initial spartan server support

1 files changed, 95 insertions, 0 deletions

diff --git a/spartan/serve.go b/spartan/serve.go
new file mode 100644
index 0000000..677d76c
--- /dev/null
+++ b/spartan/serve.go
@@ -0,0 +1,95 @@
+package spartan
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"strings"
+
+	"tildegit.org/tjp/gus"
+	"tildegit.org/tjp/gus/internal"
+	"tildegit.org/tjp/gus/logging"
+)
+
+type spartanRequestBodyKey struct{}
+type spartanRequestBodyLenKey struct{}
+
+// SpartanRequestBody is the key set in a handler's context for spartan request bodies.
+//
+// The corresponding value is a *bufio.Reader from which the request body can be read.
+var SpartanRequestBody = spartanRequestBodyKey{}
+
+// SpartanRequestBodyLen is the key set in a handler's context for the content-length of the request.
+//
+// The corresponding value is an int.
+var SpartanRequestBodyLen = spartanRequestBodyLenKey{}
+
+type spartanServer struct {
+	internal.Server
+	handler gus.Handler
+}
+
+func (ss spartanServer) Protocol() string { return "SPARTAN" }
+
+// NewServer builds a spartan server.
+func NewServer(
+	ctx context.Context,
+	hostname string,
+	network string,
+	address string,
+	handler gus.Handler,
+	errLog logging.Logger,
+) (gus.Server, error) {
+	ss := &spartanServer{handler: handler}
+
+	if strings.IndexByte(hostname, ':') < 0 {
+		hostname = net.JoinHostPort(hostname, "300")
+	}
+
+	var err error
+	ss.Server, err = internal.NewServer(ctx, hostname, network, address, errLog, ss.handleConn)
+	if err != nil {
+		return nil, err
+	}
+
+	return ss, nil
+}
+
+func (ss *spartanServer) handleConn(conn net.Conn) {
+	buf := bufio.NewReader(conn)
+
+	var response *gus.Response
+	request, clen, err := ParseRequest(buf)
+	if err != nil {
+		response = ClientError(err)
+	} else {
+		request.Server = ss
+		request.RemoteAddr = conn.RemoteAddr()
+
+		var body *bufio.Reader = nil
+		if clen > 0 {
+			body = bufio.NewReader(io.LimitReader(buf, int64(clen)))
+		}
+		ctx := context.WithValue(ss.Ctx, SpartanRequestBody, body)
+		ctx = context.WithValue(ctx, SpartanRequestBodyLen, clen)
+
+		defer func() {
+			if r := recover(); r != nil {
+				err := fmt.Errorf("%s", r)
+				_ = ss.LogError("msg", "panic in handler", "err", err)
+				rdr := NewResponseReader(ServerError(errors.New("Server error")))
+				_, _ = io.Copy(conn, rdr)
+			}
+		}()
+		response = ss.handler.Handle(ctx, request)
+		if response == nil {
+			response = ClientError(errors.New("Resource does not exist."))
+		}
+	}
+
+	defer response.Close()
+	_, _ = io.Copy(conn, NewResponseReader(response))
+}