core

func ApplyMessage ¶

func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool) ([]byte, uint64, bool, error)

ApplyMessage computes the new state by applying the given message against the old state within the environment.

ApplyMessage returns the bytes returned by any EVM execution (if it took place), the gas used (which includes gas refunds) and an error if it failed. An error always indicates a core error meaning that the message would always fail for that particular state and would never be accepted within a block.

func ApplyTransaction ¶

func ApplyTransaction(config *params.ChainConfig, bc *BlockChain, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config) (*types.Receipt, uint64, error)

ApplyTransaction attempts to apply a transaction to the given state database and uses the input parameters for its environment. It returns the receipt for the transaction, gas used and an error if the transaction failed, indicating the block was invalid.

func CalcGasLimit ¶

func CalcGasLimit(parent *types.Block) uint64

CalcGasLimit computes the gas limit of the next block after parent. This is miner strategy, not consensus protocol.

func CanTransfer ¶

func CanTransfer(db vm.StateDB, addr common.Address, amount *big.Int) bool

CanTransfer checks wether there are enough funds in the address' account to make a transfer. This does not take the necessary gas in to account to make the transfer valid.

func GenerateChain ¶

func GenerateChain(config *params.ChainConfig, parent *types.Block, engine consensus.Engine, db ethdb.Database, n int, gen func(int, *BlockGen)) ([]*types.Block, []types.Receipts)

GenerateChain creates a chain of n blocks. The first block's parent will be the provided parent. db is used to store intermediate states and should contain the parent's state trie.

The generator function is called with a new block generator for every block. Any transactions and uncles added to the generator become part of the block. If gen is nil, the blocks will be empty and their coinbase will be the zero address.

Blocks created by GenerateChain do not contain valid proof of work values. Inserting them into BlockChain requires use of FakePow or a similar non-validating proof of work implementation.

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, ethash.NewFaker(), 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), params.TxGas, 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), params.TxGas, nil, nil), signer, key1)
		tx2, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), params.TxGas, 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.
blockchain, _ := NewBlockChain(db, nil, gspec.Config, ethash.NewFaker(), vm.Config{})
defer blockchain.Stop()

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

func GenesisBlockForTesting ¶

func GenesisBlockForTesting(db ethdb.Database, addr common.Address, balance *big.Int) *types.Block

GenesisBlockForTesting creates and writes a block in which addr has the given wei balance.

func GetHashFn ¶

func GetHashFn(ref *types.Header, chain ChainContext) func(n uint64) common.Hash

GetHashFn returns a GetHashFunc which retrieves header hashes by number

func IntrinsicGas ¶

func IntrinsicGas(data []byte, contractCreation, homestead bool) (uint64, error)

IntrinsicGas computes the 'intrinsic gas' for a message with the given data.

func NewEVMContext ¶

func NewEVMContext(msg Message, header *types.Header, chain ChainContext, author *common.Address) vm.Context

NewEVMContext creates a new context for use in the EVM.

func SetReceiptsData ¶

func SetReceiptsData(config *params.ChainConfig, block *types.Block, receipts types.Receipts) error

SetReceiptsData computes all the non-consensus fields of the receipts

func SetupGenesisBlock ¶

func SetupGenesisBlock(db ethdb.Database, genesis *Genesis) (*params.ChainConfig, common.Hash, error)

SetupGenesisBlock writes or updates the genesis block in db. The block that will be used is:

                     genesis == nil       genesis != nil
                  +------------------------------------------
db has no genesis |  main-net default  |  genesis
db has genesis    |  from DB           |  genesis (if compatible)

The stored chain configuration will be updated if it is compatible (i.e. does not specify a fork block below the local head block). In case of a conflict, the error is a *params.ConfigCompatError and the new, unwritten config is returned.

The returned chain configuration is never nil.

func Transfer ¶

func Transfer(db vm.StateDB, sender, recipient common.Address, amount *big.Int)

Transfer subtracts amount from sender and adds amount to recipient using the given Db