swarm: Chunk refactor (#17659)

Co-authored-by: Janos Guljas <janos@resenje.org>
Co-authored-by: Balint Gabor <balint.g@gmail.com>
Co-authored-by: Anton Evangelatov <anton.evangelatov@gmail.com>
Co-authored-by: Viktor Trón <viktor.tron@gmail.com>

1 files changed, 459 insertions, 0 deletions

diff --git a/swarm/network/fetcher_test.go b/swarm/network/fetcher_test.go
new file mode 100644
index 000000000..21b81d652
--- /dev/null
+++ b/swarm/network/fetcher_test.go
@@ -0,0 +1,459 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package network
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+var requestedPeerID = discover.MustHexID("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439")
+var sourcePeerID = discover.MustHexID("2dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439")
+
+// mockRequester pushes every request to the requestC channel when its doRequest function is called
+type mockRequester struct {
+	// requests []Request
+	requestC  chan *Request   // when a request is coming it is pushed to requestC
+	waitTimes []time.Duration // with waitTimes[i] you can define how much to wait on the ith request (optional)
+	ctr       int             //counts the number of requests
+	quitC     chan struct{}
+}
+
+func newMockRequester(waitTimes ...time.Duration) *mockRequester {
+	return &mockRequester{
+		requestC:  make(chan *Request),
+		waitTimes: waitTimes,
+		quitC:     make(chan struct{}),
+	}
+}
+
+func (m *mockRequester) doRequest(ctx context.Context, request *Request) (*discover.NodeID, chan struct{}, error) {
+	waitTime := time.Duration(0)
+	if m.ctr < len(m.waitTimes) {
+		waitTime = m.waitTimes[m.ctr]
+		m.ctr++
+	}
+	time.Sleep(waitTime)
+	m.requestC <- request
+
+	// if there is a Source in the request use that, if not use the global requestedPeerId
+	source := request.Source
+	if source == nil {
+		source = &requestedPeerID
+	}
+	return source, m.quitC, nil
+}
+
+// TestFetcherSingleRequest creates a Fetcher using mockRequester, and run it with a sample set of peers to skip.
+// mockRequester pushes a Request on a channel every time the request function is called. Using
+// this channel we test if calling Fetcher.Request calls the request function, and whether it uses
+// the correct peers to skip which we provided for the fetcher.run function.
+func TestFetcherSingleRequest(t *testing.T) {
+	requester := newMockRequester()
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	peers := []string{"a", "b", "c", "d"}
+	peersToSkip := &sync.Map{}
+	for _, p := range peers {
+		peersToSkip.Store(p, time.Now())
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go fetcher.run(ctx, peersToSkip)
+
+	rctx := context.Background()
+	fetcher.Request(rctx)
+
+	select {
+	case request := <-requester.requestC:
+		// request should contain all peers from peersToSkip provided to the fetcher
+		for _, p := range peers {
+			if _, ok := request.peersToSkip.Load(p); !ok {
+				t.Fatalf("request.peersToSkip misses peer")
+			}
+		}
+
+		// source peer should be also added to peersToSkip eventually
+		time.Sleep(100 * time.Millisecond)
+		if _, ok := request.peersToSkip.Load(requestedPeerID.String()); !ok {
+			t.Fatalf("request.peersToSkip does not contain peer returned by the request function")
+		}
+
+		// fetch should trigger a request, if it doesn't happen in time, test should fail
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("fetch timeout")
+	}
+}
+
+// TestCancelStopsFetcher tests that a cancelled fetcher does not initiate further requests even if its fetch function is called
+func TestFetcherCancelStopsFetcher(t *testing.T) {
+	requester := newMockRequester()
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	peersToSkip := &sync.Map{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// we start the fetcher, and then we immediately cancel the context
+	go fetcher.run(ctx, peersToSkip)
+	cancel()
+
+	rctx, rcancel := context.WithTimeout(ctx, 100*time.Millisecond)
+	defer rcancel()
+	// we call Request with an active context
+	fetcher.Request(rctx)
+
+	// fetcher should not initiate request, we can only check by waiting a bit and making sure no request is happening
+	select {
+	case <-requester.requestC:
+		t.Fatalf("cancelled fetcher initiated request")
+	case <-time.After(200 * time.Millisecond):
+	}
+}
+
+// TestFetchCancelStopsRequest tests that calling a Request function with a cancelled context does not initiate a request
+func TestFetcherCancelStopsRequest(t *testing.T) {
+	requester := newMockRequester(100 * time.Millisecond)
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	peersToSkip := &sync.Map{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// we start the fetcher with an active context
+	go fetcher.run(ctx, peersToSkip)
+
+	rctx, rcancel := context.WithCancel(context.Background())
+	rcancel()
+
+	// we call Request with a cancelled context
+	fetcher.Request(rctx)
+
+	// fetcher should not initiate request, we can only check by waiting a bit and making sure no request is happening
+	select {
+	case <-requester.requestC:
+		t.Fatalf("cancelled fetch function initiated request")
+	case <-time.After(200 * time.Millisecond):
+	}
+
+	// if there is another Request with active context, there should be a request, because the fetcher itself is not cancelled
+	rctx = context.Background()
+	fetcher.Request(rctx)
+
+	select {
+	case <-requester.requestC:
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("expected request")
+	}
+}
+
+// TestOfferUsesSource tests Fetcher Offer behavior.
