Trait Value 

pub unsafe trait Value: Default + Eq {
    const WIRE_TYPE: WireType;

    // Required methods
    fn proto_len(&self) -> u64;
    fn encode<W: Write>(&self, writer: &mut W) -> Result<()>;
}

A value (or payload) is stored differently depending on the wire_type. In profiles, there two types of payloads: varints and len-prefixed types.

Safety

The Default implementation must provide all zero values.

Required Associated Constants

const WIRE_TYPE: WireType

The wire type this value uses.

Required Methods

fn proto_len(&self) -> u64

The number of bytes it takes to encode this value. Do not include the number of bytes it takes to encode the length-prefix as a varint. For example, using this snippet of the reference:

len-prefix := size (message | string | packed);
               size encoded as int32 varint

Calculate the number of bytes for (message | string | packed) only.

For a varint, returns between 1 and 10 bytes for the number of bytes used to encode the varint.

Returns u64 rather than u31 to avoid a lot of overflow checking.

fn encode<W: Write>(&self, writer: &mut W) -> Result<()>

Encode the value to the in-wire protobuf format. For length-delimited types, do not include the length-prefix; see Value::proto_len for more details.

Encoding often happens one byte at a time, so a buffered writer should probably be used.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl Value for &str

const WIRE_TYPE: WireType = WireType::LengthDelimited

fn proto_len(&self) -> u64

fn encode<W: Write>(&self, writer: &mut W) -> Result<()>

impl Value for i64

const WIRE_TYPE: WireType = WireType::Varint

fn proto_len(&self) -> u64

fn encode<W: Write>(&self, writer: &mut W) -> Result<()>

impl Value for u64

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::Varint

fn proto_len(&self) -> u64

fn encode<W: Write>(&self, writer: &mut W) -> Result<()>

impl<T: Value> Value for &[T]

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

fn proto_len(&self) -> u64

fn encode<W: Write>(&self, writer: &mut W) -> Result<()>

Implementors

impl Value for Function

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl Value for Label

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl Value for Line

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl Value for Location

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl Value for Mapping

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl Value for Sample<'_>

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl Value for StringOffset

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::Varint

impl Value for ValueType

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = WireType::LengthDelimited

impl<P: Value, const F: u32, const O: bool> Value for Record<P, F, O>

Safety

The Default implementation will return all zero-representations.

const WIRE_TYPE: WireType = P::WIRE_TYPE