When looking for a packed object, first check the MIDX for that object.
This reduces thrashing in the MRU list of packfiles.
Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
midx.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
midx.h | 3 +++
packfile.c | 5 +++-
3 files changed, 91 insertions(+), 1 deletion(-)
diff --git a/midx.c b/midx.c
index 8c643caa92..4b2398b3ee 100644
--- a/midx.c
+++ b/midx.c
@@ -329,6 +329,90 @@ int bsearch_midx(struct midxed_git *m, const unsigned char
*sha1, uint32_t *pos)
return 0;
}
+static int prepare_midx_pack(struct midxed_git *m, uint32_t pack_int_id)
+{
+ struct strbuf pack_name = STRBUF_INIT;
+
+ if (pack_int_id >= m->hdr->num_packs)
+ return 1;
+
+ if (m->packs[pack_int_id])
+ return 0;
+
+ strbuf_addstr(&pack_name, m->pack_dir);
+ strbuf_addstr(&pack_name, "/");
+ strbuf_addstr(&pack_name, m->pack_names[pack_int_id]);
+ strbuf_strip_suffix(&pack_name, ".pack");
+ strbuf_addstr(&pack_name, ".idx");
+
+ m->packs[pack_int_id] = add_packed_git(pack_name.buf, pack_name.len, 1);
+ strbuf_release(&pack_name);
+ return !m->packs[pack_int_id];
+}
+
+static int find_pack_entry_midx(const unsigned char *sha1,
+ struct midxed_git *m,
+ struct packed_git **p,
+ off_t *offset)
+{
+ uint32_t pos;
+ struct pack_midx_details d;
+
+ if (!bsearch_midx(m, sha1, &pos) ||
+ !nth_midxed_object_details(m, pos, &d))
+ return 0;
+
+ if (d.pack_int_id >= m->num_packs)
+ die(_("bad pack-int-id %d"), d.pack_int_id);
+
+ /* load packfile, if necessary */
+ if (prepare_midx_pack(m, d.pack_int_id))
+ return 0;
+
+ *p = m->packs[d.pack_int_id];
+ *offset = d.offset;
+
+ return 1;
+}
+
+int fill_pack_entry_midx(const unsigned char *sha1,
+ struct pack_entry *e)
+{
+ struct packed_git *p;
+ struct midxed_git *m;
+
+ if (!core_midx)
+ return 0;
+
+ m = midxed_git;
+ while (m)
+ {
+ off_t offset;
+ if (!find_pack_entry_midx(sha1, m, &p, &offset)) {
+ m = m->next;
+ continue;
+ }
+
+ /*
+ * We are about to tell the caller where they can locate the
+ * requested object. We better make sure the packfile is
+ * still here and can be accessed before supplying that
+ * answer, as it may have been deleted since the MIDX was
+ * loaded!
+ */
+ if (!is_pack_valid(p))
+ return 0;
+
+ e->offset = offset;
+ e->p = p;
+ hashcpy(e->sha1, sha1);
+
+ return 1;
+ }
+
+ return 0;
+}
+
int contains_pack(struct midxed_git *m, const char *pack_name)
{
uint32_t first = 0, last = m->num_packs;
diff --git a/midx.h b/midx.h
index 5598799189..b7e8b15fe4 100644
--- a/midx.h
+++ b/midx.h
@@ -11,6 +11,9 @@ extern char *get_midx_head_filename(const char *pack_dir);
extern struct object_id *get_midx_head_oid(const char *pack_dir, struct
object_id *oid);
+extern int fill_pack_entry_midx(const unsigned char *sha1,
+ struct pack_entry *e);
+
struct pack_midx_entry {
struct object_id oid;
uint32_t pack_int_id;
diff --git a/packfile.c b/packfile.c
index 866a1f30dd..9ec39a83e9 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1883,7 +1883,10 @@ int find_pack_entry(const unsigned char *sha1, struct
pack_entry *e)
{
struct mru_entry *p;
- prepare_packed_git();
+ prepare_packed_git_internal(1);
+ if (fill_pack_entry_midx(sha1, e))
+ return 1;
+
if (!packed_git)
return 0;
--
2.15.0
