compress blocs with zstd

3 files changed, 98 insertions, 25 deletions

diff --git a/src/model/Cargo.toml b/src/model/Cargo.toml
index 77084531..1b97e4f9 100644
--- a/src/model/Cargo.toml
+++ b/src/model/Cargo.toml
@@ -21,8 +21,8 @@ arc-swap = "1.0"
 hex = "0.4"
 log = "0.4"
 rand = "0.8"
-
 sled = "0.34"
+zstd = "0.6.1"
 
 rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
diff --git a/src/model/block.rs b/src/model/block.rs
index 5f428fe1..272bd884 100644
--- a/src/model/block.rs
+++ b/src/model/block.rs
@@ -9,6 +9,7 @@ use serde::{Deserialize, Serialize};
 use tokio::fs;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::sync::{watch, Mutex, Notify};
+use zstd::stream::{decode_all as zstd_decode, encode_all as zstd_encode};
 
 use garage_util::data::*;
 use garage_util::error::Error;
@@ -43,6 +44,7 @@ pub enum Message {
 	/// Message to send a block of data, either because requested, of for first delivery of new
 	/// block
 	PutBlock(PutBlockMessage),
+	PutCompressedBlock(PutBlockMessage),
 	/// Ask other node if they should have this block, but don't actually have it
 	NeedBlockQuery(Hash),
 	/// Response : whether the node do require that block
@@ -134,7 +136,8 @@ impl BlockManager {
 
 	async fn handle(self: Arc<Self>, msg: &Message) -> Result<Message, Error> {
 		match msg {
-			Message::PutBlock(m) => self.write_block(&m.hash, &m.data).await,
+			Message::PutBlock(m) => self.write_block(&m.hash, &m.data, false).await,
+			Message::PutCompressedBlock(m) => self.write_block(&m.hash, &m.data, true).await,
 			Message::GetBlock(h) => self.read_block(h).await,
 			Message::NeedBlockQuery(h) => self.need_block(h).await.map(Message::NeedBlockReply),
 			_ => Err(Error::BadRPC(format!("Unexpected RPC message"))),
@@ -157,15 +160,23 @@ impl BlockManager {
 	}
 
 	/// Write a block to disk
-	async fn write_block(&self, hash: &Hash, data: &[u8]) -> Result<Message, Error> {
+	pub async fn write_block(
+		&self,
+		hash: &Hash,
+		data: &[u8],
+		compressed: bool,
+	) -> Result<Message, Error> {
+		if self.is_block_compressed(hash).await.is_ok() {
+			return Ok(Message::Ok);
+		}
 		let _lock = self.data_dir_lock.lock().await;
 
 		let mut path = self.block_dir(hash);
 		fs::create_dir_all(&path).await?;
 
 		path.push(hex::encode(hash));
-		if fs::metadata(&path).await.is_ok() {
-			return Ok(Message::Ok);
+		if compressed {
+			path.set_extension("zst");
 		}
 
 		let mut f = fs::File::create(path).await?;
@@ -176,35 +187,61 @@ impl BlockManager {
 	}
 
 	/// Read block from disk, verifying it's integrity
-	async fn read_block(&self, hash: &Hash) -> Result<Message, Error> {
-		let path = self.block_path(hash);
+	pub async fn read_block(&self, hash: &Hash) -> Result<Message, Error> {
+		let mut path = self.block_path(hash);
 
-		let mut f = match fs::File::open(&path).await {
-			Ok(f) => f,
-			Err(e) => {
+		let mut data = vec![];
+		let block = match self.is_block_compressed(hash).await {
+			Ok(false) => {
+				let f = fs::File::open(&path).await;
+				f.map(|f| (f, false)).map_err(Into::into)
+			}
+			Ok(true) => {
+				path.set_extension("zst");
+				let f = fs::File::open(&path).await;
+				f.map(|f| (f, true)).map_err(Into::into)
+			}
+			Err(e) => Err(e),
+		};
+		let (mut f, compressed) = match block {
+			Ok(ok) => ok,
+			e => {
 				// Not found but maybe we should have had it ??
 				self.put_to_resync(hash, Duration::from_millis(0))?;
-				return Err(Into::into(e));
+				e?
 			}
 		};
-		let mut data = vec![];
 		f.read_to_end(&mut data).await?;
 		drop(f);
 
-		if blake2sum(&data[..]) != *hash {
+		let sum = if compressed {
+			zstd_decode(&data[..])
+				.ok()
+				.map(|decompressed| blake2sum(&decompressed[..]))
+		} else {
+			Some(blake2sum(&data[..]))
+		};
+		if sum.is_none() || sum.unwrap() != *hash {
 			let _lock = self.data_dir_lock.lock().await;
 			warn!(
 				"Block {:?} is corrupted. Renaming to .corrupted and resyncing.",
 				hash
 			);
 			let mut path2 = path.clone();
-			path2.set_extension(".corrupted");
+			path2.set_extension("corrupted");
 			fs::rename(path, path2).await?;
 			self.put_to_resync(&hash, Duration::from_millis(0))?;
 			return Err(Error::CorruptData(*hash));
 		}
 
