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[PATCH 4/9] test-mergesort: add generate subcommand

From
René Scharfe <l.s.r@web.de>
Date
Oct 1, 2021, 09:14 UTC
Message-ID
<1b6e34fc-b758-f6e7-39b2-e73f309591bd@web.de>
In-Reply-To
<943b1e01-465e-5def-a766-0adf667690de@web.de>

Add a subcommand for printing test data. It can be used to generate special test cases and feed them into the sort subcommand or sort(1) for performance measurements. It may also be useful to illustrate the effect of distributions, modes and their parameters.

It generates n integers with the specified distribution and its distribution-specific parameter m. E.g. m is the maximum value for the plateau distribution and the length and height of individual teeth of the sawtooth distribution.

The generated values are printed as zero-padded eight-digit hexadecimal numbers to make sure alphabetic and numeric order are the same.

Signed-off-by: René Scharfe <l.s.r@web.de>
---
 t/helper/test-mergesort.c | 60 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 59 insertions(+), 1 deletion(-)
diff --git a/t/helper/test-mergesort.c b/t/helper/test-mergesort.c
index 8006be8bf8..27ba252d4a 100644
--- a/t/helper/test-mergesort.c
+++ b/t/helper/test-mergesort.c
@@ -98,6 +98,16 @@ static struct dist {
 	DIST(shuffle),
 };

+static const struct dist *get_dist_by_name(const char *name)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(dist); i++) {
+	       if (!strcmp(dist[i].name, name))
+		       return &dist[i];
+	}
+	return NULL;
+}
+
 static void mode_copy(int *arr, int n)
 {
 	/* nothing */
@@ -154,6 +164,41 @@ static struct mode {
 	MODE(dither),
 };

+static const struct mode *get_mode_by_name(const char *name)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(mode); i++) {
+	       if (!strcmp(mode[i].name, name))
+		       return &mode[i];
+	}
+	return NULL;
+}
+
+static int generate(int argc, const char **argv)
+{
+	const struct dist *dist = NULL;
+	const struct mode *mode = NULL;
+	int i, n, m, *arr;
+
+	if (argc != 4)
+		return 1;
+
+	dist = get_dist_by_name(argv[0]);
+	mode = get_mode_by_name(argv[1]);
+	n = strtol(argv[2], NULL, 10);
+	m = strtol(argv[3], NULL, 10);
+	if (!dist || !mode)
+		return 1;
+
+	ALLOC_ARRAY(arr, n);
+	dist->fn(arr, n, m);
+	mode->fn(arr, n);
+	for (i = 0; i < n; i++)
+		printf("%08x\n", arr[i]);
+	free(arr);
+	return 0;
+}
+
 static struct stats {
 	int get_next, set_next, compare;
 } stats;
@@ -278,11 +323,24 @@ static int run_tests(int argc, const char **argv)

 int cmd__mergesort(int argc, const char **argv)
 {
+	int i;
+	const char *sep;
+
+	if (argc == 6 && !strcmp(argv[1], "generate"))
+		return generate(argc - 2, argv + 2);
 	if (argc == 2 && !strcmp(argv[1], "sort"))
 		return sort_stdin();
 	if (argc > 1 && !strcmp(argv[1], "test"))
 		return run_tests(argc - 2, argv + 2);
-	fprintf(stderr, "usage: test-tool mergesort sort\n");
+	fprintf(stderr, "usage: test-tool mergesort generate <distribution> <mode> <n> <m>\n");
+	fprintf(stderr, "   or: test-tool mergesort sort\n");
 	fprintf(stderr, "   or: test-tool mergesort test [<n>...]\n");
+	fprintf(stderr, "\n");
+	for (i = 0, sep = "distributions: "; i < ARRAY_SIZE(dist); i++, sep = ", ")
+		fprintf(stderr, "%s%s", sep, dist[i].name);
+	fprintf(stderr, "\n");
+	for (i = 0, sep = "modes: "; i < ARRAY_SIZE(mode); i++, sep = ", ")
+		fprintf(stderr, "%s%s", sep, mode[i].name);
+	fprintf(stderr, "\n");
 	return 129;
 }
--
2.33.0
Previous: Ævar Arnfjörð BjarmasonNext: René Scharfe
Message 19 of 29 in “mergesort: improve tests and performance”
  1. 0/9 mergesort: improve tests and performanceRené Scharfe, Oct 1, 2021
  2. 1/9 test-mergesort: use strbuf_getline()René Scharfe, Oct 1, 2021
  3. Ævar Arnfjörð BjarmasonOct 2, 2021
  4. René ScharfeOct 2, 2021
  5. 2/9 test-mergesort: add sort subcommandRené Scharfe, Oct 1, 2021
  6. Junio C HamanoOct 1, 2021
  7. 3/9 test-mergesort: add test subcommandRené Scharfe, Oct 1, 2021
  8. Junio C HamanoOct 1, 2021
  9. Ævar Arnfjörð BjarmasonOct 2, 2021
  10. René ScharfeOct 3, 2021
  11. René ScharfeOct 3, 2021
  12. Junio C HamanoOct 3, 2021
  13. René ScharfeOct 7, 2021
  14. 10/9 test-mergesort: use repeatable random numbersRené Scharfe, Oct 8, 2021
  15. Jeff KingOct 8, 2021
  16. Ævar Arnfjörð BjarmasonOct 8, 2021
  17. René ScharfeOct 8, 2021
  18. Ævar Arnfjörð BjarmasonOct 8, 2021
  19. 4/9 test-mergesort: add generate subcommandRené Scharfe, Oct 1, 2021
  20. 5/9 test-mergesort: add unriffle modeRené Scharfe, Oct 1, 2021
  21. 6/9 test-mergesort: add unriffle_skewed modeRené Scharfe, Oct 1, 2021
  22. 7/9 p0071: measure sorting of already sorted and reversed filesRené Scharfe, Oct 1, 2021
  23. 8/9 p0071: test performance of llist_mergesort()René Scharfe, Oct 1, 2021
  24. 9/9 mergesort: use ranks stackRené Scharfe, Oct 1, 2021
  25. Ævar Arnfjörð BjarmasonJan 17, 2022
  26. René ScharfeJan 17, 2022
  27. René ScharfeJan 18, 2022
  28. Ævar Arnfjörð BjarmasonJan 18, 2022
  29. René ScharfeJan 18, 2022

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