feat: replace fns with From impl

src/ffi/rust.rs

@@ -50,11 +50,13 @@ impl fmt::Debug for Inflate {
     }
 }
 
-fn flush_decompress_into_mzflush(flush: FlushDecompress) -> MZFlush {
-    match flush {
-        FlushDecompress::None => MZFlush::None,
-        FlushDecompress::Sync => MZFlush::Sync,
-        FlushDecompress::Finish => MZFlush::Finish,
+impl From<FlushDecompress> for MZFlush {
+    fn from(value: FlushDecompress) -> Self {
+        match value {
+            FlushDecompress::None => Self::None,
+            FlushDecompress::Sync => Self::Sync,
+            FlushDecompress::Finish => Self::Finish,
+        }
     }
 }
 
@@ -75,8 +77,8 @@ impl InflateBackend for Inflate {
         output: &mut [u8],
         flush: FlushDecompress,
     ) -> Result<Status, DecompressError> {
-        let flush = flush_decompress_into_mzflush(flush);
-        let res = inflate::stream::inflate(&mut self.inner, input, output, flush);
+        let mz_flush = flush.into();
+        let res = inflate::stream::inflate(&mut self.inner, input, output, mz_flush);
         self.total_in += res.bytes_consumed as u64;
         self.total_out += res.bytes_written as u64;
 
@@ -130,12 +132,14 @@ impl fmt::Debug for Deflate {
     }
 }
 
-fn flush_compress_into_mzflush(flush: FlushCompress) -> MZFlush {
-    match flush {
-        FlushCompress::None => MZFlush::None,
-        FlushCompress::Sync | FlushCompress::Partial => MZFlush::Sync,
-        FlushCompress::Full => MZFlush::Full,
-        FlushCompress::Finish => MZFlush::Finish,
+impl From<FlushCompress> for MZFlush {
+    fn from(value: FlushCompress) -> Self {
+        match value {
+            FlushCompress::None => Self::None,
+            FlushCompress::Sync | FlushCompress::Partial => Self::Sync,
+            FlushCompress::Full => Self::Full,
+            FlushCompress::Finish => Self::Finish,
+        }
     }
 }
 
@@ -161,8 +165,8 @@ impl DeflateBackend for Deflate {
         output: &mut [u8],
         flush: FlushCompress,
     ) -> Result<Status, CompressError> {
-        let flush = flush_compress_into_mzflush(flush);
-        let res = deflate::stream::deflate(&mut self.inner, input, output, flush);
+        let mz_flush = flush.into();
+        let res = deflate::stream::deflate(&mut self.inner, input, output, mz_flush);
         self.total_in += res.bytes_consumed as u64;
         self.total_out += res.bytes_written as u64;