diff mbox series

[v2,08/13] reftable/merged: simplify indices for subiterators

Message ID 31bdfc1e34079dd79ba3bfd39a03eacaa2929762.1715589670.git.ps@pks.im (mailing list archive)
State Accepted
Commit 701713a254e7b8c955bc9a4a39a1eab17e1c457e
Headers show
Series reftable: prepare for re-seekable iterators | expand

Commit Message

Patrick Steinhardt May 13, 2024, 8:47 a.m. UTC
When seeking on a merged table, we perform the seek for each of the
subiterators. If the subiterator has the desired record we add it to the
priority queue, otherwise we skip it and don't add it to the stack of
subiterators hosted by the merged table.

The consequence of this is that the index of the subiterator in the
merged table does not necessarily correspond to the index of it in the
merged iterator. Next to being potentially confusing, it also means that
we won't easily be able to re-seek the merged iterator because we have
no clear connection between both of the data structures.

Refactor the code so that the index stays the same in both structures.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 reftable/merged.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/reftable/merged.c b/reftable/merged.c
index 4e1b78e93f..18a2a6f09b 100644
--- a/reftable/merged.c
+++ b/reftable/merged.c
@@ -37,6 +37,7 @@  static void merged_iter_init(struct merged_iter *mi,
 	mi->advance_index = -1;
 	mi->suppress_deletions = mt->suppress_deletions;
 	REFTABLE_CALLOC_ARRAY(mi->subiters, mt->stack_len);
+	mi->stack_len = mt->stack_len;
 }
 
 static void merged_iter_close(void *p)
@@ -236,21 +237,19 @@  static int merged_table_seek_record(struct reftable_merged_table *mt,
 	merged_iter_init(&merged, mt);
 
 	for (size_t i = 0; i < mt->stack_len; i++) {
-		reftable_record_init(&merged.subiters[merged.stack_len].rec,
+		reftable_record_init(&merged.subiters[i].rec,
 				     reftable_record_type(rec));
 
 		err = reftable_table_seek_record(&mt->stack[i],
-						 &merged.subiters[merged.stack_len].iter, rec);
+						 &merged.subiters[i].iter, rec);
 		if (err < 0)
 			goto out;
 		if (err > 0)
 			continue;
 
-		err = merged_iter_advance_subiter(&merged, merged.stack_len);
+		err = merged_iter_advance_subiter(&merged, i);
 		if (err < 0)
 			goto out;
-
-		merged.stack_len++;
 	}
 
 	p = reftable_malloc(sizeof(*p));