This repository has been archived by the owner on Apr 2, 2018. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 3
/
fetcher.go
110 lines (89 loc) · 2.2 KB
/
fetcher.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
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
package inputs
import (
"io"
"github.com/concourse/turbine"
"github.com/concourse/turbine/event"
"github.com/concourse/turbine/resource"
)
type FetchedInput struct {
Input turbine.Input
Stream io.Reader
Config turbine.Config
Release func() error
}
type Fetcher interface {
Fetch([]turbine.Input, event.Emitter, <-chan struct{}) ([]FetchedInput, error)
}
type parallelFetcher struct {
tracker resource.Tracker
}
func NewParallelFetcher(tracker resource.Tracker) Fetcher {
return ¶llelFetcher{
tracker: tracker,
}
}
func (fetcher *parallelFetcher) Fetch(inputs []turbine.Input, emitter event.Emitter, abort <-chan struct{}) ([]FetchedInput, error) {
fetchedInputs := make([]FetchedInput, len(inputs))
errResults := make(chan error, len(inputs))
initializedResources := make(chan resource.Resource, len(inputs))
for i, input := range inputs {
go func(i int, input turbine.Input) {
eventLog := event.NewWriter(emitter, event.Origin{
Type: event.OriginTypeInput,
Name: input.Name,
})
resource, err := fetcher.tracker.Init(input.Type, eventLog, abort)
if err != nil {
emitInputError(emitter, input, err)
errResults <- err
return
}
initializedResources <- resource
tarStream, computedInput, buildConfig, err := resource.In(input)
if err != nil {
emitInputError(emitter, input, err)
errResults <- err
return
}
emitter.EmitEvent(event.Input{Input: computedInput})
fetchedInputs[i] = FetchedInput{
Input: computedInput,
Stream: tarStream,
Config: buildConfig,
Release: func() error {
return fetcher.tracker.Release(resource)
},
}
errResults <- nil
}(i, input)
}
var fetchErr error
for i := 0; i < len(inputs); i++ {
err := <-errResults
if err != nil {
fetchErr = err
}
}
if fetchErr != nil {
dance:
for {
select {
case res := <-initializedResources:
fetcher.tracker.Release(res)
default:
break dance
}
}
return nil, fetchErr
}
return fetchedInputs, nil
}
func emitInputError(emitter event.Emitter, input turbine.Input, err error) {
emitter.EmitEvent(event.Error{
Message: err.Error(),
Origin: event.Origin{
Type: event.OriginTypeInput,
Name: input.Name,
},
})
}