| 1 | package rpc |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "context" |
| 6 | "encoding/json" |
| 7 | "io" |
| 8 | |
| 9 | iface "github.com/ipfs/kubo/core/coreiface" |
| 10 | caopts "github.com/ipfs/kubo/core/coreiface/options" |
| 11 | "github.com/libp2p/go-libp2p/core/peer" |
| 12 | mbase "github.com/multiformats/go-multibase" |
| 13 | ) |
| 14 | |
| 15 | type PubsubAPI HttpApi |
| 16 | |
| 17 | func (api *PubsubAPI) Ls(ctx context.Context) ([]string, error) { |
| 18 | var out struct { |
| 19 | Strings []string |
| 20 | } |
| 21 | |
| 22 | if err := api.core().Request("pubsub/ls").Exec(ctx, &out); err != nil { |
| 23 | return nil, err |
| 24 | } |
| 25 | topics := make([]string, len(out.Strings)) |
| 26 | for n, mb := range out.Strings { |
| 27 | _, topic, err := mbase.Decode(mb) |
| 28 | if err != nil { |
| 29 | return nil, err |
| 30 | } |
| 31 | topics[n] = string(topic) |
| 32 | } |
| 33 | return topics, nil |
| 34 | } |
| 35 | |
| 36 | func (api *PubsubAPI) Peers(ctx context.Context, opts ...caopts.PubSubPeersOption) ([]peer.ID, error) { |
| 37 | options, err := caopts.PubSubPeersOptions(opts...) |
| 38 | if err != nil { |
| 39 | return nil, err |
| 40 | } |
| 41 | |
| 42 | var out struct { |
| 43 | Strings []string |
| 44 | } |
| 45 | |
| 46 | var optionalTopic string |
| 47 | if len(options.Topic) > 0 { |
| 48 | optionalTopic = toMultibase([]byte(options.Topic)) |
| 49 | } |
| 50 | if err := api.core().Request("pubsub/peers", optionalTopic).Exec(ctx, &out); err != nil { |
| 51 | return nil, err |
| 52 | } |
| 53 | |
| 54 | res := make([]peer.ID, len(out.Strings)) |
| 55 | for i, sid := range out.Strings { |
| 56 | id, err := peer.Decode(sid) |
| 57 | if err != nil { |
| 58 | return nil, err |
| 59 | } |
| 60 | res[i] = id |
| 61 | } |
| 62 | return res, nil |
| 63 | } |
| 64 | |
| 65 | func (api *PubsubAPI) Publish(ctx context.Context, topic string, message []byte) error { |
| 66 | return api.core().Request("pubsub/pub", toMultibase([]byte(topic))). |
| 67 | FileBody(bytes.NewReader(message)). |
| 68 | Exec(ctx, nil) |
| 69 | } |
| 70 | |
| 71 | type pubsubSub struct { |
| 72 | messages chan pubsubMessage |
| 73 | |
| 74 | done chan struct{} |
| 75 | rcloser func() error |
| 76 | } |
| 77 | |
| 78 | type pubsubMessage struct { |
| 79 | JFrom string `json:"from,omitempty"` |
| 80 | JData string `json:"data,omitempty"` |
| 81 | JSeqno string `json:"seqno,omitempty"` |
| 82 | JTopicIDs []string `json:"topicIDs,omitempty"` |
| 83 | |
| 84 | // real values after unpacking from text/multibase envelopes |
| 85 | from peer.ID |
| 86 | data []byte |
| 87 | seqno []byte |
| 88 | topics []string |
| 89 | |
| 90 | err error |
| 91 | } |
| 92 | |
| 93 | func (msg *pubsubMessage) From() peer.ID { |
| 94 | return msg.from |
| 95 | } |
| 96 | |
| 97 | func (msg *pubsubMessage) Data() []byte { |
| 98 | return msg.data |
| 99 | } |
| 100 | |
| 101 | func (msg *pubsubMessage) Seq() []byte { |
| 102 | return msg.seqno |
| 103 | } |
| 104 | |
| 105 | // TODO: do we want to keep this interface as []string, |
| 106 | // or change to more correct [][]byte? |