+// In this case there should be 1 (and only one) request initiated from the source peer, and the
+// source nodeid should appear in the peersToSkip map.
+func TestFetcherOfferUsesSource(t *testing.T) {
+	requester := newMockRequester(100 * time.Millisecond)
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	peersToSkip := &sync.Map{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// start the fetcher
+	go fetcher.run(ctx, peersToSkip)
+
+	rctx := context.Background()
+	// call the Offer function with the source peer
+	fetcher.Offer(rctx, &sourcePeerID)
+
+	// fetcher should not initiate request
+	select {
+	case <-requester.requestC:
+		t.Fatalf("fetcher initiated request")
+	case <-time.After(200 * time.Millisecond):
+	}
+
+	// call Request after the Offer
+	rctx = context.Background()
+	fetcher.Request(rctx)
+
+	// there should be exactly 1 request coming from fetcher
+	var request *Request
+	select {
+	case request = <-requester.requestC:
+		if *request.Source != sourcePeerID {
+			t.Fatalf("Expected source id %v got %v", sourcePeerID, request.Source)
+		}
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("fetcher did not initiate request")
+	}
+
+	select {
+	case <-requester.requestC:
+		t.Fatalf("Fetcher number of requests expected 1 got 2")
+	case <-time.After(200 * time.Millisecond):
+	}
+
+	// source peer should be added to peersToSkip eventually
+	time.Sleep(100 * time.Millisecond)
+	if _, ok := request.peersToSkip.Load(sourcePeerID.String()); !ok {
+		t.Fatalf("SourcePeerId not added to peersToSkip")
+	}
+}
+
+func TestFetcherOfferAfterRequestUsesSourceFromContext(t *testing.T) {
+	requester := newMockRequester(100 * time.Millisecond)
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	peersToSkip := &sync.Map{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// start the fetcher
+	go fetcher.run(ctx, peersToSkip)
+
+	// call Request first
+	rctx := context.Background()
+	fetcher.Request(rctx)
+
+	// there should be a request coming from fetcher
+	var request *Request
+	select {
+	case request = <-requester.requestC:
+		if request.Source != nil {
+			t.Fatalf("Incorrect source peer id, expected nil got %v", request.Source)
+		}
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("fetcher did not initiate request")
+	}
+
+	// after the Request call Offer
+	fetcher.Offer(context.Background(), &sourcePeerID)
+
+	// there should be a request coming from fetcher
+	select {
+	case request = <-requester.requestC:
+		if *request.Source != sourcePeerID {
+			t.Fatalf("Incorrect source peer id, expected %v got %v", sourcePeerID, request.Source)
+		}
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("fetcher did not initiate request")
+	}
+
+	// source peer should be added to peersToSkip eventually
+	time.Sleep(100 * time.Millisecond)
+	if _, ok := request.peersToSkip.Load(sourcePeerID.String()); !ok {
+		t.Fatalf("SourcePeerId not added to peersToSkip")
+	}
+}
+
+// TestFetcherRetryOnTimeout tests that fetch retries after searchTimeOut has passed
+func TestFetcherRetryOnTimeout(t *testing.T) {
+	requester := newMockRequester()
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	peersToSkip := &sync.Map{}
+
+	// set searchTimeOut to low value so the test is quicker
+	defer func(t time.Duration) {
+		searchTimeout = t
+	}(searchTimeout)
+	searchTimeout = 250 * time.Millisecond
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// start the fetcher
+	go fetcher.run(ctx, peersToSkip)
+
+	// call the fetch function with an active context
+	rctx := context.Background()
+	fetcher.Request(rctx)
+
+	// after 100ms the first request should be initiated
+	time.Sleep(100 * time.Millisecond)
+
+	select {
+	case <-requester.requestC:
+	default:
+		t.Fatalf("fetch did not initiate request")
+	}
+
+	// after another 100ms no new request should be initiated, because search timeout is 250ms
+	time.Sleep(100 * time.Millisecond)
+
+	select {
+	case <-requester.requestC:
+		t.Fatalf("unexpected request from fetcher")
+	default:
+	}
+
+	// after another 300ms search timeout is over, there should be a new request
