Merge pull request 'performance improvements' (#342) from lx-perf-improvements into main

Performance improvements included in this PR:

- [x] Use `Bytes` at a few places where appropriate, instead of `Vec<u8>`, to reduce the number of copies
  - [x] StreamChunker now accumulates incoming slices in a `Vec<Bytes>` instead of a `VecDeque<u8>`. Replaces calls to `.extend()` and `.drain()` that were quite costly by a simple `concat()` on a vec of slices which is much more optimized
- [x] Hashing (b2, sha256, md5) is now done on a Tokio thread dedicated to cpu-intensive tasks, using `spawn_blocking`
- [x] Block manager now uses 256 independant locks instead of one big lock for writing, reduces contention when writing several/many objects in parallel
- [x] Better LMDB defaults: we now put flags `NoSync` and `NoMetaSync` to avoid `fsync` at each transaction (extremely slow). Also increased number of LMDB readers to accomodate more intensive workloads

Other changes included in this PR:

- [x] Update to hashing and MAC crates: md5 and sha2 from 0.9 to 0.10, hmac from 0.10 to 0.12
- [x] switch to `tracing_subscriber` for logs, which allows to have timing of each event

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/342

1 files changed, 11 insertions, 6 deletions

diff --git a/src/block/block.rs b/src/block/block.rs
index 4d3fbcb8..f17bd2c0 100644
--- a/src/block/block.rs
+++ b/src/block/block.rs
@@ -1,3 +1,4 @@
+use bytes::Bytes;
 use serde::{Deserialize, Serialize};
 use zstd::stream::{decode_all as zstd_decode, Encoder};
 
@@ -61,13 +62,17 @@ impl DataBlock {
 		}
 	}
 
-	pub fn from_buffer(data: Vec<u8>, level: Option<i32>) -> DataBlock {
-		if let Some(level) = level {
-			if let Ok(data) = zstd_encode(&data[..], level) {
-				return DataBlock::Compressed(data);
+	pub async fn from_buffer(data: Bytes, level: Option<i32>) -> DataBlock {
+		tokio::task::spawn_blocking(move || {
+			if let Some(level) = level {
+				if let Ok(data) = zstd_encode(&data[..], level) {
+					return DataBlock::Compressed(data);
+				}
 			}
-		}
-		DataBlock::Plain(data)
+			DataBlock::Plain(data.to_vec()) // TODO: remove to_vec here
+		})
+		.await
+		.unwrap()
 	}
 }