Use buffered IO

This commit is contained in:
adnano 2020-09-24 19:02:03 -04:00
parent 891c4fbec4
commit 3980cfd28f
2 changed files with 119 additions and 81 deletions

View File

@ -26,13 +26,10 @@ func main() {
config.ClientAuth = tls.RequestClientCert
mux := &gemini.Mux{}
mux.HandleFunc("/", func(req *gemini.Request) *gemini.Response {
mux.HandleFunc("/", func(rw gemini.ResponseWriter, req *gemini.Request) {
log.Printf("Request from %s for %s with certificates %v", req.RemoteAddr.String(), req.URL.String(), req.TLS.PeerCertificates)
return &gemini.Response{
Status: gemini.StatusSuccess,
Meta: "text/gemini",
Body: []byte("You requested " + req.URL.String()),
}
rw.WriteHeader(gemini.StatusSuccess, "text/gemini")
rw.Write([]byte("You requested " + req.URL.String()))
})
server := gemini.Server{

191
gemini.go
View File

@ -3,7 +3,6 @@ package gemini
import (
"bufio"
"bytes"
"crypto/tls"
"errors"
"io"
@ -50,8 +49,13 @@ const (
// Errors.
var (
ErrProtocol = errors.New("Protocol error")
ErrInvalidURL = errors.New("Invalid URL")
ErrProtocol = errors.New("gemini: protocol error")
ErrInvalidURL = errors.New("gemini: requested URL is invalid")
ErrBodyNotAllowed = errors.New("gemini: response status code does not allow for body")
)
var (
crlf = []byte("\r\n")
)
// Request is a Gemini request.
@ -70,7 +74,8 @@ type Request struct {
URL *url.URL
// For client requests, Host specifies the host on which the URL is sought.
// If this field is not set, the host will be inferred from the URL.
// If this field is empty, the host will be inferred from the URL.
// This field is ignored by the server.
Host string
@ -126,16 +131,20 @@ func NewProxyRequest(host, rawurl string) (*Request, error) {
}, nil
}
// Write writes the Gemini request to the provided io.Writer.
func (r *Request) Write(w io.Writer) error {
// write writes the Gemini request to the provided buffered writer.
func (r *Request) write(w *bufio.Writer) error {
url := r.URL.String()
// UserInfo is invalid
if r.URL.User != nil || len(url) > 1024 {
return ErrInvalidURL
}
request := url + "\r\n"
_, err := w.Write([]byte(request))
return err
if _, err := w.WriteString(url); err != nil {
return err
}
if _, err := w.Write(crlf); err != nil {
return err
}
return nil
}
// Response is a Gemini response.
@ -159,21 +168,21 @@ type Response struct {
TLS tls.ConnectionState
}
// Write writes the Gemini response header and body to the provided io.Writer.
func (r *Response) Write(w io.Writer) error {
header := strconv.Itoa(r.Status) + " " + r.Meta + "\r\n"
if _, err := w.Write([]byte(header)); err != nil {
return err
}
// ResponseWriter is used by a Gemini handler to construct a Gemini response.
type ResponseWriter interface {
// WriteHeader writes the response header.
//
// Meta contains more information related to the response status.
// For successful responses, Meta should contain the mimetype of the response.
// For failure responses, Meta should contain a short description of the failure.
// Meta should not be longer than 1024 bytes.
WriteHeader(status int, meta string)
// Only write the response body on success
if r.Status/10 == StatusClassSuccess {
if _, err := w.Write(r.Body); err != nil {
return err
}
}
return nil
// Write writes the response body.
// If the response status does not allow for a response body, Write returns
// ErrBodyNotAllowed.
// WriteHeader must be called before Write.
Write([]byte) (int, error)
}
// Get makes a request for the provided URL. The host is inferred from the URL.
@ -204,47 +213,61 @@ func Do(req *Request) (*Response, error) {
defer conn.Close()
// Write the request
if err := req.Write(conn); err != nil {
// TODO: Is buffered I/O necessary here?
w := bufio.NewWriter(conn)
req.write(w)
if err := w.Flush(); err != nil {
return nil, err
}
// Read the response
b, err := ioutil.ReadAll(conn)
if err != nil {
// Read the response status
r := bufio.NewReader(conn)
statusB := make([]byte, 2)
if _, err := r.Read(statusB); err != nil {
return nil, err
}
// Ensure that the response is long enough
// The minimum response: <STATUS><SPACE><CR><LF> (5 bytes)
