define utility functions for object IDs

There are several utility functions (hashcmp and friends) that are used
for comparing object IDs (SHA-1 values).  Using these functions, which
take pointers to unsigned char, with struct object_id requires tiresome
access to the sha1 member, which bloats code and violates the desired
encapsulation.  Provide wrappers around these functions for struct
object_id for neater, more maintainable code.  Use the new constants to
avoid the hard-coded 20s and 40s throughout the original functions.

These functions simply call the underlying pointer-to-unsigned-char
versions to ensure that any performance improvements will be passed
through to the new functions.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
brian m. carlson
2015-03-13 23:39:28 +00:00
committed by Junio C Hamano
parent 5f7817c85d
commit aa1c6fdf47
2 changed files with 41 additions and 7 deletions

16
hex.c
View File

@@ -38,7 +38,7 @@ const signed char hexval_table[256] = {
int get_sha1_hex(const char *hex, unsigned char *sha1)
{
int i;
for (i = 0; i < 20; i++) {
for (i = 0; i < GIT_SHA1_RAWSZ; i++) {
unsigned int val;
/*
* hex[1]=='\0' is caught when val is checked below,
@@ -56,15 +56,20 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
return 0;
}
int get_oid_hex(const char *hex, struct object_id *oid)
{
return get_sha1_hex(hex, oid->hash);
}
char *sha1_to_hex(const unsigned char *sha1)
{
static int bufno;
static char hexbuffer[4][41];
static char hexbuffer[4][GIT_SHA1_HEXSZ + 1];
static const char hex[] = "0123456789abcdef";
char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
int i;
for (i = 0; i < 20; i++) {
for (i = 0; i < GIT_SHA1_RAWSZ; i++) {
unsigned int val = *sha1++;
*buf++ = hex[val >> 4];
*buf++ = hex[val & 0xf];
@@ -73,3 +78,8 @@ char *sha1_to_hex(const unsigned char *sha1)
return buffer;
}
char *oid_to_hex(const struct object_id *oid)
{
return sha1_to_hex(oid->hash);
}