Add LZ4 compression support

code/crates/wal/Cargo.toml

@@ -2,15 +2,26 @@
 name = "malachite-wal"
 version = "0.1.0"
 edition = "2021"
+rust-version = "1.82.0"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
 
 [[bench]]
 name = "wal"
 harness = false
 
+[features]
+compression = ["dep:lz4_flex"]
+force-compression = ["compression"]
+
 [dependencies]
+cfg-if = "1"
 advisory-lock = "0.3.0"
 bytes = "1.5.0"
 crc32fast = "1.4.0"
+lz4_flex = { version = "0.11.0", optional = true }
 
 [dev-dependencies]
 criterion = "0.5.1"

code/crates/wal/benches/wal.rs

@@ -12,6 +12,12 @@ struct BenchConfig {
     sync_interval: usize,
 }
 
+impl BenchConfig {
+    fn total_size(&self) -> usize {
+        self.entry_size * self.batch_size
+    }
+}
+
 fn wal_benchmarks(c: &mut Criterion) {
     let dir = tempdir().unwrap();
 
@@ -35,7 +41,7 @@ fn wal_benchmarks(c: &mut Criterion) {
             sync_interval: 100,
         };
 
-        read_group.throughput(Throughput::Bytes(*size as u64));
+        read_group.throughput(Throughput::Bytes(config.total_size() as u64));
         read_group.bench_with_input(BenchmarkId::new("sequential_read", size), size, |b, _| {
             let path = get_temp_wal_path(&dir);
             setup_wal_for_reading(&path, &config);
@@ -56,7 +62,7 @@ fn wal_benchmarks(c: &mut Criterion) {
             sync_interval: 100,
         };
 
-        write_group.throughput(Throughput::Bytes(*size as u64));
+        write_group.throughput(Throughput::Bytes(config.total_size() as u64));
         write_group.bench_with_input(BenchmarkId::new("sequential_write", size), size, |b, _| {
             let path = get_temp_wal_path(&dir);
             b.iter(|| bench_sequential_write(&path, &config));
@@ -73,7 +79,7 @@ fn wal_benchmarks(c: &mut Criterion) {
             sync_interval: *batch_size,
         };
 
-        write_group.throughput(Throughput::Elements(*batch_size as u64));
+        write_group.throughput(Throughput::Bytes(config.total_size() as u64));
         write_group.bench_with_input(
             BenchmarkId::new("batch_write", batch_size),
             batch_size,
@@ -94,6 +100,7 @@ fn wal_benchmarks(c: &mut Criterion) {
             sync_interval: *interval,
         };
 
+        write_group.throughput(Throughput::Bytes(config.total_size() as u64));
         write_group.bench_with_input(
             BenchmarkId::new("sync_interval", interval),
             interval,
@@ -182,6 +189,7 @@ fn bench_small_writes_frequent_sync(c: &mut Criterion) {
     let mut group = c.benchmark_group("small_writes_frequent_sync");
     let dir = tempdir().unwrap();
 
+    group.throughput(Throughput::Bytes(64 * 100));
     group.bench_function("write_sync_every", |b| {
         b.iter(|| {
             let path = get_temp_wal_path(&dir);

code/crates/wal/src/ext.rs

@@ -1,24 +1,36 @@
 use std::io::{self, Read, Write};
 
+#[inline(always)]
+pub fn read_u8<R: Read>(reader: &mut R) -> io::Result<u8> {
+    let mut buf = [0; 1];
+    reader.read_exact(&mut buf)?;
+    Ok(buf[0])
+}
+
+#[inline(always)]
+pub fn write_u8<W: Write>(writer: &mut W, value: u8) -> io::Result<()> {
+    writer.write_all(&[value])
+}
+
 #[inline(always)]
 pub fn read_u32<R: Read>(reader: &mut R) -> io::Result<u32> {
     let mut buf = [0; 4];
     reader.read_exact(&mut buf)?;
     Ok(u32::from_be_bytes(buf))
 }
 
+#[inline(always)]
+pub fn write_u32<W: Write>(writer: &mut W, value: u32) -> io::Result<()> {
+    writer.write_all(&value.to_be_bytes())
+}
+
 #[inline(always)]
 pub fn read_u64<R: Read>(reader: &mut R) -> io::Result<u64> {
     let mut buf = [0; 8];
     reader.read_exact(&mut buf)?;
     Ok(u64::from_be_bytes(buf))
 }
 
-#[inline(always)]
-pub fn write_u32<W: Write>(writer: &mut W, value: u32) -> io::Result<()> {
-    writer.write_all(&value.to_be_bytes())
-}
-
 #[inline(always)]
 pub fn write_u64<W: Write>(writer: &mut W, value: u64) -> io::Result<()> {
     writer.write_all(&value.to_be_bytes())

code/crates/wal/src/lib.rs

@@ -1,3 +1,5 @@
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
 //! Write-Ahead Log (WAL) implementation
 
 mod ext;