#include "reachable.h"
#include "sha1-array.h"
#include "argv-array.h"
+#include "mru.h"
static const char *pack_usage[] = {
N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
static uint32_t reuse_packfile_objects;
static off_t reuse_packfile_offset;
-static int use_bitmap_index = 1;
+static int use_bitmap_index_default = 1;
+static int use_bitmap_index = -1;
static int write_bitmap_index;
static uint16_t write_bitmap_options;
return 1;
}
+static int want_found_object(int exclude, struct packed_git *p)
+{
+ if (exclude)
+ return 1;
+ if (incremental)
+ return 0;
+
+ /*
+ * When asked to do --local (do not include an object that appears in a
+ * pack we borrow from elsewhere) or --honor-pack-keep (do not include
+ * an object that appears in a pack marked with .keep), finding a pack
+ * that matches the criteria is sufficient for us to decide to omit it.
+ * However, even if this pack does not satisfy the criteria, we need to
+ * make sure no copy of this object appears in _any_ pack that makes us
+ * to omit the object, so we need to check all the packs.
+ *
+ * We can however first check whether these options can possible matter;
+ * if they do not matter we know we want the object in generated pack.
+ * Otherwise, we signal "-1" at the end to tell the caller that we do
+ * not know either way, and it needs to check more packs.
+ */
+ if (!ignore_packed_keep &&
+ (!local || !have_non_local_packs))
+ return 1;
+
+ if (local && !p->pack_local)
+ return 0;
+ if (ignore_packed_keep && p->pack_local && p->pack_keep)
+ return 0;
+
+ /* we don't know yet; keep looking for more packs */
+ return -1;
+}
+
/*
* Check whether we want the object in the pack (e.g., we do not want
* objects found in non-local stores if the "--local" option was used).
*
- * As a side effect of this check, we will find the packed version of this
- * object, if any. We therefore pass out the pack information to avoid having
- * to look it up again later.
+ * If the caller already knows an existing pack it wants to take the object
+ * from, that is passed in *found_pack and *found_offset; otherwise this
+ * function finds if there is any pack that has the object and returns the pack
+ * and its offset in these variables.
*/
static int want_object_in_pack(const unsigned char *sha1,
int exclude,
struct packed_git **found_pack,
off_t *found_offset)
{
- struct packed_git *p;
+ struct mru_entry *entry;
+ int want;
if (!exclude && local && has_loose_object_nonlocal(sha1))
return 0;
- *found_pack = NULL;
- *found_offset = 0;
+ /*
+ * If we already know the pack object lives in, start checks from that
+ * pack - in the usual case when neither --local was given nor .keep files
+ * are present we will determine the answer right now.
+ */
+ if (*found_pack) {
+ want = want_found_object(exclude, *found_pack);
+ if (want != -1)
+ return want;
+ }
+
+ for (entry = packed_git_mru->head; entry; entry = entry->next) {
+ struct packed_git *p = entry->item;
+ off_t offset;
+
+ if (p == *found_pack)
+ offset = *found_offset;
+ else
+ offset = find_pack_entry_one(sha1, p);
- for (p = packed_git; p; p = p->next) {
- off_t offset = find_pack_entry_one(sha1, p);
if (offset) {
if (!*found_pack) {
if (!is_pack_valid(p))
*found_offset = offset;
*found_pack = p;
}
- if (exclude)
- return 1;
- if (incremental)
- return 0;
-
- /*
- * When asked to do --local (do not include an
- * object that appears in a pack we borrow
- * from elsewhere) or --honor-pack-keep (do not
- * include an object that appears in a pack marked
- * with .keep), we need to make sure no copy of this
- * object come from in _any_ pack that causes us to
- * omit it, and need to complete this loop. When
- * neither option is in effect, we know the object
- * we just found is going to be packed, so break
- * out of the loop to return 1 now.
- */
- if (!ignore_packed_keep &&
- (!local || !have_non_local_packs))
- break;
-
- if (local && !p->pack_local)
- return 0;
- if (ignore_packed_keep && p->pack_local && p->pack_keep)
- return 0;
+ want = want_found_object(exclude, p);
+ if (!exclude && want > 0)
+ mru_mark(packed_git_mru, entry);
+ if (want != -1)
+ return want;
}
}
static int add_object_entry(const unsigned char *sha1, enum object_type type,
const char *name, int exclude)
{
- struct packed_git *found_pack;
- off_t found_offset;
+ struct packed_git *found_pack = NULL;
+ off_t found_offset = 0;
uint32_t index_pos;
if (have_duplicate_entry(sha1, exclude, &index_pos))
if (have_duplicate_entry(sha1, 0, &index_pos))
return 0;
+ if (!want_object_in_pack(sha1, 0, &pack, &offset))
+ return 0;
+
create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
display_progress(progress_state, nr_result);
(a->in_pack_offset > b->in_pack_offset);
}
+/*
+ * Drop an on-disk delta we were planning to reuse. Naively, this would
+ * just involve blanking out the "delta" field, but we have to deal
+ * with some extra book-keeping:
+ *
+ * 1. Removing ourselves from the delta_sibling linked list.
