[refactor-block] refactor DataBlock and DataBlockPath

3 files changed, 85 insertions, 75 deletions

diff --git a/src/block/block.rs b/src/block/block.rs
index 34afea5d..0b14bad4 100644
--- a/src/block/block.rs
+++ b/src/block/block.rs
@@ -13,77 +13,99 @@ pub enum DataBlockHeader {
 	Compressed,
 }
 
-/// A possibly compressed block of data
-pub enum DataBlock {
-	/// Uncompressed data
-	Plain(Bytes),
-	/// Data compressed with zstd
-	Compressed(Bytes),
+#[derive(Debug)]
+pub struct DataBlockElem<T> {
+	header: DataBlockHeader,
+	elem: T,
 }
 
-#[derive(Debug)]
-pub enum DataBlockPath {
-	/// Uncompressed data fail
-	Plain(PathBuf),
-	/// Compressed data fail
-	Compressed(PathBuf),
+/// A possibly compressed block of data
+pub type DataBlock = DataBlockElem<Bytes>;
+
+/// A path to a possibly compressed block of data
+pub type DataBlockPath = DataBlockElem<PathBuf>;
+
+impl DataBlockHeader {
+	pub fn is_compressed(&self) -> bool {
+		matches!(self, DataBlockHeader::Compressed)
+	}
 }
 
-impl DataBlock {
+impl<T> DataBlockElem<T> {
+	pub fn from_parts(header: DataBlockHeader, elem: T) -> Self {
+		Self { header, elem }
+	}
+
+	pub fn plain(elem: T) -> Self {
+		Self {
+			header: DataBlockHeader::Plain,
+			elem,
+		}
+	}
+
+	pub fn compressed(elem: T) -> Self {
+		Self {
+			header: DataBlockHeader::Compressed,
+			elem,
+		}
+	}
+
+	pub fn into_parts(self) -> (DataBlockHeader, T) {
+		(self.header, self.elem)
+	}
+
+	pub fn as_parts_ref(&self) -> (DataBlockHeader, &T) {
+		(self.header, &self.elem)
+	}
+
 	/// Query whether this block is compressed
 	pub fn is_compressed(&self) -> bool {
-		matches!(self, DataBlock::Compressed(_))
+		self.header.is_compressed()
 	}
+}
 
+impl DataBlock {
 	/// Get the inner, possibly compressed buffer. You should probably use [`DataBlock::verify_get`]
 	/// instead
 	pub fn inner_buffer(&self) -> &[u8] {
-		use DataBlock::*;
-		let (Plain(ref res) | Compressed(ref res)) = self;
-		res
+		&self.elem
 	}
 
 	/// Verify data integrity. Does not return the buffer content.
 	pub fn verify(&self, hash: Hash) -> Result<(), Error> {
-		match self {
-			DataBlock::Plain(data) => {
-				if blake2sum(data) == hash {
+		match self.header {
+			DataBlockHeader::Plain => {
+				if blake2sum(&self.elem) == hash {
 					Ok(())
 				} else {
 					Err(Error::CorruptData(hash))
 				}
 			}
-			DataBlock::Compressed(data) => zstd::stream::copy_decode(&data[..], std::io::sink())
-				.map_err(|_| Error::CorruptData(hash)),
+			DataBlockHeader::Compressed => {
+				zstd::stream::copy_decode(&self.elem[..], std::io::sink())
+					.map_err(|_| Error::CorruptData(hash))
+			}
 		}
 	}
 
 	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.into());
+				if let Ok(data_compressed) = zstd_encode(&data[..], level) {
+					return DataBlock {
+						header: DataBlockHeader::Compressed,
+						elem: data_compressed.into(),
+					};
 				}
 			}
-			DataBlock::Plain(data)
+			DataBlock {
+				header: DataBlockHeader::Plain,
+				elem: data.into(),
+			}
 		})
 		.await
 		.unwrap()
 	}
-
-	pub fn into_parts(self) -> (DataBlockHeader, Bytes) {
-		match self {
-			DataBlock::Plain(data) => (DataBlockHeader::Plain, data),
-			DataBlock::Compressed(data) => (DataBlockHeader::Compressed, data),
-		}
-	}
-
-	pub fn from_parts(h: DataBlockHeader, bytes: Bytes) -> Self {
-		match h {
-			DataBlockHeader::Plain => DataBlock::Plain(bytes),
-			DataBlockHeader::Compressed => DataBlock::Compressed(bytes),
-		}
-	}
 }
 
 fn zstd_encode<R: std::io::Read>(mut source: R, level: i32) -> std::io::Result<Vec<u8>> {
diff --git a/src/block/manager.rs b/src/block/manager.rs
index 64e2ea27..6303248a 100644
--- a/src/block/manager.rs
+++ b/src/block/manager.rs
@@ -547,10 +547,7 @@ impl BlockManager {
 		hash: &Hash,
 		block_path: &DataBlockPath,
 	) -> Result<DataBlock, Error> {
-		let (path, compressed) = match block_path {
-			DataBlockPath::Plain(p) => (p, false),
-			DataBlockPath::Compressed(p) => (p, true),
-		};
+		let (header, path) = block_path.as_parts_ref();
 
 		let mut f = fs::File::open(&path).await?;
 		let mut data = vec![];
@@ -558,11 +555,7 @@ impl BlockManager {
 		self.metrics.bytes_read.add(data.len() as u64);
 		drop(f);
 
