mirror of
https://github.com/git/git
synced 2024-08-27 11:39:22 +00:00
![Christian Couder](/assets/img/avatar_default.png)
Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
320 lines
9 KiB
C
320 lines
9 KiB
C
#include "cache.h"
|
|
#include "split-index.h"
|
|
#include "ewah/ewok.h"
|
|
|
|
struct split_index *init_split_index(struct index_state *istate)
|
|
{
|
|
if (!istate->split_index) {
|
|
istate->split_index = xcalloc(1, sizeof(*istate->split_index));
|
|
istate->split_index->refcount = 1;
|
|
}
|
|
return istate->split_index;
|
|
}
|
|
|
|
int read_link_extension(struct index_state *istate,
|
|
const void *data_, unsigned long sz)
|
|
{
|
|
const unsigned char *data = data_;
|
|
struct split_index *si;
|
|
int ret;
|
|
|
|
if (sz < 20)
|
|
return error("corrupt link extension (too short)");
|
|
si = init_split_index(istate);
|
|
hashcpy(si->base_sha1, data);
|
|
data += 20;
|
|
sz -= 20;
|
|
if (!sz)
|
|
return 0;
|
|
si->delete_bitmap = ewah_new();
|
|
ret = ewah_read_mmap(si->delete_bitmap, data, sz);
|
|
if (ret < 0)
|
|
return error("corrupt delete bitmap in link extension");
|
|
data += ret;
|
|
sz -= ret;
|
|
si->replace_bitmap = ewah_new();
|
|
ret = ewah_read_mmap(si->replace_bitmap, data, sz);
|
|
if (ret < 0)
|
|
return error("corrupt replace bitmap in link extension");
|
|
if (ret != sz)
|
|
return error("garbage at the end of link extension");
|
|
return 0;
|
|
}
|
|
|
|
int write_link_extension(struct strbuf *sb,
|
|
struct index_state *istate)
|
|
{
|
|
struct split_index *si = istate->split_index;
|
|
strbuf_add(sb, si->base_sha1, 20);
|
|
if (!si->delete_bitmap && !si->replace_bitmap)
|
|
return 0;
|
|
ewah_serialize_strbuf(si->delete_bitmap, sb);
|
|
ewah_serialize_strbuf(si->replace_bitmap, sb);
|
|
return 0;
|
|
}
|
|
|
|
static void mark_base_index_entries(struct index_state *base)
|
|
{
|
|
int i;
|
|
/*
|
|
* To keep track of the shared entries between
|
|
* istate->base->cache[] and istate->cache[], base entry
|
|
* position is stored in each base entry. All positions start
|
|
* from 1 instead of 0, which is reserved to say "this is a new
|
|
* entry".
|
|
*/
|
|
for (i = 0; i < base->cache_nr; i++)
|
|
base->cache[i]->index = i + 1;
|
|
}
|
|
|
|
void move_cache_to_base_index(struct index_state *istate)
|
|
{
|
|
struct split_index *si = istate->split_index;
|
|
int i;
|
|
|
|
/*
|
|
* do not delete old si->base, its index entries may be shared
|
|
* with istate->cache[]. Accept a bit of leaking here because
|
|
* this code is only used by short-lived update-index.
