Example #1
0
func testCoinSelector(tests []coinSelectTest, t *testing.T) {
	for testIndex, test := range tests {
		cs, err := test.selector.CoinSelect(test.targetValue, test.inputCoins)
		if err != test.expectedError {
			t.Errorf("[%d] expected a different error: got=%v, expected=%v", testIndex, err, test.expectedError)
			continue
		}
		if test.expectedCoins != nil {
			if cs == nil {
				t.Errorf("[%d] expected non-nil coinset", testIndex)
				continue
			}
			coins := cs.Coins()
			if len(coins) != len(test.expectedCoins) {
				t.Errorf("[%d] expected different number of coins: got=%d, expected=%d", testIndex, len(coins), len(test.expectedCoins))
				continue
			}
			for n := 0; n < len(test.expectedCoins); n++ {
				if coins[n] != test.expectedCoins[n] {
					t.Errorf("[%d] expected different coins at coin index %d: got=%#v, expected=%#v", testIndex, n, coins[n], test.expectedCoins[n])
					continue
				}
			}
			coinSet := coinset.NewCoinSet(coins)
			if coinSet.TotalValue() < test.targetValue {
				t.Errorf("[%d] targetValue not satistifed", testIndex)
				continue
			}
		}
	}
}
Example #2
0
func TestCoinSet(t *testing.T) {
	cs := coinset.NewCoinSet(nil)
	if cs.PopCoin() != nil {
		t.Error("Expected popCoin of empty to be nil")
	}
	if cs.ShiftCoin() != nil {
		t.Error("Expected shiftCoin of empty to be nil")
	}

	cs.PushCoin(coins[0])
	cs.PushCoin(coins[1])
	cs.PushCoin(coins[2])
	if cs.PopCoin() != coins[2] {
		t.Error("Expected third coin")
	}
	if cs.ShiftCoin() != coins[0] {
		t.Error("Expected first coin")
	}

	mtx := coinset.NewMsgTxWithInputCoins(cs)
	if len(mtx.TxIn) != 1 {
		t.Errorf("Expected only 1 TxIn, got %d", len(mtx.TxIn))
	}
	op := mtx.TxIn[0].PreviousOutPoint
	if !op.Hash.IsEqual(coins[1].Hash()) || op.Index != coins[1].Index() {
		t.Errorf("Expected the second coin to be added as input to mtx")
	}
}
Example #3
0
File: wallet.go Project: mkl-/lnd
// handleFundingReserveRequest processes a message intending to create, and
// validate a funding reservation request.
func (l *LightningWallet) handleFundingReserveRequest(req *initFundingReserveMsg) {
	// Create a limbo and record entry for this newly pending funding request.
	l.limboMtx.Lock()

	id := l.nextFundingID
	reservation := newChannelReservation(req.fundingType, req.fundingAmount, req.minFeeRate, l, id)
	l.nextFundingID++
	l.fundingLimbo[id] = reservation

	l.limboMtx.Unlock()

	// Grab the mutex on the ChannelReservation to ensure thead-safety
	reservation.Lock()
	defer reservation.Unlock()

	reservation.partialState.TheirLNID = req.nodeID
	ourContribution := reservation.ourContribution
	ourContribution.CsvDelay = req.csvDelay

	// We hold the coin select mutex while querying for outputs, and
	// performing coin selection in order to avoid inadvertent double spends
	// accross funding transactions.
	// NOTE: we don't use defer her so we can properly release the lock
	// when we encounter an error condition.
	l.coinSelectMtx.Lock()

	// Find all unlocked unspent outputs with greater than 6 confirmations.
	maxConfs := int32(math.MaxInt32)
	// TODO(roasbeef): make 6 a config paramter?
	unspentOutputs, err := l.ListUnspent(6, maxConfs, nil)
	if err != nil {
		l.coinSelectMtx.Unlock()
		req.err <- err
		req.resp <- nil
		return
	}

	// Convert the outputs to coins for coin selection below.
	coins, err := outputsToCoins(unspentOutputs)
	if err != nil {
		l.coinSelectMtx.Unlock()
		req.err <- err
		req.resp <- nil
		return
	}

