#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 int pack_to_stdout;
static int num_preferred_base;
static struct progress *progress_state;
-static int pack_compression_level = Z_DEFAULT_COMPRESSION;
-static int pack_compression_seen;
static struct packed_git *reuse_packfile;
static uint32_t reuse_packfile_objects;
if (!is_pack_valid(reuse_packfile))
die("packfile is invalid: %s", reuse_packfile->pack_name);
- fd = git_open_noatime(reuse_packfile->pack_name);
+ fd = git_open(reuse_packfile->pack_name);
if (fd < 0)
die_errno("unable to open packfile for reuse: %s",
reuse_packfile->pack_name);
written, nr_result);
}
-static void setup_delta_attr_check(struct git_attr_check *check)
-{
- static struct git_attr *attr_delta;
-
- if (!attr_delta)
- attr_delta = git_attr("delta");
-
- check[0].attr = attr_delta;
-}
-
static int no_try_delta(const char *path)
{
- struct git_attr_check check[1];
+ static struct attr_check *check;
- setup_delta_attr_check(check);
- if (git_check_attr(path, ARRAY_SIZE(check), check))
+ if (!check)
+ check = attr_check_initl("delta", NULL);
+ if (git_check_attr(path, check))
return 0;
- if (ATTR_FALSE(check->value))
+ if (ATTR_FALSE(check->items[0].value))
return 1;
return 0;
}
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 want;
}
- for (p = packed_git; p; p = p->next) {
+ for (entry = packed_git_mru->head; entry; entry = entry->next) {
+ struct packed_git *p = entry->item;
off_t offset;
if (p == *found_pack)
*found_pack = p;
}
want = want_found_object(exclude, p);
+ if (!exclude && want > 0)
+ mru_mark(packed_git_mru, entry);
if (want != -1)
return want;
}
(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.
+ *
+ * 3. Resetting our delta depth, as we are now a base object.
+ */
+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;
+ entry->depth = 0;
+
+ 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).
+ *
+ * We also detect too-long reused chains that would violate our --depth
+ * limit.
+ */
+static void break_delta_chains(struct object_entry *entry)
+{
+ /*
+ * The actual depth of each object we will write is stored as an int,
+ * as it cannot exceed our int "depth" limit. But before we break
+ * changes based no that limit, we may potentially go as deep as the
+ * number of objects, which is elsewhere bounded to a uint32_t.
+ */
+ uint32_t total_depth;
+ struct object_entry *cur, *next;
+
+ for (cur = entry, total_depth = 0;
+ cur;
+ cur = cur->delta, total_depth++) {
+ if (cur->dfs_state == DFS_DONE) {
+ /*
+ * We've already seen this object and know it isn't
+ * part of a cycle. We do need to append its depth
+ * to our count.
+ */
+ total_depth += cur->depth;
+ break;
+ }
+
+ /*
+ * We break cycles before looping, so an ACTIVE state (or any
+ * other cruft which made its way into the state variable)
+ * is a bug.
+ */
+ if (cur->dfs_state != DFS_NONE)
+ die("BUG: confusing delta dfs state in first pass: %d",
+ cur->dfs_state);
+
+ /*
+ * Now we know this is the first time we've seen the object. If
+ * it's not a delta, we're done traversing, but we'll mark it
+ * done to save time on future traversals.
+ */
+ if (!cur->delta) {
+ cur->dfs_state = DFS_DONE;
+ break;
+ }
+
+ /*
+ * Mark ourselves as active and see if the next step causes
+ * us to cycle to another active object. It's important to do
+ * this _before_ we loop, because it impacts where we make the
+ * cut, and thus how our total_depth counter works.
+ * E.g., We may see a partial loop like:
+ *
+ * A -> B -> C -> D -> B
+ *
+ * Cutting B->C breaks the cycle. But now the depth of A is
+ * only 1, and our total_depth counter is at 3. The size of the
+ * error is always one less than the size of the cycle we
+ * broke. Commits C and D were "lost" from A's chain.
+ *
+ * If we instead cut D->B, then the depth of A is correct at 3.
+ * We keep all commits in the chain that we examined.
+ */
+ cur->dfs_state = DFS_ACTIVE;
+ if (cur->delta->dfs_state == DFS_ACTIVE) {
+ drop_reused_delta(cur);
+ cur->dfs_state = DFS_DONE;
+ break;
+ }
+ }
+
+ /*
+ * And now that we've gone all the way to the bottom of the chain, we
+ * need to clear the active flags and set the depth fields as
+ * appropriate. Unlike the loop above, which can quit when it drops a
+ * delta, we need to keep going to look for more depth cuts. So we need
+ * an extra "next" pointer to keep going after we reset cur->delta.
+ */
+ for (cur = entry; cur; cur = next) {
+ next = cur->delta;
+
+ /*
+ * We should have a chain of zero or more ACTIVE states down to
+ * a final DONE. We can quit after the DONE, because either it
+ * has no bases, or we've already handled them in a previous
+ * call.
+ */
+ if (cur->dfs_state == DFS_DONE)
+ break;
+ else if (cur->dfs_state != DFS_ACTIVE)
+ die("BUG: confusing delta dfs state in second pass: %d",
+ cur->dfs_state);
+
+ /*
+ * If the total_depth is more than depth, then we need to snip
+ * the chain into two or more smaller chains that don't exceed
+ * the maximum depth. Most of the resulting chains will contain
+ * (depth + 1) entries (i.e., depth deltas plus one base), and
+ * the last chain (i.e., the one containing entry) will contain
+ * whatever entries are left over, namely
+ * (total_depth % (depth + 1)) of them.
+ *
+ * Since we are iterating towards decreasing depth, we need to
+ * decrement total_depth as we go, and we need to write to the
+ * entry what its final depth will be after all of the
+ * snipping. Since we're snipping into chains of length (depth
+ * + 1) entries, the final depth of an entry will be its
+ * original depth modulo (depth + 1). Any time we encounter an
+ * entry whose final depth is supposed to be zero, we snip it
+ * from its delta base, thereby making it so.
+ */
+ cur->depth = (total_depth--) % (depth + 1);
+ if (!cur->depth)
+ drop_reused_delta(cur);
+
+ cur->dfs_state = DFS_DONE;
+ }
+}
+
static void get_object_details(void)
{
uint32_t 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);
}
depth = git_config_int(k, v);
return 0;
}
- if (!strcmp(k, "pack.compression")) {
- int level = git_config_int(k, v);
- if (level == -1)
- level = Z_DEFAULT_COMPRESSION;
- else if (level < 0 || level > Z_BEST_COMPRESSION)
- die("bad pack compression level %d", level);
- pack_compression_level = level;
- pack_compression_seen = 1;
- return 0;
- }
if (!strcmp(k, "pack.deltacachesize")) {
max_delta_cache_size = git_config_int(k, v);
return 0;
reset_pack_idx_option(&pack_idx_opts);
git_config(git_pack_config, NULL);
- if (!pack_compression_seen && core_compression_seen)
- pack_compression_level = core_compression_level;
progress = isatty(2);
argc = parse_options(argc, argv, prefix, pack_objects_options,