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

MasaoFujii · MasaoFujii · commit f1cb5e51f329 · 2024-11-27T23:05:24.000+09:00
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
@@ -3840,6 +3840,8 @@ initGenerateDataClientSide(PGconn *con)
 	PGresult   *res;
 	int			i;
 	int64		k;
+	int			chars = 0;
+	int			prev_chars = 0;
 
 	/* used to track elapsed time and estimate of the remaining time */
 	instr_time	start,
@@ -3926,10 +3928,10 @@ initGenerateDataClientSide(PGconn *con)
 			elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
 			remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
 
-			fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)%c",
-					j, (int64) naccounts * scale,
-					(int) (((int64) j * 100) / (naccounts * (int64) scale)),
-					elapsed_sec, remaining_sec, eol);
+			chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)",
+							j, (int64) naccounts * scale,
+							(int) (((int64) j * 100) / (naccounts * (int64) scale)),
+							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))
@@ -3943,14 +3945,24 @@ initGenerateDataClientSide(PGconn *con)
 			/* have we reached the next interval (or end)? */
 			if ((j == scale * naccounts) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
 			{
-				fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)%c",
-						j, (int64) naccounts * scale,
-						(int) (((int64) j * 100) / (naccounts * (int64) scale)), elapsed_sec, remaining_sec, eol);
+				chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)",
+								j, (int64) naccounts * scale,
+								(int) (((int64) j * 100) / (naccounts * (int64) scale)), 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 (eol != '\n')
