pgbench: Make set_random_seed() 64-bit everywhere.

petere · petere · commit 53a2a1564ae4 · 2025-03-29T15:24:42.000+01:00
Delete an intermediate variable, a redundant cast, a use of long and a use of long long. scanf() the seed directly into a uint64, now that we can do that with SCNu64 from <inttypes.h>. The previous coding was from pre-C99 times when %lld might not have been there, so it read into an unsigned long. Therefore behavior varied by OS, and --random-seed would accept either 32 or 64 bit seeds. Now it's the same everywhere. Author: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/b936d2fb-590d-49c3-a615-92c3a88c6c19%40eisentraut.org
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
@@ -6634,27 +6634,23 @@ set_random_seed(const char *seed)
 	}
 	else
 	{
-		/* parse unsigned-int seed value */
-		unsigned long ulseed;
 		char		garbage;
 
-		/* Don't try to use UINT64_FORMAT here; it might not work for sscanf */
-		if (sscanf(seed, "%lu%c", &ulseed, &garbage) != 1)
+		if (sscanf(seed, "%" SCNu64 "%c", &iseed, &garbage) != 1)
 		{
 			pg_log_error("unrecognized random seed option \"%s\"", seed);
 			pg_log_error_detail("Expecting an unsigned integer, \"time\" or \"rand\".");
 			return false;
 		}
-		iseed = (uint64) ulseed;
 	}
 
 	if (seed != NULL)
-		pg_log_info("setting random seed to %llu", (unsigned long long) iseed);
+		pg_log_info("setting random seed to %" PRIu64, iseed);
 
 	random_seed = iseed;
 
 	/* Initialize base_random_sequence using seed */
-	pg_prng_seed(&base_random_sequence, (uint64) iseed);
+	pg_prng_seed(&base_random_sequence, iseed);
 
 	return true;
 }

Original file line number	Diff line number	Diff line change
`@@ -6634,27 +6634,23 @@ set_random_seed(const char *seed)`
`6634`	`6634`	`}`
`6635`	`6635`	`else`
`6636`	`6636`	`{`
`6637`		`- /* parse unsigned-int seed value */`
`6638`		`- unsigned long ulseed;`
`6639`	`6637`	`char garbage;`
`6640`	`6638`
`6641`		`- /* Don't try to use UINT64_FORMAT here; it might not work for sscanf */`
`6642`		`- if (sscanf(seed, "%lu%c", &ulseed, &garbage) != 1)`
	`6639`	`+ if (sscanf(seed, "%" SCNu64 "%c", &iseed, &garbage) != 1)`
`6643`	`6640`	`{`
`6644`	`6641`	`pg_log_error("unrecognized random seed option \"%s\"", seed);`
`6645`	`6642`	`pg_log_error_detail("Expecting an unsigned integer, \"time\" or \"rand\".");`
`6646`	`6643`	`return false;`
`6647`	`6644`	`}`
`6648`		`- iseed = (uint64) ulseed;`
`6649`	`6645`	`}`
`6650`	`6646`
`6651`	`6647`	`if (seed != NULL)`
`6652`		`- pg_log_info("setting random seed to %llu", (unsigned long long) iseed);`
	`6648`	`+ pg_log_info("setting random seed to %" PRIu64, iseed);`
`6653`	`6649`
`6654`	`6650`	`random_seed = iseed;`
`6655`	`6651`
`6656`	`6652`	`/* Initialize base_random_sequence using seed */`
`6657`		`- pg_prng_seed(&base_random_sequence, (uint64) iseed);`
	`6653`	`+ pg_prng_seed(&base_random_sequence, iseed);`
`6658`	`6654`
`6659`	`6655`	`return true;`
`6660`	`6656`	`}`