lotus/blockstore/union.go
2021-03-02 21:22:24 +00:00

111 lines
2.1 KiB
Go

package blockstore
import (
"context"
blocks "github.com/ipfs/go-block-format"
"github.com/ipfs/go-cid"
)
type unionBlockstore []Blockstore
// Union returns an unioned blockstore.
//
// * Reads return from the first blockstore that has the value, querying in the
// supplied order.
// * Writes (puts and deltes) are broadcast to all stores.
//
func Union(stores ...Blockstore) Blockstore {
return unionBlockstore(stores)
}
func (m unionBlockstore) Has(cid cid.Cid) (has bool, err error) {
for _, bs := range m {
if has, err = bs.Has(cid); has || err != nil {
break
}
}
return has, err
}
func (m unionBlockstore) Get(cid cid.Cid) (blk blocks.Block, err error) {
for _, bs := range m {
if blk, err = bs.Get(cid); err == nil || err != ErrNotFound {
break
}
}
return blk, err
}
func (m unionBlockstore) View(cid cid.Cid, callback func([]byte) error) (err error) {
for _, bs := range m {
if err = bs.View(cid, callback); err == nil || err != ErrNotFound {
break
}
}
return err
}
func (m unionBlockstore) GetSize(cid cid.Cid) (size int, err error) {
for _, bs := range m {
if size, err = bs.GetSize(cid); err == nil || err != ErrNotFound {
break
}
}
return size, err
}
func (m unionBlockstore) Put(block blocks.Block) (err error) {
for _, bs := range m {
if err = bs.Put(block); err != nil {
break
}
}
return err
}
func (m unionBlockstore) PutMany(blks []blocks.Block) (err error) {
for _, bs := range m {
if err = bs.PutMany(blks); err != nil {
break
}
}
return err
}
func (m unionBlockstore) DeleteBlock(cid cid.Cid) (err error) {
for _, bs := range m {
if err = bs.DeleteBlock(cid); err != nil {
break
}
}
return err
}
func (m unionBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
// this does not deduplicate; this interface needs to be revisited.
outCh := make(chan cid.Cid)
go func() {
defer close(outCh)
for _, bs := range m {
ch, err := bs.AllKeysChan(ctx)
if err != nil {
return
}
for cid := range ch {
outCh <- cid
}
}
}()
return outCh, nil
}
func (m unionBlockstore) HashOnRead(enabled bool) {
for _, bs := range m {
bs.HashOnRead(enabled)
}
}