	// Peform coin selection over our available, unlocked unspent outputs
	// in order to find enough coins to meet the funding amount requirements.
	//
	// TODO(roasbeef): Should extend coinset with optimal coin selection
	// heuristics for our use case.
	// TODO(roasbeef): factor in fees..
	// TODO(roasbeef): possibly integrate the fee prediction project? if
	// results hold up...
	// NOTE: this current selection assumes "priority" is still a thing.
	selector := &coinset.MaxValueAgeCoinSelector{
		MaxInputs:       10,
		MinChangeAmount: 10000,
	}
	selectedCoins, err := selector.CoinSelect(req.fundingAmount, coins)
	if err != nil {
		l.coinSelectMtx.Unlock()
		req.err <- err
		req.resp <- nil
		return
	}

	// Lock the selected coins. These coins are now "reserved", this
	// prevents concurrent funding requests from referring to and this
	// double-spending the same set of coins.
	ourContribution.Inputs = make([]*wire.TxIn, len(selectedCoins.Coins()))
	for i, coin := range selectedCoins.Coins() {
		txout := wire.NewOutPoint(coin.Hash(), coin.Index())
		l.LockOutpoint(*txout)

		// Empty sig script, we'll actually sign if this reservation is
		// queued up to be completed (the other side accepts).
		outPoint := wire.NewOutPoint(coin.Hash(), coin.Index())
		ourContribution.Inputs[i] = wire.NewTxIn(outPoint, nil)
	}

	l.coinSelectMtx.Unlock()

	// Create some possibly neccessary change outputs.
	selectedTotalValue := coinset.NewCoinSet(selectedCoins.Coins()).TotalValue()
	if selectedTotalValue > req.fundingAmount {
		ourContribution.ChangeOutputs = make([]*wire.TxOut, 1)
		// Change is necessary. Query for an available change address to
		// send the remainder to.
		changeAddr, err := l.NewChangeAddress(waddrmgr.DefaultAccountNum)
		if err != nil {
			req.err <- err
			req.resp <- nil
			return
		}

		changeAddrScript, err := txscript.PayToAddrScript(changeAddr)
		if err != nil {
			req.err <- err
			req.resp <- nil
			return
		}

		changeAmount := selectedTotalValue - req.fundingAmount
		ourContribution.ChangeOutputs[0] = wire.NewTxOut(int64(changeAmount),
			changeAddrScript)
	}

	// TODO(roasbeef): re-calculate fees here to minFeePerKB, may need more inputs

	// Grab two fresh keys from out HD chain, one will be used for the
	// multi-sig funding transaction, and the other for the commitment
	// transaction.
	multiSigKey, err := l.getNextRawKey()
	if err != nil {
		req.err <- err
		req.resp <- nil
		return
	}
	commitKey, err := l.getNextRawKey()
	if err != nil {
		req.err <- err
		req.resp <- nil
		return
	}
	reservation.partialState.MultiSigKey = multiSigKey
	ourContribution.MultiSigKey = multiSigKey.PubKey()
	reservation.partialState.OurCommitKey = commitKey
	ourContribution.CommitKey = commitKey.PubKey()

	// Generate a fresh address to be used in the case of a cooperative
	// channel close.
	deliveryAddress, err := l.NewAddress(waddrmgr.DefaultAccountNum)
	if err != nil {
		req.err <- err
		req.resp <- nil
		return
	}
	reservation.partialState.OurDeliveryAddress = deliveryAddress
	ourContribution.DeliveryAddress = deliveryAddress

	// Create a new shaChain for verifiable transaction revocations. This
	// will be used to generate revocation hashes for our past/current
	// commitment transactions once we start to make payments within the
	// channel.
	shaChain, err := shachain.NewFromSeed(nil, 0)
	if err != nil {
		req.err <- err
		req.resp <- nil
		return
	}
	reservation.partialState.OurShaChain = shaChain
	copy(ourContribution.RevocationHash[:], shaChain.CurrentRevocationHash())

	// Funding reservation request succesfully handled. The funding inputs
	// will be marked as unavailable until the reservation is either
	// completed, or cancecled.
	req.resp <- reservation
	req.err <- nil
}