forked from pydio/cells
-
Notifications
You must be signed in to change notification settings - Fork 0
/
migrations.go
60 lines (50 loc) · 1.8 KB
/
migrations.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
package migrations
import (
"context"
"github.com/hashicorp/go-version"
)
// Migration defines a target version and functions to upgrade and/or downgrade.
type Migration struct {
TargetVersion *version.Version
Up func(ctx context.Context) error
Down func(ctx context.Context) error
}
// FirstRun returns version "zero".
func FirstRun() *version.Version {
obj, _ := version.NewVersion("0.0.0")
return obj
}
// ApplyMigrations browse migrations upward on downward and apply them sequentially. It returns a version to be
// saved as the current valid version of the service, or nil if no changes were necessary. In specific case where
// current version is 0.0.0 (first run), it only applies first run migration (if any) and returns target version.
func Apply(ctx context.Context, current *version.Version, target *version.Version, migrations []*Migration) (*version.Version, error) {
if migrations == nil {
return target, nil
}
if target.GreaterThan(current) {
var successVersion *version.Version
for _, migration := range migrations {
v := migration.TargetVersion
if migration.Up != nil && (current.String() == "0.0.0" || v.GreaterThan(current)) && (v.LessThan(target) || v.Equal(target)) {
if err := migration.Up(ctx); err != nil {
return successVersion, err
}
successVersion, _ = version.NewVersion(v.String())
}
}
}
if target.LessThan(current) {
var successVersion *version.Version
for i := len(migrations) - 1; i >= 0; i-- {
migration := migrations[i]
v := migration.TargetVersion
if migration.Down != nil && v.GreaterThan(target) && (v.LessThan(current) || v.Equal(current)) {
if err := migration.Down(ctx); err != nil {
return successVersion, err
}
successVersion, _ = version.NewVersion(v.String())
}
}
}
return target, nil
}