Implement encode middleware (#2)

* Implement encode middleware

* Add missing break; and add missing JSON struct field tag

1 files changed, 36 insertions, 0 deletions

diff --git a/modules/caddyhttp/encode/gzip/gzip.go b/modules/caddyhttp/encode/gzip/gzip.go
new file mode 100644
index 0000000..0da5fc3
--- /dev/null
+++ b/modules/caddyhttp/encode/gzip/gzip.go
@@ -0,0 +1,36 @@
+package caddygzip
+
+import (
+	"compress/flate"
+	"compress/gzip" // TODO: consider using https://github.com/klauspost/compress/gzip
+
+	"github.com/caddyserver/caddy2"
+	"github.com/caddyserver/caddy2/modules/caddyhttp/encode"
+)
+
+func init() {
+	caddy2.RegisterModule(caddy2.Module{
+		Name: "http.encoders.gzip",
+		New:  func() interface{} { return new(Gzip) },
+	})
+}
+
+// Gzip can create gzip encoders.
+type Gzip struct {
+	Level int `json:"level,omitempty"`
+}
+
+// NewEncoder returns a new gzip writer.
+func (g Gzip) NewEncoder() encode.Encoder {
+	if g.Level <= flate.NoCompression {
+		g.Level = defaultGzipLevel
+	}
+	if g.Level > flate.BestCompression {
+		g.Level = flate.BestCompression
+	}
+	writer, _ := gzip.NewWriterLevel(nil, g.Level)
+	return writer
+}
+
+// Informed from http://blog.klauspost.com/gzip-performance-for-go-webservers/
+var defaultGzipLevel = 5