diff --git a/cmd/circologd/http.go b/cmd/circologd/http.go index 5832a11..718d4a2 100644 --- a/cmd/circologd/http.go +++ b/cmd/circologd/http.go @@ -1,9 +1,9 @@ package main import ( - "fmt" + "errors" + "log" "net/http" - "os" "strconv" "time" @@ -12,57 +12,65 @@ import ( "gopkg.in/mcuadros/go-syslog.v2/format" ) +type requestParams struct { + // Add here the expected request parameters + errorList map[string]error + requestMessageLen int +} + func setupHTTP(hub circolog.Hub) { http.HandleFunc("/", getHTTPHandler(hub)) http.HandleFunc("/ws", getWSHandler(hub)) } +func parseParameterL(r *http.Request) (int, error) { + var requestMessageLen int + var err error + if reqL, ok := r.Form["l"]; ok { + if len(reqL) == 1 { + requestMessageLen, err = strconv.Atoi(reqL[0]) + if err != nil { + return 0, err + } + if requestMessageLen <= 0 { + return 0, errors.New("malformed request") + } + } else { + return 0, errors.New("malformed request") + } + } + return requestMessageLen, nil +} + +func (p *requestParams) parseParameters(w http.ResponseWriter, r *http.Request) { + err := r.ParseForm() + if err != nil { + log.Println("error parsing http request", err) + } + p.errorList = make(map[string]error, 1) + p.requestMessageLen, p.errorList["l"] = parseParameterL(r) +} + func getHTTPHandler(hub circolog.Hub) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { + // Looking for known parameter in the request + var params requestParams + params.parseParameters(w, r) + if params.errorList["l"] != nil { + log.Println("Request parameter \"l\":", params.errorList["l"]) + w.WriteHeader(400) + return + } + client := circolog.Client{ Messages: make(chan format.LogParts, 20), + LastMsg: params.requestMessageLen, Nofollow: true} hub.Register <- client - err := r.ParseForm() - if err != nil { - fmt.Fprintln(os.Stderr, "error parsing http request", err) - } - // Looking for known parameter in the request - // TODO: write specialized function - var requestMessageLen int - if reqL, ok := r.Form["l"]; ok { - var err error - switch { - case len(reqL) == 1: - requestMessageLen, err = strconv.Atoi(reqL[0]) - if requestMessageLen <= 0 { - fmt.Fprintln(os.Stderr, "malformed request, l non positive:", requestMessageLen) - //requestMessageLen := 0 - } - if err != nil { - fmt.Fprintln(os.Stderr, "malformed request on parameter l:", err) - } - case len(reqL) > 1: - requestMessageLen, err = strconv.Atoi(reqL[len(reqL)-1]) - fmt.Fprintln(os.Stderr, "multiple values of l parameter, taking last:", - requestMessageLen) - if err != nil { - fmt.Fprintln(os.Stderr, "malformed request on parameter l:", err) - } - default: - fmt.Fprintln(os.Stderr, "empty parameter l in request") - } - } - - i := 1 for x := range client.Messages { w.Write([]byte(circolog.FormatSyslog(x))) w.Write([]byte("\n")) - if requestMessageLen != 0 && i >= requestMessageLen { - break - } - i++ } } } diff --git a/hub.go b/hub.go index b653dc1..dfa0199 100644 --- a/hub.go +++ b/hub.go @@ -11,6 +11,7 @@ import ( // new messages are sent. type Client struct { Messages chan format.LogParts // only hub should write/close this + LastMsg int // The number of last messages to display Nofollow bool // if Nofollow is true, the hub will not keep this client permanently. Rather, it will send every message to "Messages" and close the channel. Use this if you want to get the messages one-shot }