feat(graphsync): unified graphsync instance

setup a single graphsync that loads from both the chainstore & client blockstore

node/modules/graphsync.go

@@ -0,0 +1,42 @@
+package modules
+
+import (
+	"io"
+
+	"github.com/filecoin-project/lotus/node/modules/dtypes"
+	"github.com/filecoin-project/lotus/node/modules/helpers"
+	graphsync "github.com/ipfs/go-graphsync/impl"
+	"github.com/ipfs/go-graphsync/ipldbridge"
+	gsnet "github.com/ipfs/go-graphsync/network"
+	"github.com/ipfs/go-graphsync/storeutil"
+	"github.com/ipld/go-ipld-prime"
+	"github.com/libp2p/go-libp2p-core/host"
+	"go.uber.org/fx"
+)
+
+// GraphsyncStorer creates a storer that stores data in the client blockstore
+func GraphsyncStorer(clientBs dtypes.ClientBlockstore) dtypes.GraphsyncStorer {
+	return dtypes.GraphsyncStorer(storeutil.StorerForBlockstore(clientBs))
+}
+
+// GraphsyncLoader creates a loader that reads from both the chain blockstore and the client blockstore
+func GraphsyncLoader(clientBs dtypes.ClientBlockstore, chainBs dtypes.ChainBlockstore) dtypes.GraphsyncLoader {
+	clientLoader := storeutil.LoaderForBlockstore(clientBs)
+	chainLoader := storeutil.LoaderForBlockstore(chainBs)
+	return func(lnk ipld.Link, lnkCtx ipld.LinkContext) (io.Reader, error) {
+		reader, err := chainLoader(lnk, lnkCtx)
+		if err != nil {
+			return clientLoader(lnk, lnkCtx)
+		}
+		return reader, err
+	}
+}
+
+// Graphsync creates a graphsync instance from the given loader and storer
+func Graphsync(mctx helpers.MetricsCtx, lc fx.Lifecycle, loader dtypes.GraphsyncLoader, storer dtypes.GraphsyncStorer, h host.Host) dtypes.Graphsync {
+	graphsyncNetwork := gsnet.NewFromLibp2pHost(h)
+	ipldBridge := ipldbridge.NewIPLDBridge()
+	gs := graphsync.New(helpers.LifecycleCtx(mctx, lc), graphsyncNetwork, ipldBridge, ipld.Loader(loader), ipld.Storer(storer))
+
+	return gs
+}