feat:support zstd compress and uncompressed (#1701)

* feat:support zstd compress and uncompressed

* fix:real & stackless write using different pool to avoid get stackless.writer

* fix:zstd normalize compress level

* Change empty string checks to be more idiomatic (#1684)

* chore:lint fix and rebase with master

* chore:remove 1.18 test & upgrade compress version

* fix:error default compress level

* Fix lint

---------

Co-authored-by: Erik Dubbelboer <erik@dubbelboer.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/zstd_test.go b/zstd_test.go
new file mode 100644
index 0000000..dc0c45f
--- /dev/null
+++ b/zstd_test.go
@@ -0,0 +1,102 @@
+package fasthttp
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"testing"
+)
+
+func TestZstdBytesSerial(t *testing.T) {
+	t.Parallel()
+
+	if err := testZstdBytes(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestZstdBytesConcurrent(t *testing.T) {
+	t.Parallel()
+
+	if err := testConcurrent(10, testZstdBytes); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func testZstdBytes() error {
+	for _, s := range compressTestcases {
+		if err := testZstdBytesSingleCase(s); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func testZstdBytesSingleCase(s string) error {
+	prefix := []byte("foobar")
+	ZstdpedS := AppendZstdBytes(prefix, []byte(s))
+	if !bytes.Equal(ZstdpedS[:len(prefix)], prefix) {
+		return fmt.Errorf("unexpected prefix when compressing %q: %q. Expecting %q", s, ZstdpedS[:len(prefix)], prefix)
+	}
+
+	unZstdedS, err := AppendUnzstdBytes(prefix, ZstdpedS[len(prefix):])
+	if err != nil {
+		return fmt.Errorf("unexpected error when uncompressing %q: %w", s, err)
+	}
+	if !bytes.Equal(unZstdedS[:len(prefix)], prefix) {
+		return fmt.Errorf("unexpected prefix when uncompressing %q: %q. Expecting %q", s, unZstdedS[:len(prefix)], prefix)
+	}
+	unZstdedS = unZstdedS[len(prefix):]
+	if string(unZstdedS) != s {
+		return fmt.Errorf("unexpected uncompressed string %q. Expecting %q", unZstdedS, s)
+	}
+	return nil
+}
+
+func TestZstdCompressSerial(t *testing.T) {
+	t.Parallel()
+
+	if err := testZstdCompress(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestZstdCompressConcurrent(t *testing.T) {
+	t.Parallel()
+
+	if err := testConcurrent(10, testZstdCompress); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func testZstdCompress() error {
+	for _, s := range compressTestcases {
+		if err := testZstdCompressSingleCase(s); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func testZstdCompressSingleCase(s string) error {
+	var buf bytes.Buffer
+	zw := acquireStacklessZstdWriter(&buf, CompressZstdDefault)
+	if _, err := zw.Write([]byte(s)); err != nil {
+		return fmt.Errorf("unexpected error: %w. s=%q", err, s)
+	}
+	releaseStacklessZstdWriter(zw, CompressZstdDefault)
+
+	zr, err := acquireZstdReader(&buf)
+	if err != nil {
+		return fmt.Errorf("unexpected error: %w. s=%q", err, s)
+	}
+	body, err := io.ReadAll(zr)
+	if err != nil {
+		return fmt.Errorf("unexpected error: %w. s=%q", err, s)
+	}
+	if string(body) != s {
+		return fmt.Errorf("unexpected string after decompression: %q. Expecting %q", body, s)
+	}
+	releaseZstdReader(zr)
+	return nil
+}