floodsub: add api for pub/sub

License: MIT
Signed-off-by: Jeromy <why@ipfs.io>

core/commands/pubsub.go

+package commands
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+
+	cmds "github.com/ipfs/go-ipfs/commands"
+
+	floodsub "gx/ipfs/QmQriRMW5cCJyLrzDnXi7fZ5mVbetiEZjPjbqoJhuSL94m/floodsub"
+	u "gx/ipfs/QmZNVWh8LLjAavuQ2JXuFmuYH3C11xo988vSgp7UQrTRj1/go-ipfs-util"
+)
+
+var PubsubCmd = &cmds.Command{
+	Helptext: cmds.HelpText{
+		Tagline: "An experimental publish-subscribe system on ipfs.",
+		ShortDescription: `
+ipfs pubsub allows you to publish messages to a given topic, and also to
+subscribe to new messages on a given topic.
+
+This is an experimental feature. It is not intended in its current state
+to be used in a production environment.
+`,
+	},
+	Subcommands: map[string]*cmds.Command{
+		"pub": PubsubPubCmd,
+		"sub": PubsubSubCmd,
+	},
+}
+
+var PubsubSubCmd = &cmds.Command{
+	Helptext: cmds.HelpText{
+		Tagline: "Subscribe to messages on a given topic.",
+		ShortDescription: `
+ipfs pubsub sub subscribes to messages on a given topic.
+
+This is an experimental feature. It is not intended in its current state
+to be used in a production environment.
+`,
+	},
+	Arguments: []cmds.Argument{
+		cmds.StringArg("topic", true, false, "String name of topic to subscribe to."),
+	},
+	Run: func(req cmds.Request, res cmds.Response) {
+		n, err := req.InvocContext().GetNode()
+		if err != nil {
+			res.SetError(err, cmds.ErrNormal)
+			return
+		}
+
+		// Must be online!
+		if !n.OnlineMode() {
+			res.SetError(errNotOnline, cmds.ErrClient)
+			return
+		}
+
+		topic := req.Arguments()[0]
+		msgs, err := n.Floodsub.Subscribe(topic)
+		if err != nil {
+			res.SetError(err, cmds.ErrNormal)
+			return
+		}
+
+		out := make(chan interface{})
+		res.SetOutput((<-chan interface{})(out))
+
+		ctx := req.Context()
+		go func() {
+			defer close(out)
+			for {
+				select {
+				case msg, ok := <-msgs:
+					if !ok {
+						return
+					}
+					out <- msg
+				case <-ctx.Done():
+					n.Floodsub.Unsub(topic)
+				}
+			}
+		}()
+	},
+	Marshalers: cmds.MarshalerMap{
+		cmds.Text: getPsMsgMarshaler(func(m *floodsub.Message) (io.Reader, error) {
+			log.Error("FROM: ", m.GetFrom())
+			return bytes.NewReader(m.Data), nil
+		}),
+		"ndpayload": getPsMsgMarshaler(func(m *floodsub.Message) (io.Reader, error) {
+			m.Data = append(m.Data, '\n')
+			return bytes.NewReader(m.Data), nil
+		}),
+		"lenpayload": getPsMsgMarshaler(func(m *floodsub.Message) (io.Reader, error) {
+			buf := make([]byte, 8)
+			n := binary.PutUvarint(buf, uint64(len(m.Data)))
+			return io.MultiReader(bytes.NewReader(buf[:n]), bytes.NewReader(m.Data)), nil
+		}),
+	},
+	Type: floodsub.Message{},
+}
+
+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()
+			}
+
+			return f(obj)
+		}
+
+		return &cmds.ChannelMarshaler{
+			Channel:   outChan,
+			Marshaler: marshal,
+			Res:       res,
+		}, nil
+	}
+}
+
+var PubsubPubCmd = &cmds.Command{
+	Helptext: cmds.HelpText{
+		Tagline: "Publish a message to a given pubsub topic.",
+		ShortDescription: `
+ipfs pubsub pub publishes a message to a specified topic.
+
+This is an experimental feature. It is not intended in its current state
+to be used in a production environment.
+`,
+	},
+	Arguments: []cmds.Argument{
+		cmds.StringArg("topic", true, false, "Topic to publish to."),
+		cmds.StringArg("data", true, true, "Payload of message to publish.").EnableStdin(),
+	},
+	Options: []cmds.Option{},
+	Run: func(req cmds.Request, res cmds.Response) {
+		n, err := req.InvocContext().GetNode()
+		if err != nil {
+			res.SetError(err, cmds.ErrNormal)
+			return
+		}
+
+		// Must be online!
+		if !n.OnlineMode() {
+			res.SetError(errNotOnline, cmds.ErrClient)
+			return
+		}
+
+		topic := req.Arguments()[0]
+
+		for _, data := range req.Arguments()[1:] {
+			if err := n.Floodsub.Publish(topic, []byte(data)); err != nil {
+				res.SetError(err, cmds.ErrNormal)
+				return
+			}
+		}
+	},
+}

