split-index: strip pathname of on-disk replaced entries

We know the positions of replaced entries via the replace bitmap in
"link" extension, so the "name" path does not have to be stored (it's
still in the shared index). With this, we also have a way to
distinguish additions vs replacements at load time and can catch
broken "link" extensions.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Nguyễn Thái Ngọc Duy 2014-06-13 19:19:43 +07:00 committed by Junio C Hamano
parent ce7c614bce
commit b3c96fb158
3 changed files with 23 additions and 2 deletions

View File

@ -170,6 +170,7 @@ struct cache_entry {
#define CE_MATCHED (1 << 26)
#define CE_UPDATE_IN_BASE (1 << 27)
#define CE_STRIP_NAME (1 << 28)
/*
* Extended on-disk flags

View File

@ -1787,9 +1787,15 @@ static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
{
int size;
struct ondisk_cache_entry *ondisk;
int saved_namelen = saved_namelen; /* compiler workaround */
char *name;
int result;
if (ce->ce_flags & CE_STRIP_NAME) {
saved_namelen = ce_namelen(ce);
ce->ce_namelen = 0;
}
if (!previous_name) {
size = ondisk_ce_size(ce);
ondisk = xcalloc(1, size);
@ -1821,6 +1827,10 @@ static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
strbuf_splice(previous_name, common, to_remove,
ce->name + common, ce_namelen(ce) - common);
}
if (ce->ce_flags & CE_STRIP_NAME) {
ce->ce_namelen = saved_namelen;
ce->ce_flags &= ~CE_STRIP_NAME;
}
result = ce_write(c, fd, ondisk, size);
free(ondisk);

View File

@ -89,6 +89,7 @@ static void replace_entry(size_t pos, void *data)
struct index_state *istate = data;
struct split_index *si = istate->split_index;
struct cache_entry *dst, *src;
if (pos >= istate->cache_nr)
die("position for replacement %d exceeds base index size %d",
(int)pos, istate->cache_nr);
@ -100,10 +101,14 @@ static void replace_entry(size_t pos, void *data)
die("entry %d is marked as both replaced and deleted",
(int)pos);
src = si->saved_cache[si->nr_replacements];
if (ce_namelen(src))
die("corrupt link extension, entry %d should have "
"zero length name", (int)pos);
src->index = pos + 1;
src->ce_flags |= CE_UPDATE_IN_BASE;
free(dst);
dst = src;
src->ce_namelen = dst->ce_namelen;
copy_cache_entry(dst, src);
free(src);
si->nr_replacements++;
}
@ -131,6 +136,9 @@ void merge_base_index(struct index_state *istate)
remove_marked_cache_entries(istate);
for (i = si->nr_replacements; i < si->saved_cache_nr; i++) {
if (!ce_namelen(si->saved_cache[i]))
die("corrupt link extension, entry %d should "
"have non-zero length name", i);
add_index_entry(istate, si->saved_cache[i],
ADD_CACHE_OK_TO_ADD |
ADD_CACHE_KEEP_CACHE_TREE |
@ -213,6 +221,7 @@ void prepare_to_write_split_index(struct index_state *istate)
ewah_set(si->delete_bitmap, i);
else if (ce->ce_flags & CE_UPDATE_IN_BASE) {
ewah_set(si->replace_bitmap, i);
ce->ce_flags |= CE_STRIP_NAME;
ALLOC_GROW(entries, nr_entries+1, nr_alloc);
entries[nr_entries++] = ce;
}
@ -222,6 +231,7 @@ void prepare_to_write_split_index(struct index_state *istate)
for (i = 0; i < istate->cache_nr; i++) {
ce = istate->cache[i];
if ((!si->base || !ce->index) && !(ce->ce_flags & CE_REMOVE)) {
assert(!(ce->ce_flags & CE_STRIP_NAME));
ALLOC_GROW(entries, nr_entries+1, nr_alloc);
entries[nr_entries++] = ce;
}