Commit af795e49 by Shawn O. Pearce

Add routines to convert git_oid to hex strings

[sp: Credit for some of this implementation goes to Pieter, I
     started off a patch he proposed for libgit2 but reworked
     enough of it that I don't want to blame him for any bugs.]

Suggested-by: Pieter de Bie <pdebie@ai.rug.nl>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
parent b72ca267
......@@ -13,11 +13,17 @@
*/
GIT_BEGIN_DECL
/** Size (in bytes) of a raw/binary oid */
#define GIT_OID_RAWSZ 20
/** Size (in bytes) of a hex formatted oid */
#define GIT_OID_HEXSZ (GIT_OID_RAWSZ * 2)
/** Unique identity of any object (commit, tree, blob, tag). */
typedef struct
{
/** raw binary formatted id */
unsigned char id[20];
unsigned char id[GIT_OID_RAWSZ];
} git_oid;
/**
......@@ -41,6 +47,40 @@ GIT_INLINE(void) git_oid_mkraw(git_oid *out, const unsigned char *raw)
}
/**
* Format a git_oid into a hex string.
* @param str output hex string; must be pointing at the start of
* the hex sequence and have at least the number of bytes
* needed for an oid encoded in hex (40 bytes). Only the
* oid digits are written; a '\0' terminator must be added
* by the caller if it is required.
* @param oid oid structure to format.
*/
GIT_EXTERN(void) git_oid_fmt(char *str, const git_oid *oid);
/**
* Format a git_oid into a loose-object path string.
* <p>
* The resulting string is "aa/...", where "aa" is the first two
* hex digitis of the oid and "..." is the remaining 38 digits.
*
* @param str output hex string; must be pointing at the start of
* the hex sequence and have at least the number of bytes
* needed for an oid encoded in hex (41 bytes). Only the
* oid digits are written; a '\0' terminator must be added
* by the caller if it is required.
* @param oid oid structure to format.
*/
GIT_EXTERN(void) git_oid_pathfmt(char *str, const git_oid *oid);
/**
* Format a gid_oid into a newly allocated c-string.
* @param oid theoid structure to format
* @return the c-string; NULL if memory is exhausted. Caller must
* deallocate the string with free().
*/
GIT_EXTERN(char *) git_oid_allocfmt(const git_oid *oid);
/**
* Copy an oid from one structure to another.
* @param out oid structure the result is written into.
* @param src oid structure to copy from.
......
......@@ -44,6 +44,7 @@ static signed char from_hex[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
};
static char to_hex[] = "0123456789abcdef";
int git_oid_mkstr(git_oid *out, const char *str)
{
......@@ -57,3 +58,38 @@ int git_oid_mkstr(git_oid *out, const char *str)
}
return GIT_SUCCESS;
}
static inline char *fmt_one(char *str, unsigned int val)
{
*str++ = to_hex[val >> 4];
*str++ = to_hex[val & 0xf];
return str;
}
void git_oid_fmt(char *str, const git_oid *oid)
{
int i;
for (i = 0; i < sizeof(oid->id); i++)
str = fmt_one(str, oid->id[i]);
}
void git_oid_pathfmt(char *str, const git_oid *oid)
{
int i;
str = fmt_one(str, oid->id[0]);
*str++ = '/';
for (i = 1; i < sizeof(oid->id); i++)
str = fmt_one(str, oid->id[i]);
}
char *git_oid_allocfmt(const git_oid *oid)
{
char *str = malloc(GIT_OID_HEXSZ + 1);
if (!str)
return NULL;
git_oid_fmt(str, oid);
str[GIT_OID_HEXSZ] = '\0';
return str;
}
#include "test_lib.h"
#include <git/oid.h>
BEGIN_TEST(oid_szs)
git_oid out;
must_be_true(20 == GIT_OID_RAWSZ);
must_be_true(40 == GIT_OID_HEXSZ);
must_be_true(sizeof(out) == GIT_OID_RAWSZ);
must_be_true(sizeof(out.id) == GIT_OID_RAWSZ);
END_TEST
BEGIN_TEST(empty_string)
git_oid out;
must_fail(git_oid_mkstr(&out, ""));
......@@ -150,3 +158,51 @@ BEGIN_TEST(cmp_oid_gt)
git_oid_mkraw(&b, b_in);
must_be_true(git_oid_cmp(&a, &b) > 0);
END_TEST
BEGIN_TEST(cmp_oid_fmt)
const char *exp = "16a0123456789abcdef4b775213c23a8bd74f5e0";
git_oid in;
char out[GIT_OID_HEXSZ + 1];
must_pass(git_oid_mkstr(&in, exp));
/* Format doesn't touch the last byte */
out[GIT_OID_HEXSZ] = 'Z';
git_oid_fmt(out, &in);
must_be_true(out[GIT_OID_HEXSZ] == 'Z');
/* Format produced the right result */
out[GIT_OID_HEXSZ] = '\0';
must_pass(strcmp(exp, out));
END_TEST
BEGIN_TEST(cmp_oid_allocfmt)
const char *exp = "16a0123456789abcdef4b775213c23a8bd74f5e0";
git_oid in;
char *out;
must_pass(git_oid_mkstr(&in, exp));
out = git_oid_allocfmt(&in);
must_be_true(out);
must_pass(strcmp(exp, out));
END_TEST
BEGIN_TEST(cmp_oid_pathfmt)
const char *exp1 = "16a0123456789abcdef4b775213c23a8bd74f5e0";
const char *exp2 = "16/a0123456789abcdef4b775213c23a8bd74f5e0";
git_oid in;
char out[GIT_OID_HEXSZ + 2];
must_pass(git_oid_mkstr(&in, exp1));
/* Format doesn't touch the last byte */
out[GIT_OID_HEXSZ + 1] = 'Z';
git_oid_pathfmt(out, &in);
must_be_true(out[GIT_OID_HEXSZ + 1] == 'Z');
/* Format produced the right result */
out[GIT_OID_HEXSZ + 1] = '\0';
must_pass(strcmp(exp2, out));
END_TEST
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