Figured out it was the filters for XZ that was causing problems

Added lzma and xz decompression.
Renamed Zlib to Gzip

internal/compression/gzip.go

@@ -0,0 +1,40 @@
+package compression
+
+import (
+	"bytes"
+	"compress/zlib"
+	"io"
+)
+
+//Gzip is a decompressor for gzip type compression. Uses zlib for compression and decompression
+type Gzip struct{}
+
+//Decompress reads the entirety of the given reader and returns it uncompressed as a byte slice.
+func (g *Gzip) Decompress(r io.Reader) ([]byte, error) {
+	rdr, err := zlib.NewReader(r)
+	if err != nil {
+		return nil, err
+	}
+	var data bytes.Buffer
+	_, err = io.Copy(&data, rdr)
+	if err != nil {
+		return nil, err
+	}
+	return data.Bytes(), nil
+}
+
+//Compress compresses the given data (as a byte array) and returns the compressed data.
+func (g *Gzip) Compress(data []byte) ([]byte, error) {
+	var buf bytes.Buffer
+	wrt := zlib.NewWriter(&buf)
+	defer wrt.Close()
+	_, err := wrt.Write(data)
+	if err != nil {
+		return nil, err
+	}
+	err = wrt.Flush()
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}