/
outbox.go
54 lines (45 loc) · 1.65 KB
/
outbox.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
// Copyright (c) 2021 - The Event Horizon authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tracing
import (
"context"
eh "github.com/looplab/eventhorizon"
)
// Outbox is an event bus wrapper that adds tracing.
type Outbox struct {
eh.Outbox
h eh.EventHandler
}
// NewOutbox creates a Outbox.
func NewOutbox(outbox eh.Outbox) *Outbox {
return &Outbox{
Outbox: outbox,
// Wrap the eh.EventHandler part of the bus with tracing middleware,
// set as producer to set the correct tags.
h: eh.UseEventHandlerMiddleware(outbox, NewEventHandlerMiddleware()),
}
}
// HandleEvent implements the HandleEvent method of the eventhorizon.EventHandler interface.
func (b *Outbox) HandleEvent(ctx context.Context, event eh.Event) error {
return b.h.HandleEvent(ctx, event)
}
// AddHandler implements the AddHandler method of the eventhorizon.Outbox interface.
func (b *Outbox) AddHandler(ctx context.Context, m eh.EventMatcher, h eh.EventHandler) error {
if h == nil {
return eh.ErrMissingHandler
}
// Wrap the handlers in tracing middleware.
h = eh.UseEventHandlerMiddleware(h, NewEventHandlerMiddleware())
return b.Outbox.AddHandler(ctx, m, h)
}