Add CKB Payment Channel Example

.github/workflows/ci.yml

@@ -36,6 +36,41 @@ jobs:
           go run .
           docker stop ganache
 
+      - name: Payment Channel CKB
+        working-directory: payment-channel-ckb
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y jq sed gawk tmux tmuxp expect make
+          curl -LO https://github.com/nervosnetwork/ckb/releases/download/v0.109.0/ckb_v0.109.0_x86_64-unknown-linux-gnu.tar.gz
+          tar -xzf ckb_v0.109.0_x86_64-unknown-linux-gnu.tar.gz
+          sudo cp ckb_v0.109.0_x86_64-unknown-linux-gnu/ckb /usr/local/bin/
+          curl -LO https://github.com/nervosnetwork/ckb-cli/releases/download/v1.4.0/ckb-cli_v1.4.0_x86_64-unknown-linux-gnu.tar.gz
+          tar -xzf ckb-cli_v1.4.0_x86_64-unknown-linux-gnu.tar.gz
+          sudo cp ckb-cli_v1.4.0_x86_64-unknown-linux-gnu/ckb-cli /usr/local/bin/
+          curl -LO https://github.com/nervosnetwork/capsule/releases/download/v0.9.2/capsule_v0.9.2_x86_64-linux.tar.gz
+          tar -xzf capsule_v0.9.2_x86_64-linux.tar.gz
+          sudo cp capsule_v0.9.2_x86_64-linux/capsule /usr/local/bin/
+          cd ./devnet
+          chmod +x setup-devnet.sh print_accounts.sh deploy_contracts.sh sudt_helper.sh 
+          ./setup-devnet.sh
+          ckb run > /dev/null 2>&1 &
+          sleep 3
+          ckb miner > /dev/null 2>&1 &
+          sleep 3
+          ./print_accounts.sh
+          sleep 6
+          expect fund_accounts.expect
+          sleep 10
+          ./deploy_contracts.sh
+          sleep 15
+          ./sudt_helper.sh fund
+          sleep 10
+          ./sudt_helper.sh balances
+
+          sleep 30
+          cd ..
+          go run main.go
+
       - name: Payment Channel ETH
         working-directory: payment-channel
         env:

payment-channel-ckb/.gitignore

@@ -0,0 +1,28 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# log files
+*.log
+
+perun-ckb-demo
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+devnet/accounts
+devnet/data
+devnet/specs
+devnet/ckb-miner.toml
+devnet/ckb.toml
+devnet/default.db-options
+devnet/system_scripts
+.vscode/

payment-channel-ckb/.gitmodules

@@ -0,0 +1,3 @@
+[submodule "devnet/contracts"]
+	path = devnet/contracts
+	url = [email protected]:perun-network/perun-ckb-contract

payment-channel-ckb/client/balances.go

@@ -0,0 +1,91 @@
+// Copyright 2024 PolyCrypt GmbH
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+	"log"
+	"math"
+	"math/big"
+	"strconv"
+	"time"
+
+	"github.com/nervosnetwork/ckb-sdk-go/v2/indexer"
+	"github.com/nervosnetwork/ckb-sdk-go/v2/types"
+	"perun.network/perun-ckb-backend/wallet/address"
+)
+
+type BalanceExtractor func(*indexer.LiveCell) *big.Int
+
+func ckbBalanceExtractor(cell *indexer.LiveCell) *big.Int {
+	return new(big.Int).SetUint64(cell.Output.Capacity)
+}
+
+func sudtBalanceExtractor(cell *indexer.LiveCell) *big.Int {
+	if len(cell.OutputData) != 16 {
+		return big.NewInt(0)
+	}
+	return new(big.Int).SetUint64(binary.LittleEndian.Uint64(cell.OutputData))
+}
+
+func (p *PaymentClient) PollBalances() {
+	pollingInterval := time.Second
+	searchKey := &indexer.SearchKey{
+		Script:           address.AsParticipant(p.Account.Address()).PaymentScript,
+		ScriptType:       types.ScriptTypeLock,
+		ScriptSearchMode: types.ScriptSearchModeExact,
+		Filter:           nil,
+		WithData:         true,
+	}
+	updateBalance := func() {
+		ctx, _ := context.WithTimeout(context.Background(), pollingInterval)
+
+		cells, err := p.rpcClient.GetCells(ctx, searchKey, indexer.SearchOrderDesc, math.MaxUint32, "")
+		if err != nil {
+			log.Println("balance poll error: ", err)
+			return
+		}
+		ckbBalance := big.NewInt(0)
+		sudtBalance := big.NewInt(0)
+		for _, cell := range cells.Objects {
+			ckbBalance = new(big.Int).Add(ckbBalance, ckbBalanceExtractor(cell))
+			sudtBalance = new(big.Int).Add(sudtBalance, sudtBalanceExtractor(cell))
+		}
+
+		p.balanceMutex.Lock()
+		if ckbBalance.Cmp(p.balance) != 0 || sudtBalance.Cmp(p.sudtBalance) != 0 {
+			// Update ckb balance.
+			p.balance = ckbBalance
+
+			// Update sudt balance.
+			p.sudtBalance = sudtBalance
+
+			p.balanceMutex.Unlock()
+		} else {
+			p.balanceMutex.Unlock()
+		}
+	}
+	updateBalance()
+
+}
+
+func FormatBalance(ckbBal, sudtBal *big.Int) string {
+	balCKByte, _ := ShannonToCKByte(ckbBal).Float64()
+	return fmt.Sprintf("[green]%s\t[yellow]%s[white]",
+		strconv.FormatFloat(balCKByte, 'f', 2, 64)+" CKByte",
+		fmt.Sprintf("%v", sudtBal.Int64())+" SUDT")
+}

payment-channel-ckb/client/channel.go

@@ -0,0 +1,86 @@
+// Copyright 2024 PolyCrypt GmbH
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"context"
+	"math/big"
+
+	"perun.network/go-perun/channel"
+	"perun.network/go-perun/client"
+)
+
+type PaymentChannel struct {
+	ch     *client.Channel
+	assets []channel.Asset
+}
+
+// newPaymentChannel creates a new payment channel.
+func newPaymentChannel(ch *client.Channel, assets []channel.Asset) *PaymentChannel {
+	return &PaymentChannel{
+		ch:     ch,
+		assets: assets,
+	}
+}
+
+func (c PaymentChannel) State() *channel.State {
+	return c.ch.State().Clone()
+}
+
+func (c PaymentChannel) SendPayment(amounts map[channel.Asset]float64) {
+	// Transfer the given amount from us to peer.
+	// Use UpdateBy to update the channel state.
+	err := c.ch.Update(context.TODO(), func(state *channel.State) {
+		actor := c.ch.Idx()
+		peer := 1 - actor
+		for a, amount := range amounts {
+
+			if amount < 0 {
+				continue
+			}
+
+			shannonAmount := CKByteToShannon(big.NewFloat(amount))
+			state.Allocation.TransferBalance(actor, peer, a, shannonAmount)
+
+		}
+
+	})
+	if err != nil {
+		panic(err)
+	}
+
+}
+
+// Settle settles the payment channel and withdraws the funds.
+func (c PaymentChannel) Settle() {
+	// Finalize the channel to enable fast settlement.
+	if !c.ch.State().IsFinal {
+		err := c.ch.Update(context.TODO(), func(state *channel.State) {
+			state.IsFinal = true
+		})
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	// Settle concludes the channel and withdraws the funds.
+	err := c.ch.Settle(context.TODO())
+	if err != nil {
+		panic(err)
+	}
+
+	// Close frees up channel resources.
+	c.ch.Close()
+}