+ *
+ * 2. Updating our size/type to the non-delta representation. These were
+ * either not recorded initially (size) or overwritten with the delta type
+ * (type) when check_object() decided to reuse the delta.
+ */
+static void drop_reused_delta(struct object_entry *entry)
+{
+ struct object_entry **p = &entry->delta->delta_child;
+ struct object_info oi = OBJECT_INFO_INIT;
+
+ while (*p) {
+ if (*p == entry)
+ *p = (*p)->delta_sibling;
+ else
+ p = &(*p)->delta_sibling;
+ }
+ entry->delta = NULL;
+
+ oi.sizep = &entry->size;
+ oi.typep = &entry->type;
+ if (packed_object_info(entry->in_pack, entry->in_pack_offset, &oi) < 0) {
+ /*
+ * We failed to get the info from this pack for some reason;
+ * fall back to sha1_object_info, which may find another copy.
+ * And if that fails, the error will be recorded in entry->type
+ * and dealt with in prepare_pack().
+ */
+ entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
+ }
+}
+
+/*
+ * Follow the chain of deltas from this entry onward, throwing away any links
+ * that cause us to hit a cycle (as determined by the DFS state flags in
+ * the entries).
+ */
+static void break_delta_chains(struct object_entry *entry)
+{
+ /* If it's not a delta, it can't be part of a cycle. */
+ if (!entry->delta) {
+ entry->dfs_state = DFS_DONE;
+ return;
+ }
+
+ switch (entry->dfs_state) {
+ case DFS_NONE:
+ /*
+ * This is the first time we've seen the object. We mark it as
+ * part of the active potential cycle and recurse.
+ */
+ entry->dfs_state = DFS_ACTIVE;
+ break_delta_chains(entry->delta);
+ entry->dfs_state = DFS_DONE;
+ break;
+
+ case DFS_DONE:
+ /* object already examined, and not part of a cycle */
+ break;
+
+ case DFS_ACTIVE:
+ /*
+ * We found a cycle that needs broken. It would be correct to
+ * break any link in the chain, but it's convenient to
+ * break this one.
+ */
+ drop_reused_delta(entry);
+ entry->dfs_state = DFS_DONE;
+ break;
+ }
+}
+
static void get_object_details(void)
{
uint32_t i;
sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
for (i = 0; i < to_pack.nr_objects; i++)
sorted_by_offset[i] = to_pack.objects + i;
- qsort(sorted_by_offset, to_pack.nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
+ QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
for (i = 0; i < to_pack.nr_objects; i++) {
struct object_entry *entry = sorted_by_offset[i];
entry->no_try_delta = 1;
}
+ /*
+ * This must happen in a second pass, since we rely on the delta
+ * information for the whole list being completed.
+ */
+ for (i = 0; i < to_pack.nr_objects; i++)
+ break_delta_chains(&to_pack.objects[i]);
+
free(sorted_by_offset);
}
if (progress)
progress_state = start_progress(_("Compressing objects"),
nr_deltas);
- qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
+ QSORT(delta_list, n, type_size_sort);
ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
stop_progress(&progress_state);
if (nr_done != nr_deltas)
write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
}
if (!strcmp(k, "pack.usebitmaps")) {
- use_bitmap_index = git_config_bool(k, v);
+ use_bitmap_index_default = git_config_bool(k, v);
return 0;
}
if (!strcmp(k, "pack.threads")) {
}
if (in_pack.nr) {
- qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
- ofscmp);
+ QSORT(in_pack.array, in_pack.nr, ofscmp);
for (i = 0; i < in_pack.nr; i++) {
struct object *o = in_pack.array[i].object;
add_object_entry(o->oid.hash, o->type, "", 0);
}
/*
- * This tracks any options which a reader of the pack might
- * not understand, and which would therefore prevent blind reuse
- * of what we have on disk.
+ * This tracks any options which pack-reuse code expects to be on, or which a
+ * reader of the pack might not understand, and which would therefore prevent
+ * blind reuse of what we have on disk.
*/
static int pack_options_allow_reuse(void)
{
- return allow_ofs_delta;
+ return pack_to_stdout && allow_ofs_delta;
}
static int get_object_list_from_bitmap(struct rev_info *revs)
if (!rev_list_all || !rev_list_reflog || !rev_list_index)
unpack_unreachable_expiration = 0;
- if (!use_internal_rev_list || !pack_to_stdout || is_repository_shallow())
+ /*
+ * "soft" reasons not to use bitmaps - for on-disk repack by default we want
+ *
+ * - to produce good pack (with bitmap index not-yet-packed objects are
+ * packed in suboptimal order).
+ *
+ * - to use more robust pack-generation codepath (avoiding possible
+ * bugs in bitmap code and possible bitmap index corruption).
+ */
+ if (!pack_to_stdout)
+ use_bitmap_index_default = 0;
+
+ if (use_bitmap_index < 0)
+ use_bitmap_index = use_bitmap_index_default;
+
+ /* "hard" reasons not to use bitmaps; these just won't work at all */
+ if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow())
use_bitmap_index = 0;
if (pack_to_stdout || !rev_list_all)