add lz4 compression and decompression

backhand/Cargo.toml

@@ -32,9 +32,10 @@ solana-nohash-hasher = "0.2.1"
 libz-sys = { version = "1.1.20", features = ["zlib-ng-no-cmake-experimental-community-maintained"], default-features = false }
 # Temporary workaround for https://github.com/rust-lang/libz-sys/issues/225
 libz-ng-sys = { version = "<1.1.20", optional = true }
+lz4_flex = { version = "0.11.3", optional = true, default-features = false }
 
 [features]
-default = ["xz", "gzip", "zstd"]
+default = ["xz", "gzip", "zstd", "lz4"]
 ## Enables xz compression inside library and binaries
 xz = ["dep:xz2"]
 ## Enables xz compression and forces static build inside library and binaries
@@ -47,6 +48,8 @@ gzip-zlib-ng = ["any-flate2", "any-gzip", "dep:flate2", "flate2?/zlib-ng"]
 lzo = ["dep:rust-lzo"]
 ## Enables zstd compression inside library and binaries
 zstd = ["dep:zstd", "dep:zstd-safe"]
+## Enables Lz4 compression
+lz4 = ["dep:lz4_flex"]
 ## Internal only
 any-gzip = []
 ## Internal only

backhand/src/compressor.rs

@@ -240,6 +240,12 @@ impl CompressionAction for DefaultCompressor {
                 let mut decoder = zstd::bulk::Decompressor::new().unwrap();
                 decoder.decompress_to_buffer(bytes, out)?;
             }
+            #[cfg(feature = "lz4")]
+            Compressor::Lz4 => {
+                out.resize(out.capacity(), 0u8);
+                let out_size = lz4_flex::decompress_into(bytes, out.as_mut_slice()).unwrap();
+                out.truncate(out_size);
+            }
             _ => return Err(BackhandError::UnsupportedCompression(compressor)),
         }
         Ok(())
@@ -351,6 +357,8 @@ impl CompressionAction for DefaultCompressor {
                 encoder.compress_to_buffer(bytes, &mut buf)?;
                 Ok(buf)
             }
+            #[cfg(feature = "lz4")]
+            (Compressor::Lz4, _option, _) => Ok(lz4_flex::compress(bytes)),
             _ => Err(BackhandError::UnsupportedCompression(fc.id)),
         }
     }