git/reachable.c
Max Kirillov c40fdd01dd reachable.c: add HEAD to reachability starting commits
HEAD is not explicitly used as a starting commit for
calculating reachability, so if it's detached and reflogs
are disabled it may be pruned.

Add tests which demonstrate it. Test 'prune: prune former HEAD after checking
out branch' also reverts changes to repository.

Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-03 10:47:44 -07:00

251 lines
6.2 KiB
C

#include "cache.h"
#include "refs.h"
#include "tag.h"
#include "commit.h"
#include "blob.h"
#include "diff.h"
#include "revision.h"
#include "reachable.h"
#include "cache-tree.h"
#include "progress.h"
struct connectivity_progress {
struct progress *progress;
unsigned long count;
};
static void update_progress(struct connectivity_progress *cp)
{
cp->count++;
if ((cp->count & 1023) == 0)
display_progress(cp->progress, cp->count);
}
static void process_blob(struct blob *blob,
struct object_array *p,
struct name_path *path,
const char *name,
struct connectivity_progress *cp)
{
struct object *obj = &blob->object;
if (!blob)
die("bad blob object");
if (obj->flags & SEEN)
return;
obj->flags |= SEEN;
update_progress(cp);
/* Nothing to do, really .. The blob lookup was the important part */
}
static void process_gitlink(const unsigned char *sha1,
struct object_array *p,
struct name_path *path,
const char *name)
{
/* I don't think we want to recurse into this, really. */
}
static void process_tree(struct tree *tree,
struct object_array *p,
struct name_path *path,
const char *name,
struct connectivity_progress *cp)
{
struct object *obj = &tree->object;
struct tree_desc desc;
struct name_entry entry;
struct name_path me;
if (!tree)
die("bad tree object");
if (obj->flags & SEEN)
return;
obj->flags |= SEEN;
update_progress(cp);
if (parse_tree(tree) < 0)
die("bad tree object %s", sha1_to_hex(obj->sha1));
add_object(obj, p, path, name);
me.up = path;
me.elem = name;
me.elem_len = strlen(name);
init_tree_desc(&desc, tree->buffer, tree->size);
while (tree_entry(&desc, &entry)) {
if (S_ISDIR(entry.mode))
process_tree(lookup_tree(entry.sha1), p, &me, entry.path, cp);
else if (S_ISGITLINK(entry.mode))
process_gitlink(entry.sha1, p, &me, entry.path);
else
process_blob(lookup_blob(entry.sha1), p, &me, entry.path, cp);
}
free_tree_buffer(tree);
}
static void process_tag(struct tag *tag, struct object_array *p,
const char *name, struct connectivity_progress *cp)
{
struct object *obj = &tag->object;
if (obj->flags & SEEN)
return;
obj->flags |= SEEN;
update_progress(cp);
if (parse_tag(tag) < 0)
die("bad tag object %s", sha1_to_hex(obj->sha1));
if (tag->tagged)
add_object(tag->tagged, p, NULL, name);
}
static void walk_commit_list(struct rev_info *revs,
struct connectivity_progress *cp)
{
int i;
struct commit *commit;
struct object_array objects = OBJECT_ARRAY_INIT;
/* Walk all commits, process their trees */
while ((commit = get_revision(revs)) != NULL) {
process_tree(commit->tree, &objects, NULL, "", cp);
update_progress(cp);
}
/* Then walk all the pending objects, recursively processing them too */
for (i = 0; i < revs->pending.nr; i++) {
struct object_array_entry *pending = revs->pending.objects + i;
struct object *obj = pending->item;
const char *name = pending->name;
if (obj->type == OBJ_TAG) {
process_tag((struct tag *) obj, &objects, name, cp);
continue;
}
if (obj->type == OBJ_TREE) {
process_tree((struct tree *)obj, &objects, NULL, name, cp);
continue;
}
if (obj->type == OBJ_BLOB) {
process_blob((struct blob *)obj, &objects, NULL, name, cp);
continue;
}
die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
}
}
static int add_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct object *object;
struct rev_info *revs = (struct rev_info *)cb_data;
object = parse_object(osha1);
if (object)
add_pending_object(revs, object, "");
object = parse_object(nsha1);
if (object)
add_pending_object(revs, object, "");
return 0;
}
static int add_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
{
struct object *object = parse_object_or_die(sha1, path);
struct rev_info *revs = (struct rev_info *)cb_data;
add_pending_object(revs, object, "");
return 0;
}
static int add_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
{
for_each_reflog_ent(path, add_one_reflog_ent, cb_data);
return 0;
}
static void add_one_tree(const unsigned char *sha1, struct rev_info *revs)
{
struct tree *tree = lookup_tree(sha1);
if (tree)
add_pending_object(revs, &tree->object, "");
}
static void add_cache_tree(struct cache_tree *it, struct rev_info *revs)
{
int i;
if (it->entry_count >= 0)
add_one_tree(it->sha1, revs);
for (i = 0; i < it->subtree_nr; i++)
add_cache_tree(it->down[i]->cache_tree, revs);
}
static void add_cache_refs(struct rev_info *revs)
{
int i;
read_cache();
for (i = 0; i < active_nr; i++) {
/*
* The index can contain blobs and GITLINKs, GITLINKs are hashes
* that don't actually point to objects in the repository, it's
* almost guaranteed that they are NOT blobs, so we don't call
* lookup_blob() on them, to avoid populating the hash table
* with invalid information
*/
if (S_ISGITLINK(active_cache[i]->ce_mode))
continue;
lookup_blob(active_cache[i]->sha1);
/*
* We could add the blobs to the pending list, but quite
* frankly, we don't care. Once we've looked them up, and
* added them as objects, we've really done everything
* there is to do for a blob
*/
}
if (active_cache_tree)
add_cache_tree(active_cache_tree, revs);
}
void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
struct progress *progress)
{
struct connectivity_progress cp;
/*
* Set up revision parsing, and mark us as being interested
* in all object types, not just commits.
*/
revs->tag_objects = 1;
revs->blob_objects = 1;
revs->tree_objects = 1;
/* Add all refs from the index file */
add_cache_refs(revs);
/* Add all external refs */
for_each_ref(add_one_ref, revs);
/* detached HEAD is not included in the list above */
head_ref(add_one_ref, revs);
/* Add all reflog info */
if (mark_reflog)
for_each_reflog(add_one_reflog, revs);
cp.progress = progress;
cp.count = 0;
/*
* Set up the revision walk - this will move all commits
* from the pending list to the commit walking list.
*/
if (prepare_revision_walk(revs))
die("revision walk setup failed");
walk_commit_list(revs, &cp);
display_progress(cp.progress, cp.count);
}