Golang btcutil.NewBlock函數代碼示例

// This example demonstrates creating a new database and inserting the genesis
// block into it.
func ExampleCreateDB() {
	// Notice in these example imports that the memdb driver is loaded.
	// Ordinarily this would be whatever driver(s) your application
	// requires.
	// import (
	//	"github.com/btcsuite/btcd/database"
	// 	_ "github.com/btcsuite/btcd/database/memdb"
	// )

	// Create a database and schedule it to be closed on exit.  This example
	// uses a memory-only database to avoid needing to write anything to
	// the disk.  Typically, you would specify a persistent database driver
	// such as "leveldb" and give it a database name as the second
	// parameter.
	db, err := database.CreateDB("memdb")
	if err != nil {
		fmt.Println(err)
		return
	}
	defer db.Close()

	// Insert the main network genesis block.
	genesis := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	newHeight, err := db.InsertBlock(genesis)
	if err != nil {
		fmt.Println(err)
		return
	}

	fmt.Println("New height:", newHeight)

	// Output:
	// New height: 0
}

// Receive waits for the response promised by the future and returns the raw
// block requested from the server given its hash.
func (r FutureGetBlockResult) Receive() (*btcutil.Block, error) {
	res, err := receiveFuture(r)
	if err != nil {
		return nil, err
	}

	// Unmarshal result as a string.
	var blockHex string
	err = json.Unmarshal(res, &blockHex)
	if err != nil {
		return nil, err
	}

	// Decode the serialized block hex to raw bytes.
	serializedBlock, err := hex.DecodeString(blockHex)
	if err != nil {
		return nil, err
	}

	// Deserialize the block and return it.
	var msgBlock wire.MsgBlock
	err = msgBlock.Deserialize(bytes.NewReader(serializedBlock))
	if err != nil {
		return nil, err
	}
	return btcutil.NewBlock(&msgBlock), nil
}

// GenerateAndSubmitBlock creates a block whose contents include the passed
// transactions and submits it to the running simnet node. For generating
// blocks with only a coinbase tx, callers can simply pass nil instead of
// transactions to be mined. Additionally, a custom block version can be set by
// the caller. A blockVersion of -1 indicates that the current default block
// version should be used. An uninitialized time.Time should be used for the
// blockTime parameter if one doesn't wish to set a custom time.
//
// This function is safe for concurrent access.
func (h *Harness) GenerateAndSubmitBlock(txns []*btcutil.Tx, blockVersion int32,
	blockTime time.Time) (*btcutil.Block, error) {

	h.Lock()
	defer h.Unlock()

	if blockVersion == -1 {
		blockVersion = wire.BlockVersion
	}

	prevBlockHash, prevBlockHeight, err := h.Node.GetBestBlock()
	if err != nil {
		return nil, err
	}
	mBlock, err := h.Node.GetBlock(prevBlockHash)
	if err != nil {
		return nil, err
	}
	prevBlock := btcutil.NewBlock(mBlock)
	prevBlock.SetHeight(prevBlockHeight)

	// Create a new block including the specified transactions
	newBlock, err := createBlock(prevBlock, txns, blockVersion,
		blockTime, h.wallet.coinbaseAddr, h.ActiveNet)
	if err != nil {
		return nil, err
	}

	// Submit the block to the simnet node.
	if err := h.Node.SubmitBlock(newBlock, nil); err != nil {
		return nil, err
	}

	return newBlock, nil
}

// BenchmarkIsCoinBase performs a simple benchmark against the IsCoinBase
// function.
func BenchmarkIsCoinBase(b *testing.B) {
	tx, _ := btcutil.NewBlock(&Block100000).Tx(1)
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		blockchain.IsCoinBase(tx)
	}
}

// loadBlockDB opens the block database and returns a handle to it.
func loadBlockDB() (database.Db, error) {
	db, err := setupBlockDB()
	if err != nil {
		return nil, err
	}

