Struct VarInt 

pub struct VarInt(pub u64);

A Bitcoin protocol variable-length integer.

VarInt is used in transaction data to indicate the number of upcoming fields or the length of an upcoming field. The encoding uses 1, 3, 5, or 9 bytes depending on the magnitude of the value.

See http://learnmeabitcoin.com/glossary/varint

Tuple Fields

0: u64

Implementations

impl VarInt

pub fn from_bytes(data: &[u8]) -> Result<(Self, usize), PrimitivesError>

Decode a VarInt from a byte slice.

Returns the decoded value and the number of bytes consumed.

Arguments

• data - Byte slice starting with a VarInt encoding.

Returns

Ok((VarInt, bytes_consumed)) or Err if the slice is too short.

Panics

None — all bounds are checked.

pub fn length(&self) -> usize

Return the wire-format byte length of this VarInt.

Returns

1, 3, 5, or 9 depending on the value.

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

Encode the VarInt into a new byte vector.

Returns

A Vec<u8> of 1, 3, 5, or 9 bytes.

pub fn put_bytes(&self, dst: &mut [u8]) -> usize

Write the VarInt into a destination buffer.

The buffer must be at least self.length() bytes long.

Arguments

• dst - Destination buffer to write into.

Returns

The number of bytes written.

pub fn upper_limit_inc(&self) -> i32

Check if this value is at the upper boundary of a VarInt size class.

Returns how many extra bytes would be needed if the value were incremented by 1. Returns -1 at u64::MAX (cannot increment).

Returns

0 if not at a boundary, 2 or 4 for size-class transitions, -1 at max.

pub fn value(&self) -> u64

Return the underlying u64 value.

Returns

The integer value.

Trait Implementations

impl Clone for VarInt

fn clone(&self) -> VarInt

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VarInt

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

Formats the value using the given formatter.

impl From<u64> for VarInt

fn from(v: u64) -> Self

Converts to this type from the input type.

impl From<usize> for VarInt

fn from(v: usize) -> Self

Converts to this type from the input type.

impl PartialEq for VarInt

fn eq(&self, other: &VarInt) -> 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 Copy for VarInt

impl Eq for VarInt

impl StructuralPartialEq for VarInt