coreapi: pubsub interface

License: MIT
Signed-off-by: Łukasz Magiera <magik6k@gmail.com>

options/pubsub.go

+package options
+
+type PubSubPeersSettings struct {
+	Topic string
+}
+
+type PubSubSubscribeSettings struct {
+	Discover bool
+}
+
+type PubSubPeersOption func(*PubSubPeersSettings) error
+type PubSubSubscribeOption func(*PubSubSubscribeSettings) error
+
+func PubSubPeersOptions(opts ...PubSubPeersOption) (*PubSubPeersSettings, error) {
+	options := &PubSubPeersSettings{
+		Topic: "",
+	}
+
+	for _, opt := range opts {
+		err := opt(options)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return options, nil
+}
+
+func PubSubSubscribeOptions(opts ...PubSubSubscribeOption) (*PubSubSubscribeSettings, error) {
+	options := &PubSubSubscribeSettings{
+		Discover: false,
+	}
+
+	for _, opt := range opts {
+		err := opt(options)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return options, nil
+}
+
+type PubSubOptions struct{}
+
+func (api *PubSubOptions) WithTopic(topic string) PubSubPeersOption {
+	return func(settings *PubSubPeersSettings) error {
+		settings.Topic = topic
+		return nil
+	}
+}
+
+func (api *PubSubOptions) WithDiscover(discover bool) PubSubSubscribeOption {
+	return func(settings *PubSubSubscribeSettings) error {
+		settings.Discover = discover
+		return nil
+	}
+}

pubsub.go

+package iface
+
+import (
+	"context"
+	"io"
+
+	options "github.com/ipfs/go-ipfs/core/coreapi/interface/options"
+
+	peer "gx/ipfs/QmZoWKhxUmZ2seW4BzX6fJkNR8hh9PsGModr7q171yq2SS/go-libp2p-peer"
+)
+
+// PubSubSubscription is an active PubSub subscription
+type PubSubSubscription interface {
+	io.Closer
+
+	// Chan return incoming message channel
+	Chan(context.Context) <-chan PubSubMessage
+}
+
+// PubSubMessage is a single PubSub message
+type PubSubMessage interface {
+	// From returns id of a peer from which the message has arrived
+	From() peer.ID
+
+	// Data returns the message body
+	Data() []byte
+}
+
+// PubSubAPI specifies the interface to PubSub
+type PubSubAPI interface {
+	// Ls lists subscribed topics by name
+	Ls(context.Context) ([]string, error)
+
+	// Peers list peers we are currently pubsubbing with
+	// TODO: WithTopic
+	Peers(context.Context, ...options.PubSubPeersOption) ([]peer.ID, error)
+
+	// WithTopic is an option for peers which specifies a topic filter for the
+	// function
+	WithTopic(topic string) options.PubSubPeersOption
+
+	// Publish a message to a given pubsub topic
+	Publish(context.Context, string, []byte) error
+
+	// Subscribe to messages on a given topic
+	Subscribe(context.Context, string) (PubSubSubscription, error)
+
+	// WithDiscover is an option for Subscribe which specifies whether to try to
+	// discover other peers subscribed to the same topic
+	WithDiscover(discover bool) options.PubSubSubscribeOption
+}