Struct BlockHeader

pub struct BlockHeader {
    pub version: i32,
    pub prev_blockhash: BlockHash,
    pub merkle_root: TxMerkleNode,
    pub time: u32,
    pub bits: u32,
    pub nonce: u32,
}

Bitcoin block header.

Contains all the block’s information except the actual transactions, but including a root of a merkle tree commiting to all transactions in the block.

Bitcoin Core References

• CBlockHeader definition

Fields

version: i32

Originally protocol version, but repurposed for soft-fork signaling.

Relevant BIPs

• BIP9 - Version bits with timeout and delay (current usage)
• BIP34 - Block v2, Height in Coinbase

prev_blockhash: BlockHash

Reference to the previous block in the chain.

merkle_root: TxMerkleNode

The root hash of the merkle tree of transactions in the block.

time: u32

The timestamp of the block, as claimed by the miner.

bits: u32

The target value below which the blockhash must lie, encoded as a a float (with well-defined rounding, of course).

nonce: u32

The nonce, selected to obtain a low enough blockhash.

Implementations

impl BlockHeader

pub fn block_hash(&self) -> BlockHash

Returns the block hash.

pub fn target(&self) -> Uint256

Computes the target [0, T] that a blockhash must land in to be valid.

pub fn u256_from_compact_target(bits: u32) -> Uint256

Computes the target value in Uint256 format, from a compact representation.

use bitcoin::blockdata::block::BlockHeader;

assert_eq!(0x1d00ffff,
    BlockHeader::compact_target_from_u256(
        &BlockHeader::u256_from_compact_target(0x1d00ffff)
    )
);

pub fn compact_target_from_u256(value: &Uint256) -> u32

Computes the target value in float format from Uint256 format.

pub fn difficulty(&self, network: Network) -> u64

Computes the popular “difficulty” measure for mining.

pub fn validate_pow( &self, required_target: &Uint256, ) -> Result<BlockHash, Error>

Checks that the proof-of-work for the block is valid, returning the block hash.

pub fn work(&self) -> Uint256

Returns the total work of the block.

Trait Implementations

impl Clone for BlockHeader

fn clone(&self) -> BlockHeader

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BlockHeader

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Decodable for BlockHeader

fn consensus_decode_from_finite_reader<R>( r: &mut R, ) -> Result<BlockHeader, Error>

where R: Read + ?Sized,

Decode Self from a size-limited reader.

fn consensus_decode<R>(r: &mut R) -> Result<BlockHeader, Error>

where R: Read + ?Sized,

Decode an object with a well-defined format.

impl Encodable for BlockHeader

fn consensus_encode<R>(&self, r: &mut R) -> Result<usize, Error>

where R: Write + ?Sized,

Encode an object with a well-defined format. Returns the number of bytes written on success.

impl Hash for BlockHeader

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for BlockHeader

fn cmp(&self, other: &BlockHeader) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for BlockHeader

fn eq(&self, other: &BlockHeader) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for BlockHeader

fn partial_cmp(&self, other: &BlockHeader) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for BlockHeader

impl Eq for BlockHeader

impl StructuralPartialEq for BlockHeader