Merge pull request #140 from libp2p/documentation

Some documentation

README.md

@@ -6,12 +6,19 @@
 
 > A pubsub system with flooding and gossiping variants.
 
-PubSub is a work in progress, with floodsub as an initial protocol, followed by gossipsub ([spec](https://github.com/libp2p/specs/tree/master/pubsub/gossipsub), [gossipsub.go](https://github.com/libp2p/go-libp2p-pubsub/blob/master/gossipsub.go)).
+This is the canonical pubsub implementation for libp2p.
+
+We currently provide three implementations:
+- floodsub, which is the baseline flooding protocol.
+- gossipsub, which is a more advanced router with mesh formation and gossip propagation.
+  See [spec](https://github.com/libp2p/specs/tree/master/pubsub/gossipsub) and  [implementation](https://github.com/libp2p/go-libp2p-pubsub/blob/master/gossipsub.go) for more details.
+- randomsub, which is a simple probabilistic router that propagates to random subsets of peers.
 
 ## Table of Contents
 
 - [Install](#install)
 - [Usage](#usage)
+- [Documentation](#documentation)
 - [Contribute](#contribute)
 - [License](#license)
 
@@ -29,6 +36,12 @@ To be used for messaging in p2p instrastructure (as part of libp2p) such as IPFS
 
 See [libp2p/specs/pubsub#Implementations](https://github.com/libp2p/specs/tree/master/pubsub#Implementations).
 
+## Documentation
+
+See the [libp2p specs](https://github.com/libp2p/specs/tree/master/pubsub) for high level documentation
+and [godoc](https://godoc.org/github.com/libp2p/go-libp2p-pubsub) for API documentation.
+
+
 ## Contribute
 
 Contributions welcome. Please check out [the issues](https://github.com/libp2p/go-libp2p-pubsub/issues).

doc.go

@@ -0,0 +1,25 @@
+package pubsub
+
+// The pubsub package provides facilities for the Publish/Subscribe pattern of message
+// propagation, also known as overlay multicast.
+// The implementation provides topic-based pubsub, with pluggable routing algorithms.
+//
+// The main interface to the library is the `PubSub` object.
+// You can construct this object with the following constructors
+// - `NewFloodSub` creates an instance that uses the floodsub routing algorithm.
+// - `NewGossipSub` creates an instance that uses the gossipsub routing algorithm.
+// - `NewRandomSub` creates an instance that uses the randomsub routing algorithm.
+//
+// In addition, there is a generic constructor that creates a pubsub instance with
+// a custom PubSubRouter interface. This procedure is currently reserved for internal
+// use within the package.
+//
+// Once you have constructed a `PubSub` instance, you need to establish some connections
+// to your peers; the implementation relies on ambient peer discovery, leaving bootstrap
+// and active peer discovery up to the client.
+//
+// To publish a message to some topic, use `Publish`; you don't need to be subscribed
+// to the topic in order to publish.
+//
+// To subscribe to a topic, use `Subscribe`; this will give you a subscription interface
+// from which new messages can be pumped.

floodsub.go

@@ -14,7 +14,7 @@ const (
 	FloodSubID = protocol.ID("/floodsub/1.0.0")
 )
 
-// NewFloodsubWithProtocols returns a new floodsub-enabled PubSub objecting using the protocols specified in ps
+// NewFloodsubWithProtocols returns a new floodsub-enabled PubSub objecting using the protocols specified in ps.
 func NewFloodsubWithProtocols(ctx context.Context, h host.Host, ps []protocol.ID, opts ...Option) (*PubSub, error) {
 	rt := &FloodSubRouter{
 		protocols: ps,
@@ -22,7 +22,7 @@ func NewFloodsubWithProtocols(ctx context.Context, h host.Host, ps []protocol.ID
 	return NewPubSub(ctx, h, rt, opts...)
 }
 
-// NewFloodSub returns a new PubSub object using the FloodSubRouter
+// NewFloodSub returns a new PubSub object using the FloodSubRouter.
 func NewFloodSub(ctx context.Context, h host.Host, opts ...Option) (*PubSub, error) {
 	return NewFloodsubWithProtocols(ctx, h, []protocol.ID{FloodSubID}, opts...)
 }

gossipsub.go

@@ -35,7 +35,7 @@ var (
 	GossipSubFanoutTTL = 60 * time.Second
 )
 
-// NewGossipSub returns a new PubSub object using GossipSubRouter as the router
+// NewGossipSub returns a new PubSub object using GossipSubRouter as the router.
 func NewGossipSub(ctx context.Context, h host.Host, opts ...Option) (*PubSub, error) {
 	rt := &GossipSubRouter{
 		peers:   make(map[peer.ID]protocol.ID),

pubsub.go

@@ -27,6 +27,7 @@ const (
 
 var log = logging.Logger("pubsub")
 
