, 0};
-       char *cmd;
+       int status, ret = wait_for_process(rm_pid, &status);
 
-       if (!conf.post_create_hook_given) {
-               snapshot_creation_status = SCS_READY;
-               compute_next_snapshot_time();
-               return 0;
-       }
-       cmd = make_message("%s %s", conf.post_create_hook_arg,
-               path_to_last_complete_snapshot);
-       DSS_NOTICE_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
-       free(cmd);
        if (ret < 0)
                return ret;
-       snapshot_creation_status = SCS_POST_HOOK_RUNNING;
-       return ret;
+       return handle_rm_exit(status);
 }
 
-int create_snapshot(char **argv)
+int handle_rsync_exit(int status)
 {
-       int ret, fds[3] = {0, 0, 0};
-       char *name;
+       int es, ret;
 
-       name = incomplete_name(current_snapshot_creation_time);
-       DSS_NOTICE_LOG("creating new snapshot %s\n", name);
-       free(name);
-       ret = dss_exec(&rsync_pid, argv[0], argv, fds);
+       if (!WIFEXITED(status)) {
+               DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
+               ret = -E_INVOLUNTARY_EXIT;
+               snapshot_creation_status = SCS_READY;
+               compute_next_snapshot_time();
+               goto out;
+       }
+       es = WEXITSTATUS(status);
+       if (es != 0 && es != 23 && es != 24) {
+               DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
+               ret = -E_BAD_EXIT_CODE;
+               snapshot_creation_status = SCS_READY;
+               compute_next_snapshot_time();
+               goto out;
+       }
+       ret = rename_incomplete_snapshot(current_snapshot_creation_time);
        if (ret < 0)
-               return ret;
-       snapshot_creation_status = SCS_RSYNC_RUNNING;
+               goto out;
+       snapshot_creation_status = SCS_RSYNC_SUCCESS;
+out:
+       rsync_pid = 0;
+       rsync_stopped = 0;
        return ret;
 }
 
@@ -867,7 +520,7 @@ out:
        return ret;
 }
 
-int handle_sigchld()
+int handle_sigchld(void)
 {
        pid_t pid;
        int status, ret = reap_child(&pid, &status);
@@ -889,6 +542,95 @@ int handle_sigchld()
        exit(EXIT_FAILURE);
 }
 
+
+int check_config(void)
+{
+       if (conf.unit_interval_arg <= 0) {
+               DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
+               return -E_INVALID_NUMBER;
+       }
+       DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
+       if (conf.num_intervals_arg <= 0) {
+               DSS_ERROR_LOG("bad number of intervals  %i\n", conf.num_intervals_arg);
+               return -E_INVALID_NUMBER;
+       }
+       DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
+       return 1;
+}
+
+/* exits on errors */
+void parse_config_file(int override)
+{
+       int ret;
+       char *config_file;
+       struct stat statbuf;
+       char *old_logfile_arg = NULL;
+       int old_daemon_given = 0;
+
+       if (conf.config_file_given)
+               config_file = dss_strdup(conf.config_file_arg);
+       else {
+               char *home = get_homedir();
+               config_file = make_message("%s/.dssrc", home);
+               free(home);
+       }
+       if (override) { /* SIGHUP */
+               if (conf.logfile_given)
+                       old_logfile_arg = dss_strdup(conf.logfile_arg);
+               old_daemon_given = conf.daemon_given;
+       }
+
+       ret = stat(config_file, &statbuf);
+       if (ret && conf.config_file_given) {
+               ret = -ERRNO_TO_DSS_ERROR(errno);
+               DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
+               goto out;
+       }
+       if (!ret) {
+               struct cmdline_parser_params params = {
+                       .override = override,
+                       .initialize = 0,
+                       .check_required = 1,
+                       .check_ambiguity = 0
+               };
+               cmdline_parser_config_file(config_file, &conf, &params);
+       }
+       ret = check_config();
+       if (ret < 0)
+               goto out;
+       if (override) {
+               /* don't change daemon mode on SIGHUP */
+               conf.daemon_given = old_daemon_given;
+               close_log(logfile);
+               logfile = NULL;
+               if (conf.logfile_given)
+                       free(old_logfile_arg);
+               else if (conf.daemon_given) { /* re-use old logfile */
+                       conf.logfile_arg = old_logfile_arg;
+                       conf.logfile_given = 1;
+               }
+       }
+       if (conf.logfile_given) {
+               logfile = open_log(conf.logfile_arg);
+               log_welcome(conf.loglevel_arg);
+       }
+       DSS_EMERG_LOG("loglevel: %d\n", conf.loglevel_arg);
+//     cmdline_parser_dump(logfile? logfile : stdout, &conf);
+       ret = dss_chdir(conf.dest_dir_arg);
+out:
+       free(config_file);
+       if (ret >= 0)
+               return;
+       DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
+       exit(EXIT_FAILURE);
+}
+
+void handle_sighup(void)
+{
+       DSS_NOTICE_LOG("SIGHUP\n");
+       parse_config_file(1);
+}
+
 void handle_signal(void)
 {
        int sig, ret = next_signal();
@@ -916,59 +658,68 @@ out:
                DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
 }
 
