forked from moby/buildkit
/
result.go
105 lines (85 loc) · 2.01 KB
/
result.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
package solver
import (
"context"
"sync"
"sync/atomic"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
// SharedResult is a result that can be cloned
type SharedResult struct {
mu sync.Mutex
main Result
}
func NewSharedResult(main Result) *SharedResult {
return &SharedResult{main: main}
}
func (r *SharedResult) Clone() Result {
r.mu.Lock()
defer r.mu.Unlock()
r1, r2 := dup(r.main)
r.main = r1
return r2
}
func (r *SharedResult) Release(ctx context.Context) error {
r.mu.Lock()
defer r.mu.Unlock()
return r.main.Release(ctx)
}
func dup(res Result) (Result, Result) {
sem := int64(0)
return &splitResult{Result: res, sem: &sem}, &splitResult{Result: res, sem: &sem}
}
type splitResult struct {
Result
released int64
sem *int64
}
func (r *splitResult) Release(ctx context.Context) error {
if atomic.AddInt64(&r.released, 1) > 1 {
err := errors.Errorf("releasing already released reference")
logrus.Error(err)
return err
}
if atomic.AddInt64(r.sem, 1) == 2 {
return r.Result.Release(ctx)
}
return nil
}
// NewCachedResult combines a result and cache key into cached result
func NewCachedResult(res Result, k []ExportableCacheKey) CachedResult {
return &cachedResult{res, k}
}
type cachedResult struct {
Result
k []ExportableCacheKey
}
func (cr *cachedResult) CacheKeys() []ExportableCacheKey {
return cr.k
}
func NewSharedCachedResult(res CachedResult) *SharedCachedResult {
return &SharedCachedResult{
SharedResult: NewSharedResult(res),
CachedResult: res,
}
}
func (r *SharedCachedResult) Clone() CachedResult {
return &clonedCachedResult{Result: r.SharedResult.Clone(), cr: r.CachedResult}
}
func (r *SharedCachedResult) Release(ctx context.Context) error {
return r.SharedResult.Release(ctx)
}
type clonedCachedResult struct {
Result
cr CachedResult
}
func (r *clonedCachedResult) ID() string {
return r.Result.ID()
}
func (cr *clonedCachedResult) CacheKeys() []ExportableCacheKey {
return cr.cr.CacheKeys()
}
type SharedCachedResult struct {
*SharedResult
CachedResult
}