lotus/node/repo/importmgr/multistore.go
Łukasz Magiera 5a117d8edf gofmt
2020-07-08 23:05:54 +02:00

125 lines
2.2 KiB
Go

package importmgr
import (
"fmt"
"path"
"sync"
"sync/atomic"
"github.com/hashicorp/go-multierror"
"golang.org/x/xerrors"
"github.com/ipfs/go-datastore"
)
type dsProvider interface {
Datastore(namespace string) (datastore.Batching, error)
ListDatastores(namespace string) ([]int64, error)
DeleteDatastore(namespace string) error
}
type MultiStore struct {
provider dsProvider
namespace string
open map[int64]*Store
next int64
lk sync.RWMutex
}
func NewMultiDstore(provider dsProvider, namespace string) (*MultiStore, error) {
ids, err := provider.ListDatastores(namespace)
if err != nil {
return nil, xerrors.Errorf("listing datastores: %w", err)
}
mds := &MultiStore{
provider: provider,
namespace: namespace,
open: map[int64]*Store{},
}
for _, i := range ids {
if i > mds.next {
mds.next = i
}
_, err := mds.Get(i)
if err != nil {
return nil, xerrors.Errorf("open store %d: %w", i, err)
}
}
return mds, nil
}
func (mds *MultiStore) path(i int64) string {
return path.Join("/", mds.namespace, fmt.Sprintf("%d", i))
}
func (mds *MultiStore) Next() int64 {
return atomic.AddInt64(&mds.next, 1)
}
func (mds *MultiStore) Get(i int64) (*Store, error) {
mds.lk.Lock()
defer mds.lk.Unlock()
store, ok := mds.open[i]
if ok {
return store, nil
}
ds, err := mds.provider.Datastore(mds.path(i))
if err != nil {
return nil, err
}
mds.open[i], err = openStore(ds)
return mds.open[i], err
}
func (mds *MultiStore) List() []int64 {
mds.lk.RLock()
defer mds.lk.RUnlock()
out := make([]int64, 0, len(mds.open))
for i := range mds.open {
out = append(out, i)
}
return out
}
func (mds *MultiStore) Delete(i int64) error {
mds.lk.Lock()
defer mds.lk.Unlock()
store, ok := mds.open[i]
if ok {
if err := store.Close(); err != nil {
return xerrors.Errorf("closing sub-datastore %d: %w", i, err)
}
delete(mds.open, i)
}
return mds.provider.DeleteDatastore(mds.path(i))
}
func (mds *MultiStore) Close() error {
mds.lk.Lock()
defer mds.lk.Unlock()
var err error
for i, store := range mds.open {
cerr := store.Close()
if cerr != nil {
err = multierror.Append(err, xerrors.Errorf("closing sub-datastore %d: %w", i, cerr))
}
}
return err
}