initial spartan server support

1 files changed, 62 insertions, 0 deletions

diff --git a/spartan/request.go b/spartan/request.go
new file mode 100644
index 0000000..331b68c
--- /dev/null
+++ b/spartan/request.go
@@ -0,0 +1,62 @@
+package spartan
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"tildegit.org/tjp/gus"
+)
+
+var (
+	// InvalidRequestLine indicates a malformed first-line of a spartan request.
+	InvalidRequestLine = errors.New("invalid request line")
+
+	// InvalidRequestLineEnding says that a spartan request's first line wasn't terminated with CRLF.
+	InvalidRequestLineEnding = errors.New("invalid request line ending")
+)
+
+// ParseRequest parses a single spartan request and the indicated content-length from a reader.
+//
+// If ther reader artument is a *bufio.Reader, it will only read a single line from it.
+func ParseRequest(rdr io.Reader) (*gus.Request, int, error) {
+	bufrdr, ok := rdr.(*bufio.Reader)
+	if !ok {
+		bufrdr = bufio.NewReader(rdr)
+	}
+
+	line, err := bufrdr.ReadString('\n')
+	if err != io.EOF && err != nil {
+		return nil, 0, err
+	}
+
+	host, rest, ok := strings.Cut(line, " ")
+	if !ok {
+		return nil, 0, InvalidRequestLine
+	}
+	path, rest, ok := strings.Cut(line, " ")
+	if !ok {
+		return nil, 0, InvalidRequestLine
+	}
+
+	if len(rest) < 2 || line[len(line)-2:] != "\r\n" {
+		return nil, 0, InvalidRequestLineEnding
+	}
+
+	contentlen, err := strconv.Atoi(line[:len(line)-2])
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return &gus.Request{
+		URL: &url.URL{
+			Scheme:  "spartan",
+			Host:    host,
+			Path:    path,
+			RawPath: path,
+		},
+	}, contentlen, nil
+}