pgbench: Ensure previous progress message is fully cleared when updating.

During pgbench's table initialization, progress updates could display
leftover characters from the previous message if the new message
was shorter. This commit resolves the issue by appending spaces to
the current message to fully overwrite any remaining characters from
the previous line.

Back-patch to all the supported versions.

Author: Yushi Ogiwara, Tatsuo Ishii, Fujii Masao
Reviewed-by: Tatsuo Ishii, Fujii Masao
Discussion: https://postgr.es/m/9a9b8b95b6a709877ae48ad5b0c59bb9@oss.nttdata.com

diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 86ffb3c8683d04e003c330f953baf8ea4e68e0f4..47467c32dd8b96159364c5de3dd3e3eda1623538 100644 (file)
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -4943,6 +4943,7 @@ initPopulateTable(PGconn *con, const char *table, int64 base,
        int                     n;
        int64           k;
        int                     chars = 0;
+       int                     prev_chars = 0;
        PGresult   *res;
        PQExpBufferData sql;
        char            copy_statement[256];
@@ -5003,10 +5004,10 @@ initPopulateTable(PGconn *con, const char *table, int64 base,
                        double          elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
                        double          remaining_sec = ((double) total - j) * elapsed_sec / j;
 
-                       chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)%c",
+                       chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)",
                                                        j, total,
                                                        (int) ((j * 100) / total),
-                                                       table, elapsed_sec, remaining_sec, eol);
+                                                       table, elapsed_sec, remaining_sec);
                }
                /* let's not call the timing for each row, but only each 100 rows */
                else if (use_quiet && (j % 100 == 0))
@@ -5017,19 +5018,29 @@ initPopulateTable(PGconn *con, const char *table, int64 base,
                        /* have we reached the next interval (or end)? */
                        if ((j == total) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
                        {
-                               chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)%c",
+                               chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)",
                                                                j, total,
                                                                (int) ((j * 100) / total),
-                                                               table, elapsed_sec, remaining_sec, eol);
+                                                               table, elapsed_sec, remaining_sec);
 
                                /* skip to the next interval */
                                log_interval = (int) ceil(elapsed_sec / LOG_STEP_SECONDS);
                        }
                }
+
+               /*
+                * If the previous progress message is longer than the current one,
+                * add spaces to the current line to fully overwrite any remaining
+                * characters from the previous message.
+                */
+               if (prev_chars > chars)
+                       fprintf(stderr, "%*c", prev_chars - chars, ' ');
+               fputc(eol, stderr);
+               prev_chars = chars;
        }
 
        if (chars != 0 && eol != '\n')
-               fprintf(stderr, "%*c\r", chars - 1, ' ');       /* Clear the current line */
+               fprintf(stderr, "%*c\r", chars, ' ');   /* Clear the current line */
 
        if (PQputline(con, "\\.\n"))
                pg_fatal("very last PQputline failed");