	// Get the latest block height from the database.
	_, height, err := db.NewestSha()
	if err != nil {
		db.Close()
		return nil, err
	}

	// Insert the appropriate genesis block for the bitcoin network being
	// connected to if needed.
	if height == -1 {
		genesis := btcutil.NewBlock(activeNetParams.GenesisBlock)
		_, err := db.InsertBlock(genesis)
		if err != nil {
			db.Close()
			return nil, err
		}
		btcdLog.Infof("Inserted genesis block %v",
			activeNetParams.GenesisHash)
		height = 0
	}

	btcdLog.Infof("Block database loaded with block height %d", height)
	return db, nil
}

// createBlock creates a new block building from the previous block.
func createBlock(prevBlock *btcutil.Block, inclusionTxs []*btcutil.Tx,
	blockVersion int32, blockTime time.Time,
	miningAddr btcutil.Address, net *chaincfg.Params) (*btcutil.Block, error) {

	prevHash := prevBlock.Hash()
	blockHeight := prevBlock.Height() + 1

	// If a target block time was specified, then use that as the header's
	// timestamp. Otherwise, add one second to the previous block unless
	// it's the genesis block in which case use the current time.
	var ts time.Time
	switch {
	case !blockTime.IsZero():
		ts = blockTime
	default:
		ts = prevBlock.MsgBlock().Header.Timestamp.Add(time.Second)
	}

	extraNonce := uint64(0)
	coinbaseScript, err := standardCoinbaseScript(blockHeight, extraNonce)
	if err != nil {
		return nil, err
	}
	coinbaseTx, err := createCoinbaseTx(coinbaseScript, blockHeight,
		miningAddr, net)
	if err != nil {
		return nil, err
	}

	// Create a new block ready to be solved.
	blockTxns := []*btcutil.Tx{coinbaseTx}
	if inclusionTxs != nil {
		blockTxns = append(blockTxns, inclusionTxs...)
	}
	merkles := blockchain.BuildMerkleTreeStore(blockTxns)
	var block wire.MsgBlock
	block.Header = wire.BlockHeader{
		Version:    blockVersion,
		PrevBlock:  *prevHash,
		MerkleRoot: *merkles[len(merkles)-1],
		Timestamp:  ts,
		Bits:       net.PowLimitBits,
	}
	for _, tx := range blockTxns {
		if err := block.AddTransaction(tx.MsgTx()); err != nil {
			return nil, err
		}
	}

	found := solveBlock(&block.Header, net.PowLimit)
	if !found {
		return nil, errors.New("Unable to solve block")
	}

	utilBlock := btcutil.NewBlock(&block)
	utilBlock.SetHeight(blockHeight)
	return utilBlock, nil
}

// TestMerkle tests the BuildMerkleTreeStore API.
func TestMerkle(t *testing.T) {
	block := btcutil.NewBlock(&Block100000)
	merkles := blockchain.BuildMerkleTreeStore(block.Transactions())
	calculatedMerkleRoot := merkles[len(merkles)-1]
	wantMerkle := &Block100000.Header.MerkleRoot
	if !wantMerkle.IsEqual(calculatedMerkleRoot) {
		t.Errorf("BuildMerkleTreeStore: merkle root mismatch - "+
			"got %v, want %v", calculatedMerkleRoot, wantMerkle)
	}
}

// This example demonstrates how to create a new chain instance and use
// ProcessBlock to attempt to attempt add a block to the chain.  As the package
// overview documentation describes, this includes all of the Bitcoin consensus
// rules.  This example intentionally attempts to insert a duplicate genesis
// block to illustrate how an invalid block is handled.
func ExampleBlockChain_ProcessBlock() {
	// Create a new database to store the accepted blocks into.  Typically
	// this would be opening an existing database and would not be deleting
	// and creating a new database like this, but it is done here so this is
	// a complete working example and does not leave temporary files laying
	// around.
	dbPath := filepath.Join(os.TempDir(), "exampleprocessblock")
	_ = os.RemoveAll(dbPath)
	db, err := database.Create("ffldb", dbPath, chaincfg.MainNetParams.Net)
	if err != nil {
		fmt.Printf("Failed to create database: %v\n", err)
		return
	}
	defer os.RemoveAll(dbPath)
	defer db.Close()