core/commands/root.go

@@ -105,6 +105,7 @@ var rootSubcommands = map[string]*cmds.Command{
 	"stats":     StatsCmd,
 	"swarm":     SwarmCmd,
 	"tar":       TarCmd,
+	"pubsub":    PubsubCmd,
 	"tour":      tourCmd,
 	"file":      unixfs.UnixFSCmd,
 	"update":    ExternalBinary(),

core/core.go

@@ -17,7 +17,8 @@ import (
 	"time"
 
 	diag "github.com/ipfs/go-ipfs/diagnostics"
-	goprocess "gx/ipfs/QmQopLATEYMNg7dVqZRNDfeE2S1yKy8zrRh5xnYiuqeZBn/goprocess"
+	floodsub "gx/ipfs/QmQriRMW5cCJyLrzDnXi7fZ5mVbetiEZjPjbqoJhuSL94m/floodsub"
+	goprocess "gx/ipfs/QmSF8fPo3jgVBAy8fpdjjYqgG87dkJgUprRBHRd2tmfgpP/goprocess"
 	mamask "gx/ipfs/QmSMZwvs3n4GBikZ7hKzT17c3bk65FmyZo2JqtJ16swqCv/multiaddr-filter"
 	logging "gx/ipfs/QmSpJByNKFX1sCsHBEp3R73FL4NF6FnQTEGyNAXHm2GS52/go-log"
 	b58 "gx/ipfs/QmT8rehPR3F6bmwL6zjUN8XpiDBFFpMP2myPdC6ApsWfJf/go-base58"
@@ -112,6 +113,8 @@ type IpfsNode struct {
 	Reprovider   *rp.Reprovider // the value reprovider system
 	IpnsRepub    *ipnsrp.Republisher
 
+	Floodsub *floodsub.PubSub
+
 	proc goprocess.Process
 	ctx  context.Context
 
@@ -184,6 +187,8 @@ func (n *IpfsNode) startOnlineServices(ctx context.Context, routingOption Routin
 		go n.Reprovider.ProvideEvery(ctx, interval)
 	}
 
+	n.Floodsub = floodsub.NewFloodSub(ctx, peerhost)
+
 	// setup local discovery
 	if do != nil {
 		service, err := do(ctx, n.PeerHost)

package.json

@@ -263,6 +263,12 @@
       "hash": "QmdCL8M8DXJdSRnwhpDhukX5r8ydjxnzPJpaKrFudDA8yn",
       "name": "hang-fds",
       "version": "0.0.0"
+	},
+	{
+      "author": "whyrusleeping",
+      "hash": "QmQriRMW5cCJyLrzDnXi7fZ5mVbetiEZjPjbqoJhuSL94m",
+      "name": "floodsub",
+      "version": "0.3.0"
     }
   ],
   "gxVersion": "0.4.0",