cachemanager: basic releasing

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
docker-18.09
Tonis Tiigi 2017-05-26 10:59:33 -07:00
parent f2739f0728
commit 8a2699611e
2 changed files with 86 additions and 6 deletions

View File

@ -17,6 +17,12 @@ import (
const dbFile = "cache.db"
var (
errLocked = errors.New("locked")
errNotFound = errors.New("not found")
errInvalid = errors.New("invalid")
)
type CacheManagerOpt struct {
Snapshotter snapshot.Snapshotter
Root string
@ -41,6 +47,7 @@ type GCPolicy struct {
type SnapshotRef interface {
Mountable
ID() string
Release() error
Size() (int64, error)
// Prepare() / ChainID() / Meta()
@ -48,6 +55,7 @@ type SnapshotRef interface {
type ActiveRef interface {
Mountable
ID() string
ReleaseActive() (SnapshotRef, error)
ReleaseAndCommit(ctx context.Context) (SnapshotRef, error)
Size() (int64, error)
@ -127,7 +135,7 @@ func (cm *cacheManager) Get(id string) (SnapshotRef, error) {
rec, ok := cm.records[id]
if !ok {
// TODO: lazy-load from Snapshotter
return nil, errors.Errorf("not found")
return nil, errors.Wrapf(errNotFound, "%s not found", id)
}
return rec.ref(), nil
}
@ -149,10 +157,34 @@ func (cm *cacheManager) New(s SnapshotRef) (ActiveRef, error) {
refs: make(map[*snapshotRef]struct{}),
}
cm.mu.Lock()
defer cm.mu.Unlock()
cm.records[id] = rec // TODO: save to db
return rec.ref(), nil
}
func (cm *cacheManager) GetActive(id string) (ActiveRef, error) { // Rebase?
return nil, errors.New("GetActive not implemented")
cm.mu.Lock()
defer cm.mu.Unlock()
rec, ok := cm.records[id]
if !ok {
return nil, errors.Wrapf(errNotFound, "%s not found", id)
}
rec.mu.Lock()
defer rec.mu.Unlock()
if !rec.active {
return nil, errors.Wrapf(errInvalid, "%s is not active", id)
}
if rec.sharedActive || len(rec.refs) != 0 {
return nil, errors.Wrapf(errLocked, "%s is locked", id)
}
return rec.ref(), nil
}
func (cm *cacheManager) DiskUsage(ctx context.Context) (map[string]int64, error) {
@ -170,6 +202,7 @@ func (cm *cacheManager) GC(ctx context.Context) error {
type cacheRecord struct {
mu sync.Mutex
active bool
sharedActive bool
// meta SnapMeta
refs map[*snapshotRef]struct{}
id string
@ -203,11 +236,36 @@ func (sr *snapshotRef) Mount() ([]mount.Mount, error) {
}
func (sr *snapshotRef) Release() error {
return errors.New("Release not implemented")
sr.cm.mu.Lock()
defer sr.cm.mu.Unlock()
delete(sr.refs, sr)
if len(sr.refs) == 0 {
//go sr.cm.GC()
}
sr.sharedActive = false
return nil
}
func (sr *snapshotRef) ReleaseActive() (SnapshotRef, error) {
return nil, errors.New("ReleaseActive not implemented")
sr.cm.mu.Lock()
defer sr.cm.mu.Unlock()
sr.mu.Lock()
defer sr.mu.Unlock()
if !sr.active || sr.sharedActive || len(sr.refs) != 1 {
return nil, errors.New("invalid active")
}
if _, ok := sr.refs[sr]; !ok {
return nil, errors.New("invalid active")
}
sr.sharedActive = true
return sr, nil
}
func (sr *snapshotRef) ReleaseAndCommit(ctx context.Context) (SnapshotRef, error) {
@ -218,6 +276,10 @@ func (sr *snapshotRef) Size() (int64, error) {
return -1, errors.New("Size not implemented")
}
func (sr *snapshotRef) ID() string {
return sr.id
}
func generateID() string {
b := make([]byte, 32)
if _, err := rand.Read(b); err != nil {

View File

@ -7,6 +7,7 @@ import (
"testing"
"github.com/containerd/containerd/snapshot/naive"
"github.com/pkg/errors"
"github.com/stretchr/testify/assert"
"github.com/tonistiigi/buildkit_poc/snapshot"
)
@ -45,6 +46,23 @@ func TestCacheManager(t *testing.T) {
err = lm.Unmount()
assert.NoError(t, err)
_, err = cm.GetActive(active.ID())
assert.Error(t, err)
assert.Equal(t, errors.Cause(err), errLocked)
snap, err := active.ReleaseActive()
assert.NoError(t, err)
_, err = cm.GetActive(active.ID())
assert.Error(t, err)
assert.Equal(t, errors.Cause(err), errLocked)
err = snap.Release()
assert.NoError(t, err)
_, err = cm.GetActive(active.ID())
assert.NoError(t, err)
err = cm.Close()
assert.NoError(t, err)
}