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
|
package resource
import (
"fmt"
"log"
"sync"
)
var (
repo repository
once sync.Once
)
func getRepository() *repository {
once.Do(func() {
repo = newRepository()
})
return &repo
}
func ResetRepository() {
repo = newRepository()
}
type repository struct {
registered map[string]Resource
mu sync.Mutex
}
func newRepository() repository {
return repository{
registered: make(map[string]Resource),
}
}
func (r *repository) register(res Resource) error {
r.mu.Lock()
defer r.mu.Unlock()
if _, exists := r.registered[res.ID()]; exists {
return fmt.Errorf("resource %v already registered", res)
}
r.registered[res.ID()] = res
log.Printf("Registered resource %v\n", res)
return nil
}
func (r *repository) apply() error {
r.mu.Lock()
defer r.mu.Unlock()
visited := make(map[string]bool)
visiting := make(map[string]bool)
var order []Resource
var visit func(id string) error
visit = func(id string) error {
if visiting[id] {
return fmt.Errorf("circular dependency detected involving %s", id)
}
if visited[id] {
return nil
}
res, ok := r.registered[id]
if !ok {
return fmt.Errorf("resource %s is depended upon but not registered", id)
}
visiting[id] = true
for depID := range res.dependsOn {
if err := visit(depID); err != nil {
return err
}
}
delete(visiting, id)
visited[id] = true
order = append(order, res)
return nil
}
for id := range r.registered {
if err := visit(id); err != nil {
return err
}
}
for _, res := range order {
log.Printf("Applying resource %v", res)
if err := res.Apply(); err != nil {
return fmt.Errorf("failed to apply %v: %w", res, err)
}
}
return nil
}
func Apply() error {
return getRepository().apply()
}
|
