[PATCH v2 1/2] t: add "test-tool genbytes" to avoid slow tr(1) on macOS

@@ -825,8 +825,8 @@ TEST_BUILTINS_OBJS += test-env-helper.o
 TEST_BUILTINS_OBJS += test-example-tap.o
 TEST_BUILTINS_OBJS += test-find-pack.o
 TEST_BUILTINS_OBJS += test-fsmonitor-client.o
+TEST_BUILTINS_OBJS += test-genbytes.o
 TEST_BUILTINS_OBJS += test-genrandom.o
-TEST_BUILTINS_OBJS += test-genzeros.o
 TEST_BUILTINS_OBJS += test-getcwd.o
 TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-hash.o

@@ -22,8 +22,8 @@ test_tool_sources = [
   'test-example-tap.c',
   'test-find-pack.c',
   'test-fsmonitor-client.c',
+  'test-genbytes.c',
   'test-genrandom.c',
-  'test-genzeros.c',
   'test-getcwd.c',
   'test-hash-speed.c',
   'test-hash.c',

@@ -0,0 +1,61 @@
+#define DISABLE_SIGN_COMPARE_WARNINGS
+
+#include "test-tool.h"
+#include "git-compat-util.h"
+#include "hex-ll.h"
+
+/*
+ * Write "count" copies of "byte" to stdout, or an endless stream of them if
+ * "count" is negative.
+ */
+static int generate_bytes(char byte, intmax_t count)
+{
+	char buf[256 * 1024];
+	ssize_t n;
+
+	memset(buf, byte, sizeof(buf));
+
+	/* Writing out individual bytes is slow... */
+	while (count < 0)
+		if (xwrite(1, buf, ARRAY_SIZE(buf)) < 0)
+			die_errno("write error");
+
+	while (count > 0) {
+		n = xwrite(1, buf,
+			   count < ARRAY_SIZE(buf)
+			   ? count : ARRAY_SIZE(buf));
+
+		if (n < 0)
+			die_errno("write error");
+
+		count -= n;
+	}
+
+	return 0;
+}
+
+static intmax_t parse_count(int argc, const char **argv, int pos)
+{
+	return pos < argc ? strtoimax(argv[pos], NULL, 0) : -1;
+}
+
+int cmd__genbytes(int argc, const char **argv)
+{
+	if (argc < 2 || argc > 3 || strlen(argv[1]) != 2 ||
+	    strspn(argv[1], "0123456789abcdef") != 2) {
+		fprintf(stderr, "usage: %s <hex-byte> [<count>]\n", argv[0]);
+		return 1;
+	}
+
+	return generate_bytes(hex2chr(argv[1]), parse_count(argc, argv, 2));
+}
+
+int cmd__genzeros(int argc, const char **argv)
+{
+	if (argc > 2) {
+		fprintf(stderr, "usage: %s [<count>]\n", argv[0]);
+		return 1;
+	}
+
+	return generate_bytes('\0', parse_count(argc, argv, 1));
+}

@@ -1,37 +0,0 @@
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
-#include "test-tool.h"
-#include "git-compat-util.h"
-
-int cmd__genzeros(int argc, const char **argv)
-{
-	/* static, so that it is NUL-initialized */
-	static const char zeros[256 * 1024];
-	intmax_t count;
-	ssize_t n;
-
-	if (argc > 2) {
-		fprintf(stderr, "usage: %s [<count>]\n", argv[0]);
-		return 1;
-	}
-
-	count = argc > 1 ? strtoimax(argv[1], NULL, 0) : -1;
-
-	/* Writing out individual NUL bytes is slow... */
-	while (count < 0)
-		if (xwrite(1, zeros, ARRAY_SIZE(zeros)) < 0)
-			die_errno("write error");
-
-	while (count > 0) {
-		n = xwrite(1, zeros,
-			   count < ARRAY_SIZE(zeros)
-			   ? count : ARRAY_SIZE(zeros));
-
-		if (n < 0)
-			die_errno("write error");
-
-		count -= n;
-	}
-
-	return 0;
-}

@@ -33,6 +33,7 @@ static struct test_cmd cmds[] = {
 	{ "example-tap", cmd__example_tap },
 	{ "find-pack", cmd__find_pack },
 	{ "fsmonitor-client", cmd__fsmonitor_client },
+	{ "genbytes", cmd__genbytes },
 	{ "genrandom", cmd__genrandom },
 	{ "genzeros", cmd__genzeros },
 	{ "getcwd", cmd__getcwd },

@@ -26,6 +26,7 @@ int cmd__env_helper(int argc, const char **argv);
 int cmd__example_tap(int argc, const char **argv);
 int cmd__find_pack(int argc, const char **argv);
 int cmd__fsmonitor_client(int argc, const char **argv);
+int cmd__genbytes(int argc, const char **argv);
 int cmd__genrandom(int argc, const char **argv);
 int cmd__genzeros(int argc, const char **argv);
 int cmd__getcwd(int argc, const char **argv);

@@ -146,7 +146,7 @@ test_expect_success 'small block size fails with large reflog message' '
 	(
 		cd repo &&
 		test_commit A &&
-		test-tool genzeros 500 | tr "\000" "a" >logmsg &&
+		test-tool genbytes 61 500 >logmsg &&
 		cat >expect <<-EOF &&
 		fatal: update_ref failed for ref ${SQ}refs/heads/logme${SQ}: reftable: transaction failure: entry too large
 		EOF

@@ -1182,7 +1182,7 @@ test_expect_success EXPENSIVE,SIZE_T_IS_64BIT 'log --pretty with huge commit mes
 '
 
 test_expect_success EXPENSIVE,SIZE_T_IS_64BIT 'set up huge commit' '
-	test-tool genzeros 2147483649 | tr "\000" "1" >expect &&
+	test-tool genbytes 31 2147483649 >expect &&
 	huge_commit=$(git commit-tree -F expect HEAD^{tree})
 '
 

@@ -9,9 +9,9 @@ test_description='git pack-object'
 
 test_expect_success 'setup' '
 	rm -f .git/index* &&
-	test-tool genzeros 4096 | tr "\000" "a" >a &&
-	test-tool genzeros 4096 | tr "\000" "b" >b &&
-	test-tool genzeros 4096 | tr "\000" "c" >c &&
+	test-tool genbytes 61 4096 >a &&
+	test-tool genbytes 62 4096 >b &&
+	test-tool genbytes 63 4096 >c &&
 	test-tool genrandom "seed a" 2097152 >a_big &&
 	test-tool genrandom "seed b" 2097152 >b_big &&
 	git update-index --add a a_big b b_big c &&

@@ -662,8 +662,7 @@ test_expect_success 'setup trace2' '
 '
 
 test_expect_success 'setup large log output' '
-	test-tool genzeros 50000 |
-	tr "\000" "a" |
+	test-tool genbytes 61 50000 |
 	sed "s/a/this is a long commit message/g" >commit-msg &&
 	git commit --allow-empty -F commit-msg
 '

@@ -30,7 +30,7 @@ test_expect_success 'shell allows interactive command' '
 '
 
 test_expect_success 'shell complains of overlong commands' '
-	test-tool genzeros | tr "\000" "a" |
+	test-tool genbytes 61 |
 	test_must_fail git shell 2>err &&
 	test_grep "too long" err
 '