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package core
import (
"context"
"github.com/pkg/errors"
tmquery "github.com/tendermint/tendermint/libs/pubsub/query"
ctypes "github.com/tendermint/tendermint/rpc/core/types"
rpctypes "github.com/tendermint/tendermint/rpc/lib/types"
tmtypes "github.com/tendermint/tendermint/types"
)
// Subscribe for events via WebSocket.
//
// To tell which events you want, you need to provide a query. query is a
// string, which has a form: "condition AND condition ..." (no OR at the
// moment). condition has a form: "key operation operand". key is a string with
// a restricted set of possible symbols ( \t\n\r\\()"'=>< are not allowed).
// operation can be "=", "<", "<=", ">", ">=", "CONTAINS". operand can be a
// string (escaped with single quotes), number, date or time.
//
// Examples:
// tm.event = 'NewBlock' # new blocks
// tm.event = 'CompleteProposal' # node got a complete proposal
// tm.event = 'Tx' AND tx.hash = 'XYZ' # single transaction
// tm.event = 'Tx' AND tx.height = 5 # all txs of the fifth block
// tx.height = 5 # all txs of the fifth block
//
// Tendermint provides a few predefined keys: tm.event, tx.hash and tx.height.
// Note for transactions, you can define additional keys by providing tags with
// DeliverTx response.
//
// DeliverTx{
// Tags: []*KVPair{
// "agent.name": "K",
// }
// }
//
// tm.event = 'Tx' AND agent.name = 'K'
// tm.event = 'Tx' AND account.created_at >= TIME 2013-05-03T14:45:00Z
// tm.event = 'Tx' AND contract.sign_date = DATE 2017-01-01
// tm.event = 'Tx' AND account.owner CONTAINS 'Igor'
//
// See list of all possible events here
// https://godoc.org/github.com/tendermint/tendermint/types#pkg-constants
//
// For complete query syntax, check out
// https://godoc.org/github.com/tendermint/tendermint/libs/pubsub/query.
//
// ```go
// import "github.com/tendermint/tendermint/libs/pubsub/query"
// import "github.com/tendermint/tendermint/types"
//
// client := client.NewHTTP("tcp://0.0.0.0:26657", "/websocket")
// ctx, cancel := context.WithTimeout(context.Background(), timeout)
// defer cancel()
// query := query.MustParse("tm.event = 'Tx' AND tx.height = 3")
// txs := make(chan interface{})
// err := client.Subscribe(ctx, "test-client", query, txs)
//
// go func() {
// for e := range txs {
// fmt.Println("got ", e.(types.EventDataTx))
// }
// }()
// ```
//
// > The above command returns JSON structured like this:
//
// ```json
// {
// "error": "",
// "result": {},
// "id": "",
// "jsonrpc": "2.0"
// }
// ```
//
// ### Query Parameters
//
// | Parameter | Type | Default | Required | Description |
// |-----------+--------+---------+----------+-------------|
// | query | string | "" | true | Query |
//
// <aside class="notice">WebSocket only</aside>
func Subscribe(wsCtx rpctypes.WSRPCContext, query string) (*ctypes.ResultSubscribe, error) {
addr := wsCtx.GetRemoteAddr()
logger.Info("Subscribe to query", "remote", addr, "query", query)
q, err := tmquery.New(query)
if err != nil {
return nil, errors.Wrap(err, "failed to parse query")
}
ctx, cancel := context.WithTimeout(context.Background(), subscribeTimeout)
defer cancel()
ch := make(chan interface{})
err = eventBusFor(wsCtx).Subscribe(ctx, addr, q, ch)
if err != nil {
return nil, err
}
go func() {
for event := range ch {
tmResult := &ctypes.ResultEvent{query, event.(tmtypes.TMEventData)}
wsCtx.TryWriteRPCResponse(rpctypes.NewRPCSuccessResponse(wsCtx.Codec(), wsCtx.Request.ID+"#event", tmResult))
}
}()
return &ctypes.ResultSubscribe{}, nil
}
// Unsubscribe from events via WebSocket.
//
// ```go
// client := client.NewHTTP("tcp://0.0.0.0:26657", "/websocket")
// err := client.Unsubscribe("test-client", query)
// ```
//
// > The above command returns JSON structured like this:
//
// ```json
// {
// "error": "",
// "result": {},
// "id": "",
// "jsonrpc": "2.0"
// }
// ```
//
// ### Query Parameters
//
// | Parameter | Type | Default | Required | Description |
// |-----------+--------+---------+----------+-------------|
// | query | string | "" | true | Query |
//
// <aside class="notice">WebSocket only</aside>
func Unsubscribe(wsCtx rpctypes.WSRPCContext, query string) (*ctypes.ResultUnsubscribe, error) {
addr := wsCtx.GetRemoteAddr()
logger.Info("Unsubscribe from query", "remote", addr, "query", query)
q, err := tmquery.New(query)
if err != nil {
return nil, errors.Wrap(err, "failed to parse query")
}
err = eventBusFor(wsCtx).Unsubscribe(context.Background(), addr, q)
if err != nil {
return nil, err
}
return &ctypes.ResultUnsubscribe{}, nil
}
// Unsubscribe from all events via WebSocket.
//
// ```go
// client := client.NewHTTP("tcp://0.0.0.0:26657", "/websocket")
// err := client.UnsubscribeAll("test-client")
// ```
//
// > The above command returns JSON structured like this:
//
// ```json
// {
// "error": "",
// "result": {},
// "id": "",
// "jsonrpc": "2.0"
// }
// ```
//
// <aside class="notice">WebSocket only</aside>
func UnsubscribeAll(wsCtx rpctypes.WSRPCContext) (*ctypes.ResultUnsubscribe, error) {
addr := wsCtx.GetRemoteAddr()
logger.Info("Unsubscribe from all", "remote", addr)
err := eventBusFor(wsCtx).UnsubscribeAll(context.Background(), addr)
if err != nil {
return nil, err
}
return &ctypes.ResultUnsubscribe{}, nil
}
func eventBusFor(wsCtx rpctypes.WSRPCContext) tmtypes.EventBusSubscriber {
es := wsCtx.GetEventSubscriber()
if es == nil {
es = eventBus
}
return es
}