should be it

external/duckdb/extension/tpch/dbgen/permute.cpp

@@ -0,0 +1,61 @@
+/*
+ * Copyright owned by the Transaction Processing Performance Council.
+ *
+ * A copy of the license is included under extension/tpch/dbgen/LICENSE
+ * in this repository.
+ *
+ * You may not use this file except in compliance with the License.
+ *
+ * THE TPC SOFTWARE IS AVAILABLE WITHOUT CHARGE FROM TPC.
+ *//*
+ * permute.c -- a permutation generator for the query
+ *              sequences in TPC-H and TPC-R
+ */
+
+#include "dbgen/config.h"
+#include "dbgen/dss.h"
+#include <memory>
+
+DSS_HUGE NextRand(DSS_HUGE seed);
+void permute(long *set, int cnt, seed_t *seed);
+void permute_dist(distribution *d, seed_t *seed, DBGenContext *ctx);
+long seed;
+char *eol[2] = {" ", "},"};
+
+#define MAX_QUERY 22
+#define ITERATIONS 1000
+#define UNSET 0
+
+void permute(long *a, int c, seed_t *seed) {
+	int i;
+	DSS_HUGE source;
+	long temp;
+
+	if (a != (long *)NULL) {
+		for (i = 0; i < c; i++) {
+			RANDOM(source, (long)i, (long)(c - 1), seed);
+			temp = *(a + source);
+			*(a + source) = *(a + i);
+			*(a + i) = temp;
+		}
+	}
+
+	return;
+}
+
+void permute_dist(distribution *d, seed_t *seed, DBGenContext *ctx) {
+	int i;
+
+	if (d != NULL) {
+		if (ctx->permute == (long *)NULL) {
+			ctx->permute = (long *)malloc(sizeof(long) * DIST_SIZE(d));
+			MALLOC_CHECK(ctx->permute);
+		}
+		for (i = 0; i < DIST_SIZE(d); i++)
+			*(ctx->permute + i) = i;
+		permute(ctx->permute, DIST_SIZE(d), seed);
+	} else
+		INTERNAL_ERROR("Bad call to permute_dist");
+
+	return;
+}