Add benchmark for just the time it takes to cat

test/integration/bench_cat_test.go

+package integrationtest
+
+import (
+	"bytes"
+	"io"
+	"math"
+	"testing"
+
+	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
+	"github.com/ipfs/go-ipfs/core"
+	coreunix "github.com/ipfs/go-ipfs/core/coreunix"
+	mocknet "github.com/ipfs/go-ipfs/p2p/net/mock"
+	"github.com/ipfs/go-ipfs/p2p/peer"
+	"github.com/ipfs/go-ipfs/thirdparty/unit"
+	errors "github.com/ipfs/go-ipfs/util/debugerror"
+	testutil "github.com/ipfs/go-ipfs/util/testutil"
+)
+
+func BenchmarkCat1MB(b *testing.B) { benchmarkVarCat(b, unit.MB*1) }
+func BenchmarkCat2MB(b *testing.B) { benchmarkVarCat(b, unit.MB*2) }
+func BenchmarkCat4MB(b *testing.B) { benchmarkVarCat(b, unit.MB*4) }
+
+func benchmarkVarCat(b *testing.B, size int64) {
+	data := RandomBytes(size)
+	b.SetBytes(size)
+	for n := 0; n < b.N; n++ {
+		err := benchCat(b, data, instant)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func benchCat(b *testing.B, data []byte, conf testutil.LatencyConfig) error {
+	b.StopTimer()
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	const numPeers = 2
+
+	// create network
+	mn, err := mocknet.FullMeshLinked(ctx, numPeers)
+	if err != nil {
+		return errors.Wrap(err)
+	}
+	mn.SetLinkDefaults(mocknet.LinkOptions{
+		Latency: conf.NetworkLatency,
+		// TODO add to conf. This is tricky because we want 0 values to be functional.
+		Bandwidth: math.MaxInt32,
+	})
+
+	peers := mn.Peers()
+	if len(peers) < numPeers {
+		return errors.New("test initialization error")
+	}
+
+	adder, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(peers[0], mn.Host(peers[0]), conf, core.DHTOption)))
+	if err != nil {
+		return err
+	}
+	defer adder.Close()
+	catter, err := core.NewIPFSNode(ctx, core.ConfigOption(MocknetTestRepo(peers[1], mn.Host(peers[1]), conf, core.DHTOption)))
+	if err != nil {
+		return err
+	}
+	defer catter.Close()
+
+	bs1 := []peer.PeerInfo{adder.Peerstore.PeerInfo(adder.Identity)}
+	bs2 := []peer.PeerInfo{catter.Peerstore.PeerInfo(catter.Identity)}
+
+	if err := catter.Bootstrap(core.BootstrapConfigWithPeers(bs1)); err != nil {
+		return err
+	}
+	if err := adder.Bootstrap(core.BootstrapConfigWithPeers(bs2)); err != nil {
+		return err
+	}
+
+	added, err := coreunix.Add(adder, bytes.NewReader(data))
+	if err != nil {
+		return err
+	}
+
+	b.StartTimer()
+	readerCatted, err := coreunix.Cat(catter, added)
+	if err != nil {
+		return err
+	}
+
+	// verify
+	var bufout bytes.Buffer
+	io.Copy(&bufout, readerCatted)
+	if 0 != bytes.Compare(bufout.Bytes(), data) {
+		return errors.New("catted data does not match added data")
+	}
+	return nil
+}