Struct exonum::blockchain::Block

pub struct Block {
    pub height: Height,
    pub tx_count: u32,
    pub prev_hash: Hash,
    pub tx_hash: Hash,
    pub state_hash: Hash,
    pub error_hash: Hash,
    pub additional_headers: AdditionalHeaders,
}

Header of a block.

A block is essentially a list of transactions. Blocks are produced as a result of the consensus algorithm (thus authenticated by the supermajority of validators) and are applied atomically to the blockchain state. The header contains a block summary, such as the number of transactions and the transactions root hash, but not the transactions themselves.

Note that this structure is export-only, meaning that one can rely on the serialization format provided by corresponding Protobuf definitions, but cannot expect Exonum nodes or the exonum crate to accept and process Blocks created externally.

Fields

height: Height

Height of the block, which is also the number of this particular block in the blockchain.

tx_count: u32

Number of transactions in this block.

prev_hash: Hash

Hash link to the previous block in the blockchain.

tx_hash: Hash

Root hash of the Merkle tree of transactions in this block.

state_hash: Hash

Hash of the blockchain state after applying transactions in the block.

error_hash: Hash

Root hash of the Merkle Patricia tree of the erroneous calls performed within the block. These calls can include transactions, before_transactions and/or after_transactions hooks for services.

additional_headers: AdditionalHeaders

Additional information that can be added into the block.

Methods

impl Block

pub fn epoch(&self) -> Option<Height>

Retrieves the epoch associated with this block, or None if the epoch is not recorded.

pub fn is_skip(&self) -> bool

Checks if this block is formed as a result of skipping ordinary block creation.

pub fn get_header<K: BlockHeaderKey>(&self) -> Result<Option<K::Value>>

Gets the value of an additional header for the specified key type, which is specified via the type parameter.

Examples

// Suppose we store a list of active service IDs in a block.
// We can do this by defining a corresponding BlockHeaderKey implementation.
struct ActiveServices {
    service_ids: Vec<u32>,
}

// To implement `BlockHeaderKey` we need to provide the key name and a corresponding
// value type. In this case it's `Self`.
impl BlockHeaderKey for ActiveServices {
    const NAME: &'static str = "active_services";
    type Value = Self;
}

// Create an empty block.
let block = Block {
    // other fields skipped...
    additional_headers: AdditionalHeaders::new(),
};

let services = block.get_header::<ActiveServices>().unwrap();
assert!(services.is_none());

Trait Implementations

impl BinaryValue for Block

fn to_bytes(&self) -> Vec<u8>

Serializes the given value to the vector of bytes.

fn from_bytes(value: Cow<[u8]>) -> Result<Self, Error>

Deserializes the value from the given bytes array.

fn into_bytes(self) -> Vec<u8>

Consumes and serializes the given value to the vector of bytes. This method is faster with the wrapped values, thus if you wouldn't use value after serialization use it.

impl Clone for Block

fn clone(&self) -> Block

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Block

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Block

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

Deserialize this value from the given Serde deserializer.

impl Eq for Block

impl ObjectHash for Block

fn object_hash(&self) -> Hash

Returns a hash of the value.

impl Ord for Block

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

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<Block> for Block

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Block> for Block

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

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

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

This method tests less than (for self and other) and is used by the < operator.

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

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

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

This method tests greater than (for self and other) and is used by the > operator.

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

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

impl ProtobufConvert for Block

type ProtoStruct = Block

Type generated from the Protobuf definition.

fn from_pb(pb: Self::ProtoStruct) -> Result<Self, Error>

Performs conversion from the type generated from Protobuf.

fn to_pb(&self) -> Self::ProtoStruct

Performs conversion to the type generated from Protobuf.

impl Serialize for Block

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

Serialize this value into the given Serde serializer.

impl StructuralEq for Block

impl StructuralPartialEq for Block