Added optional support for LZ4 via LZ4-flex crate (thus enabling wasm)

.github/workflows/test.yml

@@ -24,6 +24,8 @@ jobs:
           deactivate
       - name: Run
         run: cargo test
+      - name: Run lz4-flex
+        run: cargo test --no-default-features --features lz4_flex,bloom_filter,stream,snappy,brotli,zstd,gzip
 
   clippy:
     name: Clippy

Cargo.toml

@@ -24,6 +24,7 @@ brotli = { version = "^3.3", optional = true }
 flate2 = { version = "^1.0", optional = true }
 lz4 = { version = "1.23.3", optional = true }
 zstd = { version = "^0.11", optional = true, default-features = false }
+lz4_flex = { version = "^0.9.2", optional = true }
 
 xxhash-rust = { version="0.8.3", optional = true, features = ["xxh64"] }
 

src/compression.rs

@@ -62,6 +62,17 @@ pub fn compress(
             crate::error::Feature::Snappy,
             "compress to snappy".to_string(),
         )),
+        #[cfg(all(feature = "lz4_flex", not(feature = "lz4")))]
+        Compression::Lz4Raw => {
+            let output_buf_len = output_buf.len();
+            let required_len = lz4_flex::block::get_maximum_output_size(input_buf.len());
+            output_buf.resize(output_buf_len + required_len, 0);
+
+            let compressed_size =
+                lz4_flex::block::compress_into(input_buf, &mut output_buf[output_buf_len..])?;
+            output_buf.truncate(output_buf_len + compressed_size);
+            Ok(())
+        }
         #[cfg(feature = "lz4")]
         Compression::Lz4Raw => {
             let output_buf_len = output_buf.len();
@@ -76,7 +87,7 @@ pub fn compress(
             output_buf.truncate(output_buf_len + size);
             Ok(())
         }
-        #[cfg(not(feature = "lz4"))]
+        #[cfg(all(not(feature = "lz4"), not(feature = "lz4_flex")))]
         Compression::Lz4Raw => Err(Error::FeatureNotActive(
             crate::error::Feature::Lz4,
             "compress to lz4".to_string(),
@@ -153,13 +164,17 @@ pub fn decompress(compression: Compression, input_buf: &[u8], output_buf: &mut [
             crate::error::Feature::Snappy,
             "decompress with snappy".to_string(),
         )),
+        #[cfg(all(feature = "lz4_flex", not(feature = "lz4")))]
+        Compression::Lz4Raw => lz4_flex::block::decompress_into(input_buf, output_buf)
+            .map(|_| {})
+            .map_err(|e| e.into()),
         #[cfg(feature = "lz4")]
         Compression::Lz4Raw => {
             lz4::block::decompress_to_buffer(input_buf, Some(output_buf.len() as i32), output_buf)
                 .map(|_| {})
                 .map_err(|e| e.into())
         }
-        #[cfg(not(feature = "lz4"))]
+        #[cfg(all(not(feature = "lz4"), not(feature = "lz4_flex")))]
         Compression::Lz4Raw => Err(Error::FeatureNotActive(
             crate::error::Feature::Lz4,
             "decompress with lz4".to_string(),

src/error.rs

@@ -64,6 +64,20 @@ impl From<snap::Error> for Error {
     }
 }
 
+#[cfg(feature = "lz4_flex")]
+impl From<lz4_flex::block::DecompressError> for Error {
+    fn from(e: lz4_flex::block::DecompressError) -> Error {
+        Error::General(format!("underlying lz4_flex error: {}", e))
+    }
+}
+
+#[cfg(feature = "lz4_flex")]
+impl From<lz4_flex::block::CompressError> for Error {
+    fn from(e: lz4_flex::block::CompressError) -> Error {
+        Error::General(format!("underlying lz4_flex error: {}", e))
+    }
+}
+
 impl From<parquet_format_async_temp::thrift::Error> for Error {
     fn from(e: parquet_format_async_temp::thrift::Error) -> Error {
         Error::General(format!("underlying thrift error: {}", e))