Initial commit

application/controller/static.go

@@ -0,0 +1,154 @@
+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package controller
+
+import (
+	"mime"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/niruix/sshwifty/application/log"
+)
+
+type staticData struct {
+	data          []byte
+	dataHash      string
+	compressd     []byte
+	compressdHash string
+	created       time.Time
+}
+
+func (s staticData) hasCompressed() bool {
+	return len(s.compressd) > 0
+}
+
+func staticFileExt(fileName string) string {
+	extIdx := strings.LastIndex(fileName, ".")
+
+	if extIdx < 0 {
+		return ""
+	}
+
+	return strings.ToLower(fileName[extIdx:])
+}
+
+func serveStaticPage(
+	dataName string,
+	w http.ResponseWriter,
+	r *http.Request,
+	l log.Logger,
+) error {
+	d, dFound := staticPages[dataName]
+
+	if !dFound {
+		return ErrNotFound
+	}
+
+	selectedData := d.data
+
+	if clientSupportGZIP(r) && d.hasCompressed() {
+		selectedData = d.compressd
+
+		w.Header().Add("Vary", "Accept-Encoding")
+		w.Header().Add("Content-Encoding", "gzip")
+	}
+
+	mimeType := mime.TypeByExtension(staticFileExt(dataName))
+
+	if len(mimeType) > 0 {
+		w.Header().Add("Content-Type", mimeType)
+	} else {
+		w.Header().Add("Content-Type", "application/binary")
+	}
+
+	_, wErr := w.Write(selectedData)
+
+	return wErr
+}
+
+func serveStaticData(
+	dataName string,
+	w http.ResponseWriter,
+	r *http.Request,
+	l log.Logger,
+) error {
+	if strings.ToUpper(r.Method) != "GET" {
+		return ErrControllerNotImplemented
+	}
+
+	fileExt := staticFileExt(dataName)
+
+	if fileExt == ".html" || fileExt == ".htm" {
+		return ErrNotFound
+	}
+
+	d, dFound := staticPages[dataName]
+
+	if !dFound {
+		return ErrNotFound
+	}
+
+	selectedData := d.data
+	selectedDataHash := d.dataHash
+	compressEnabled := false
+
+	if clientSupportGZIP(r) && d.hasCompressed() {
+		selectedData = d.compressd
+		selectedDataHash = d.compressdHash
+
+		compressEnabled = true
+
+		w.Header().Add("Vary", "Accept-Encoding")
+	}
+
+	canUseCache := true
+
+	if !clientContentEtagIsValid(r, selectedDataHash) {
+		canUseCache = false
+	}
+
+	if clientContentModifiedSince(r, d.created) {
+		canUseCache = false
+	}
+
+	if canUseCache {
+		w.WriteHeader(http.StatusNotModified)
+
+		return nil
+	}
+
+	w.Header().Add("Cache-Control", "public, max-age=31536000")
+	w.Header().Add("ETag", "\""+selectedDataHash+"\"")
+
+	mimeType := mime.TypeByExtension(fileExt)
+
+	if len(mimeType) > 0 {
+		w.Header().Add("Content-Type", mimeType)
+	} else {
+		w.Header().Add("Content-Type", "application/binary")
+	}
+
+	if compressEnabled {
+		w.Header().Add("Content-Encoding", "gzip")
+	}
+
+	_, wErr := w.Write([]byte(selectedData))
+
+	return wErr
+}