You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
264 lines
7.9 KiB
264 lines
7.9 KiB
package core
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"time"
|
|
|
|
"github.com/tendermint/tendermint/internal/eventlog"
|
|
"github.com/tendermint/tendermint/internal/eventlog/cursor"
|
|
"github.com/tendermint/tendermint/internal/jsontypes"
|
|
tmpubsub "github.com/tendermint/tendermint/internal/pubsub"
|
|
tmquery "github.com/tendermint/tendermint/internal/pubsub/query"
|
|
"github.com/tendermint/tendermint/rpc/coretypes"
|
|
rpctypes "github.com/tendermint/tendermint/rpc/jsonrpc/types"
|
|
)
|
|
|
|
const (
|
|
// Buffer on the Tendermint (server) side to allow some slowness in clients.
|
|
subBufferSize = 100
|
|
|
|
// maxQueryLength is the maximum length of a query string that will be
|
|
// accepted. This is just a safety check to avoid outlandish queries.
|
|
maxQueryLength = 512
|
|
)
|
|
|
|
// Subscribe for events via WebSocket.
|
|
// More: https://docs.tendermint.com/master/rpc/#/Websocket/subscribe
|
|
func (env *Environment) Subscribe(ctx context.Context, query string) (*coretypes.ResultSubscribe, error) {
|
|
callInfo := rpctypes.GetCallInfo(ctx)
|
|
addr := callInfo.RemoteAddr()
|
|
|
|
if env.EventBus.NumClients() >= env.Config.MaxSubscriptionClients {
|
|
return nil, fmt.Errorf("max_subscription_clients %d reached", env.Config.MaxSubscriptionClients)
|
|
} else if env.EventBus.NumClientSubscriptions(addr) >= env.Config.MaxSubscriptionsPerClient {
|
|
return nil, fmt.Errorf("max_subscriptions_per_client %d reached", env.Config.MaxSubscriptionsPerClient)
|
|
} else if len(query) > maxQueryLength {
|
|
return nil, errors.New("maximum query length exceeded")
|
|
}
|
|
|
|
env.Logger.Info("WARNING: Websocket subscriptions are deprecated and will be removed " +
|
|
"in Tendermint v0.37. See https://tinyurl.com/adr075 for more information.")
|
|
env.Logger.Info("Subscribe to query", "remote", addr, "query", query)
|
|
|
|
q, err := tmquery.New(query)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to parse query: %w", err)
|
|
}
|
|
|
|
subCtx, cancel := context.WithTimeout(ctx, SubscribeTimeout)
|
|
defer cancel()
|
|
|
|
sub, err := env.EventBus.SubscribeWithArgs(subCtx, tmpubsub.SubscribeArgs{
|
|
ClientID: addr,
|
|
Query: q,
|
|
Limit: subBufferSize,
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Capture the current ID, since it can change in the future.
|
|
subscriptionID := callInfo.RPCRequest.ID
|
|
go func() {
|
|
opctx, opcancel := context.WithCancel(context.TODO())
|
|
defer opcancel()
|
|
|
|
for {
|
|
msg, err := sub.Next(opctx)
|
|
if errors.Is(err, tmpubsub.ErrUnsubscribed) {
|
|
// The subscription was removed by the client.
|
|
return
|
|
} else if errors.Is(err, tmpubsub.ErrTerminated) {
|
|
// The subscription was terminated by the publisher.
|
|
resp := callInfo.RPCRequest.MakeError(err)
|
|
ok := callInfo.WSConn.TryWriteRPCResponse(opctx, resp)
|
|
if !ok {
|
|
env.Logger.Info("Unable to write response (slow client)",
|
|
"to", addr, "subscriptionID", subscriptionID, "err", err)
|
|
}
|
|
return
|
|
}
|
|
|
|
// We have a message to deliver to the client.
|
|
resp := callInfo.RPCRequest.MakeResponse(&coretypes.ResultEvent{
|
|
Query: query,
|
|
Data: msg.Data(),
|
|
Events: msg.Events(),
|
|
})
|
|
wctx, cancel := context.WithTimeout(opctx, 10*time.Second)
|
|
err = callInfo.WSConn.WriteRPCResponse(wctx, resp)
|
|
cancel()
|
|
if err != nil {
|
|
env.Logger.Info("Unable to write response (slow client)",
|
|
"to", addr, "subscriptionID", subscriptionID, "err", err)
|
|
}
|
|
}
|
|
}()
|
|
|
|
return &coretypes.ResultSubscribe{}, nil
|
|
}
|
|
|
|
// Unsubscribe from events via WebSocket.
|
|
// More: https://docs.tendermint.com/master/rpc/#/Websocket/unsubscribe
|
|
func (env *Environment) Unsubscribe(ctx context.Context, query string) (*coretypes.ResultUnsubscribe, error) {
|
|
args := tmpubsub.UnsubscribeArgs{Subscriber: rpctypes.GetCallInfo(ctx).RemoteAddr()}
|
|
env.Logger.Info("Unsubscribe from query", "remote", args.Subscriber, "subscription", query)
|
|
|
|
var err error
|
|
args.Query, err = tmquery.New(query)
|
|
|
|
if err != nil {
|
|
args.ID = query
|
|
}
|
|
|
|
err = env.EventBus.Unsubscribe(ctx, args)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &coretypes.ResultUnsubscribe{}, nil
|
|
}
|
|
|
|
// UnsubscribeAll from all events via WebSocket.