if len(b) < 5 {
return nil, ErrProtocol
}
// Parse the response header
status, err := strconv.Atoi(string(b[:2]))
status, err := strconv.Atoi(string(statusB))
if err != nil {
return nil, err
}
// Read one space
if b[2] != ' ' {
return nil, ErrProtocol
}
// Find the first <CR><LF>
i := bytes.Index(b, []byte("\r\n"))
if i < 3 {
if b, err := r.ReadByte(); err != nil {
return nil, err
} else if b != ' ' {
return nil, ErrProtocol
}
// Read the meta
meta := string(b[3:i])
meta, err := r.ReadString('\r')
if err != nil {
return nil, err
}
// Read terminating newline
if b, err := r.ReadByte(); err != nil {
return nil, err
} else if b != '\n' {
return nil, ErrProtocol
}
// Trim carriage return
meta = meta[:len(meta)-1]
// Ensure meta is less than 1024 bytes
if len(meta) > 1024 {
return nil, ErrProtocol
}
// Read the response body
body := b[i+2:]
// Read response body
var body []byte
if status/10 == StatusClassSuccess {
var err error
body, err = ioutil.ReadAll(r)
if err != nil {
return nil, err
}
}
return &Response{
Status: status,
@ -316,26 +339,47 @@ func (s *Server) Serve(l net.Listener) error {
}
}
// response represents the server side of a Gemini response.
type response struct {
w *bufio.Writer
bodyAllowed bool
}
func newResponse(conn net.Conn) *response {
return &response{
w: bufio.NewWriter(conn),
}
}
func (r *response) WriteHeader(status int, meta string) {
r.w.WriteString(strconv.Itoa(status))
r.w.WriteByte(' ')
r.w.WriteString(meta)
r.w.Write(crlf)
// Only allow body to be written on successful status codes.
if status/10 == StatusClassSuccess {
r.bodyAllowed = true
}
}
func (r *response) Write(b []byte) (int, error) {
if !r.bodyAllowed {
return 0, ErrBodyNotAllowed
}
return r.w.Write(b)
}
// respond responds to a connection.
func (s *Server) respond(rw net.Conn) {
var resp *Response
resp := newResponse(rw)
if rawurl, err := readLine(rw); err != nil {
resp = &Response{
Status: StatusBadRequest,
Meta: "Bad request",
}
resp.WriteHeader(StatusBadRequest, "Bad request")
} else if len(rawurl) > 1024 {
resp = &Response{
Status: StatusBadRequest,
Meta: "Requested URL exceeds 1024 bytes",
}
resp.WriteHeader(StatusBadRequest, "Requested URL exceeds 1024 bytes")
} else if url, err := url.Parse(rawurl); err != nil || url.User != nil {
// Note that we return an error if User is specified in the URL.
resp = &Response{
Status: StatusBadRequest,
Meta: "Requested URL is invalid",
}
resp.WriteHeader(StatusBadRequest, "Requested URL is invalid")
} else {
// Gather information about the request
req := &Request{
@ -343,17 +387,16 @@ func (s *Server) respond(rw net.Conn) {
RemoteAddr: rw.RemoteAddr(),
TLS: rw.(*tls.Conn).ConnectionState(),
}
resp = s.Handler.Serve(req)
s.Handler.Serve(resp, req)
}
resp.Write(rw)
resp.w.Flush()
rw.Close()
}
// A Handler responds to a Gemini request.
type Handler interface {
// Serve accepts a Request and returns a Response.
Serve(*Request) *Response
// Serve accepts a Request and constructs a Response.
Serve(ResponseWriter, *Request)
}
// Mux is a Gemini request multiplexer.
@ -397,28 +440,26 @@ func (m *Mux) Handle(pattern string, handler Handler) {
}
// HandleFunc registers a HandlerFunc for the given pattern.
func (m *Mux) HandleFunc(pattern string, handlerFunc func(req *Request) *Response) {
func (m *Mux) HandleFunc(pattern string, handlerFunc func(ResponseWriter, *Request)) {
handler := HandlerFunc(handlerFunc)
m.Handle(pattern, handler)
}
// Serve responds to the request with the appropriate handler.
func (m *Mux) Serve(req *Request) *Response {
func (m *Mux) Serve(rw ResponseWriter, req *Request) {
h := m.match(req.URL)
if h == nil {
return &Response{
Status: StatusNotFound,
Meta: "Not found",
}
rw.WriteHeader(StatusNotFound, "Not found")
return
}
return h.Serve(req)
h.Serve(rw, req)
}
// A wrapper around a bare function that implements Handler.
type HandlerFunc func(req *Request) *Response
type HandlerFunc func(ResponseWriter, *Request)
func (f HandlerFunc) Serve(req *Request) *Response {
return f(req)
func (f HandlerFunc) Serve(rw ResponseWriter, req *Request) {
f(rw, req)
}
// readLine reads a line.