git/test-dump-cache-tree.c
Nguyễn Thái Ngọc Duy 9c5e6c802c Convert "struct cache_entry *" to "const ..." wherever possible
I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is

 - diff-lib.c: setting CE_UPTODATE

 - name-hash.c: setting CE_HASHED

 - preload-index.c, read-cache.c, unpack-trees.c and
   builtin/update-index: obvious

 - entry.c: write_entry() may refresh the checked out entry via
   fill_stat_cache_info(). This causes "non-const struct cache_entry
   *" in builtin/apply.c, builtin/checkout-index.c and
   builtin/checkout.c

 - builtin/ls-files.c: --with-tree changes stagemask and may set
   CE_UPDATE

Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.

So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.

The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:

    diff --git a/cache.h b/cache.h
    index 430d021..1692891 100644
    --- a/cache.h
    +++ b/cache.h
    @@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
     #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)

     struct index_state {
    -	struct cache_entry **cache;
    +	const struct cache_entry **cache;
     	unsigned int version;
     	unsigned int cache_nr, cache_alloc, cache_changed;
     	struct string_list *resolve_undo;

will help quickly identify them without bogus warnings.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-09 09:12:48 -07:00

67 lines
1.5 KiB
C

#include "cache.h"
#include "tree.h"
#include "cache-tree.h"
static void dump_one(struct cache_tree *it, const char *pfx, const char *x)
{
if (it->entry_count < 0)
printf("%-40s %s%s (%d subtrees)\n",
"invalid", x, pfx, it->subtree_nr);
else
printf("%s %s%s (%d entries, %d subtrees)\n",
sha1_to_hex(it->sha1), x, pfx,
it->entry_count, it->subtree_nr);
}
static int dump_cache_tree(struct cache_tree *it,
struct cache_tree *ref,
const char *pfx)
{
int i;
int errs = 0;
if (!it || !ref)
/* missing in either */
return 0;
if (it->entry_count < 0) {
dump_one(it, pfx, "");
dump_one(ref, pfx, "#(ref) ");
if (it->subtree_nr != ref->subtree_nr)
errs = 1;
}
else {
dump_one(it, pfx, "");
if (hashcmp(it->sha1, ref->sha1) ||
ref->entry_count != it->entry_count ||
ref->subtree_nr != it->subtree_nr) {
dump_one(ref, pfx, "#(ref) ");
errs = 1;
}
}
for (i = 0; i < it->subtree_nr; i++) {
char path[PATH_MAX];
struct cache_tree_sub *down = it->down[i];
struct cache_tree_sub *rdwn;
rdwn = cache_tree_sub(ref, down->name);
sprintf(path, "%s%.*s/", pfx, down->namelen, down->name);
if (dump_cache_tree(down->cache_tree, rdwn->cache_tree, path))
errs = 1;
}
return errs;
}
int main(int ac, char **av)
{
struct cache_tree *another = cache_tree();
if (read_cache() < 0)
die("unable to read index file");
cache_tree_update(another,
(const struct cache_entry * const *)active_cache,
active_nr, WRITE_TREE_DRY_RUN);
return dump_cache_tree(active_cache_tree, another, "");
}