+	time.Sleep(300 * time.Millisecond)
+
+	select {
+	case <-requester.requestC:
+	default:
+		t.Fatalf("fetch did not retry request")
+	}
+}
+
+// TestFetcherFactory creates a FetcherFactory and checks if the factory really creates and starts
+// a Fetcher when it return a fetch function. We test the fetching functionality just by checking if
+// a request is initiated when the fetch function is called
+func TestFetcherFactory(t *testing.T) {
+	requester := newMockRequester(100 * time.Millisecond)
+	addr := make([]byte, 32)
+	fetcherFactory := NewFetcherFactory(requester.doRequest, false)
+
+	peersToSkip := &sync.Map{}
+
+	fetcher := fetcherFactory.New(context.Background(), addr, peersToSkip)
+
+	fetcher.Request(context.Background())
+
+	// check if the created fetchFunction really starts a fetcher and initiates a request
+	select {
+	case <-requester.requestC:
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("fetch timeout")
+	}
+
+}
+
+func TestFetcherRequestQuitRetriesRequest(t *testing.T) {
+	requester := newMockRequester()
+	addr := make([]byte, 32)
+	fetcher := NewFetcher(addr, requester.doRequest, true)
+
+	// make sure searchTimeout is long so it is sure the request is not retried because of timeout
+	defer func(t time.Duration) {
+		searchTimeout = t
+	}(searchTimeout)
+	searchTimeout = 10 * time.Second
+
+	peersToSkip := &sync.Map{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go fetcher.run(ctx, peersToSkip)
+
+	rctx := context.Background()
+	fetcher.Request(rctx)
+
+	select {
+	case <-requester.requestC:
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("request is not initiated")
+	}
+
+	close(requester.quitC)
+
+	select {
+	case <-requester.requestC:
+	case <-time.After(200 * time.Millisecond):
+		t.Fatalf("request is not initiated after failed request")
+	}
+}
+
+// TestRequestSkipPeer checks if PeerSkip function will skip provided peer
+// and not skip unknown one.
+func TestRequestSkipPeer(t *testing.T) {
+	addr := make([]byte, 32)
+	peers := []discover.NodeID{
+		discover.MustHexID("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+		discover.MustHexID("2dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
+	}
+
+	peersToSkip := new(sync.Map)
+	peersToSkip.Store(peers[0].String(), time.Now())
+	r := NewRequest(addr, false, peersToSkip)
+
+	if !r.SkipPeer(peers[0].String()) {
+		t.Errorf("peer not skipped")
+	}
+
+	if r.SkipPeer(peers[1].String()) {
+		t.Errorf("peer skipped")
+	}
+}
+
+// TestRequestSkipPeerExpired checks if a peer to skip is not skipped
+// after RequestTimeout has passed.
+func TestRequestSkipPeerExpired(t *testing.T) {
+	addr := make([]byte, 32)
+	peer := discover.MustHexID("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439")
+
+	// set RequestTimeout to a low value and reset it after the test
+	defer func(t time.Duration) { RequestTimeout = t }(RequestTimeout)
+	RequestTimeout = 250 * time.Millisecond
+
+	peersToSkip := new(sync.Map)
+	peersToSkip.Store(peer.String(), time.Now())
+	r := NewRequest(addr, false, peersToSkip)
+
+	if !r.SkipPeer(peer.String()) {
+		t.Errorf("peer not skipped")
+	}
+
+	time.Sleep(500 * time.Millisecond)
+
+	if r.SkipPeer(peer.String()) {
+		t.Errorf("peer skipped")
+	}
+}
+
+// TestRequestSkipPeerPermanent checks if a peer to skip is not skipped
+// after RequestTimeout is not skipped if it is set for a permanent skipping
+// by value to peersToSkip map is not time.Duration.
+func TestRequestSkipPeerPermanent(t *testing.T) {
+	addr := make([]byte, 32)
+	peer := discover.MustHexID("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439")
+
+	// set RequestTimeout to a low value and reset it after the test
+	defer func(t time.Duration) { RequestTimeout = t }(RequestTimeout)
+	RequestTimeout = 250 * time.Millisecond
+
+	peersToSkip := new(sync.Map)
+	peersToSkip.Store(peer.String(), true)
+	r := NewRequest(addr, false, peersToSkip)
+
+	if !r.SkipPeer(peer.String()) {
+		t.Errorf("peer not skipped")
+	}
+
+	time.Sleep(500 * time.Millisecond)
+
+	if !r.SkipPeer(peer.String()) {
+		t.Errorf("peer not skipped")
+	}
+}