|
|
// More: https://docs.tendermint.com/master/rpc/#/Websocket/unsubscribe_all
|
|
func (env *Environment) UnsubscribeAll(ctx context.Context) (*coretypes.ResultUnsubscribe, error) {
|
|
addr := rpctypes.GetCallInfo(ctx).RemoteAddr()
|
|
env.Logger.Info("Unsubscribe from all", "remote", addr)
|
|
err := env.EventBus.UnsubscribeAll(ctx, addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &coretypes.ResultUnsubscribe{}, nil
|
|
}
|
|
|
|
// Events applies a query to the event log. If an event log is not enabled,
|
|
// Events reports an error. Otherwise, it filters the current contents of the
|
|
// log to return matching events.
|
|
//
|
|
// Events returns up to maxItems of the newest eligible event items. An item is
|
|
// eligible if it is older than before (or before is zero), it is newer than
|
|
// after (or after is zero), and its data matches the filter. A nil filter
|
|
// matches all event data.
|
|
//
|
|
// If before is zero and no eligible event items are available, Events waits
|
|
// for up to waitTime for a matching item to become available. The wait is
|
|
// terminated early if ctx ends.
|
|
//
|
|
// If maxItems ≤ 0, a default positive number of events is chosen. The values
|
|
// of maxItems and waitTime may be capped to sensible internal maxima without
|
|
// reporting an error to the caller.
|
|
func (env *Environment) Events(ctx context.Context,
|
|
filter *coretypes.EventFilter,
|
|
maxItems int,
|
|
before, after cursor.Cursor,
|
|
waitTime time.Duration,
|
|
) (*coretypes.ResultEvents, error) {
|
|
if env.EventLog == nil {
|
|
return nil, errors.New("the event log is not enabled")
|
|
}
|
|
|
|
// Parse and validate parameters.
|
|
if maxItems <= 0 {
|
|
maxItems = 10
|
|
} else if maxItems > 100 {
|
|
maxItems = 100
|
|
}
|
|
|
|
const minWaitTime = 1 * time.Second
|
|
const maxWaitTime = 30 * time.Second
|
|
if waitTime < minWaitTime {
|
|
waitTime = minWaitTime
|
|
} else if waitTime > maxWaitTime {
|
|
waitTime = maxWaitTime
|
|
}
|
|
|
|
query := tmquery.All
|
|
if filter != nil && filter.Query != "" {
|
|
q, err := tmquery.New(filter.Query)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("invalid filter query: %w", err)
|
|
}
|
|
query = q
|
|
}
|
|
|
|
var info eventlog.Info
|
|
var items []*eventlog.Item
|
|
var err error
|
|
accept := func(itm *eventlog.Item) error {
|
|
// N.B. We accept up to one item more than requested, so we can tell how
|
|
// to set the "more" flag in the response.
|
|
if len(items) > maxItems || itm.Cursor.Before(after) {
|
|
return eventlog.ErrStopScan
|
|
}
|
|
if cursorInRange(itm.Cursor, before, after) && query.Matches(itm.Events) {
|
|
items = append(items, itm)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
if before.IsZero() {
|
|
ctx, cancel := context.WithTimeout(ctx, waitTime)
|
|
defer cancel()
|
|
|
|
// Long poll. The loop here is because new items may not match the query,
|
|
// and we want to keep waiting until we have relevant results (or time out).
|
|
cur := after
|
|
for len(items) == 0 {
|
|
info, err = env.EventLog.WaitScan(ctx, cur, accept)
|
|
if err != nil {
|
|
// Don't report a timeout as a request failure.
|
|
if errors.Is(err, context.DeadlineExceeded) {
|
|
err = nil
|
|
}
|
|
break
|
|
}
|
|
cur = info.Newest
|
|
}
|
|
} else {
|
|
// Quick poll, return only what is already available.
|
|
info, err = env.EventLog.Scan(accept)
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
more := len(items) > maxItems
|
|
if more {
|
|
items = items[:len(items)-1]
|
|
}
|
|
enc, err := marshalItems(items)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &coretypes.ResultEvents{
|
|
Items: enc,
|
|
More: more,
|
|
Oldest: cursorString(info.Oldest),
|
|
Newest: cursorString(info.Newest),
|
|
}, nil
|
|
}
|
|
|
|
func cursorString(c cursor.Cursor) string {
|
|
if c.IsZero() {
|
|
return ""
|
|
}
|
|
return c.String()
|
|
}
|
|
|
|
func cursorInRange(c, before, after cursor.Cursor) bool {
|
|
return (before.IsZero() || c.Before(before)) && (after.IsZero() || after.Before(c))
|
|
}
|
|
|
|
func marshalItems(items []*eventlog.Item) ([]*coretypes.EventItem, error) {
|
|
out := make([]*coretypes.EventItem, len(items))
|
|
for i, itm := range items {
|
|
v, err := jsontypes.Marshal(itm.Data)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("encoding event data: %w", err)
|
|
}
|
|
out[i] = &coretypes.EventItem{Cursor: itm.Cursor.String(), Event: itm.Type}
|
|
out[i].Data = v
|
|
}
|
|
return out, nil
|
|
}
|