-		let data = if compressed {
-			DataBlock::Compressed(data.into())
-		} else {
-			DataBlock::Plain(data.into())
-		};
+		let data = DataBlock::from_parts(header, data.into());
 
 		if data.verify(*hash).is_err() {
 			self.metrics.corruption_counter.add(1);
@@ -615,20 +608,20 @@ impl BlockManager {
 				// first and then a compressed one (as compression may have been
 				// previously enabled).
 				if fs::metadata(&path).await.is_ok() {
-					return Some(DataBlockPath::Plain(path));
+					return Some(DataBlockPath::plain(path));
 				}
 				path.set_extension("zst");
 				if fs::metadata(&path).await.is_ok() {
-					return Some(DataBlockPath::Compressed(path));
+					return Some(DataBlockPath::compressed(path));
 				}
 			} else {
 				path.set_extension("zst");
 				if fs::metadata(&path).await.is_ok() {
-					return Some(DataBlockPath::Compressed(path));
+					return Some(DataBlockPath::compressed(path));
 				}
 				path.set_extension("");
 				if fs::metadata(&path).await.is_ok() {
-					return Some(DataBlockPath::Plain(path));
+					return Some(DataBlockPath::plain(path));
 				}
 			}
 		}
@@ -709,24 +702,25 @@ impl BlockManagerLocked {
 			tgt_path.set_extension("zst");
 		}
 
-		let to_delete = match (existing_path, compressed) {
+		let existing_info = existing_path.map(|x| x.into_parts());
+		let to_delete = match (existing_info, compressed) {
 			// If the block is stored in the wrong directory,
 			// write it again at the correct path and delete the old path
-			(Some(DataBlockPath::Plain(p)), false) if p != tgt_path => Some(p),
-			(Some(DataBlockPath::Compressed(p)), true) if p != tgt_path => Some(p),
+			(Some((DataBlockHeader::Plain, p)), false) if p != tgt_path => Some(p),
+			(Some((DataBlockHeader::Compressed, p)), true) if p != tgt_path => Some(p),
 
 			// If the block is already stored not compressed but we have a compressed
 			// copy, write the compressed copy and delete the uncompressed one
-			(Some(DataBlockPath::Plain(plain_path)), true) => Some(plain_path),
+			(Some((DataBlockHeader::Plain, plain_path)), true) => Some(plain_path),
 
 			// If the block is already stored compressed,
 			// keep the stored copy, we have nothing to do
-			(Some(DataBlockPath::Compressed(_)), _) => return Ok(()),
+			(Some((DataBlockHeader::Compressed, _)), _) => return Ok(()),
 
 			// If the block is already stored not compressed,
 			// and we don't have a compressed copy either,
 			// keep the stored copy, we have nothing to do
-			(Some(DataBlockPath::Plain(_)), false) => return Ok(()),
+			(Some((DataBlockHeader::Plain, _)), false) => return Ok(()),
 
 			// If the block isn't stored already, just store what is given to us
 			(None, _) => None,
@@ -778,18 +772,14 @@ impl BlockManagerLocked {
 	}
 
 	async fn move_block_to_corrupted(&self, block_path: &DataBlockPath) -> Result<(), Error> {
-		let (path, path2) = match block_path {
-			DataBlockPath::Plain(p) => {
-				let mut p2 = p.clone();
-				p2.set_extension("corrupted");
-				(p, p2)
-			}
-			DataBlockPath::Compressed(p) => {
-				let mut p2 = p.clone();
-				p2.set_extension("zst.corrupted");
-				(p, p2)
-			}
-		};
+		let (header, path) = block_path.as_parts_ref();
+
+		let mut path2 = path.clone();
+		if header.is_compressed() {
+			path2.set_extension("zst.corrupted");
+		} else {
+			path2.set_extension("corrupted");
+		}
 
 		fs::rename(path, path2).await?;
 		Ok(())
@@ -799,9 +789,7 @@ impl BlockManagerLocked {
 		let rc = mgr.rc.get_block_rc(hash)?;
 		if rc.is_deletable() {
 			while let Some(path) = mgr.find_block(hash).await {
-				let path = match path {
-					DataBlockPath::Plain(p) | DataBlockPath::Compressed(p) => p,
-				};
+				let (_header, path) = path.as_parts_ref();
 				fs::remove_file(path).await?;
 				mgr.metrics.delete_counter.add(1);
 			}
diff --git a/src/block/repair.rs b/src/block/repair.rs
index 77ee0d14..2c8acbc9 100644
--- a/src/block/repair.rs
+++ b/src/block/repair.rs
@@ -584,8 +584,8 @@ impl Worker for RebalanceWorker {
 			let prim_loc = self.manager.data_layout.load().primary_block_dir(&hash);
 			if path.ancestors().all(|x| x != prim_loc) {
 				let block_path = match path.extension() {
-					None => DataBlockPath::Plain(path.clone()),
-					Some(x) if x.to_str() == Some("zst") => DataBlockPath::Compressed(path.clone()),
+					None => DataBlockPath::plain(path.clone()),
+					Some(x) if x.to_str() == Some("zst") => DataBlockPath::compressed(path.clone()),
 					_ => {
 						warn!("not rebalancing file: {}", path.to_string_lossy());
 						return Ok(WorkerState::Busy);