|
|
*/
|
|
si->base = xcalloc(1, sizeof(*si->base));
|
|
si->base->version = istate->version;
|
|
/* zero timestamp disables racy test in ce_write_index() */
|
|
si->base->timestamp = istate->timestamp;
|
|
ALLOC_GROW(si->base->cache, istate->cache_nr, si->base->cache_alloc);
|
|
si->base->cache_nr = istate->cache_nr;
|
|
COPY_ARRAY(si->base->cache, istate->cache, istate->cache_nr);
|
|
mark_base_index_entries(si->base);
|
|
for (i = 0; i < si->base->cache_nr; i++)
|
|
si->base->cache[i]->ce_flags &= ~CE_UPDATE_IN_BASE;
|
|
}
|
|
|
|
static void mark_entry_for_delete(size_t pos, void *data)
|
|
{
|
|
struct index_state *istate = data;
|
|
if (pos >= istate->cache_nr)
|
|
die("position for delete %d exceeds base index size %d",
|
|
(int)pos, istate->cache_nr);
|
|
istate->cache[pos]->ce_flags |= CE_REMOVE;
|
|
istate->split_index->nr_deletions = 1;
|
|
}
|
|
|
|
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);
|
|
if (si->nr_replacements >= si->saved_cache_nr)
|
|
die("too many replacements (%d vs %d)",
|
|
si->nr_replacements, si->saved_cache_nr);
|
|
dst = istate->cache[pos];
|
|
if (dst->ce_flags & CE_REMOVE)
|
|
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;
|
|
src->ce_namelen = dst->ce_namelen;
|
|
copy_cache_entry(dst, src);
|
|
free(src);
|
|
si->nr_replacements++;
|
|
}
|
|
|
|
void merge_base_index(struct index_state *istate)
|
|
{
|
|
struct split_index *si = istate->split_index;
|
|
unsigned int i;
|
|
|
|
mark_base_index_entries(si->base);
|
|
|
|
si->saved_cache = istate->cache;
|
|
si->saved_cache_nr = istate->cache_nr;
|
|
istate->cache_nr = si->base->cache_nr;
|
|
istate->cache = NULL;
|
|
istate->cache_alloc = 0;
|
|
ALLOC_GROW(istate->cache, istate->cache_nr, istate->cache_alloc);
|
|
COPY_ARRAY(istate->cache, si->base->cache, istate->cache_nr);
|
|
|
|
si->nr_deletions = 0;
|
|
si->nr_replacements = 0;
|
|
ewah_each_bit(si->replace_bitmap, replace_entry, istate);
|
|
ewah_each_bit(si->delete_bitmap, mark_entry_for_delete, istate);
|
|
if (si->nr_deletions)
|
|
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 |
|
|
/*
|
|
* we may have to replay what
|
|
* merge-recursive.c:update_stages()
|
|
* does, which has this flag on
|
|
*/
|
|
ADD_CACHE_SKIP_DFCHECK);
|
|
si->saved_cache[i] = NULL;
|
|
}
|
|
|
|
ewah_free(si->delete_bitmap);
|
|
ewah_free(si->replace_bitmap);
|
|
free(si->saved_cache);
|
|
si->delete_bitmap = NULL;
|
|
si->replace_bitmap = NULL;
|
|
si->saved_cache = NULL;
|
|
si->saved_cache_nr = 0;
|
|
}
|
|
|
|
void prepare_to_write_split_index(struct index_state *istate)
|
|
{
|
|
struct split_index *si = init_split_index(istate);
|
|
struct cache_entry **entries = NULL, *ce;
|
|
int i, nr_entries = 0, nr_alloc = 0;
|
|
|
|
si->delete_bitmap = ewah_new();
|
|
si->replace_bitmap = ewah_new();
|
|
|
|
if (si->base) {
|
|
/* Go through istate->cache[] and mark CE_MATCHED to
|
|
* entry with positive index. We'll go through
|
|
* base->cache[] later to delete all entries in base
|
|
* that are not marked with either CE_MATCHED or
|
|
* CE_UPDATE_IN_BASE. If istate->cache[i] is a
|
|
* duplicate, deduplicate it.
