98 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			98 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright 2015 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package core
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import (
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	"fmt"
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	"math/big"
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	"github.com/ethereum/go-ethereum/core/types"
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	"github.com/ethereum/go-ethereum/crypto"
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	"github.com/ethereum/go-ethereum/ethdb"
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	"github.com/ethereum/go-ethereum/event"
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	"github.com/ethereum/go-ethereum/params"
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)
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func ExampleGenerateChain() {
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	params.MinGasLimit = big.NewInt(125000)      // Minimum the gas limit may ever be.
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	params.GenesisGasLimit = big.NewInt(3141592) // Gas limit of the Genesis block.
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	var (
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		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
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		key2, _ = crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
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		key3, _ = crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
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		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
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		addr2   = crypto.PubkeyToAddress(key2.PublicKey)
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		addr3   = crypto.PubkeyToAddress(key3.PublicKey)
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		db, _   = ethdb.NewMemDatabase()
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	)
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	// Ensure that key1 has some funds in the genesis block.
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	genesis := WriteGenesisBlockForTesting(db, addr1, big.NewInt(1000000))
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	// This call generates a chain of 5 blocks. The function runs for
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	// each block and adds different features to gen based on the
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	// block index.
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	chain := GenerateChain(genesis, db, 5, func(i int, gen *BlockGen) {
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		switch i {
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		case 0:
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			// In block 1, addr1 sends addr2 some ether.
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			tx, _ := types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(key1)
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			gen.AddTx(tx)
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		case 1:
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			// In block 2, addr1 sends some more ether to addr2.
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			// addr2 passes it on to addr3.
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			tx1, _ := types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(key1)
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			tx2, _ := types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(key2)
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			gen.AddTx(tx1)
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			gen.AddTx(tx2)
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		case 2:
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			// Block 3 is empty but was mined by addr3.
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			gen.SetCoinbase(addr3)
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			gen.SetExtra([]byte("yeehaw"))
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		case 3:
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			// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
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			b2 := gen.PrevBlock(1).Header()
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			b2.Extra = []byte("foo")
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			gen.AddUncle(b2)
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			b3 := gen.PrevBlock(2).Header()
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			b3.Extra = []byte("foo")
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			gen.AddUncle(b3)
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		}
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	})
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	// Import the chain. This runs all block validation rules.
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	evmux := &event.TypeMux{}
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	chainman, _ := NewChainManager(db, FakePow{}, evmux)
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	chainman.SetProcessor(NewBlockProcessor(db, FakePow{}, chainman, evmux))
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	if i, err := chainman.InsertChain(chain); err != nil {
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		fmt.Printf("insert error (block %d): %v\n", i, err)
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		return
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	}
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	state := chainman.State()
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	fmt.Printf("last block: #%d\n", chainman.CurrentBlock().Number())
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	fmt.Println("balance of addr1:", state.GetBalance(addr1))
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	fmt.Println("balance of addr2:", state.GetBalance(addr2))
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	fmt.Println("balance of addr3:", state.GetBalance(addr3))
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	// Output:
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	// last block: #5
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	// balance of addr1: 989000
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	// balance of addr2: 10000
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	// balance of addr3: 19687500000000001000
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}
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