/
survey.go
110 lines (100 loc) · 2.87 KB
/
survey.go
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package survey
import (
"context"
"fmt"
"github.com/centrifugal/centrifugo/v4/internal/apiproto"
"github.com/centrifugal/centrifuge"
"github.com/gobwas/glob"
"google.golang.org/protobuf/proto"
)
// Handler can handle survey.
type Handler func(node *centrifuge.Node, data []byte) centrifuge.SurveyReply
type Caller struct {
node *centrifuge.Node
handlers map[string]Handler
}
func NewCaller(node *centrifuge.Node) *Caller {
c := &Caller{
node: node,
handlers: map[string]Handler{
"channels": respondChannelsSurvey,
},
}
c.node.OnSurvey(func(event centrifuge.SurveyEvent, cb centrifuge.SurveyCallback) {
h, ok := c.handlers[event.Op]
if !ok {
cb(centrifuge.SurveyReply{Code: MethodNotFound})
return
}
cb(h(c.node, event.Data))
})
return c
}
const (
InternalError uint32 = 1
InvalidRequest uint32 = 2
MethodNotFound uint32 = 3
)
func (c *Caller) Channels(ctx context.Context, cmd *apiproto.ChannelsRequest) (map[string]*apiproto.ChannelInfo, error) {
return surveyChannels(ctx, c.node, cmd)
}
func surveyChannels(ctx context.Context, node *centrifuge.Node, cmd *apiproto.ChannelsRequest) (map[string]*apiproto.ChannelInfo, error) {
req, _ := proto.Marshal(cmd)
results, err := node.Survey(ctx, "channels", req, "")
if err != nil {
return nil, err
}
channels := map[string]*apiproto.ChannelInfo{}
for nodeID, result := range results {
if result.Code > 0 {
return nil, fmt.Errorf("non-zero code from node %s: %d", nodeID, result.Code)
}
var nodeChannels apiproto.ChannelsResult
err := proto.Unmarshal(result.Data, &nodeChannels)
if err != nil {
return nil, fmt.Errorf("error unmarshaling data from node %s: %v", nodeID, err)
}
for ch, chInfo := range nodeChannels.Channels {
info, ok := channels[ch]
if !ok {
channels[ch] = &apiproto.ChannelInfo{NumClients: chInfo.NumClients}
} else {
info.NumClients += chInfo.NumClients
channels[ch] = info
}
}
}
return channels, nil
}
func respondChannelsSurvey(node *centrifuge.Node, params []byte) centrifuge.SurveyReply {
var req apiproto.ChannelsRequest
err := proto.Unmarshal(params, &req)
if err != nil {
return centrifuge.SurveyReply{Code: InvalidRequest}
}
var g glob.Glob
if req.Pattern != "" {
var err error
g, err = glob.Compile(req.Pattern)
if err != nil {
return centrifuge.SurveyReply{Code: InvalidRequest}
}
}
channels := node.Hub().Channels()
channelsMap := make(map[string]*apiproto.ChannelInfo, len(channels))
for _, ch := range channels {
if g != nil && !g.Match(ch) {
continue
}
if numSubscribers := node.Hub().NumSubscribers(ch); numSubscribers > 0 {
channelsMap[ch] = &apiproto.ChannelInfo{
NumClients: uint32(numSubscribers),
}
}
}
data, err := proto.Marshal(&apiproto.ChannelsResult{Channels: channelsMap})
if err != nil {
return centrifuge.SurveyReply{Code: InternalError}
}
return centrifuge.SurveyReply{Data: data}
}