Struct Header

pub struct Header {

    pub parent_hash: FixedBytes<32>,
    pub ommers_hash: FixedBytes<32>,
    pub beneficiary: Address,
    pub state_root: FixedBytes<32>,
    pub transactions_root: FixedBytes<32>,
    pub receipts_root: FixedBytes<32>,
    pub logs_bloom: Bloom,
    pub difficulty: Uint<256, 4>,
    pub number: u64,
    pub gas_limit: u64,
    pub gas_used: u64,
    pub timestamp: u64,
    pub extra_data: Bytes,
    pub mix_hash: FixedBytes<32>,
    pub nonce: FixedBytes<8>,
    pub base_fee_per_gas: Option<u64>,
    pub withdrawals_root: Option<FixedBytes<32>>,
    pub blob_gas_used: Option<u64>,
    pub excess_blob_gas: Option<u64>,
    pub parent_beacon_block_root: Option<FixedBytes<32>>,
    pub requests_hash: Option<FixedBytes<32>>,
}

Ethereum Block header

Fields

parent_hash: FixedBytes<32>

The Keccak 256-bit hash of the parent block’s header, in its entirety; formally Hp.

ommers_hash: FixedBytes<32>

The Keccak 256-bit hash of the ommers list portion of this block; formally Ho.

beneficiary: Address

The 160-bit address to which all fees collected from the successful mining of this block be transferred; formally Hc.

state_root: FixedBytes<32>

The Keccak 256-bit hash of the root node of the state trie, after all transactions are executed and finalisations applied; formally Hr.

transactions_root: FixedBytes<32>

The Keccak 256-bit hash of the root node of the trie structure populated with each transaction in the transactions list portion of the block; formally Ht.

receipts_root: FixedBytes<32>

The Keccak 256-bit hash of the root node of the trie structure populated with the receipts of each transaction in the transactions list portion of the block; formally He.

logs_bloom: Bloom

The Bloom filter composed from indexable information (logger address and log topics) contained in each log entry from the receipt of each transaction in the transactions list; formally Hb.

difficulty: Uint<256, 4>

A scalar value corresponding to the difficulty level of this block. This can be calculated from the previous block’s difficulty level and the timestamp; formally Hd.

number: u64

A scalar value equal to the number of ancestor blocks. The genesis block has a number of zero; formally Hi.

gas_limit: u64

A scalar value equal to the current limit of gas expenditure per block; formally Hl.

gas_used: u64

A scalar value equal to the total gas used in transactions in this block; formally Hg.

timestamp: u64

A scalar value equal to the reasonable output of Unix’s time() at this block’s inception; formally Hs.

extra_data: Bytes

An arbitrary byte array containing data relevant to this block. This must be 32 bytes or fewer; formally Hx.

mix_hash: FixedBytes<32>

A 256-bit hash which, combined with the nonce, proves that a sufficient amount of computation has been carried out on this block; formally Hm.

nonce: FixedBytes<8>

A 64-bit value which, combined with the mixhash, proves that a sufficient amount of computation has been carried out on this block; formally Hn.

base_fee_per_gas: Option<u64>

A scalar representing EIP1559 base fee which can move up or down each block according to a formula which is a function of gas used in parent block and gas target (block gas limit divided by elasticity multiplier) of parent block. The algorithm results in the base fee per gas increasing when blocks are above the gas target, and decreasing when blocks are below the gas target. The base fee per gas is burned.

withdrawals_root: Option<FixedBytes<32>>

The Keccak 256-bit hash of the withdrawals list portion of this block. https://eips.ethereum.org/EIPS/eip-4895

blob_gas_used: Option<u64>

The total amount of blob gas consumed by the transactions within the block, added in EIP-4844.

excess_blob_gas: Option<u64>

A running total of blob gas consumed in excess of the target, prior to the block. Blocks with above-target blob gas consumption increase this value, blocks with below-target blob gas consumption decrease it (bounded at 0). This was added in EIP-4844.

parent_beacon_block_root: Option<FixedBytes<32>>

The hash of the parent beacon block’s root is included in execution blocks, as proposed by EIP-4788.

This enables trust-minimized access to consensus state, supporting staking pools, bridges, and more.

