Struct Target 

pub struct Target(/* private fields */);

A 256 bit integer representing target.

The SHA-256 hash of a block’s header must be lower than or equal to the current target for the block to be accepted by the network. The lower the target, the more difficult it is to generate a block. (See also Work.)

Target does not limit its value to the maximum attainable value for any network when it is constructed. If you need to enforce that invariant, you should compare the constructed value against the required network’s MAX_ATTAINABLE_* target constant.

ref: https://en.bitcoin.it/wiki/Target

Implementations

impl Target

pub const ZERO: Self

When parsing nBits, Bitcoin Core converts a negative target threshold into a target of zero.

pub const MAX: Self

The maximum possible target.

This value is used to calculate difficulty, which is defined as how difficult the current target makes it to find a block relative to how difficult it would be at the highest possible target. Remember highest target == lowest difficulty.

ref: https://en.bitcoin.it/wiki/Target

pub const MAX_ATTAINABLE_MAINNET: Self

The maximum attainable target value on mainnet.

Not all target values are attainable because consensus code uses the compact format to represent targets (see CompactTarget).

pub const MAX_ATTAINABLE_TESTNET: Self

The maximum attainable target value on testnet.

pub const MAX_ATTAINABLE_REGTEST: Self

The maximum attainable target value on regtest.

pub const MAX_ATTAINABLE_SIGNET: Self

The maximum attainable target value on signet.

pub fn from_compact(c: CompactTarget) -> Result<Self, InvalidCompactTargetError>

Computes the Target value from a compact representation.

Bitcoin Core parses a negative or overflowing compact value as a zero target. Use .unwrap_or(Target::ZERO) to match that behavior.

ref: https://developer.bitcoin.org/reference/block_chain.html#target-nbits

Errors

• If the compact value is negative or overflows 256 bits.

pub fn to_compact_lossy(self) -> CompactTarget

Computes the compact value from a Target representation.

The compact form is by definition lossy, this means that t == Target::from_compact(t.to_compact_lossy()) does not always hold.

pub fn to_work(self) -> Result<Work, ZeroConversionError>

Converts this Target to Work, work = 2^256 / (target + 1).

“Work” is defined as the work done to mine a block with this target value (recorded in the block header in compact form as nBits). This is not the same as the difficulty to mine a block with this target (see Self::difficulty).

When validating a chain, Bitcoin Core counts a zero target as zero work. Use .unwrap_or(Work::ZERO) to match that behavior.

Errors

If the target is zero.

impl Target

pub fn from_hex(s: &str) -> Result<Self, PrefixedHexError>

Constructs a new Target from a prefixed hex string.

Errors

• If the input string does not contain a 0x (or 0X) prefix.
• If the input string is not a valid hex encoding of a Target.

pub fn from_unprefixed_hex(s: &str) -> Result<Self, UnprefixedHexError>

Constructs a new Target from an unprefixed hex string.

Errors

• If the input string contains a 0x (or 0X) prefix.
• If the input string is not a valid hex encoding of a Target.

pub fn from_be_bytes(bytes: [u8; 32]) -> Target

Constructs Target from a big-endian byte array.

pub fn from_le_bytes(bytes: [u8; 32]) -> Target

Constructs Target from a little-endian byte array.

pub fn to_be_bytes(self) -> [u8; 32]

Converts Target to a big-endian byte array.

pub fn to_le_bytes(self) -> [u8; 32]

Converts Target to a little-endian byte array.

Trait Implementations

impl<'a> Arbitrary<'a> for Target

Available on crate feature arbitrary only.

fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self>

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 Binary for Target

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

Formats the value using the given formatter.

impl Clone for Target

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Target

impl Debug for Target

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Target

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Target

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

Formats the value using the given formatter.

impl Eq for Target

impl FromStr for Target

type Err = ParseTargetError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Target

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

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 LowerHex for Target

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

Formats the value using the given formatter.

impl Octal for Target

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

Formats the value using the given formatter.

impl Ord for Target

fn cmp(&self, other: &Self) -> 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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

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

Restrict a value to a certain range.

impl PartialEq for Target

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Target

fn partial_cmp(&self, other: &Self) -> 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 Serialize for Target

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Target

impl TryFrom<CompactTarget> for Target

type Error = InvalidCompactTargetError

The type returned in the event of a conversion error.

fn try_from(c: CompactTarget) -> Result<Self, Self::Error>

Performs the conversion.

impl UpperHex for Target

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

Formats the value using the given formatter.