path: root/eth/downloader/downloader_test.go

package downloader

import (
    "encoding/binary"
    "math/big"
    "testing"
    "time"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core/types"
)

var knownHash = common.Hash{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}

func createHashes(start, amount int) (hashes []common.Hash) {
    hashes = make([]common.Hash, amount+1)
    hashes[len(hashes)-1] = knownHash

    for i := range hashes[:len(hashes)-1] {
        binary.BigEndian.PutUint64(hashes[i][:8], uint64(i+2))
    }

    return
}

func createBlock(i int, prevHash, hash common.Hash) *types.Block {
    header := &types.Header{Number: big.NewInt(int64(i))}
    block := types.NewBlockWithHeader(header)
    block.HeaderHash = hash
    block.ParentHeaderHash = knownHash
    return block
}

func createBlocksFromHashes(hashes []common.Hash) map[common.Hash]*types.Block {
    blocks := make(map[common.Hash]*types.Block)

    for i, hash := range hashes {
        blocks[hash] = createBlock(len(hashes)-i, knownHash, hash)
    }

    return blocks
}

type downloadTester struct {
    downloader   *Downloader
    hashes       []common.Hash
    blocks       map[common.Hash]*types.Block
    t            *testing.T
    pcount       int
    done         chan bool
    activePeerId string
}

func newTester(t *testing.T, hashes []common.Hash, blocks map[common.Hash]*types.Block) *downloadTester {
    tester := &downloadTester{t: t, hashes: hashes, blocks: blocks, done: make(chan bool)}
    downloader := New(tester.hasBlock, tester.getBlock)
    tester.downloader = downloader

    return tester
}

func (dl *downloadTester) sync(peerId string, hash common.Hash) error {
    dl.activePeerId = peerId
    return dl.downloader.Synchronise(peerId, hash)
}

func (dl *downloadTester) hasBlock(hash common.Hash) bool {
    if knownHash == hash {
        return true
    }
    return false
}

func (dl *downloadTester) getBlock(hash common.Hash) *types.Block {
    return dl.blocks[knownHash]
}

func (dl *downloadTester) getHashes(hash common.Hash) error {
    dl.downloader.AddHashes(dl.activePeerId, dl.hashes)
    return nil
}

func (dl *downloadTester) getBlocks(id string) func([]common.Hash) error {
    return func(hashes []common.Hash) error {
        blocks := make([]*types.Block, len(hashes))
        for i, hash := range hashes {
            blocks[i] = dl.blocks[hash]
        }

        go dl.downloader.DeliverChunk(id, blocks)

        return nil
    }
}

func (dl *downloadTester) newPeer(id string, td *big.Int, hash common.Hash) {
    dl.pcount++

    dl.downloader.RegisterPeer(id, hash, dl.getHashes, dl.getBlocks(id))
}

func (dl *downloadTester) badBlocksPeer(id string, td *big.Int, hash common.Hash) {
    dl.pcount++

    // This bad peer never returns any blocks
    dl.downloader.RegisterPeer(id, hash, dl.getHashes, func([]common.Hash) error {
        return nil
    })
}

func TestDownload(t *testing.T) {
    minDesiredPeerCount = 4
    blockTtl = 1 * time.Second

    targetBlocks := 1000
    hashes := createHashes(0, targetBlocks)
    blocks := createBlocksFromHashes(hashes)
    tester := newTester(t, hashes, blocks)

    tester.newPeer("peer1", big.NewInt(10000), hashes[0])
    tester.newPeer("peer2", big.NewInt(0), common.Hash{})
    tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{})
    tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{})
    tester.activePeerId = "peer1"

    err := tester.sync("peer1", hashes[0])
    if err != nil {
        t.Error("download error", err)
    }

    inqueue := len(tester.downloader.queue.blockCache)
    if inqueue != targetBlocks {
        t.Error("expected", targetBlocks, "have", inqueue)
    }
}

func TestMissing(t *testing.T) {
    targetBlocks := 1000
    hashes := createHashes(0, 1000)
    extraHashes := createHashes(1001, 1003)
    blocks := createBlocksFromHashes(append(extraHashes, hashes...))
    tester := newTester(t, hashes, blocks)