The beacon roots contract handles root storage, enhancing Ethereum’s functionalities.

requests_hash: Option<FixedBytes<32>>

The Keccak 256-bit hash of the an RLP encoded list with each EIP-7685 request in the block body.

Implementations

impl Header

pub fn hash_slow(&self) -> FixedBytes<32>

Heavy function that will calculate hash of data and will not save the change to metadata.

Use Header::seal_slow and unlock if you need the hash to be persistent.

pub fn is_empty(&self) -> bool

Checks if the header is empty - has no transactions and no ommers

pub fn ommers_hash_is_empty(&self) -> bool

Check if the ommers hash equals to empty hash list.

pub fn transaction_root_is_empty(&self) -> bool

Check if the transaction root equals to empty root.

pub fn blob_fee(&self) -> Option<u128>

Returns the blob fee for this block according to the EIP-4844 spec.

Returns None if excess_blob_gas is None

pub fn next_block_blob_fee(&self) -> Option<u128>

Returns the blob fee for the next block according to the EIP-4844 spec.

Returns None if excess_blob_gas is None.

See also Self::next_block_excess_blob_gas

pub fn next_block_base_fee(&self, base_fee_params: BaseFeeParams) -> Option<u64>

Calculate base fee for next block according to the EIP-1559 spec.

Returns a None if no base fee is set, no EIP-1559 support

pub fn next_block_excess_blob_gas(&self) -> Option<u64>

Calculate excess blob gas for the next block according to the EIP-4844 spec.

Returns a None if no excess blob gas is set, no EIP-4844 support

pub fn size(&self) -> usize

Calculate a heuristic for the in-memory size of the Header.

pub const fn parent_num_hash(&self) -> NumHash

Returns the parent block’s number and hash

Note: for the genesis block the parent number is 0 and the parent hash is the zero hash.

pub fn num_hash_slow(&self) -> NumHash

Returns the block’s number and hash.

Note: this hashes the header.

pub fn is_zero_difficulty(&self) -> bool

Checks if the block’s difficulty is set to zero, indicating a Proof-of-Stake header.

This function is linked to EIP-3675, proposing the consensus upgrade to Proof-of-Stake: EIP-3675

Verifies whether, as per the EIP, the block’s difficulty is updated to zero, signifying the transition to a Proof-of-Stake mechanism.

Returns true if the block’s difficulty matches the constant zero set by the EIP.

pub const fn exceeds_allowed_future_timestamp( &self, present_timestamp: u64, ) -> bool

Checks if the block’s timestamp is in the future based on the present timestamp.

Clock can drift but this can be consensus issue.

Note: This check is relevant only pre-merge.

pub const fn seal(self, hash: FixedBytes<32>) -> Sealed<Header>

Seal the header with a known hash.

WARNING: This method does not perform validation whether the hash is correct.

Trait Implementations

impl<'a> Arbitrary<'a> for Header

Available on crate feature arbitrary only.

fn arbitrary(u: &mut Unstructured<'a>) -> Result<Header, Error>

Generate an arbitrary value of Self from the given unstructured data.

fn arbitrary_take_rest(u: Unstructured<'a>) -> Result<Self, Error>

Generate an arbitrary value of Self from the entirety of the given unstructured data.

fn size_hint(depth: usize) -> (usize, Option<usize>)

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

fn try_size_hint( depth: usize, ) -> Result<(usize, Option<usize>), MaxRecursionReached>

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

impl AsRef<Header> for Header

fn as_ref(&self) -> &Header

Converts this type into a shared reference of the (usually inferred) input type.