	// Create a new BlockChain instance using the underlying database for
	// the main bitcoin network.  This example does not demonstrate some
	// of the other available configuration options such as specifying a
	// notification callback and signature cache.
	chain, err := blockchain.New(&blockchain.Config{
		DB:          db,
		ChainParams: &chaincfg.MainNetParams,
	})
	if err != nil {
		fmt.Printf("Failed to create chain instance: %v\n", err)
		return
	}

	// Create a new median time source that is required by the upcoming
	// call to ProcessBlock.  Ordinarily this would also add time values
	// obtained from other peers on the network so the local time is
	// adjusted to be in agreement with other peers.
	timeSource := blockchain.NewMedianTime()

	// Process a block.  For this example, we are going to intentionally
	// cause an error by trying to process the genesis block which already
	// exists.
	genesisBlock := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	isOrphan, err := chain.ProcessBlock(genesisBlock, timeSource, blockchain.BFNone)
	if err != nil {
		fmt.Printf("Failed to process block: %v\n", err)
		return
	}
	fmt.Printf("Block accepted. Is it an orphan?: %v", isOrphan)

	// Output:
	// Failed to process block: already have block 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
}

// exampleLoadDB is used in the example to elide the setup code.
func exampleLoadDB() (database.Db, error) {
	db, err := database.CreateDB("memdb")
	if err != nil {
		return nil, err
	}

	// Insert the main network genesis block.
	genesis := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	_, err = db.InsertBlock(genesis)
	if err != nil {
		return nil, err
	}

	return db, err
}

// TestCheckConnectBlock tests the CheckConnectBlock function to ensure it
// fails.
func TestCheckConnectBlock(t *testing.T) {
	// Create a new database and chain instance to run tests against.
	chain, teardownFunc, err := chainSetup("checkconnectblock")
	if err != nil {
		t.Errorf("Failed to setup chain instance: %v", err)
		return
	}
	defer teardownFunc()

	// The genesis block should fail to connect since it's already inserted.
	genesisBlock := chaincfg.MainNetParams.GenesisBlock
	err = chain.CheckConnectBlock(btcutil.NewBlock(genesisBlock))
	if err == nil {
		t.Errorf("CheckConnectBlock: Did not received expected error")
	}
}

// FetchBlockBySha returns a btcutil.Block.  The implementation may cache the
// underlying data if desired.  This is part of the database.Db interface
// implementation.
//
// This implementation does not use any additional cache since the entire
// database is already in memory.
func (db *MemDb) FetchBlockBySha(sha *wire.ShaHash) (*btcutil.Block, error) {
	db.Lock()
	defer db.Unlock()

	if db.closed {
		return nil, ErrDbClosed
	}

	if blockHeight, exists := db.blocksBySha[*sha]; exists {
		block := btcutil.NewBlock(db.blocks[int(blockHeight)])
		block.SetHeight(blockHeight)
		return block, nil
	}

	return nil, fmt.Errorf("block %v is not in database", sha)
}

// This example demonstrates how to create a new chain instance and use
// ProcessBlock to attempt to attempt add a block to the chain.  As the package
// overview documentation describes, this includes all of the Bitcoin consensus
// rules.  This example intentionally attempts to insert a duplicate genesis
// block to illustrate how an invalid block is handled.
func ExampleBlockChain_ProcessBlock() {
	// Create a new database to store the accepted blocks into.  Typically
	// this would be opening an existing database and would not use memdb
	// which is a memory-only database backend, but we create a new db
	// here so this is a complete working example.
	db, err := database.CreateDB("memdb")
	if err != nil {
		fmt.Printf("Failed to create database: %v\n", err)
		return
	}
	defer db.Close()