-int remove_oldest_snapshot(struct snapshot_list *sl)
+void create_rsync_argv(char ***argv, int64_t *num)
 {
-       struct snapshot *s = oldest_snapshot(sl);
+       char *logname, *newest;
+       int i = 0, j;
+       struct snapshot_list sl;
 
-       if (!s) /* no snapshot found */
-               return 0;
-       DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
-       if (s->creation_time == current_snapshot_creation_time)
-               return 0; /* do not remove the snapshot currently being created */
-       return remove_snapshot(s);
+       dss_get_snapshot_list(&sl);
+       newest = name_of_newest_complete_snapshot(&sl);
+       free_snapshot_list(&sl);
+
+       *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
+       (*argv)[i++] = dss_strdup("rsync");
+       (*argv)[i++] = dss_strdup("-aq");
+       (*argv)[i++] = dss_strdup("--delete");
+       for (j = 0; j < conf.rsync_option_given; j++)
+               (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
+       if (newest) {
+               DSS_INFO_LOG("using %s as reference snapshot\n", newest);
+               (*argv)[i++] = make_message("--link-dest=../%s", newest);
+               free(newest);
+       } else
+               DSS_INFO_LOG("no previous snapshot found\n");
+       if (conf.exclude_patterns_given) {
+               (*argv)[i++] = dss_strdup("--exclude-from");
+               (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
+
+       }
+       logname = dss_logname();
+       if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
+               (*argv)[i++] = dss_strdup(conf.source_dir_arg);
+       else
+               (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
+                       conf.remote_user_arg : logname,
+                       conf.remote_host_arg, conf.source_dir_arg);
+       free(logname);
+       *num = get_current_time();
+       (*argv)[i++] = incomplete_name(*num);
+       (*argv)[i++] = NULL;
+       for (j = 0; j < i; j++)
+               DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
 }
 
-/* TODO: Also consider number of inodes. */
-int disk_space_low(void)
+void free_rsync_argv(char **argv)
 {
-       struct disk_space ds;
-       int ret = get_disk_space(".", &ds);
-
-       if (ret < 0)
-               return ret;
-       if (conf.min_free_mb_arg)
-               if (ds.free_mb < conf.min_free_mb_arg)
-                       return 1;
-       if (conf.min_free_percent_arg)
-               if (ds.percent_free < conf.min_free_percent_arg)
-                       return 1;
-       return 0;
+       int i;
+       for (i = 0; argv[i]; i++)
+               free(argv[i]);
+       free(argv);
 }
 
-int try_to_free_disk_space(int low_disk_space)
+int create_snapshot(char **argv)
 {
-       int ret;
-       struct snapshot_list sl;
+       int ret, fds[3] = {0, 0, 0};
+       char *name;
 
-       get_snapshot_list(&sl);
-       ret = remove_outdated_snapshot(&sl);
-       if (ret) /* error, or we are removing something */
-               goto out;
-       /* no outdated snapshot */
-       ret = remove_redundant_snapshot(&sl);
-       if (ret)
-               goto out;
-       ret = 0;
-       if (!low_disk_space)
-               goto out;
-       DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
-       ret = remove_oldest_snapshot(&sl);
-       if (ret)
-               goto out;
-       DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
-       ret= -ENOSPC;
-out:
-       free_snapshot_list(&sl);
+       name = incomplete_name(current_snapshot_creation_time);
+       DSS_NOTICE_LOG("creating new snapshot %s\n", name);
+       free(name);
+       ret = dss_exec(&rsync_pid, argv[0], argv, fds);
+       if (ret < 0)
+               return ret;
+       snapshot_creation_status = SCS_RSYNC_RUNNING;
        return ret;
 }
 
