feat: Add compression level configuration to ZstdCompressor

Signed-off-by: ddukbg <[email protected]>

lib/fluent/plugin/out_s3.rb

@@ -634,8 +634,8 @@ def compress(chunk, tmp)
     class ZstdCompressor < Compressor
       DEFAULT_LEVEL = 3
 
-      def initialize(level = DEFAULT_LEVEL)
-        @level = level
+      def initialize(level = nil)
+        @level = level || DEFAULT_LEVEL
       end
 
       def ext
@@ -647,11 +647,14 @@ def content_type
       end
 
       def compress(chunk, tmp)
-        compressed_data = Zstd.compress(chunk.read, level: @level)
-        tmp.write(compressed_data)
-      rescue => e
-        log.warn "zstd compression failed: #{e.message}"
-        raise e
+        begin
+          data = chunk.read
+          compressed_data = Zstd.compress(data, level: @level)
+          tmp.write(compressed_data)
+        rescue => e
+          log.warn "zstd compression failed: #{e.message}"
+          raise e
+        end
       end
     end