-		Ok(Message::PutBlock(PutBlockMessage { hash: *hash, data }))
+		if compressed {
+			Ok(Message::PutCompressedBlock(PutBlockMessage {
+				hash: *hash,
+				data,
+			}))
+		} else {
+			Ok(Message::PutBlock(PutBlockMessage { hash: *hash, data }))
+		}
 	}
 
 	/// Check if this node should have a block, but don't actually have it
@@ -215,14 +252,22 @@ impl BlockManager {
 			.map(|x| u64_from_be_bytes(x) > 0)
 			.unwrap_or(false);
 		if needed {
-			let path = self.block_path(hash);
-			let exists = fs::metadata(&path).await.is_ok();
+			let exists = self.is_block_compressed(hash).await.is_ok();
 			Ok(!exists)
 		} else {
 			Ok(false)
 		}
 	}
 
+	async fn is_block_compressed(&self, hash: &Hash) -> Result<bool, Error> {
+		let mut path = self.block_path(hash);
+		if fs::metadata(&path).await.is_ok() {
+			return Ok(false);
+		}
+		path.set_extension("zst");
+		fs::metadata(&path).await.map(|_| true).map_err(Into::into)
+	}
+
 	fn block_dir(&self, hash: &Hash) -> PathBuf {
 		let mut path = self.data_dir.clone();
 		path.push(hex::encode(&hash.as_slice()[0..1]));
@@ -323,7 +368,7 @@ impl BlockManager {
 
 		let path = self.block_path(hash);
 
-		let exists = fs::metadata(&path).await.is_ok();
+		let exists = self.is_block_compressed(hash).await.is_ok();
 		let needed = self
 			.rc
 			.get(hash.as_ref())?
@@ -402,15 +447,14 @@ impl BlockManager {
 			// TODO find a way to not do this if they are sending it to us
 			// Let's suppose this isn't an issue for now with the BLOCK_RW_TIMEOUT delay
 			// between the RC being incremented and this part being called.
-			let block_data = self.rpc_get_block(&hash).await?;
-			self.write_block(hash, &block_data[..]).await?;
+			let (block_data, compressed) = self.rpc_get_raw_block(&hash).await?;
+			self.write_block(hash, &block_data[..], compressed).await?;
 		}
 
 		Ok(())
 	}
 
-	/// Ask nodes that might have a block for it
-	pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> {
+	async fn rpc_get_raw_block(&self, hash: &Hash) -> Result<(Vec<u8>, bool), Error> {
 		let who = self.replication.read_nodes(&hash);
 		let resps = self
 			.rpc_client
@@ -424,8 +468,10 @@ impl BlockManager {
 			.await?;
 
 		for resp in resps {
-			if let Message::PutBlock(msg) = resp {
-				return Ok(msg.data);
+			match resp {
+				Message::PutBlock(msg) => return Ok((msg.data, false)),
+				Message::PutCompressedBlock(msg) => return Ok((msg.data, true)),
+				_ => {}
 			}
 		}
 		Err(Error::Message(format!(
@@ -434,13 +480,36 @@ impl BlockManager {
 		)))
 	}
 
+	/// Ask nodes that might have a block for it
+	pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> {
+		self.rpc_get_raw_block(hash)
+			.await
+			.and_then(|(data, compressed)| {
+				if compressed {
+					zstd_decode(&data[..]).map_err(|_| Error::CorruptData(*hash))
+				} else {
+					Ok(data)
+				}
+			})
+	}
+
 	/// Send block to nodes that should have it
 	pub async fn rpc_put_block(&self, hash: Hash, data: Vec<u8>) -> Result<(), Error> {
+		let garage = self.garage.load_full().unwrap();
+		let compressed = zstd_encode(&data[..], garage.config.compression_level);
+		let message = if compressed.is_ok() && compressed.as_ref().unwrap().len() < data.len() {
+			Message::PutCompressedBlock(PutBlockMessage {
+				hash,
+				data: compressed.unwrap(),
+			})
+		} else {
+			Message::PutBlock(PutBlockMessage { hash, data })
+		};
 		let who = self.replication.write_nodes(&hash);
 		self.rpc_client
 			.try_call_many(
 				&who[..],
-				Message::PutBlock(PutBlockMessage { hash, data }),
+				message,
 				RequestStrategy::with_quorum(self.replication.write_quorum())
 					.with_timeout(BLOCK_RW_TIMEOUT),
 			)
diff --git a/src/util/config.rs b/src/util/config.rs
index bb70467b..ab9cae6c 100644
--- a/src/util/config.rs
+++ b/src/util/config.rs
@@ -45,6 +45,10 @@ pub struct Config {
 	#[serde(default = "default_replication_factor")]
 	pub data_replication_factor: usize,
 
+    /// Zstd compression level used on data blocks
+	#[serde(default)]
+	pub compression_level: i32,
+
 	/// Configuration for RPC TLS
 	pub rpc_tls: Option<TlsConfig>,