	// Insert the main network genesis block.  This is part of the initial
	// database setup.  Like above, this typically would not be needed when
	// opening an existing database.
	genesisBlock := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	_, err = db.InsertBlock(genesisBlock)
	if err != nil {
		fmt.Printf("Failed to insert genesis block: %v\n", err)
		return
	}

	// Create a new BlockChain instance without an initialized signature
	// verification cache, using the underlying database for the main
	// bitcoin network and ignore notifications.
	chain := blockchain.New(db, &chaincfg.MainNetParams, nil, nil)

	// Create a new median time source that is required by the upcoming
	// call to ProcessBlock.  Ordinarily this would also add time values
	// obtained from other peers on the network so the local time is
	// adjusted to be in agreement with other peers.
	timeSource := blockchain.NewMedianTime()

	// Process a block.  For this example, we are going to intentionally
	// cause an error by trying to process the genesis block which already
	// exists.
	isOrphan, err := chain.ProcessBlock(genesisBlock, timeSource, blockchain.BFNone)
	if err != nil {
		fmt.Printf("Failed to process block: %v\n", err)
		return
	}
	fmt.Printf("Block accepted. Is it an orphan?: %v", isOrphan)

	// Output:
	// Failed to process block: already have block 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
}

// setupDB is used to create a new db instance with the genesis block already
// inserted.  In addition to the new db instance, it returns a teardown function
// the caller should invoke when done testing to clean up.
func setupDB(dbType, dbName string) (database.Db, func(), error) {
	db, teardown, err := createDB(dbType, dbName, true)
	if err != nil {
		return nil, nil, err
	}

	// Insert the main network genesis block.  This is part of the initial
	// database setup.
	genesisBlock := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	_, err = db.InsertBlock(genesisBlock)
	if err != nil {
		teardown()
		err := fmt.Errorf("failed to insert genesis block: %v", err)
		return nil, nil, err
	}

	return db, teardown, nil
}

// TestCheckBlockSanity tests the CheckBlockSanity function to ensure it works
// as expected.
func TestCheckBlockSanity(t *testing.T) {
	powLimit := chaincfg.MainNetParams.PowLimit
	block := btcutil.NewBlock(&Block100000)
	timeSource := blockchain.NewMedianTime()
	err := blockchain.CheckBlockSanity(block, powLimit, timeSource)
	if err != nil {
		t.Errorf("CheckBlockSanity: %v", err)
	}

	// Ensure a block that has a timestamp with a precision higher than one
	// second fails.
	timestamp := block.MsgBlock().Header.Timestamp
	block.MsgBlock().Header.Timestamp = timestamp.Add(time.Nanosecond)
	err = blockchain.CheckBlockSanity(block, powLimit, timeSource)
	if err == nil {
		t.Errorf("CheckBlockSanity: error is nil when it shouldn't be")
	}
}

// BenchmarkBlockHeader benchmarks how long it takes to load the mainnet genesis
// block.
func BenchmarkBlock(b *testing.B) {
	// Start by creating a new database and populating it with the mainnet
	// genesis block.
	dbPath := filepath.Join(os.TempDir(), "ffldb-benchblk")
	_ = os.RemoveAll(dbPath)
	db, err := database.Create("ffldb", dbPath, blockDataNet)
	if err != nil {
		b.Fatal(err)
	}
	defer os.RemoveAll(dbPath)
	defer db.Close()
	err = db.Update(func(tx database.Tx) error {
		block := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
		if err := tx.StoreBlock(block); err != nil {
			return err
		}
		return nil
	})
	if err != nil {
		b.Fatal(err)
	}

	b.ReportAllocs()
	b.ResetTimer()
	err = db.View(func(tx database.Tx) error {
		blockHash := chaincfg.MainNetParams.GenesisHash
		for i := 0; i < b.N; i++ {
			_, err := tx.FetchBlock(blockHash)
			if err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		b.Fatal(err)
	}

	// Don't benchmark teardown.
	b.StopTimer()
}