ipld-eth-server/pkg/serve/api.go
2020-08-31 10:59:41 -05:00

129 lines
3.8 KiB
Go

// VulcanizeDB
// Copyright © 2019 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package serve
import (
"context"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/rpc"
log "github.com/sirupsen/logrus"
"github.com/vulcanize/ipfs-blockchain-watcher/pkg/node"
"github.com/vulcanize/ipld-eth-server/pkg/eth"
"github.com/vulcanize/ipld-eth-server/pkg/shared"
v "github.com/vulcanize/ipld-eth-server/version"
)
// APIName is the namespace used for the state diffing service API
const APIName = "vdb"
// APIVersion is the version of the state diffing service API
const APIVersion = "0.0.1"
// PublicServerAPI is the public api for the watcher
type PublicServerAPI struct {
w Server
}
// NewPublicServerAPI creates a new PublicServerAPI with the provided underlying Server process
func NewPublicServerAPI(w Server) *PublicServerAPI {
return &PublicServerAPI{
w: w,
}
}
// Stream is the public method to setup a subscription that fires off IPLD payloads as they are processed
func (api *PublicServerAPI) Stream(ctx context.Context, params eth.SubscriptionSettings) (*rpc.Subscription, error) {
// ensure that the RPC connection supports subscriptions
notifier, supported := rpc.NotifierFromContext(ctx)
if !supported {
return nil, rpc.ErrNotificationsUnsupported
}
// create subscription and start waiting for stream events
rpcSub := notifier.CreateSubscription()
go func() {
// subscribe to events from the SyncPublishScreenAndServe service
payloadChannel := make(chan SubscriptionPayload, PayloadChanBufferSize)
quitChan := make(chan bool, 1)
go api.w.Subscribe(rpcSub.ID, payloadChannel, quitChan, params)
// loop and await payloads and relay them to the subscriber using notifier
for {
select {
case packet := <-payloadChannel:
if err := notifier.Notify(rpcSub.ID, packet); err != nil {
log.Error("Failed to send watcher data packet", "err", err)
api.w.Unsubscribe(rpcSub.ID)
return
}
case <-rpcSub.Err():
api.w.Unsubscribe(rpcSub.ID)
return
case <-quitChan:
// don't need to unsubscribe from the watcher, the service does so before sending the quit signal this way
return
}
}
}()
return rpcSub, nil
}
// Node is a public rpc method to allow transformers to fetch the node info for the watcher
// NOTE: this is the node info for the node that the watcher is syncing from, not the node info for the watcher itself
func (api *PublicServerAPI) Node() *node.Info {
return api.w.Node()
}
// Chain returns the chain type that this watcher instance supports
func (api *PublicServerAPI) Chain() shared.ChainType {
return api.w.Chain()
}
// Struct for holding watcher meta data
type InfoAPI struct{}
// NewInfoAPI creates a new InfoAPI
func NewInfoAPI() *InfoAPI {
return &InfoAPI{}
}
// Modules returns modules supported by this api
func (iapi *InfoAPI) Modules() map[string]string {
return map[string]string{
"vdb": "Stream",
}
}
// NodeInfo gathers and returns a collection of metadata for the watcher
func (iapi *InfoAPI) NodeInfo() *p2p.NodeInfo {
return &p2p.NodeInfo{
// TODO: formalize this
ID: "vulcanizeDB",
Name: "ipld-eth-server",
}
}
// Version returns the version of the watcher
func (iapi *InfoAPI) Version() string {
return v.VersionWithMeta
}