コード例 #1
0
ファイル: blockstore.go プロジェクト: tswindell/go-ipfs
// AllKeysChan runs a query for keys from the blockstore.
// this is very simplistic, in the future, take dsq.Query as a param?
//
// AllKeysChan respects context
func (bs *blockstore) AllKeysChan(ctx context.Context) (<-chan *cid.Cid, error) {

	// KeysOnly, because that would be _a lot_ of data.
	q := dsq.Query{KeysOnly: true}
	// datastore/namespace does *NOT* fix up Query.Prefix
	q.Prefix = BlockPrefix.String()
	res, err := bs.datastore.Query(q)
	if err != nil {
		return nil, err
	}

	output := make(chan *cid.Cid, dsq.KeysOnlyBufSize)
	go func() {
		defer func() {
			res.Close() // ensure exit (signals early exit, too)
			close(output)
		}()

		for {
			e, ok := res.NextSync()
			if !ok {
				return
			}
			if e.Error != nil {
				log.Errorf("blockstore.AllKeysChan got err:", e.Error)
				return
			}

			// need to convert to key.Key using key.KeyFromDsKey.
			k, err := dshelp.DsKeyToCid(ds.RawKey(e.Key))
			if err != nil {
				log.Warningf("error parsing key from DsKey: ", err)
				continue
			}

			select {
			case <-ctx.Done():
				return
			case output <- k:
			}
		}
	}()

	return output, nil
}
コード例 #2
0
ファイル: blockstore.go プロジェクト: VictorBjelkholm/go-ipfs
// AllKeysChan runs a query for keys from the blockstore.
// this is very simplistic, in the future, take dsq.Query as a param?
//
// AllKeysChan respects context
func (bs *blockstore) AllKeysChan(ctx context.Context) (<-chan *cid.Cid, error) {

	// KeysOnly, because that would be _a lot_ of data.
	q := dsq.Query{KeysOnly: true}
	// datastore/namespace does *NOT* fix up Query.Prefix
	q.Prefix = BlockPrefix.String()
	res, err := bs.datastore.Query(q)
	if err != nil {
		return nil, err
	}

	// this function is here to compartmentalize
	get := func() (*cid.Cid, bool) {
		select {
		case <-ctx.Done():
			return nil, false
		case e, more := <-res.Next():
			if !more {
				return nil, false
			}
			if e.Error != nil {
				log.Debug("blockstore.AllKeysChan got err:", e.Error)
				return nil, false
			}

			// need to convert to key.Key using key.KeyFromDsKey.
			c, err := dshelp.DsKeyStringToCid(e.Key)
			if err != nil {
				log.Warningf("error parsing key from DsKey: ", err)
				return nil, true
			}

			return c, true
		}
	}

	output := make(chan *cid.Cid, dsq.KeysOnlyBufSize)
	go func() {
		defer func() {
			res.Process().Close() // ensure exit (signals early exit, too)
			close(output)
		}()

		for {
			k, ok := get()
			if !ok {
				return
			}
			if k == nil {
				continue
			}

			select {
			case <-ctx.Done():
				return
			case output <- k:
			}
		}
	}()

	return output, nil
}