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|
package fzf
import (
"bufio"
"bytes"
"errors"
"fmt"
"net"
"strconv"
"strings"
)
const (
crlf = "\r\n"
httpOk = "HTTP/1.1 200 OK" + crlf
httpBadRequest = "HTTP/1.1 400 Bad Request" + crlf
)
func startHttpServer(port int, channel chan []*action) {
if port == 0 {
return
}
listener, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
if err != nil {
return
}
go func() {
for {
conn, err := listener.Accept()
if err != nil {
if errors.Is(err, net.ErrClosed) {
break
} else {
continue
}
}
conn.Write([]byte(handleHttpRequest(conn, channel)))
conn.Close()
}
listener.Close()
}()
}
// Here we are writing a simplistic HTTP server without using net/http
// package to reduce the size of the binary.
//
// * No --listen: 2.8MB
// * --listen with net/http: 5.7MB
// * --listen w/o net/http: 3.3MB
func handleHttpRequest(conn net.Conn, channel chan []*action) string {
line := 0
headerRead := false
contentLength := 0
body := ""
bad := func(message string) string {
message += "\n"
return httpBadRequest + fmt.Sprintf("Content-Length: %d%s", len(message), crlf+crlf+message)
}
scanner := bufio.NewScanner(conn)
scanner.Split(func(data []byte, atEOF bool) (int, []byte, error) {
found := bytes.Index(data, []byte(crlf))
if found >= 0 {
token := data[:found+len(crlf)]
return len(token), token, nil
}
if atEOF || len(body)+len(data) >= contentLength {
return 0, data, bufio.ErrFinalToken
}
return 0, nil, nil
})
for scanner.Scan() {
text := scanner.Text()
if line == 0 && !strings.HasPrefix(text, "POST / HTTP") {
return bad("invalid request method")
}
if text == crlf {
headerRead = true
}
if !headerRead {
pair := strings.SplitN(text, ":", 2)
if len(pair) == 2 && strings.ToLower(pair[0]) == "content-length" {
length, err := strconv.Atoi(strings.TrimSpace(pair[1]))
if err != nil {
return bad("invalid content length")
}
contentLength = length
}
} else if contentLength <= 0 {
break
} else {
body += text
}
line++
}
errorMessage := ""
actions := parseSingleActionList(strings.TrimSpace(string(body)), func(message string) {
errorMessage = message
})
if len(errorMessage) > 0 {
return bad(errorMessage)
}
if len(actions) == 0 {
return bad("no action specified")
}
channel <- actions
return httpOk
}
|