@@ -1001,13 +752,13 @@ int select_loop(void)
                if (ret < 0)
                        break;
                low_disk_space = ret;
-               if (low_disk_space)
-                       stop_rsync_process();
                ret = try_to_free_disk_space(low_disk_space);
                if (ret < 0)
                        break;
-               if (rm_pid)
+               if (rm_pid) {
+                       stop_rsync_process();
                        continue;
+               }
                restart_rsync_process();
                gettimeofday(&now, NULL);
                if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
@@ -1068,7 +819,7 @@ int com_prune(void)
                return ret;
        log_disk_space(&ds);
        for (;;) {
-               get_snapshot_list(&sl);
+               dss_get_snapshot_list(&sl);
                ret = remove_outdated_snapshot(&sl);
                free_snapshot_list(&sl);
                if (ret < 0)
@@ -1080,7 +831,7 @@ int com_prune(void)
                        goto out;
        }
        for (;;) {
-               get_snapshot_list(&sl);
+               dss_get_snapshot_list(&sl);
                ret = remove_redundant_snapshot(&sl);
                free_snapshot_list(&sl);
                if (ret < 0)
@@ -1150,7 +901,8 @@ int com_ls(void)
        int i;
        struct snapshot_list sl;
        struct snapshot *s;
-       get_snapshot_list(&sl);
+
+       dss_get_snapshot_list(&sl);
        FOR_EACH_SNAPSHOT(s, i, &sl)
                dss_msg("%u\t%s\n", s->interval, s->name);
        free_snapshot_list(&sl);
@@ -1178,6 +930,7 @@ err:
        exit(EXIT_FAILURE);
 }
 
