Allow the delay in psql's \watch command to be a fractional second.

Instead of just "2" seconds, allow eg. "2.5" seconds.  Per request
from Alvaro Herrera.  No docs change since the docs didn't say you
couldn't do this already.

diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 6319b030c7a61d55eabf30d7c472b3a12154c2c0..3ea12b8f8f955f17c10ce64ed22eb51db2c72190 100644 (file)
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -66,7 +66,7 @@ static bool do_edit(const char *filename_arg, PQExpBuffer query_buf,
        int lineno, bool *edited);
 static bool do_connect(char *dbname, char *user, char *host, char *port);
 static bool do_shell(const char *command);
-static bool do_watch(PQExpBuffer query_buf, long sleep);
+static bool do_watch(PQExpBuffer query_buf, double sleep);
 static bool lookup_object_oid(EditableObjectType obj_type, const char *desc,
                  Oid *obj_oid);
 static bool get_create_object_cmd(EditableObjectType obj_type, Oid oid,
@@ -1577,12 +1577,12 @@ exec_command(const char *cmd,
    {
        char       *opt = psql_scan_slash_option(scan_state,
                                                 OT_NORMAL, NULL, true);
-       long        sleep = 2;
+       double      sleep = 2;
 
        /* Convert optional sleep-length argument */
        if (opt)
        {
-           sleep = strtol(opt, NULL, 10);
+           sleep = strtod(opt, NULL);
            if (sleep <= 0)
                sleep = 1;
            free(opt);
@@ -3017,8 +3017,9 @@ do_shell(const char *command)
  * onto a bunch of exec_command's variables to silence stupider compilers.
  */
 static bool
-do_watch(PQExpBuffer query_buf, long sleep)
+do_watch(PQExpBuffer query_buf, double sleep)
 {
+   long        sleep_ms = (long) (sleep * 1000);
    printQueryOpt myopt = pset.popt;
    const char *user_title;
    char       *title;
@@ -3064,10 +3065,10 @@ do_watch(PQExpBuffer query_buf, long sleep)
            asctimebuf[i] = '\0';
 
        if (user_title)
-           snprintf(title, title_len, _("%s\t%s (every %lds)\n"),
+           snprintf(title, title_len, _("%s\t%s (every %gs)\n"),
                     user_title, asctimebuf, sleep);
        else
-           snprintf(title, title_len, _("%s (every %lds)\n"),
+           snprintf(title, title_len, _("%s (every %gs)\n"),
                     asctimebuf, sleep);
        myopt.title = title;
 
@@ -3091,15 +3092,19 @@ do_watch(PQExpBuffer query_buf, long sleep)
 
        /*
         * Enable 'watch' cancellations and wait a while before running the
-        * query again.  Break the sleep into short intervals since pg_usleep
-        * isn't interruptible on some platforms.
+        * query again.  Break the sleep into short intervals (at most 1s)
+        * since pg_usleep isn't interruptible on some platforms.
         */
        sigint_interrupt_enabled = true;
-       for (i = 0; i < sleep; i++)
+       i = sleep_ms;
+       while (i > 0)
        {
-           pg_usleep(1000000L);
+           long        s = Min(i, 1000L);
+
+           pg_usleep(s * 1000L);
            if (cancel_pressed)
                break;
+           i -= s;
        }
        sigint_interrupt_enabled = false;
    }