implement a simple wantlist command to allow the user to view their wantlist

core/commands/root.go

@@ -98,6 +98,7 @@ var rootSubcommands = map[string]*cmds.Command{
 	"swarm":     SwarmCmd,
 	"update":    UpdateCmd,
 	"version":   VersionCmd,
+	"wantlist":  WantlistCmd,
 }
 
 func init() {

core/commands/wantlist.go

@@ -0,0 +1,34 @@
+package commands
+
+import cmds "github.com/jbenet/go-ipfs/commands"
+
+var WantlistCmd = &cmds.Command{
+	Helptext: cmds.HelpText{
+		Tagline:          "A set of commands to work with the bitswap wantlist",
+		ShortDescription: ``,
+	},
+	Subcommands: map[string]*cmds.Command{
+		"show": showWantlistCmd,
+	},
+}
+
+var showWantlistCmd = &cmds.Command{
+	Helptext: cmds.HelpText{
+		Tagline: "Show blocks currently on the wantlist",
+		ShortDescription: `
+Print out all blocks currently on the bitswap wantlist for the local peer`,
+	},
+	Type: KeyList{},
+	Run: func(req cmds.Request, res cmds.Response) {
+		nd, err := req.Context().GetNode()
+		if err != nil {
+			res.SetError(err, cmds.ErrNormal)
+			return
+		}
+
+		res.SetOutput(&KeyList{nd.Exchange.GetWantlist()})
+	},
+	Marshalers: cmds.MarshalerMap{
+		cmds.Text: KeyListTextMarshaler,
+	},
+}

exchange/bitswap/bitswap.go

@@ -402,3 +402,11 @@ func (bs *bitswap) send(ctx context.Context, p peer.ID, m bsmsg.BitSwapMessage)
 func (bs *bitswap) Close() error {
 	return bs.process.Close()
 }
+
+func (bs *bitswap) GetWantlist() []u.Key {
+	var out []u.Key
+	for _, e := range bs.wantlist.Entries() {
+		out = append(out, e.Key)
+	}
+	return out
+}

exchange/interface.go

@@ -21,5 +21,7 @@ type Interface interface {
 	// available on the network?
 	HasBlock(context.Context, *blocks.Block) error
 
+	GetWantlist() []u.Key
+
 	io.Closer
 }

exchange/offline/offline.go

@@ -66,3 +66,8 @@ func (e *offlineExchange) GetBlocks(ctx context.Context, ks []u.Key) (<-chan *bl
 	}()
 	return out, nil
 }
+
+// implement Exchange
+func (e *offlineExchange) GetWantlist() []u.Key {
+	return nil
+}