+
 int main(int argc, char **argv)
 {
        int ret;
diff --git a/snap.c b/snap.c
new file mode 100644 (file)
index 0000000..1bc97b5
--- /dev/null
+++ b/snap.c
@@ -0,0 +1,217 @@
+#include <stdlib.h>
+#include <assert.h>
+#include <inttypes.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <errno.h>
+#include <time.h>
+
+#include "gcc-compat.h"
+#include "error.h"
+#include "snap.h"
+#include "string.h"
+#include "time.h"
+#include "fd.h"
+
+/**
+ * Return the desired number of snapshots of an interval.
+ */
+unsigned desired_number_of_snapshots(int interval_num, int num_intervals)
+{
+       unsigned n;
+
+       assert(interval_num >= 0);
+
+       if (interval_num >= num_intervals)
+               return 0;
+       n = num_intervals - interval_num - 1;
+       return 1 << n;
+}
+
+/* return: Whether dirname is a snapshot directory (0: no, 1: yes) */
+static int is_snapshot(const char *dirname, int64_t now, int unit_interval,
+               struct snapshot *s)
+{
+       int i, ret;
+       char *dash, *dot, *tmp;
+       int64_t num;
+
+       assert(dirname);
+       dash = strchr(dirname, '-');
+       if (!dash || !dash[1] || dash == dirname)
+               return 0;
+       for (i = 0; dirname[i] != '-'; i++)
+               if (!isdigit(dirname[i]))
+                       return 0;
+       tmp = dss_strdup(dirname);
+       tmp[i] = '\0';
+       ret = dss_atoi64(tmp, &num);
+       free(tmp);
+       if (ret < 0)
+               return 0;
+       assert(num >= 0);
+       if (num > now)
+               return 0;
+       s->creation_time = num;
+       //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
+       s->interval = (long long) ((now - s->creation_time)
+               / unit_interval / 24 / 3600);
+       if (!strcmp(dash + 1, "incomplete")) {
+               s->completion_time = -1;
+               s->flags = 0; /* neither complete, nor being deleted */
+               goto success;
+       }
+       if (!strcmp(dash + 1, "incomplete.being_deleted")) {
+               s->completion_time = -1;
+               s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
+               goto success;
+       }
+       tmp = dash + 1;
+       dot = strchr(tmp, '.');
+       if (!dot || !dot[1] || dot == tmp)
+               return 0;
+       for (i = 0; tmp[i] != '.'; i++)
+               if (!isdigit(tmp[i]))
+                       return 0;
+       tmp = dss_strdup(dash + 1);
+       tmp[i] = '\0';
+       ret = dss_atoi64(tmp, &num);
+       free(tmp);
+       if (ret < 0)
+               return 0;
+       if (num > now)
+               return 0;
+       s->completion_time = num;
+       s->flags = SS_COMPLETE;
+       if (!strcmp(dot + 1, "being_deleted"))
+               s->flags |= SS_BEING_DELETED;
+success:
+       s->name = dss_strdup(dirname);
+       return 1;
+}
+
+struct add_snapshot_data {
+       int unit_interval;
+       int num_intervals;
+       struct snapshot_list *sl;
+};
+
+/** Compute the minimum of \a a and \a b. */
+#define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
+
+static int add_snapshot(const char *dirname, void *private)
+{
+       struct add_snapshot_data *asd = private;
+       struct snapshot_list *sl = asd->sl;
+       struct snapshot s;
+       int ret = is_snapshot(dirname, sl->now, asd->unit_interval, &s);
+
+       if (!ret)
+               return 1;
+       if (sl->num_snapshots >= sl->array_size) {
+               sl->array_size = 2 * sl->array_size + 1;
+               sl->snapshots = dss_realloc(sl->snapshots,
+                       sl->array_size * sizeof(struct snapshot *));
+       }
+       sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
+       *(sl->snapshots[sl->num_snapshots]) = s;
+       sl->interval_count[DSS_MIN(s.interval, asd->num_intervals)]++;
+       sl->num_snapshots++;
+       return 1;
+}
+
+#define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
+
+static int compare_snapshots(const void *a, const void *b)
+{
+       struct snapshot *s1 = *(struct snapshot **)a;
+       struct snapshot *s2 = *(struct snapshot **)b;
+       return NUM_COMPARE(s2->creation_time, s1->creation_time);
+}
+
+
+void get_snapshot_list(struct snapshot_list *sl, int unit_interval,
+               int num_intervals)
+{
+       struct add_snapshot_data asd = {
+               .unit_interval = unit_interval,
+               .num_intervals = num_intervals,
+               .sl = sl
+       };
+       sl->now = get_current_time();
+       sl->num_snapshots = 0;
+       sl->array_size = 0;
+       sl->snapshots = NULL;
+       sl->interval_count = dss_calloc((num_intervals + 1) * sizeof(unsigned));
+       for_each_subdir(add_snapshot, &asd);
+       qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
+               compare_snapshots);
+}
+
+void free_snapshot_list(struct snapshot_list *sl)
+{
+       int i;
+       struct snapshot *s;
+
+       FOR_EACH_SNAPSHOT(s, i, sl) {
+               free(s->name);
+               free(s);
+       }
+       free(sl->interval_count);
+       sl->interval_count = NULL;
+       free(sl->snapshots);
+       sl->snapshots = NULL;
+       sl->num_snapshots = 0;
+}
+
+__malloc char *incomplete_name(int64_t start)
+{
+       return make_message("%lli-incomplete", (long long)start);
