Golang Request.Path方法代码示例

func callCommand(ctx context.Context, req cmds.Request, root *cmds.Command, cmd *cmds.Command) (cmds.Response, error) {
	log.Info(config.EnvDir, " ", req.InvocContext().ConfigRoot)
	var res cmds.Response

	err := req.SetRootContext(ctx)
	if err != nil {
		return nil, err
	}

	details, err := commandDetails(req.Path(), root)
	if err != nil {
		return nil, err
	}

	client, err := commandShouldRunOnDaemon(*details, req, root)
	if err != nil {
		return nil, err
	}

	err = callPreCommandHooks(ctx, *details, req, root)
	if err != nil {
		return nil, err
	}

	if cmd.PreRun != nil {
		err = cmd.PreRun(req)
		if err != nil {
			return nil, err
		}
	}

	if client != nil {
		log.Debug("Executing command via API")
		res, err = client.Send(req)
		if err != nil {
			if isConnRefused(err) {
				err = repo.ErrApiNotRunning
			}
			return nil, err
		}

	} else {
		log.Debug("Executing command locally")

		err := req.SetRootContext(ctx)
		if err != nil {
			return nil, err
		}

		// Okay!!!!! NOW we can call the command.
		res = root.Call(req)

	}

	if cmd.PostRun != nil {
		cmd.PostRun(req, res)
	}

	return res, 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
}

func (c *client) Send(req cmds.Request) (cmds.Response, error) {

	if req.Context() == nil {
		log.Warningf("no context set in request")
		if err := req.SetRootContext(context.TODO()); err != nil {
			return nil, err
		}
	}

	// save user-provided encoding
	previousUserProvidedEncoding, found, err := req.Option(cmds.EncShort).String()
	if err != nil {
		return nil, err
	}

	// override with json to send to server
	req.SetOption(cmds.EncShort, cmds.JSON)

	// stream channel output
	req.SetOption(cmds.ChanOpt, "true")

	query, err := getQuery(req)
	if err != nil {
		return nil, err
	}

	var fileReader *MultiFileReader
	var reader io.Reader

	if req.Files() != nil {
		fileReader = NewMultiFileReader(req.Files(), true)
		reader = fileReader
	} else {
		// if we have no file data, use an empty Reader
		// (http.NewRequest panics when a nil Reader is used)
		reader = strings.NewReader("")
	}

	path := strings.Join(req.Path(), "/")
	url := fmt.Sprintf(ApiUrlFormat, c.serverAddress, ApiPath, path, query)

	httpReq, err := http.NewRequest("POST", url, reader)
	if err != nil {
		return nil, err
	}

	// TODO extract string consts?
	if fileReader != nil {
		httpReq.Header.Set(contentTypeHeader, "multipart/form-data; boundary="+fileReader.Boundary())
		httpReq.Header.Set(contentDispHeader, "form-data: name=\"files\"")
	} else {
		httpReq.Header.Set(contentTypeHeader, applicationOctetStream)
	}
	version := config.CurrentVersionNumber
	httpReq.Header.Set(uaHeader, fmt.Sprintf("/go-ipfs/%s/", version))

	ec := make(chan error, 1)
	rc := make(chan cmds.Response, 1)
	dc := req.Context().Done()

	go func() {
		httpRes, err := c.httpClient.Do(httpReq)
		if err != nil {
			ec <- err
			return
		}

		// using the overridden JSON encoding in request
		res, err := getResponse(httpRes, req)
		if err != nil {
			ec <- err
			return
		}

		rc <- res
	}()

	for {
		select {
		case <-dc:
			log.Debug("Context cancelled, cancelling HTTP request...")
			tr := http.DefaultTransport.(*http.Transport)
			tr.CancelRequest(httpReq)
			dc = nil // Wait for ec or rc
		case err := <-ec:
			return nil, err
		case res := <-rc:
			if found && len(previousUserProvidedEncoding) > 0 {
				// reset to user provided encoding after sending request
				// NB: if user has provided an encoding but it is the empty string,
				// still leave it as JSON.
				req.SetOption(cmds.EncShort, previousUserProvidedEncoding)
			}
			return res, nil
		}
	}
}