Initial commit

application/application.go

@@ -0,0 +1,176 @@
+// 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 application
+
+import (
+	"fmt"
+	"io"
+	goLog "log"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	"github.com/niruix/sshwifty/application/configuration"
+	"github.com/niruix/sshwifty/application/log"
+	"github.com/niruix/sshwifty/application/server"
+)
+
+// ProccessSignaller send signal to the running application
+type ProccessSignaller chan os.Signal
+
+// ProccessSignallerBuilder builds a ProccessSignaler
+type ProccessSignallerBuilder func() chan os.Signal
+
+// DefaultProccessSignallerBuilder the default ProccessSignallerBuilder
+func DefaultProccessSignallerBuilder() chan os.Signal {
+	return make(chan os.Signal, 1)
+}
+
+var (
+	screenLineWipper = []byte("\r")
+)
+
+// Application contains data required for the application, and yes I don't like
+// to write comments
+type Application struct {
+	screen io.Writer
+	logger log.Logger
+}
+
+// New creates a new Application
+func New(screen io.Writer, logger log.Logger) Application {
+	return Application{
+		screen: screen,
+		logger: logger,
+	}
+}
+
+// Run execute the application. It will return when the application is finished
+// running
+func (a Application) run(
+	cLoader configuration.Loader,
+	closeSigBuilder ProccessSignallerBuilder,
+	handlerBuilder server.HandlerBuilder,
+) (bool, error) {
+	var err error
+
+	loaderName, c, cErr := cLoader(a.logger.Context("Configuration"))
+
+	if cErr != nil {
+		a.logger.Error("\"%s\" loader cannot load configuration: %s",
+			loaderName, cErr)
+
+		return false, cErr
+	}
+
+	err = c.Verify()
+
+	if err != nil {
+		a.logger.Error("Configuration was invalid: %s", err)
+
+		return false, err
+	}
+
+	closeNotify := closeSigBuilder()
+	signal.Notify(closeNotify, os.Kill, os.Interrupt, syscall.SIGHUP)
+	defer signal.Stop(closeNotify)
+
+	servers := make([]*server.Serving, 0, len(c.Servers))
+	s := server.New(a.logger)
+
+	defer func() {
+		for i := len(servers); i > 0; i-- {
+			servers[i-1].Close()
+		}
+
+		s.Wait()
+	}()
+
+	closeNotifyDisableLock := sync.Mutex{}
+
+	for _, ss := range c.Servers {
+		newServer := s.Serve(c.Common(), ss, func(e error) {
+			closeNotifyDisableLock.Lock()
+			defer closeNotifyDisableLock.Unlock()
+
+			if closeNotify == nil {
+				return
+			}
+
+			err = e
+
+			close(closeNotify)
+			closeNotify = nil
+		}, handlerBuilder)
+
+		servers = append(servers, newServer)
+	}
+
+	switch <-closeNotify {
+	case syscall.SIGHUP:
+		return true, nil
+
+	case os.Kill:
+		fallthrough
+	case os.Interrupt:
+		a.screen.Write(screenLineWipper)
+
+		return false, nil
+
+	default:
+		closeNotifyDisableLock.Lock()
+		defer closeNotifyDisableLock.Unlock()
+
+		return false, err
+	}
+}
+
+// Run execute the application. It will return when the application is finished
+// running
+func (a Application) Run(
+	cLoader configuration.Loader,
+	closeSigBuilder ProccessSignallerBuilder,
+	handlerBuilder server.HandlerBuilder,
+) error {
+	fmt.Fprintf(a.screen, banner, FullName, version, Author, URL)
+
+	goLog.SetOutput(a.logger)
+	defer goLog.SetOutput(os.Stderr)
+
+	a.logger.Info("Initializing")
+	defer a.logger.Info("Closed")
+
+	for {
+		restart, runErr := a.run(cLoader, closeSigBuilder, handlerBuilder)
+
+		if runErr != nil {
+			a.logger.Error("Unable to start due to error: %s", runErr)
+
+			return runErr
+		}
+
+		if restart {
+			a.logger.Info("Restarting")
+
+			continue
+		}
+
+		return nil
+	}
+}