|
|
*/
|
|
for (i = 0; i < istate->cache_nr; i++) {
|
|
struct cache_entry *base;
|
|
/* namelen is checked separately */
|
|
const unsigned int ondisk_flags =
|
|
CE_STAGEMASK | CE_VALID | CE_EXTENDED_FLAGS;
|
|
unsigned int ce_flags, base_flags, ret;
|
|
ce = istate->cache[i];
|
|
if (!ce->index)
|
|
continue;
|
|
if (ce->index > si->base->cache_nr) {
|
|
ce->index = 0;
|
|
continue;
|
|
}
|
|
ce->ce_flags |= CE_MATCHED; /* or "shared" */
|
|
base = si->base->cache[ce->index - 1];
|
|
if (ce == base)
|
|
continue;
|
|
if (ce->ce_namelen != base->ce_namelen ||
|
|
strcmp(ce->name, base->name)) {
|
|
ce->index = 0;
|
|
continue;
|
|
}
|
|
ce_flags = ce->ce_flags;
|
|
base_flags = base->ce_flags;
|
|
/* only on-disk flags matter */
|
|
ce->ce_flags &= ondisk_flags;
|
|
base->ce_flags &= ondisk_flags;
|
|
ret = memcmp(&ce->ce_stat_data, &base->ce_stat_data,
|
|
offsetof(struct cache_entry, name) -
|
|
offsetof(struct cache_entry, ce_stat_data));
|
|
ce->ce_flags = ce_flags;
|
|
base->ce_flags = base_flags;
|
|
if (ret)
|
|
ce->ce_flags |= CE_UPDATE_IN_BASE;
|
|
free(base);
|
|
si->base->cache[ce->index - 1] = ce;
|
|
}
|
|
for (i = 0; i < si->base->cache_nr; i++) {
|
|
ce = si->base->cache[i];
|
|
if ((ce->ce_flags & CE_REMOVE) ||
|
|
!(ce->ce_flags & CE_MATCHED))
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
ce->ce_flags &= ~CE_MATCHED;
|
|
}
|
|
|
|
/*
|
|
* take cache[] out temporarily, put entries[] in its place
|
|
* for writing
|
|
*/
|
|
si->saved_cache = istate->cache;
|
|
si->saved_cache_nr = istate->cache_nr;
|
|
istate->cache = entries;
|
|
istate->cache_nr = nr_entries;
|
|
}
|
|
|
|
void finish_writing_split_index(struct index_state *istate)
|
|
{
|
|
struct split_index *si = init_split_index(istate);
|
|
|
|
ewah_free(si->delete_bitmap);
|
|
ewah_free(si->replace_bitmap);
|
|
si->delete_bitmap = NULL;
|
|
si->replace_bitmap = NULL;
|
|
free(istate->cache);
|
|
istate->cache = si->saved_cache;
|
|
istate->cache_nr = si->saved_cache_nr;
|
|
}
|
|
|
|
void discard_split_index(struct index_state *istate)
|
|
{
|
|
struct split_index *si = istate->split_index;
|
|
if (!si)
|
|
return;
|
|
istate->split_index = NULL;
|
|
si->refcount--;
|
|
if (si->refcount)
|
|
return;
|
|
if (si->base) {
|
|
discard_index(si->base);
|
|
free(si->base);
|
|
}
|
|
free(si);
|
|
}
|
|
|
|
void save_or_free_index_entry(struct index_state *istate, struct cache_entry *ce)
|
|
{
|
|
if (ce->index &&
|
|
istate->split_index &&
|
|
istate->split_index->base &&
|
|
ce->index <= istate->split_index->base->cache_nr &&
|
|
ce == istate->split_index->base->cache[ce->index - 1])
|
|
ce->ce_flags |= CE_REMOVE;
|
|
else
|
|
free(ce);
|
|
}
|
|
|
|
void replace_index_entry_in_base(struct index_state *istate,
|
|
struct cache_entry *old,
|
|
struct cache_entry *new)
|
|
{
|
|
if (old->index &&
|
|
istate->split_index &&
|
|
istate->split_index->base &&
|
|
old->index <= istate->split_index->base->cache_nr) {
|
|
new->index = old->index;
|
|
if (old != istate->split_index->base->cache[new->index - 1])
|
|
free(istate->split_index->base->cache[new->index - 1]);
|
|
istate->split_index->base->cache[new->index - 1] = new;
|
|
}
|
|
}
|