Initial QSfera import

Server/vendor/github.com/segmentio/kafka-go/compress/lz4/lz4.go

@@ -0,0 +1,68 @@
+package lz4
+
+import (
+	"io"
+	"sync"
+
+	"github.com/pierrec/lz4/v4"
+)
+
+var (
+	readerPool sync.Pool
+	writerPool sync.Pool
+)
+
+// Codec is the implementation of a compress.Codec which supports creating
+// readers and writers for kafka messages compressed with lz4.
+type Codec struct{}
+
+// Code implements the compress.Codec interface.
+func (c *Codec) Code() int8 { return 3 }
+
+// Name implements the compress.Codec interface.
+func (c *Codec) Name() string { return "lz4" }
+
+// NewReader implements the compress.Codec interface.
+func (c *Codec) NewReader(r io.Reader) io.ReadCloser {
+	z, _ := readerPool.Get().(*lz4.Reader)
+	if z != nil {
+		z.Reset(r)
+	} else {
+		z = lz4.NewReader(r)
+	}
+	return &reader{Reader: z}
+}
+
+// NewWriter implements the compress.Codec interface.
+func (c *Codec) NewWriter(w io.Writer) io.WriteCloser {
+	z, _ := writerPool.Get().(*lz4.Writer)
+	if z != nil {
+		z.Reset(w)
+	} else {
+		z = lz4.NewWriter(w)
+	}
+	return &writer{Writer: z}
+}
+
+type reader struct{ *lz4.Reader }
+
+func (r *reader) Close() (err error) {
+	if z := r.Reader; z != nil {
+		r.Reader = nil
+		z.Reset(nil)
+		readerPool.Put(z)
+	}
+	return
+}
+
+type writer struct{ *lz4.Writer }
+
+func (w *writer) Close() (err error) {
+	if z := w.Writer; z != nil {
+		w.Writer = nil
+		err = z.Close()
+		z.Reset(nil)
+		writerPool.Put(z)
+	}
+	return
+}