Update gomod and vendor

vendor/github.com/moby/buildkit/snapshot/snapshotter.go

@@ -0,0 +1,151 @@
+package snapshot
+
+import (
+	"context"
+	"os"
+	"sync"
+	"sync/atomic"
+
+	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/snapshots"
+	"github.com/docker/docker/pkg/idtools"
+)
+
+type Mountable interface {
+	// ID() string
+	Mount() ([]mount.Mount, func() error, error)
+	IdentityMapping() *idtools.IdentityMapping
+}
+
+// Snapshotter defines interface that any snapshot implementation should satisfy
+type Snapshotter interface {
+	Name() string
+	Mounts(ctx context.Context, key string) (Mountable, error)
+	Prepare(ctx context.Context, key, parent string, opts ...snapshots.Opt) error
+	View(ctx context.Context, key, parent string, opts ...snapshots.Opt) (Mountable, error)
+
+	Stat(ctx context.Context, key string) (snapshots.Info, error)
+	Update(ctx context.Context, info snapshots.Info, fieldpaths ...string) (snapshots.Info, error)
+	Usage(ctx context.Context, key string) (snapshots.Usage, error)
+	Commit(ctx context.Context, name, key string, opts ...snapshots.Opt) error
+	Remove(ctx context.Context, key string) error
+	Walk(ctx context.Context, fn snapshots.WalkFunc, filters ...string) error
+	Close() error
+	IdentityMapping() *idtools.IdentityMapping
+}
+
+func FromContainerdSnapshotter(name string, s snapshots.Snapshotter, idmap *idtools.IdentityMapping) Snapshotter {
+	return &fromContainerd{name: name, Snapshotter: s, idmap: idmap}
+}
+
+type fromContainerd struct {
+	name string
+	snapshots.Snapshotter
+	idmap *idtools.IdentityMapping
+}
+
+func (s *fromContainerd) Name() string {
+	return s.name
+}
+
+func (s *fromContainerd) Mounts(ctx context.Context, key string) (Mountable, error) {
+	mounts, err := s.Snapshotter.Mounts(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	return &staticMountable{mounts: mounts, idmap: s.idmap, id: key}, nil
+}
+func (s *fromContainerd) Prepare(ctx context.Context, key, parent string, opts ...snapshots.Opt) error {
+	_, err := s.Snapshotter.Prepare(ctx, key, parent, opts...)
+	return err
+}
+func (s *fromContainerd) View(ctx context.Context, key, parent string, opts ...snapshots.Opt) (Mountable, error) {
+	mounts, err := s.Snapshotter.View(ctx, key, parent, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return &staticMountable{mounts: mounts, idmap: s.idmap, id: key}, nil
+}
+func (s *fromContainerd) IdentityMapping() *idtools.IdentityMapping {
+	return s.idmap
+}
+
+type staticMountable struct {
+	count  int32
+	id     string
+	mounts []mount.Mount
+	idmap  *idtools.IdentityMapping
+}
+
+func (cm *staticMountable) Mount() ([]mount.Mount, func() error, error) {
+	atomic.AddInt32(&cm.count, 1)
+	return cm.mounts, func() error {
+		if atomic.AddInt32(&cm.count, -1) < 0 {
+			if v := os.Getenv("BUILDKIT_DEBUG_PANIC_ON_ERROR"); v == "1" {
+				panic("release of released mount " + cm.id)
+			}
+		}
+		return nil
+	}, nil
+}
+
+func (cm *staticMountable) IdentityMapping() *idtools.IdentityMapping {
+	return cm.idmap
+}
+
+// NewContainerdSnapshotter converts snapshotter to containerd snapshotter
+func NewContainerdSnapshotter(s Snapshotter) (snapshots.Snapshotter, func() error) {
+	cs := &containerdSnapshotter{Snapshotter: s}
+	return cs, cs.release
+}
+
+type containerdSnapshotter struct {
+	mu        sync.Mutex
+	releasers []func() error
+	Snapshotter
+}
+
+func (cs *containerdSnapshotter) release() error {
+	cs.mu.Lock()
+	defer cs.mu.Unlock()
+	var err error
+	for _, f := range cs.releasers {
+		if err1 := f(); err1 != nil && err == nil {
+			err = err1
+		}
+	}
+	return err
+}
+
+func (cs *containerdSnapshotter) returnMounts(mf Mountable) ([]mount.Mount, error) {
+	mounts, release, err := mf.Mount()
+	if err != nil {
+		return nil, err
+	}
+	cs.mu.Lock()
+	cs.releasers = append(cs.releasers, release)
+	cs.mu.Unlock()
+	return mounts, nil
+}
+
+func (cs *containerdSnapshotter) Mounts(ctx context.Context, key string) ([]mount.Mount, error) {
+	mf, err := cs.Snapshotter.Mounts(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	return cs.returnMounts(mf)
+}
+
+func (cs *containerdSnapshotter) Prepare(ctx context.Context, key, parent string, opts ...snapshots.Opt) ([]mount.Mount, error) {
+	if err := cs.Snapshotter.Prepare(ctx, key, parent, opts...); err != nil {
+		return nil, err
+	}
+	return cs.Mounts(ctx, key)
+}
+func (cs *containerdSnapshotter) View(ctx context.Context, key, parent string, opts ...snapshots.Opt) ([]mount.Mount, error) {
+	mf, err := cs.Snapshotter.View(ctx, key, parent, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return cs.returnMounts(mf)
+}