slim down "git show-index"

As the documentation says, this is primarily for debugging, and
in the longer term we should rename it to test-show-index or something.

In the meantime, just avoid xmalloc (which slurps in the rest of git), and
separating out the trivial hex functions into "hex.o".

This results in

  [torvalds@nehalem git]$ size git-show-index
       text    data     bss     dec     hex filename
     222818    2276  112688  337782   52776 git-show-index (before)
       5696     624    1264    7584    1da0 git-show-index (after)

which is a whole lot better.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/hex.c b/hex.c
new file mode 100644
index 0000000000..bb402fbaa2
--- /dev/null
+++ b/hex.c
@@ -0,0 +1,67 @@
+#include "cache.h"
+
+const signed char hexval_table[256] = {
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 00-07 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 08-0f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 10-17 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 18-1f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 20-27 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 28-2f */
+	  0,  1,  2,  3,  4,  5,  6,  7,		/* 30-37 */
+	  8,  9, -1, -1, -1, -1, -1, -1,		/* 38-3f */
+	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 40-47 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 48-4f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 50-57 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 58-5f */
+	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 60-67 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 68-67 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 70-77 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 78-7f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 80-87 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 88-8f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 90-97 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 98-9f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* a0-a7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* a8-af */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* b0-b7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* b8-bf */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* c0-c7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* c8-cf */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* d0-d7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* d8-df */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* e0-e7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* e8-ef */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f0-f7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f8-ff */
+};
+
+int get_sha1_hex(const char *hex, unsigned char *sha1)
+{
+	int i;
+	for (i = 0; i < 20; i++) {
+		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+		if (val & ~0xff)
+			return -1;
+		*sha1++ = val;
+		hex += 2;
+	}
+	return 0;
+}
+
+char *sha1_to_hex(const unsigned char *sha1)
+{
+	static int bufno;
+	static char hexbuffer[4][50];
+	static const char hex[] = "0123456789abcdef";
+	char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
+	int i;
+
+	for (i = 0; i < 20; i++) {
+		unsigned int val = *sha1++;
+		*buf++ = hex[val >> 4];
+		*buf++ = hex[val & 0xf];
+	}
+	*buf = '\0';
+
+	return buffer;
+}