+// PubSub is the implementation of the pubsub system.
 type PubSub struct {
 	// atomic counter for seqnos
 	// NOTE: Must be declared at the top of the struct as we perform atomic
@@ -106,7 +107,7 @@ type PubSub struct {
 	ctx context.Context
 }
 
-// PubSubRouter is the message router component of PubSub
+// PubSubRouter is the message router component of PubSub.
 type PubSubRouter interface {
 	// Protocols returns the list of protocols supported by the router.
 	Protocols() []protocol.ID
@@ -147,7 +148,7 @@ type RPC struct {
 
 type Option func(*PubSub) error
 
-// NewPubSub returns a new PubSub management object
+// NewPubSub returns a new PubSub management object.
 func NewPubSub(ctx context.Context, h host.Host, rt PubSubRouter, opts ...Option) (*PubSub, error) {
 	ps := &PubSub{
 		host:             h,
@@ -758,14 +759,14 @@ type topicReq struct {
 	resp chan []string
 }
 
-// GetTopics returns the topics this node is subscribed to
+// GetTopics returns the topics this node is subscribed to.
 func (p *PubSub) GetTopics() []string {
 	out := make(chan []string, 1)
 	p.getTopics <- &topicReq{resp: out}
 	return <-out
 }
 
-// Publish publishes data under the given topic
+// Publish publishes data to the given topic.
 func (p *PubSub) Publish(topic string, data []byte) error {
 	seqno := p.nextSeqno()
 	m := &pb.Message{
@@ -804,7 +805,7 @@ type sendReq struct {
 	msg  *Message
 }
 
-// ListPeers returns a list of peers we are connected to.
+// ListPeers returns a list of peers we are connected to in the given topic.
 func (p *PubSub) ListPeers(topic string) []peer.ID {
 	out := make(chan []peer.ID)
 	p.getPeers <- &listPeerReq{
@@ -835,13 +836,13 @@ type topicVal struct {
 	validateThrottle chan struct{}
 }
 
-// Validator is a function that validates a message
+// Validator is a function that validates a message.
 type Validator func(context.Context, *Message) bool
 
-// ValidatorOpt is an option for RegisterTopicValidator
+// ValidatorOpt is an option for RegisterTopicValidator.
 type ValidatorOpt func(addVal *addValReq) error
 
-// WithValidatorTimeout is an option that sets the topic validator timeout
+// WithValidatorTimeout is an option that sets the topic validator timeout.
 func WithValidatorTimeout(timeout time.Duration) ValidatorOpt {
 	return func(addVal *addValReq) error {
 		addVal.timeout = timeout
@@ -849,7 +850,7 @@ func WithValidatorTimeout(timeout time.Duration) ValidatorOpt {
 	}
 }
 
-// WithValidatorConcurrency is an option that sets topic validator throttle
+// WithValidatorConcurrency is an option that sets topic validator throttle.
 func WithValidatorConcurrency(n int) ValidatorOpt {
 	return func(addVal *addValReq) error {
 		addVal.throttle = n
@@ -857,7 +858,7 @@ func WithValidatorConcurrency(n int) ValidatorOpt {
 	}
 }
 
-// RegisterTopicValidator registers a validator for topic
+// RegisterTopicValidator registers a validator for topic.
 func (p *PubSub) RegisterTopicValidator(topic string, val Validator, opts ...ValidatorOpt) error {
 	addVal := &addValReq{
 		topic:    topic,
@@ -904,8 +905,8 @@ func (ps *PubSub) addValidator(req *addValReq) {
 	req.resp <- nil
 }
 
-// UnregisterTopicValidator removes a validator from a topic
-// returns an error if there was no validator registered with the topic
+// UnregisterTopicValidator removes a validator from a topic.
+// Returns an error if there was no validator registered with the topic.
 func (p *PubSub) UnregisterTopicValidator(topic string) error {
 	rmVal := &rmValReq{
 		topic: topic,

randomsub.go

@@ -18,7 +18,7 @@ var (
 	RandomSubD = 6
 )
 
-// NewRandomSub returns a new PubSub object using RandomSubRouter as the router
+// NewRandomSub returns a new PubSub object using RandomSubRouter as the router.
 func NewRandomSub(ctx context.Context, h host.Host, opts ...Option) (*PubSub, error) {
 	rt := &RandomSubRouter{
 		peers: make(map[peer.ID]protocol.ID),