Hi,
this is the third version of my patch series that aims to improve raw
ref iteration performance with the reftable backend. Changes compared to
v2:
- Reversed the order of the second set of `SWAP()` macro calls.
- Fixed typos in commit messages.
Thanks!
Patrick
Patrick Steinhardt (13):
reftable/pq: use `size_t` to track iterator index
reftable/merged: make `merged_iter` structure private
reftable/merged: advance subiter on subsequent iteration
reftable/merged: make subiters own their records
reftable/merged: remove unnecessary null check for subiters
reftable/merged: handle subiter cleanup on close only
reftable/merged: circumvent pqueue with single subiter
reftable/merged: avoid duplicate pqueue emptiness check
reftable/record: reuse refname when decoding
reftable/record: reuse refname when copying
reftable/record: decode keys in place
reftable: allow inlining of a few functions
refs/reftable: precompute prefix length
refs/reftable-backend.c | 6 +-
reftable/block.c | 25 +++----
reftable/block.h | 2 -
reftable/iter.c | 5 --
reftable/iter.h | 4 --
reftable/merged.c | 139 +++++++++++++++++++------------------
reftable/merged.h | 11 +--
reftable/pq.c | 18 +----
reftable/pq.h | 16 +++--
reftable/pq_test.c | 41 +++++------
reftable/record.c | 64 +++++++++--------
reftable/record.h | 21 ++++--
reftable/record_test.c | 3 +-
reftable/reftable-record.h | 1 +
14 files changed, 175 insertions(+), 181 deletions(-)
Range-diff against v2:
1: 292e5f8888 = 1: c998039333 reftable/pq: use `size_t` to track iterator index
2: 95e1ccafc4 = 2: cb144e28a1 reftable/merged: make `merged_iter` structure private
3: 0e327e5fe3 = 3: 1bf09661e5 reftable/merged: advance subiter on subsequent iteration
4: 494d74deff = 4: 9aa1733aef reftable/merged: make subiters own their records
5: 0adf34d08b = 5: b413006159 reftable/merged: remove unnecessary null check for subiters
6: 01152ce130 = 6: 0ab1be740e reftable/merged: handle subiter cleanup on close only
7: 370b6cfc6c = 7: 2199881d47 reftable/merged: circumvent pqueue with single subiter
8: 1e279f21e6 ! 8: 04435f515c reftable/merged: avoid duplicate pqueue emptiness check
@@ Commit message
down the stack in `merged_iter_next_entry()` though, which makes this
check redundant.
- Now if this check was there to accellerate the common case it might have
+ Now if this check was there to accelerate the common case it might have
made sense to keep it. But the iterator being exhausted is rather the
uncommon case because you can expect most reftable stacks to contain
more than two refs.
9: 15a8cbf678 ! 9: 92f83dd404 reftable/record: reuse refname when decoding
@@ Commit message
to the required number of bytes via `REFTABLE_ALLOC_GROW()`.
This refactoring is safe to do because all functions that assigning to
- the refname will first call `release_reftable_record()`, which will zero
- out the complete record after releasing memory.
+ the refname will first call `reftable_ref_record_release()`, which will
+ zero out the complete record after releasing memory.
This change results in a nice speedup when iterating over 1 million
refs:
@@ reftable/record.c: static int reftable_ref_record_decode(void *rec, struct strbu
+ SWAP(refname, r->refname);
+ SWAP(refname_cap, r->refname_cap);
reftable_ref_record_release(r);
-+ SWAP(refname, r->refname);
-+ SWAP(refname_cap, r->refname_cap);
++ SWAP(r->refname, refname);
++ SWAP(r->refname_cap, refname_cap);
- assert(hash_size > 0);
-
10: 35b1af2f06 ! 10: eb600f3bf3 reftable/record: reuse refname when copying
@@ reftable/record.c: static void reftable_ref_record_copy_from(void *rec, const vo
+ SWAP(refname, ref->refname);
+ SWAP(refname_cap, ref->refname_cap);
reftable_ref_record_release(ref);
-+ SWAP(refname, ref->refname);
-+ SWAP(refname_cap, ref->refname_cap);
++ SWAP(ref->refname, refname);
++ SWAP(ref->refname_cap, refname_cap);
+
if (src->refname) {
- ref->refname = xstrdup(src->refname);
11: d7151ef361 = 11: f7915f1df8 reftable/record: decode keys in place
12: 99b238a40d = 12: 527c15e5da reftable: allow inlining of a few functions
13: 627bd1f5f7 ! 13: de4a1e2239 refs/reftable: precompute prefix length
@@ refs/reftable-backend.c: static int reftable_ref_iterator_advance(struct ref_ite
}
@@ refs/reftable-backend.c: static struct reftable_ref_iterator *ref_iterator_for_stack(struct reftable_ref_
iter = xcalloc(1, sizeof(*iter));
- base_ref_iterator_init(&iter->base, &reftable_ref_iterator_vtable, 1);
+ base_ref_iterator_init(&iter->base, &reftable_ref_iterator_vtable);
iter->prefix = prefix;
+ iter->prefix_len = prefix ? strlen(prefix) : 0;
iter->base.oid = &iter->oid;
base-commit: b387623c12f3f4a376e4d35a610fd3e55d7ea907
--
2.44.0
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