feat(consumer): use buffer pools for decompression

Signed-off-by: Ronan Harmegnies <ronan.harmegnies@gmail.com>

decompress.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"compress/gzip"
 	"fmt"
-	"io"
 	"sync"
 
 	snappy "github.com/eapache/go-xerial-snappy"
@@ -19,6 +18,19 @@ var (
 	}
 
 	gzipReaderPool sync.Pool
+
+	bufferPool = sync.Pool{
+		New: func() interface{} {
+			return new(bytes.Buffer)
+		},
+	}
+
+	bytesPool = sync.Pool{
+		New: func() interface{} {
+			res := make([]byte, 0, 4096)
+			return &res
+		},
+	}
 )
 
 func decompress(cc CompressionCodec, data []byte) ([]byte, error) {
@@ -38,9 +50,17 @@ func decompress(cc CompressionCodec, data []byte) ([]byte, error) {
 			return nil, err
 		}
 
-		defer gzipReaderPool.Put(reader)
+		buffer := bufferPool.Get().(*bytes.Buffer)
+		_, err = buffer.ReadFrom(reader)
+		// copy the buffer to a new slice with the correct length
+		// reuse gzipReader and buffer
+		gzipReaderPool.Put(reader)
+		res := make([]byte, buffer.Len())
+		copy(res, buffer.Bytes())
+		buffer.Reset()
+		bufferPool.Put(buffer)
 
-		return io.ReadAll(reader)
+		return res, err
 	case CompressionSnappy:
 		return snappy.Decode(data)
 	case CompressionLZ4:
@@ -50,11 +70,28 @@ func decompress(cc CompressionCodec, data []byte) ([]byte, error) {
 		} else {
 			reader.Reset(bytes.NewReader(data))
 		}
-		defer lz4ReaderPool.Put(reader)
+		buffer := bufferPool.Get().(*bytes.Buffer)
+		_, err := buffer.ReadFrom(reader)
+		// copy the buffer to a new slice with the correct length
+		// reuse lz4Reader and buffer
+		lz4ReaderPool.Put(reader)
+		res := make([]byte, buffer.Len())
+		copy(res, buffer.Bytes())
+		buffer.Reset()
+		bufferPool.Put(buffer)
 
-		return io.ReadAll(reader)
+		return res, err
 	case CompressionZSTD:
-		return zstdDecompress(ZstdDecoderParams{}, nil, data)
+		buffer := *bytesPool.Get().(*[]byte)
+		var err error
+		buffer, err = zstdDecompress(ZstdDecoderParams{}, buffer, data)
+		// copy the buffer to a new slice with the correct length and reuse buffer
+		res := make([]byte, len(buffer))
+		copy(res, buffer)
+		buffer = buffer[:0]
+		bytesPool.Put(&buffer)
+
+		return res, err
 	default:
 		return nil, PacketDecodingError{fmt.Sprintf("invalid compression specified (%d)", cc)}
 	}