plugeth/core/chain_makers_test.go
Felix Lange 37dd9086ec core: refactor genesis handling
This commit solves several issues concerning the genesis block:

* Genesis/ChainConfig loading was handled by cmd/geth code. This left
  library users in the cold. They could specify a JSON-encoded
  string and overwrite the config, but didn't get any of the additional
  checks performed by geth.
* Decoding and writing of genesis JSON was conflated in
  WriteGenesisBlock. This made it a lot harder to embed the genesis
  block into the forthcoming config file loader. This commit changes
  things so there is a single Genesis type that represents genesis
  blocks. All uses of Write*Genesis* are changed to use the new type
  instead.
* If the chain config supplied by the user was incompatible with the
  current chain (i.e. the chain had already advanced beyond a scheduled
  fork), it got overwritten. This is not an issue in practice because
  previous forks have always had the highest total difficulty. It might
  matter in the future though. The new code reverts the local chain to
  the point of the fork when upgrading configuration.

The change to genesis block data removes compression library
dependencies from package core.
2017-03-23 15:58:43 +01:00

101 lines
3.8 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/pow"
)
func ExampleGenerateChain() {
var (
key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
key2, _ = crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
key3, _ = crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
addr1 = crypto.PubkeyToAddress(key1.PublicKey)
addr2 = crypto.PubkeyToAddress(key2.PublicKey)
addr3 = crypto.PubkeyToAddress(key3.PublicKey)
db, _ = ethdb.NewMemDatabase()
)
// Ensure that key1 has some funds in the genesis block.
gspec := &Genesis{
Config: &params.ChainConfig{HomesteadBlock: new(big.Int)},
Alloc: GenesisAlloc{addr1: {Balance: big.NewInt(1000000)}},
}
genesis := gspec.MustCommit(db)
// This call generates a chain of 5 blocks. The function runs for
// each block and adds different features to gen based on the
// block index.
signer := types.HomesteadSigner{}
chain, _ := GenerateChain(gspec.Config, genesis, db, 5, func(i int, gen *BlockGen) {
switch i {
case 0:
// In block 1, addr1 sends addr2 some ether.
tx, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(10000), bigTxGas, nil, nil), signer, key1)
gen.AddTx(tx)
case 1:
// In block 2, addr1 sends some more ether to addr2.
// addr2 passes it on to addr3.
tx1, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(1000), bigTxGas, nil, nil), signer, key1)
tx2, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), bigTxGas, nil, nil), signer, key2)
gen.AddTx(tx1)
gen.AddTx(tx2)
case 2:
// Block 3 is empty but was mined by addr3.
gen.SetCoinbase(addr3)
gen.SetExtra([]byte("yeehaw"))
case 3:
// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
b2 := gen.PrevBlock(1).Header()
b2.Extra = []byte("foo")
gen.AddUncle(b2)
b3 := gen.PrevBlock(2).Header()
b3.Extra = []byte("foo")
gen.AddUncle(b3)
}
})
// Import the chain. This runs all block validation rules.
evmux := &event.TypeMux{}
blockchain, _ := NewBlockChain(db, gspec.Config, pow.FakePow{}, evmux, vm.Config{})
if i, err := blockchain.InsertChain(chain); err != nil {
fmt.Printf("insert error (block %d): %v\n", chain[i].NumberU64(), err)
return
}
state, _ := blockchain.State()
fmt.Printf("last block: #%d\n", blockchain.CurrentBlock().Number())
fmt.Println("balance of addr1:", state.GetBalance(addr1))
fmt.Println("balance of addr2:", state.GetBalance(addr2))
fmt.Println("balance of addr3:", state.GetBalance(addr3))
// Output:
// last block: #5
// balance of addr1: 989000
// balance of addr2: 10000
// balance of addr3: 19687500000000001000
}