git-commit-vandalism/replace_object.c
Michael Haggerty 2b2a5be394 each_ref_fn: change to take an object_id parameter
Change typedef each_ref_fn to take a "const struct object_id *oid"
parameter instead of "const unsigned char *sha1".

To aid this transition, implement an adapter that can be used to wrap
old-style functions matching the old typedef, which is now called
"each_ref_sha1_fn"), and make such functions callable via the new
interface. This requires the old function and its cb_data to be
wrapped in a "struct each_ref_fn_sha1_adapter", and that object to be
used as the cb_data for an adapter function, each_ref_fn_adapter().

This is an enormous diff, but most of it consists of simple,
mechanical changes to the sites that call any of the "for_each_ref"
family of functions. Subsequent to this change, the call sites can be
rewritten one by one to use the new interface.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-25 12:19:27 -07:00

125 lines
3.1 KiB
C

#include "cache.h"
#include "sha1-lookup.h"
#include "refs.h"
#include "commit.h"
/*
* An array of replacements. The array is kept sorted by the original
* sha1.
*/
static struct replace_object {
unsigned char original[20];
unsigned char replacement[20];
} **replace_object;
static int replace_object_alloc, replace_object_nr;
static const unsigned char *replace_sha1_access(size_t index, void *table)
{
struct replace_object **replace = table;
return replace[index]->original;
}
static int replace_object_pos(const unsigned char *sha1)
{
return sha1_pos(sha1, replace_object, replace_object_nr,
replace_sha1_access);
}
static int register_replace_object(struct replace_object *replace,
int ignore_dups)
{
int pos = replace_object_pos(replace->original);
if (0 <= pos) {
if (ignore_dups)
free(replace);
else {
free(replace_object[pos]);
replace_object[pos] = replace;
}
return 1;
}
pos = -pos - 1;
ALLOC_GROW(replace_object, replace_object_nr + 1, replace_object_alloc);
replace_object_nr++;
if (pos < replace_object_nr)
memmove(replace_object + pos + 1,
replace_object + pos,
(replace_object_nr - pos - 1) *
sizeof(*replace_object));
replace_object[pos] = replace;
return 0;
}
static int register_replace_ref(const char *refname,
const unsigned char *sha1,
int flag, void *cb_data)
{
/* Get sha1 from refname */
const char *slash = strrchr(refname, '/');
const char *hash = slash ? slash + 1 : refname;
struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
if (strlen(hash) != 40 || get_sha1_hex(hash, repl_obj->original)) {
free(repl_obj);
warning("bad replace ref name: %s", refname);
return 0;
}
/* Copy sha1 from the read ref */
hashcpy(repl_obj->replacement, sha1);
/* Register new object */
if (register_replace_object(repl_obj, 1))
die("duplicate replace ref: %s", refname);
return 0;
}
static void prepare_replace_object(void)
{
static int replace_object_prepared;
struct each_ref_fn_sha1_adapter wrapped_register_replace_ref =
{register_replace_ref, NULL};
if (replace_object_prepared)
return;
for_each_replace_ref(each_ref_fn_adapter, &wrapped_register_replace_ref);
replace_object_prepared = 1;
if (!replace_object_nr)
check_replace_refs = 0;
}
/* We allow "recursive" replacement. Only within reason, though */
#define MAXREPLACEDEPTH 5
/*
* If a replacement for object sha1 has been set up, return the
* replacement object's name (replaced recursively, if necessary).
* The return value is either sha1 or a pointer to a
* permanently-allocated value. This function always respects replace
* references, regardless of the value of check_replace_refs.
*/
const unsigned char *do_lookup_replace_object(const unsigned char *sha1)
{
int pos, depth = MAXREPLACEDEPTH;
const unsigned char *cur = sha1;
prepare_replace_object();
/* Try to recursively replace the object */
do {
if (--depth < 0)
die("replace depth too high for object %s",
sha1_to_hex(sha1));
pos = replace_object_pos(cur);
if (0 <= pos)
cur = replace_object[pos]->replacement;
} while (0 <= pos);
return cur;
}