[LogServer] Reduce heap allocations for db keys #3624
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This was referenced Aug 4, 2025
AhmedSoliman
commented
Aug 4, 2025
| let value_bytes = DataRecordEncoder::from(payload).encode_to_disk_format(buffer); | ||
| DataRecordKey::new(store_message.header.loglet_id, offset).to_binary_array(); | ||
| let encoder = DataRecordEncoder::from(payload); | ||
| buffer.reserve(encoder.estimated_encode_size()); |
There was a problem hiding this comment.
This avoid unnecessary memory ballooning since it'll try to allocate a single buffer that's big enough for all records combined although we just need one big enough for the biggest record.
muhamadazmy
approved these changes
Aug 5, 2025
| let mut buf = [0u8; Self::size()]; | ||
| let mut b = &mut buf[..]; | ||
| KeyPrefix::new(KeyPrefixKind::DataRecord, loglet_id).encode_exclusive_upper_bound(&mut b); | ||
| (&mut b).put_u64(0); |
There was a problem hiding this comment.
Since the array is already initialised with 0 on allocation. in line 116, this call is not necessary imho
There was a problem hiding this comment.
it's true, but it'd be an implicit assumption that future eyes would miss.
- In log-server, keys have fixed lengths. This PR avoids small heap allocations when generating rocksdb keys. - Fixes a bug where we overshoot ths writer's buffer size to account for the entire batch although we don't need to do that.
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Uh oh!
There was an error while loading. Please reload this page.