reftable/basics: merge "publicbasics" into "basics"

The split between "basics" and "publicbasics" is somewhat arbitrary and
not in line with how we typically structure code in the reftable
library. While we do indeed split up headers into a public and internal
part, we don't do that for the compilation unit itself. Furthermore, the
declarations for "publicbasics.c" are in "reftable-malloc.h", which
isn't in line with our naming schema, either.

Fix these inconsistencies by:

  - Merging "publicbasics.c" into "basics.c".

  - Renaming "reftable-malloc.h" to "reftable-basics.h" as the public
    header.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

reftable/basics.c

@@ -7,6 +7,49 @@ https://developers.google.com/open-source/licenses/bsd
 */
 
 #include "basics.h"
+#include "reftable-basics.h"
+
+static void *(*reftable_malloc_ptr)(size_t sz);
+static void *(*reftable_realloc_ptr)(void *, size_t);
+static void (*reftable_free_ptr)(void *);
+
+void *reftable_malloc(size_t sz)
+{
+	if (reftable_malloc_ptr)
+		return (*reftable_malloc_ptr)(sz);
+	return malloc(sz);
+}
+
+void *reftable_realloc(void *p, size_t sz)
+{
+	if (reftable_realloc_ptr)
+		return (*reftable_realloc_ptr)(p, sz);
+	return realloc(p, sz);
+}
+
+void reftable_free(void *p)
+{
+	if (reftable_free_ptr)
+		reftable_free_ptr(p);
+	else
+		free(p);
+}
+
+void *reftable_calloc(size_t nelem, size_t elsize)
+{
+	size_t sz = st_mult(nelem, elsize);
+	void *p = reftable_malloc(sz);
+	memset(p, 0, sz);
+	return p;
+}
+
+void reftable_set_alloc(void *(*malloc)(size_t),
+			void *(*realloc)(void *, size_t), void (*free)(void *))
+{
+	reftable_malloc_ptr = malloc;
+	reftable_realloc_ptr = realloc;
+	reftable_free_ptr = free;
+}
 
 void put_be24(uint8_t *out, uint32_t i)
 {
@@ -121,3 +164,15 @@ int common_prefix_size(struct strbuf *a, struct strbuf *b)
 
 	return p;
 }
+
+int hash_size(uint32_t id)
+{
+	switch (id) {
+	case 0:
+	case GIT_SHA1_FORMAT_ID:
+		return GIT_SHA1_RAWSZ;
+	case GIT_SHA256_FORMAT_ID:
+		return GIT_SHA256_RAWSZ;
+	}
+	abort();
+}