Struct VarInt 

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

The Variable Byte Integer is encoded using an encoding scheme which uses a single byte for values up to 127.

Larger values are handled as follows. The least significant seven bits of each byte encode the data, and the most significant bit is used to indicate whether there are bytes following in the representation. Thus, each byte encodes 128 values and a “continuation bit”. The maximum number of bytes in the Variable Byte Integer field is four. The encoded value MUST use the minimum number of bytes necessary to represent the value [MQTT-1.5.5-1].

Implementations

impl VarInt

pub const fn new() -> Self

Returns an empty var int object.

pub const fn from(len: usize) -> Result<Self, VarIntError>

Convert usize value into VarInt.

Errors

Returns error if len is too large.

pub const fn len(&self) -> usize

Returns number of bytes of this var int object consums.

pub const fn is_empty(&self) -> bool

Returns true if var int is zero.

pub const fn value(&self) -> usize

Returns integer value this var int object presents.

pub fn unchecked_add(&mut self, v: usize)

pub fn unchecked_sub(&mut self, v: usize)

pub fn add(&mut self, v: usize) -> Result<(), EncodeError>

Add value v with current value.

Errors

Returns error if result is overflow.

pub fn sub(&mut self, v: usize) -> Result<(), EncodeError>

Substract value v from current value.

Errors

Returns error if result is underflow.

pub const fn bytes(&self) -> usize

Returns number of bytes of this var int object consums.

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 DecodePacket for VarInt

fn decode(ba: &mut ByteArray<'_>) -> Result<Self, DecodeError>

Decode byte array into a mqtt packet.

impl Default for VarInt

fn default() -> VarInt

Returns the “default value” for a type.

impl Display for VarInt

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

Formats the value using the given formatter.

impl EncodePacket for VarInt

fn encode(&self, buf: &mut Vec<u8>) -> Result<usize, EncodeError>

Encode packets into byte array.

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