major rewrite, reorg of blockpool + new features

- blockpool moves to its own package
- uses errs pkg for its own coded errors
- publicly settable config of params (time intervals and batchsizes)
- test helpers in subpackage
- optional TD in blocks used now to update peers chain info
- major improvement in algorithm
- fix fragility and sync/parallelisation bugs
- implement status for reporting on sync status (peers/hashes/blocks etc)
- several tests added and further corner cases covered

blockpool/errors_test.go

@@ -0,0 +1,124 @@
+package blockpool
+
+import (
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/pow"
+)
+
+func TestInvalidBlock(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(2)
+	blockPoolTester.refBlockChain[2] = []int{}
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	go peer1.serveBlocks(2, 3)
+	go peer1.serveBlockHashes(3, 2, 1, 0)
+	peer1.serveBlocks(0, 1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[2] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrInvalidBlock {
+			t.Errorf("wrong error, got %v, expected %v", peer1.peerErrors[0], ErrInvalidBlock)
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrInvalidBlock, peer1.peerErrors)
+	}
+}
+
+func TestVerifyPoW(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(3)
+	first := false
+	blockPoolTester.blockPool.verifyPoW = func(b pow.Block) bool {
+		bb, _ := b.(*types.Block)
+		indexes := blockPoolTester.hashPool.HashesToIndexes([][]byte{bb.Hash()})
+		if indexes[0] == 2 && !first {
+			first = true
+			return false
+		} else {
+			return true
+		}
+
+	}
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer2 := blockPoolTester.newPeer("peer2", 1, 3)
+	peer1.AddPeer()
+	peer2.AddPeer()
+	go peer1.serveBlocks(2, 3)
+	go peer1.serveBlockHashes(3, 2, 1, 0)
+	peer1.serveBlocks(0, 1, 2, 3)
+	blockPoolTester.blockPool.verifyPoW = func(b pow.Block) bool {
+		return true
+	}
+	peer2.serveBlocks(1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[3] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrInvalidPoW {
+			t.Errorf("wrong error, expected %v, got %v", ErrInvalidPoW, peer1.peerErrors[0])
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrInvalidPoW, peer1.peerErrors)
+	}
+}
+
+func TestUnrequestedBlock(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	peer1.sendBlocks(1, 2)
+
+	// blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrUnrequestedBlock {
+			t.Errorf("wrong error, got %v, expected %v", peer1.peerErrors[0], ErrUnrequestedBlock)
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrUnrequestedBlock, peer1.peerErrors)
+	}
+}
+
+func TestErrInsufficientChainInfo(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPool.Config.BlockHashesTimeout = 100 * time.Millisecond
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrInsufficientChainInfo {
+			t.Errorf("wrong error, got %v, expected %v", peer1.peerErrors[0], ErrInsufficientChainInfo)
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrInsufficientChainInfo, peer1.peerErrors)
+	}
+}