+}
+
+__malloc char *being_deleted_name(struct snapshot *s)
+{
+       if (s->flags & SS_COMPLETE)
+               return make_message("%lli-%lli.being_deleted",
+                       (long long)s->creation_time,
+                       (long long)s->completion_time);
+       return make_message("%lli-incomplete.being_deleted",
+               (long long)s->creation_time);
+}
+
+int complete_name(int64_t start, int64_t end, char **result)
+{
+       struct tm start_tm, end_tm;
+       time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
+       time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
+       char start_str[200], end_str[200];
+
+       if (!localtime_r(start_seconds, &start_tm))
+               return -E_LOCALTIME;
+       if (!localtime_r(end_seconds, &end_tm))
+               return -E_LOCALTIME;
+       if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm))
+               return -E_STRFTIME;
+       if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm))
+               return -E_STRFTIME;
+       *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
+               start_str, end_str);
+       return 1;
+}
+
+__malloc char *name_of_newest_complete_snapshot(struct snapshot_list *sl)
+{
+       struct snapshot *s;
+       int i;
+       char *name = NULL;
+
+       FOR_EACH_SNAPSHOT_REVERSE(s, i, sl) {
+               if (s->flags != SS_COMPLETE) /* incomplete or being deleted */
+                       continue;
+               name = dss_strdup(s->name);
+               break;
+       }
+       return name;
+}
+
diff --git a/snap.h b/snap.h
new file mode 100644 (file)
index 0000000..1e9fc2b
--- /dev/null
+++ b/snap.h
@@ -0,0 +1,72 @@
+enum {
+       /** We are ready to take the next snapshot. */
+       SCS_READY,
+       /** The pre-creation hook has been started. */
+       SCS_PRE_HOOK_RUNNING,
+       /** The pre-creation hook exited successfully. */
+       SCS_PRE_HOOK_SUCCESS,
+       /** The rsync process is running. */
+       SCS_RSYNC_RUNNING,
+       /** The rsync process exited successfully. */
+       SCS_RSYNC_SUCCESS,
+       /** The post-create hook has been started- */
+       SCS_POST_HOOK_RUNNING,
+};
+
+/*
+ * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
+ * complete, being deleted: 1204565370-1204565371.being_deleted
+ * incomplete, not being deleted: 1204565370-incomplete
+ * incomplete, being deleted: 1204565370-incomplete.being_deleted
+ */
+enum snapshot_status_flags {
+       /** The rsync process terminated successfully. */
+       SS_COMPLETE = 1,
+       /** The rm process is running to remove this snapshot. */
+       SS_BEING_DELETED = 2,
+};
+
+struct snapshot {
+       char *name;
+       int64_t creation_time;
+       int64_t completion_time;
+       enum snapshot_status_flags flags;
+       unsigned interval;
+};
+
+struct snapshot_list {
+       int64_t now;
+       unsigned num_snapshots;
+       unsigned array_size;
+       struct snapshot **snapshots;
+       /**
+        * Array of size num_intervals + 1
+        *
+        * It contains the number of snapshots in each interval. interval_count[num_intervals]
+        * is the number of snapshots which belong to any interval greater than num_intervals.
+        */
+       unsigned *interval_count;
+};
+
+#define FOR_EACH_SNAPSHOT(s, i, sl) \
+       for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
+
+#define FOR_EACH_SNAPSHOT_REVERSE(s, i, sl) \
+       for ((i) = (sl)->num_snapshots; (i) > 0 && ((s) = (sl)->snapshots[(i - 1)]); (i)--)
+
+
+unsigned desired_number_of_snapshots(int interval_num, int num_intervals);
+void get_snapshot_list(struct snapshot_list *sl, int unit_interval,
+               int num_intervals);
+void free_snapshot_list(struct snapshot_list *sl);
+__malloc char *incomplete_name(int64_t start);
+__malloc char *being_deleted_name(struct snapshot *s);
+int complete_name(int64_t start, int64_t end, char **result);
+__malloc char *name_of_newest_complete_snapshot(struct snapshot_list *sl);
+
+static inline struct snapshot *get_oldest_snapshot(struct snapshot_list *sl)
+{
+       if (!sl->num_snapshots)
+               return NULL;
+       return sl->snapshots[0];
+}
diff --git a/time.c b/time.c
index 18366cd..b54e34c 100644 (file)
--- a/time.c
+++ b/time.c
@@ -1,6 +1,13 @@
 #include <sys/time.h>
 #include <time.h>
 #include <inttypes.h>
+#include <assert.h>
+#include <string.h>
+
+#include "gcc-compat.h"
+#include "error.h"
+#include "string.h"
+#include "log.h"
 
 /*
  * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
@@ -129,3 +136,11 @@ void tv_divide(const unsigned long divisor, const struct timeval *tv,
        result->tv_sec = x / 1000 / 1000;
        result->tv_usec = x % (1000 * 1000);
 }
+
+int64_t get_current_time(void)
+{
+       time_t now;
+       time(&now);
+       DSS_DEBUG_LOG("now: %lli\n", (long long) now);
+       return (int64_t)now;
+}
diff --git a/time.h b/time.h
index 97b3065..f2021e0 100644 (file)
--- a/time.h
+++ b/time.h
@@ -6,3 +6,4 @@ void tv_scale(const unsigned long, const struct timeval *, struct timeval *);
 void tv_divide(const unsigned long divisor, const struct timeval *tv,
        struct timeval *result);
 void ms2tv(const long unsigned n, struct timeval *tv);
+int64_t get_current_time(void);