| 107 | func (msg *pubsubMessage) Topics() []string { |
| 108 | return msg.topics |
| 109 | } |
| 110 | |
| 111 | func (s *pubsubSub) Next(ctx context.Context) (iface.PubSubMessage, error) { |
| 112 | select { |
| 113 | case msg, ok := <-s.messages: |
| 114 | if !ok { |
| 115 | return nil, io.EOF |
| 116 | } |
| 117 | if msg.err != nil { |
| 118 | return nil, msg.err |
| 119 | } |
| 120 | // unpack values from text/multibase envelopes |
| 121 | var err error |
| 122 | msg.from, err = peer.Decode(msg.JFrom) |
| 123 | if err != nil { |
| 124 | return nil, err |
| 125 | } |
| 126 | _, msg.data, err = mbase.Decode(msg.JData) |
| 127 | if err != nil { |
| 128 | return nil, err |
| 129 | } |
| 130 | _, msg.seqno, err = mbase.Decode(msg.JSeqno) |
| 131 | if err != nil { |
| 132 | return nil, err |
| 133 | } |
| 134 | for _, mbt := range msg.JTopicIDs { |
| 135 | _, topic, err := mbase.Decode(mbt) |
| 136 | if err != nil { |
| 137 | return nil, err |
| 138 | } |
| 139 | msg.topics = append(msg.topics, string(topic)) |
| 140 | } |
| 141 | return &msg, nil |
| 142 | case <-ctx.Done(): |
| 143 | return nil, ctx.Err() |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | func (api *PubsubAPI) Subscribe(ctx context.Context, topic string, opts ...caopts.PubSubSubscribeOption) (iface.PubSubSubscription, error) { |
| 148 | /* right now we have no options (discover got deprecated) |
| 149 | options, err := caopts.PubSubSubscribeOptions(opts...) |
| 150 | if err != nil { |
| 151 | return nil, err |
| 152 | } |
| 153 | */ |
| 154 | resp, err := api.core().Request("pubsub/sub", toMultibase([]byte(topic))).Send(ctx) |
| 155 | if err != nil { |
| 156 | return nil, err |
| 157 | } |
| 158 | if resp.Error != nil { |
| 159 | return nil, resp.Error |
| 160 | } |
| 161 | |
| 162 | sub := &pubsubSub{ |
| 163 | messages: make(chan pubsubMessage), |
| 164 | done: make(chan struct{}), |
| 165 | rcloser: func() error { |
| 166 | return resp.Cancel() |
| 167 | }, |
| 168 | } |
| 169 | |
| 170 | dec := json.NewDecoder(resp.Output) |
| 171 | |
| 172 | go func() { |
| 173 | defer close(sub.messages) |
| 174 | |
| 175 | for { |
| 176 | var msg pubsubMessage |
| 177 | if err := dec.Decode(&msg); err != nil { |
| 178 | if err == io.EOF { |
| 179 | return |
| 180 | } |
| 181 | msg.err = err |
| 182 | } |
| 183 | |
| 184 | select { |
| 185 | case sub.messages <- msg: |
| 186 | case <-sub.done: |
| 187 | return |
| 188 | case <-ctx.Done(): |
| 189 | return |
| 190 | } |
| 191 | } |
| 192 | }() |
| 193 | |
| 194 | return sub, nil |
| 195 | } |
| 196 | |
| 197 | func (s *pubsubSub) Close() error { |
| 198 | if s.done != nil { |
| 199 | close(s.done) |
| 200 | s.done = nil |
| 201 | } |
| 202 | return s.rcloser() |
| 203 | } |
| 204 | |
| 205 | func (api *PubsubAPI) core() *HttpApi { |
| 206 | return (*HttpApi)(api) |
| 207 | } |
| 208 | |
| 209 | // Encodes bytes into URL-safe multibase that can be sent over HTTP RPC (URL or body). |
| 210 | func toMultibase(data []byte) string { |
| 211 | mb, _ := mbase.Encode(mbase.Base64url, data) |
| 212 | return mb |
| 213 | } |