Golang Request.Context方法代码示例

func addLinkCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 4 {
		return "", fmt.Errorf("not enough arguments for add-link")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	path := req.Arguments()[2]
	childk := key.B58KeyDecode(req.Arguments()[3])

	create, _, err := req.Option("create").Bool()
	if err != nil {
		return "", err
	}

	var createfunc func() *dag.Node
	if create {
		createfunc = func() *dag.Node {
			return &dag.Node{Data: ft.FolderPBData()}
		}
	}

	e := dagutils.NewDagEditor(nd.DAG, root)

	childnd, err := nd.DAG.Get(req.Context(), childk)
	if err != nil {
		return "", err
	}

	err = e.InsertNodeAtPath(req.Context(), path, childnd, createfunc)
	if err != nil {
		return "", err
	}

	nnode := e.GetNode()

	return nnode.Key()
}

// 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:
		}
	}
}

func rmLinkCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 3 {
		return "", fmt.Errorf("not enough arguments for rm-link")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	path := req.Arguments()[2]

	e := dagutils.NewDagEditor(nd.DAG, root)

	err = e.RmLink(req.Context(), path)
	if err != nil {
		return "", err
	}

	nnode := e.GetNode()

	return nnode.Key()
}

func getBlockForKey(req cmds.Request, skey string) (*blocks.Block, error) {
	n, err := req.InvocContext().GetNode()
	if err != nil {
		return nil, err
	}

	if !u.IsValidHash(skey) {
		return nil, errors.New("Not a valid hash")
	}

	h, err := mh.FromB58String(skey)
	if err != nil {
		return nil, err
	}

	k := key.Key(h)
	b, err := n.Blocks.GetBlock(req.Context(), k)
	if err != nil {
		return nil, err
	}

	log.Debugf("ipfs block: got block with key: %q", b.Key())
	return b, 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
		}
	}
}

func daemonFunc(req cmds.Request, res cmds.Response) {
	// let the user know we're going.
	fmt.Printf("Initializing daemon...\n")

	ctx := req.InvocContext()

	go func() {
		select {
		case <-req.Context().Done():
			fmt.Println("Received interrupt signal, shutting down...")
		}
	}()

	// check transport encryption flag.
	unencrypted, _, _ := req.Option(unencryptTransportKwd).Bool()
	if unencrypted {
		log.Warningf(`Running with --%s: All connections are UNENCRYPTED.
		You will not be able to connect to regular encrypted networks.`, unencryptTransportKwd)
		conn.EncryptConnections = false
	}

	// first, whether user has provided the initialization flag. we may be
	// running in an uninitialized state.
	initialize, _, err := req.Option(initOptionKwd).Bool()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	if initialize {

		// now, FileExists is our best method of detecting whether IPFS is
		// configured. Consider moving this into a config helper method
		// `IsInitialized` where the quality of the signal can be improved over
		// time, and many call-sites can benefit.
		if !util.FileExists(req.InvocContext().ConfigRoot) {
			err := initWithDefaults(os.Stdout, req.InvocContext().ConfigRoot)
			if err != nil {
				res.SetError(err, cmds.ErrNormal)
				return
			}
		}
	}

	// acquire the repo lock _before_ constructing a node. we need to make
	// sure we are permitted to access the resources (datastore, etc.)
	repo, err := fsrepo.Open(req.InvocContext().ConfigRoot)
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	cfg, err := ctx.GetConfig()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}

	// Start assembling node config
	ncfg := &core.BuildCfg{
		Online: true,
		Repo:   repo,
	}

	routingOption, _, err := req.Option(routingOptionKwd).String()
	if err != nil {
		res.SetError(err, cmds.ErrNormal)
		return
	}
	if routingOption == routingOptionSupernodeKwd {
		servers, err := cfg.SupernodeRouting.ServerIPFSAddrs()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			repo.Close() // because ownership hasn't been transferred to the node
			return
		}
		var infos []peer.PeerInfo
		for _, addr := range servers {
			infos = append(infos, peer.PeerInfo{
				ID:    addr.ID(),
				Addrs: []ma.Multiaddr{addr.Transport()},
			})
		}

		ncfg.Routing = corerouting.SupernodeClient(infos...)
	}

	node, err := core.NewNode(req.Context(), ncfg)
	if err != nil {
		log.Error("error from node construction: ", err)
		res.SetError(err, cmds.ErrNormal)
		return
	}

	printSwarmAddrs(node)

	defer func() {
		// We wait for the node to close first, as the node has children
		// that it will wait for before closing, such as the API server.
		node.Close()
//.........这里部分代码省略.........