    tester.newPeer("peer1", big.NewInt(10000), hashes[len(hashes)-1])

    hashes = append(extraHashes, hashes[:len(hashes)-1]...)
    tester.newPeer("peer2", big.NewInt(0), common.Hash{})

    err := tester.sync("peer1", hashes[0])
    if err != nil {
        t.Error("download error", err)
    }

    inqueue := len(tester.downloader.queue.blockCache)
    if inqueue != targetBlocks {
        t.Error("expected", targetBlocks, "have", inqueue)
    }
}

func TestTaking(t *testing.T) {
    minDesiredPeerCount = 4
    blockTtl = 1 * time.Second

    targetBlocks := 1000
    hashes := createHashes(0, targetBlocks)
    blocks := createBlocksFromHashes(hashes)
    tester := newTester(t, hashes, blocks)

    tester.newPeer("peer1", big.NewInt(10000), hashes[0])
    tester.newPeer("peer2", big.NewInt(0), common.Hash{})
    tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{})
    tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{})

    err := tester.sync("peer1", hashes[0])
    if err != nil {
        t.Error("download error", err)
    }

    bs1 := tester.downloader.TakeBlocks()
    if len(bs1) != 1000 {
        t.Error("expected to take 1000, got", len(bs1))
    }
}

func TestInactiveDownloader(t *testing.T) {
    targetBlocks := 1000
    hashes := createHashes(0, targetBlocks)
    blocks := createBlocksFromHashSet(createHashSet(hashes))
    tester := newTester(t, hashes, nil)

    err := tester.downloader.AddHashes("bad peer 001", hashes)
    if err != errNoSyncActive {
        t.Error("expected no sync error, got", err)
    }

    err = tester.downloader.DeliverChunk("bad peer 001", blocks)
    if err != errNoSyncActive {
        t.Error("expected no sync error, got", err)
    }
}

func TestCancel(t *testing.T) {
    minDesiredPeerCount = 4
    blockTtl = 1 * time.Second

    targetBlocks := 1000
    hashes := createHashes(0, targetBlocks)
    blocks := createBlocksFromHashes(hashes)
    tester := newTester(t, hashes, blocks)

    tester.newPeer("peer1", big.NewInt(10000), hashes[0])

    err := tester.sync("peer1", hashes[0])
    if err != nil {
        t.Error("download error", err)
    }

    if !tester.downloader.Cancel() {
        t.Error("cancel operation unsuccessfull")
    }

    hashSize, blockSize := tester.downloader.queue.Size()
    if hashSize > 0 || blockSize > 0 {
        t.Error("block (", blockSize, ") or hash (", hashSize, ") not 0")
    }
}

func TestThrottling(t *testing.T) {
    minDesiredPeerCount = 4
    blockTtl = 1 * time.Second

    targetBlocks := 16 * blockCacheLimit
    hashes := createHashes(0, targetBlocks)
    blocks := createBlocksFromHashes(hashes)
    tester := newTester(t, hashes, blocks)

    tester.newPeer("peer1", big.NewInt(10000), hashes[0])
    tester.newPeer("peer2", big.NewInt(0), common.Hash{})
    tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{})
    tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{})

    // Concurrently download and take the blocks
    errc := make(chan error, 1)
    go func() {
        errc <- tester.sync("peer1", hashes[0])
    }()

    done := make(chan struct{})
    took := []*types.Block{}
    go func() {
        for {
            select {
            case <-done:
                took = append(took, tester.downloader.TakeBlocks()...)
                done <- struct{}{}
                return
            default:
                took = append(took, tester.downloader.TakeBlocks()...)
                time.Sleep(time.Millisecond)
            }
        }
    }()

    // Synchronise the two threads and verify
    err := <-errc
    done <- struct{}{}
    <-done

    if err != nil {
        t.Fatalf("failed to synchronise blocks: %v", err)
    }
    if len(took) != targetBlocks {
        t.Fatalf("downloaded block mismatch: have %v, want %v", len(took), targetBlocks)
    }
}