96 lines
2.2 KiB
Go
96 lines
2.2 KiB
Go
package blockstore
|
|
|
|
import (
|
|
"context"
|
|
"sync"
|
|
"time"
|
|
|
|
"golang.org/x/xerrors"
|
|
|
|
blocks "github.com/ipfs/go-block-format"
|
|
"github.com/ipfs/go-cid"
|
|
blockstore "github.com/ipfs/go-ipfs-blockstore"
|
|
logging "github.com/ipfs/go-log"
|
|
)
|
|
|
|
var log = logging.Logger("blockstore")
|
|
|
|
type FallbackStore struct {
|
|
blockstore.Blockstore
|
|
|
|
fallbackGetBlock func(context.Context, cid.Cid) (blocks.Block, error)
|
|
lk sync.RWMutex
|
|
}
|
|
|
|
func (fbs *FallbackStore) SetFallback(fg func(context.Context, cid.Cid) (blocks.Block, error)) {
|
|
fbs.lk.Lock()
|
|
defer fbs.lk.Unlock()
|
|
|
|
fbs.fallbackGetBlock = fg
|
|
}
|
|
|
|
func (fbs *FallbackStore) getFallback(c cid.Cid) (blocks.Block, error) {
|
|
log.Errorw("fallbackstore: Block not found locally, fetching from the network", "cid", c)
|
|
fbs.lk.RLock()
|
|
defer fbs.lk.RUnlock()
|
|
|
|
if fbs.fallbackGetBlock == nil {
|
|
// FallbackStore wasn't configured yet (chainstore/bitswap aren't up yet)
|
|
// Wait for a bit and retry
|
|
fbs.lk.RUnlock()
|
|
time.Sleep(5 * time.Second)
|
|
fbs.lk.RLock()
|
|
|
|
if fbs.fallbackGetBlock == nil {
|
|
log.Errorw("fallbackstore: fallbackGetBlock not configured yet")
|
|
return nil, blockstore.ErrNotFound
|
|
}
|
|
}
|
|
|
|
ctx, cancel := context.WithTimeout(context.TODO(), 120*time.Second)
|
|
defer cancel()
|
|
|
|
b, err := fbs.fallbackGetBlock(ctx, c)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// chain bitswap puts blocks in temp blockstore which is cleaned up
|
|
// every few min (to drop any messages we fetched but don't want)
|
|
// in this case we want to keep this block around
|
|
if err := fbs.Put(b); err != nil {
|
|
return nil, xerrors.Errorf("persisting fallback-fetched block: %w", err)
|
|
}
|
|
return b, nil
|
|
}
|
|
|
|
func (fbs *FallbackStore) Get(c cid.Cid) (blocks.Block, error) {
|
|
b, err := fbs.Blockstore.Get(c)
|
|
switch err {
|
|
case nil:
|
|
return b, nil
|
|
case blockstore.ErrNotFound:
|
|
return fbs.getFallback(c)
|
|
default:
|
|
return b, err
|
|
}
|
|
}
|
|
|
|
func (fbs *FallbackStore) GetSize(c cid.Cid) (int, error) {
|
|
sz, err := fbs.Blockstore.GetSize(c)
|
|
switch err {
|
|
case nil:
|
|
return sz, nil
|
|
case blockstore.ErrNotFound:
|
|
b, err := fbs.getFallback(c)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
return len(b.RawData()), nil
|
|
default:
|
|
return sz, err
|
|
}
|
|
}
|
|
|
|
var _ blockstore.Blockstore = &FallbackStore{}
|