[RFC PATCH 03/12] hex: introduce functions to print arbitrary hashes

From

brian m. carlson <sandals@crustytoothpaste.net>

Date

Aug 29, 2018, 00:58 UTC

Message-ID

<20180829005857.980820-4-sandals@crustytoothpaste.net>

In-Reply-To

<20180829005857.980820-1-sandals@crustytoothpaste.net>

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
 cache.h | 14 ++++++++------
 hex.c   | 32 ++++++++++++++++++++++++--------
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/cache.h b/cache.h
index 4d014541ab..3cb953445c 100644
--- a/cache.h
+++ b/cache.h
@@ -1351,9 +1351,9 @@ extern int get_oid_hex(const char *hex, struct object_id *sha1);
 extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
 
 /*
- * Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
+ * Convert a binary hash to its hex equivalent. The `_r` variant is reentrant,
  * and writes the NUL-terminated output to the buffer `out`, which must be at
- * least `GIT_SHA1_HEXSZ + 1` bytes, and returns a pointer to out for
+ * least `GIT_MAX_HEXSZ + 1` bytes, and returns a pointer to out for
  * convenience.
  *
  * The non-`_r` variant returns a static buffer, but uses a ring of 4
@@ -1361,10 +1361,12 @@ extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
  *
  *   printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
  */
-extern char *sha1_to_hex_r(char *out, const unsigned char *sha1);
-extern char *oid_to_hex_r(char *out, const struct object_id *oid);
-extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
-extern char *oid_to_hex(const struct object_id *oid);	/* same static buffer as sha1_to_hex */
+char *hash_to_hex_algo_r(char *buffer, const unsigned char *hash, int algo);
+char *sha1_to_hex_r(char *out, const unsigned char *sha1);
+char *oid_to_hex_r(char *out, const struct object_id *oid);
+char *hash_to_hex_algo(const unsigned char *hash, int algo);	/* static buffer result! */
+char *sha1_to_hex(const unsigned char *sha1);			/* same static buffer */
+char *oid_to_hex(const struct object_id *oid);			/* same static buffer */
 
 /*
  * Parse a 40-character hexadecimal object ID starting from hex, updating the
diff --git a/hex.c b/hex.c
index 10af1a29e8..870032a868 100644
--- a/hex.c
+++ b/hex.c
@@ -73,14 +73,15 @@ int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
 	return ret;
 }
 
-char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
+static inline char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
+					const struct git_hash_algo *algop)
 {
 	static const char hex[] = "0123456789abcdef";
 	char *buf = buffer;
 	int i;
 
-	for (i = 0; i < the_hash_algo->rawsz; i++) {
-		unsigned int val = *sha1++;
+	for (i = 0; i < algop->rawsz; i++) {
+		unsigned int val = *hash++;
 		*buf++ = hex[val >> 4];
 		*buf++ = hex[val & 0xf];
 	}
@@ -89,20 +90,35 @@ char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
 	return buffer;
 }
 
-char *oid_to_hex_r(char *buffer, const struct object_id *oid)
+char *hash_to_hex_algo_r(char *buffer, const unsigned char *hash, int algo)
 {
-	return sha1_to_hex_r(buffer, oid->hash);
+	return hash_to_hex_algop_r(buffer, hash, &hash_algos[algo]);
 }
 
-char *sha1_to_hex(const unsigned char *sha1)
+char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
+{
+	return hash_to_hex_algo_r(buffer, sha1, GIT_HASH_SHA1);
+}
+
+char *oid_to_hex_r(char *buffer, const struct object_id *oid)
+{
+	return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
+}
+
+char *hash_to_hex_algo(const unsigned char *hash, int algo)
 {
 	static int bufno;
 	static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
 	bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
-	return sha1_to_hex_r(hexbuffer[bufno], sha1);
+	return hash_to_hex_algo_r(hexbuffer[bufno], hash, algo);
+}
+
+char *sha1_to_hex(const unsigned char *sha1)
+{
+	return hash_to_hex_algo(sha1, GIT_HASH_SHA1);
 }
 
 char *oid_to_hex(const struct object_id *oid)
 {
-	return sha1_to_hex(oid->hash);
+	return hash_to_hex_algo(oid->hash, hash_algo_by_ptr(the_hash_algo));
 }