impl BlockHeader for Header

fn parent_hash(&self) -> FixedBytes<32>

Retrieves the parent hash of the block

fn ommers_hash(&self) -> FixedBytes<32>

Retrieves the ommers hash of the block

fn beneficiary(&self) -> Address

Retrieves the beneficiary (miner) of the block

fn state_root(&self) -> FixedBytes<32>

Retrieves the state root hash of the block

fn transactions_root(&self) -> FixedBytes<32>

Retrieves the transactions root hash of the block

fn receipts_root(&self) -> FixedBytes<32>

Retrieves the receipts root hash of the block

fn withdrawals_root(&self) -> Option<FixedBytes<32>>

Retrieves the withdrawals root hash of the block, if available

fn logs_bloom(&self) -> Bloom

Retrieves the logs bloom filter of the block

fn difficulty(&self) -> Uint<256, 4>

Retrieves the difficulty of the block

fn number(&self) -> u64

Retrieves the block number

fn gas_limit(&self) -> u64

Retrieves the gas limit of the block

fn gas_used(&self) -> u64

Retrieves the gas used by the block

fn timestamp(&self) -> u64

Retrieves the timestamp of the block

fn mix_hash(&self) -> Option<FixedBytes<32>>

Retrieves the mix hash of the block, if available

fn nonce(&self) -> Option<FixedBytes<8>>

Retrieves the nonce of the block, if avaialble

fn base_fee_per_gas(&self) -> Option<u64>

Retrieves the base fee per gas of the block, if available

fn blob_gas_used(&self) -> Option<u64>

Retrieves the blob gas used by the block, if available

fn excess_blob_gas(&self) -> Option<u64>

Retrieves the excess blob gas of the block, if available

fn parent_beacon_block_root(&self) -> Option<FixedBytes<32>>

Retrieves the parent beacon block root of the block, if available

fn requests_hash(&self) -> Option<FixedBytes<32>>

Retrieves the requests hash of the block, if available

fn extra_data(&self) -> &Bytes

Retrieves the block’s extra data field

fn next_block_excess_blob_gas(&self) -> Option<u64>

Calculate excess blob gas for the next block according to the EIP-4844 spec.

fn next_block_blob_fee(&self) -> Option<u128>

Returns the blob fee for the next block according to the EIP-4844 spec.

impl Clone for Header

fn clone(&self) -> Header

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Compact for Header

fn to_compact<B>(&self, buf: &mut B) -> usize

where B: BufMut + AsMut<[u8]>,

Takes a buffer which can be written to. Ideally, it returns the length written to.

fn from_compact(buf: &[u8], len: usize) -> (Header, &[u8])

Takes a buffer which can be read from. Returns the object and buf with its internal cursor advanced (eg..advance(len)).

fn specialized_to_compact<B>(&self, buf: &mut B) -> usize

where B: BufMut + AsMut<[u8]>,

“Optional”: If there’s no good reason to use it, don’t.

fn specialized_from_compact(buf: &[u8], len: usize) -> (Self, &[u8])

“Optional”: If there’s no good reason to use it, don’t.

impl Debug for Header

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

Formats the value using the given formatter.

impl Decodable for Header

fn decode(buf: &mut &[u8]) -> Result<Header, Error>

Decodes the blob into the appropriate type. buf must be advanced past the decoded object.

impl Default for Header

fn default() -> Header

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Header

fn deserialize<__D>( __deserializer: __D, ) -> Result<Header, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Encodable for Header

fn encode(&self, out: &mut dyn BufMut)

Encodes the type into the out buffer.

fn length(&self) -> usize

Returns the length of the encoding of this type in bytes.

impl<'a> From<Header<'a>> for Header

fn from(value: Header<'a>) -> Header

Converts to this type from the input type.

impl Hash for Header

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 InMemorySize for Header

fn size(&self) -> usize

Returns a heuristic for the in-memory size of a struct.

impl PartialEq for Header

fn eq(&self, other: &Header) -> 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 Sealable for Header

fn hash_slow(&self) -> FixedBytes<32>

Calculate the seal hash, this may be slow.

fn seal_slow(self) -> Sealed<Self>

Seal the object by calculating the hash. This may be slow.

fn seal_ref_slow(&self) -> Sealed<&Self>

Seal a borrowed object by calculating the hash. This may be slow.

fn seal_unchecked(self, seal: FixedBytes<32>) -> Sealed<Self>

Instantiate an unchecked seal. This should be used with caution.

fn seal_ref_unchecked(&self, seal: FixedBytes<32>) -> Sealed<&Self>

Instantiate an unchecked seal. This should be used with caution.

impl Serialize for Header

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for Header

impl StructuralPartialEq for Header

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 720 bytes