reftable/record: constify some parts of the interface

We're about to convert reftable records to stop storing their object IDs
as allocated hashes. Prepare for this refactoring by constifying some
parts of the interface that will be impacted by this.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

reftable/record.c

@@ -76,7 +76,7 @@ int reftable_is_block_type(uint8_t typ)
 	return 0;
 }
 
-uint8_t *reftable_ref_record_val1(const struct reftable_ref_record *rec)
+const unsigned char *reftable_ref_record_val1(const struct reftable_ref_record *rec)
 {
 	switch (rec->value_type) {
 	case REFTABLE_REF_VAL1:
@@ -88,7 +88,7 @@ uint8_t *reftable_ref_record_val1(const struct reftable_ref_record *rec)
 	}
 }
 
-uint8_t *reftable_ref_record_val2(const struct reftable_ref_record *rec)
+const unsigned char *reftable_ref_record_val2(const struct reftable_ref_record *rec)
 {
 	switch (rec->value_type) {
 	case REFTABLE_REF_VAL2:
@@ -242,7 +242,7 @@ static char hexdigit(int c)
 	return 'a' + (c - 10);
 }
 
-static void hex_format(char *dest, uint8_t *src, int hash_size)
+static void hex_format(char *dest, const unsigned char *src, int hash_size)
 {
 	assert(hash_size > 0);
 	if (src) {
@@ -1164,7 +1164,7 @@ int reftable_record_equal(struct reftable_record *a, struct reftable_record *b,
 		reftable_record_data(a), reftable_record_data(b), hash_size);
 }
 
-static int hash_equal(uint8_t *a, uint8_t *b, int hash_size)
+static int hash_equal(const unsigned char *a, const unsigned char *b, int hash_size)
 {
 	if (a && b)
 		return !memcmp(a, b, hash_size);

reftable/reftable-record.h

@@ -49,11 +49,11 @@ struct reftable_ref_record {
 
 /* Returns the first hash, or NULL if `rec` is not of type
  * REFTABLE_REF_VAL1 or REFTABLE_REF_VAL2. */
-uint8_t *reftable_ref_record_val1(const struct reftable_ref_record *rec);
+const unsigned char *reftable_ref_record_val1(const struct reftable_ref_record *rec);
 
 /* Returns the second hash, or NULL if `rec` is not of type
  * REFTABLE_REF_VAL2. */
-uint8_t *reftable_ref_record_val2(const struct reftable_ref_record *rec);
+const unsigned char *reftable_ref_record_val2(const struct reftable_ref_record *rec);
 
 /* returns whether 'ref' represents a deletion */
 int reftable_ref_record_is_deletion(const struct reftable_ref_record *ref);