1 files changed, 60 insertions, 0 deletions
diff --git a/system/api/gzip.go b/system/api/gzip.go
new file mode 100644
index 0000000..9f50cf7
--- /dev/null
+++ b/system/api/gzip.go
@@ -0,0 +1,60 @@
+package api
+
+import (
+	"compress/gzip"
+	"net/http"
+	"strings"
+
+	"github.com/ponzu-cms/ponzu/system/db"
+)
+
+// Gzip wraps a HandlerFunc to compress responses when possible
+func Gzip(next http.HandlerFunc) http.HandlerFunc {
+	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
+		if db.ConfigCache("gzip_disabled").(bool) == true {
+			next.ServeHTTP(res, req)
+			return
+		}
+
+		// check if req header content-encoding supports gzip
+		if strings.Contains(req.Header.Get("Accept-Encoding"), "gzip") {
+			// gzip response data
+			res.Header().Set("Content-Encoding", "gzip")
+			var gzres gzipResponseWriter
+			if pusher, ok := res.(http.Pusher); ok {
+				gzres = gzipResponseWriter{res, pusher, gzip.NewWriter(res)}
+			} else {
+				gzres = gzipResponseWriter{res, nil, gzip.NewWriter(res)}
+			}
+
+			next.ServeHTTP(gzres, req)
+			return
+		}
+
+		next.ServeHTTP(res, req)
+	})
+}
+
+type gzipResponseWriter struct {
+	http.ResponseWriter
+	pusher http.Pusher
+
+	gw *gzip.Writer
+}
+
+func (gzw gzipResponseWriter) Write(p []byte) (int, error) {
+	defer gzw.gw.Close()
+	return gzw.gw.Write(p)
+}
+
+func (gzw gzipResponseWriter) Push(target string, opts *http.PushOptions) error {
+	if opts == nil {
+		opts = &http.PushOptions{
+			Header: make(http.Header),
+		}
+	}
+
+	opts.Header.Set("Accept-Encoding", "gzip")
+
+	return gzw.pusher.Push(target, opts)
+}