Golang go-ipfs-util.ErrCast函數代碼示例

func ParseArgs(req cmds.Request, inputs []string, stdin *os.File, argDefs []cmds.Argument, root *cmds.Command) ([]string, []files.File, error) {
	var err error

	// if -r is provided, and it is associated with the package builtin
	// recursive path option, allow recursive file paths
	recursiveOpt := req.Option(cmds.RecShort)
	recursive := false
	if recursiveOpt != nil && recursiveOpt.Definition() == cmds.OptionRecursivePath {
		recursive, _, err = recursiveOpt.Bool()
		if err != nil {
			return nil, nil, u.ErrCast()
		}
	}

	// if '--hidden' is provided, enumerate hidden paths
	hiddenOpt := req.Option("hidden")
	hidden := false
	if hiddenOpt != nil {
		hidden, _, err = hiddenOpt.Bool()
		if err != nil {
			return nil, nil, u.ErrCast()
		}
	}
	return parseArgs(inputs, stdin, argDefs, recursive, hidden, root)
}

func getPsMsgMarshaler(f func(m *floodsub.Message) (io.Reader, error)) func(cmds.Response) (io.Reader, error) {
	return func(res cmds.Response) (io.Reader, error) {
		outChan, ok := res.Output().(<-chan interface{})
		if !ok {
			return nil, u.ErrCast()
		}

		marshal := func(v interface{}) (io.Reader, error) {
			obj, ok := v.(*floodsub.Message)
			if !ok {
				return nil, u.ErrCast()
			}
			if obj.Message == nil {
				return strings.NewReader(""), nil
			}

			return f(obj)
		}

		return &cmds.ChannelMarshaler{
			Channel:   outChan,
			Marshaler: marshal,
			Res:       res,
		}, nil
	}
}

func objectMarshaler(res cmds.Response) (io.Reader, error) {
	o, ok := res.Output().(*Object)
	if !ok {
		return nil, u.ErrCast()
	}

	return strings.NewReader(o.Hash + "\n"), nil
}

func bootstrapMarshaler(res cmds.Response) (io.Reader, error) {
	v, ok := res.Output().(*BootstrapOutput)
	if !ok {
		return nil, u.ErrCast()
	}

	buf := new(bytes.Buffer)
	err := bootstrapWritePeers(buf, "", v.Peers)
	return buf, err
}

func (r *request) ConvertOptions() error {
	for k, v := range r.options {
		opt, ok := r.optionDefs[k]
		if !ok {
			continue
		}

		kind := reflect.TypeOf(v).Kind()
		if kind != opt.Type() {
			if kind == String {
				convert := converters[opt.Type()]
				str, ok := v.(string)
				if !ok {
					return u.ErrCast()
				}
				val, err := convert(str)
				if err != nil {
					value := fmt.Sprintf("value '%v'", v)
					if len(str) == 0 {
						value = "empty value"
					}
					return fmt.Errorf("Could not convert %s to type '%s' (for option '-%s')",
						value, opt.Type().String(), k)
				}
				r.options[k] = val

			} else {
				return fmt.Errorf("Option '%s' should be type '%s', but got type '%s'",
					k, opt.Type().String(), kind.String())
			}
		} else {
			r.options[k] = v
		}

		for _, name := range opt.Names() {
			if _, ok := r.options[name]; name != k && ok {
				return fmt.Errorf("Duplicate command options were provided ('%s' and '%s')",
					k, name)
			}
		}
	}

	return nil
}

		depth := 1
		if recursive {
			depth = namesys.DefaultDepthLimit
		}

		if !strings.HasPrefix(name, "/ipns/") {
			name = "/ipns/" + name
		}

		output, err := resolver.ResolveN(req.Context(), name, depth)
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		// TODO: better errors (in the case of not finding the name, we get "failed to find any peer in table")

		res.SetOutput(&ResolvedPath{output})
	},
	Marshalers: cmds.MarshalerMap{
		cmds.Text: func(res cmds.Response) (io.Reader, error) {
			output, ok := res.Output().(*ResolvedPath)
			if !ok {
				return nil, u.ErrCast()
			}
			return strings.NewReader(output.Path.String() + "\n"), nil
		},
	},
	Type: ResolvedPath{},
}

		go func() {
			defer close(outChan)
			if err := addAllAndPin(req.Files()); err != nil {
				res.SetError(err, cmds.ErrNormal)
				return
			}

		}()
	},
	PostRun: func(req cmds.Request, res cmds.Response) {
		if res.Error() != nil {
			return
		}
		outChan, ok := res.Output().(<-chan interface{})
		if !ok {
			res.SetError(u.ErrCast(), cmds.ErrNormal)
			return
		}
		res.SetOutput(nil)

		quiet, _, err := req.Option("quiet").Bool()
		if err != nil {
			res.SetError(u.ErrCast(), cmds.ErrNormal)
			return
		}

		progress, _, err := req.Option(progressOptionName).Bool()
		if err != nil {
			res.SetError(u.ErrCast(), cmds.ErrNormal)
			return
		}

	},
	Run: func(req cmds.Request, res cmds.Response) {
		nd, err := req.InvocContext().GetNode()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		if !nd.OnlineMode() {
			res.SetError(errNotOnline, cmds.ErrClient)
			return
		}

		bs, ok := nd.Exchange.(*bitswap.Bitswap)
		if !ok {
			res.SetError(u.ErrCast(), cmds.ErrNormal)
			return
		}

		var ks []*cid.Cid
		for _, arg := range req.Arguments() {
			c, err := cid.Decode(arg)
			if err != nil {
				res.SetError(err, cmds.ErrNormal)
				return
			}

			ks = append(ks, c)
		}

		bs.CancelWants(ks)