Golang Request.Command方法代码示例

func getQuery(req cmds.Request) (string, error) {
	query := url.Values{}
	for k, v := range req.Options() {
		str := fmt.Sprintf("%v", v)
		query.Set(k, str)
	}

	args := req.Arguments()
	argDefs := req.Command().Arguments

	argDefIndex := 0

	for _, arg := range args {
		argDef := argDefs[argDefIndex]
		// skip ArgFiles
		for argDef.Type == cmds.ArgFile {
			argDefIndex++
			argDef = argDefs[argDefIndex]
		}

		query.Add("arg", arg)

		if len(argDefs) > argDefIndex+1 {
			argDefIndex++
		}
	}

	return query.Encode(), nil
}

// commandShouldRunOnDaemon determines, from commmand details, whether a
// command ought to be executed on an IPFS daemon.
//
// It returns a client if the command should be executed on a daemon and nil if
// it should be executed on a client. It returns an error if the command must
// NOT be executed on either.
func commandShouldRunOnDaemon(details cmdDetails, req cmds.Request, root *cmds.Command) (cmdsHttp.Client, error) {
	path := req.Path()
	// root command.
	if len(path) < 1 {
		return nil, nil
	}

	if details.cannotRunOnClient && details.cannotRunOnDaemon {
		return nil, fmt.Errorf("command disabled: %s", path[0])
	}

	if details.doesNotUseRepo && details.canRunOnClient() {
		return nil, nil
	}

	// at this point need to know whether api is running. we defer
	// to this point so that we dont check unnecessarily

	// did user specify an api to use for this command?
	apiAddrStr, _, err := req.Option(coreCmds.ApiOption).String()
	if err != nil {
		return nil, err
	}

	client, err := getApiClient(req.InvocContext().ConfigRoot, apiAddrStr)
	if err == repo.ErrApiNotRunning {
		if apiAddrStr != "" && req.Command() != daemonCmd {
			// if user SPECIFIED an api, and this cmd is not daemon
			// we MUST use it. so error out.
			return nil, err
		}

		// ok for api not to be running
	} else if err != nil { // some other api error
		return nil, err
	}

	if client != nil { // daemon is running
		if details.cannotRunOnDaemon {
			e := "cannot use API with this command."

			// check if daemon locked. legacy error text, for now.
			daemonLocked, _ := fsrepo.LockedByOtherProcess(req.InvocContext().ConfigRoot)
			if daemonLocked {
				e = "ipfs daemon is running. please stop it to run this command"
			}

			return nil, cmds.ClientError(e)
		}

		return client, nil
	}

	if details.cannotRunOnClient {
		return nil, cmds.ClientError("must run on the ipfs daemon")
	}

	return nil, nil
}

// read json objects off of the given stream, and write the objects out to
// the 'out' channel
func readStreamedJson(req cmds.Request, rr io.Reader, out chan<- interface{}) {
	defer close(out)
	dec := json.NewDecoder(rr)
	outputType := reflect.TypeOf(req.Command().Type)

	ctx := req.Context()

	for {
		v, err := decodeTypedVal(outputType, dec)
		if err != nil {
			if err != io.EOF {
				log.Error(err)
			}
			return
		}

		select {
		case <-ctx.Done():
			return
		case out <- v:
		}
	}
}

// getResponse decodes a http.Response to create a cmds.Response
func getResponse(httpRes *http.Response, req cmds.Request) (cmds.Response, error) {
	var err error
	res := cmds.NewResponse(req)

	contentType := httpRes.Header.Get(contentTypeHeader)
	contentType = strings.Split(contentType, ";")[0]

	lengthHeader := httpRes.Header.Get(contentLengthHeader)
	if len(lengthHeader) > 0 {
		length, err := strconv.ParseUint(lengthHeader, 10, 64)
		if err != nil {
			return nil, err
		}
		res.SetLength(length)
	}

	rr := &httpResponseReader{httpRes}
	res.SetCloser(rr)

	if contentType != applicationJson {
		// for all non json output types, just stream back the output
		res.SetOutput(rr)
		return res, nil

	} else if len(httpRes.Header.Get(channelHeader)) > 0 {
		// if output is coming from a channel, decode each chunk
		outChan := make(chan interface{})

		go readStreamedJson(req, rr, outChan)

		res.SetOutput((<-chan interface{})(outChan))
		return res, nil
	}

	dec := json.NewDecoder(rr)

	// If we ran into an error
	if httpRes.StatusCode >= http.StatusBadRequest {
		e := cmds.Error{}

		switch {
		case httpRes.StatusCode == http.StatusNotFound:
			// handle 404s
			e.Message = "Command not found."
			e.Code = cmds.ErrClient

		case contentType == plainText:
			// handle non-marshalled errors
			mes, err := ioutil.ReadAll(rr)
			if err != nil {
				return nil, err
			}
			e.Message = string(mes)
			e.Code = cmds.ErrNormal

		default:
			// handle marshalled errors
			err = dec.Decode(&e)
			if err != nil {
				return nil, err
			}
		}

		res.SetError(e, e.Code)

		return res, nil
	}

	outputType := reflect.TypeOf(req.Command().Type)
	v, err := decodeTypedVal(outputType, dec)
	if err != nil && err != io.EOF {
		return nil, err
	}

	res.SetOutput(v)

	return res, nil
}