Struct Data

pub struct Data {
    body: Vec<u8>,
}

A Data message represents data sent along a stream.

Upon receiving a Data message for a live stream, the client or exit sends that data onto the associated TCP connection.

These messages hold between 1 and Data::MAXLEN bytes of data each; they are the most numerous messages on the Tor network.

Fields

body: Vec<u8>

Contents of the cell, to be sent on a specific stream

INVARIANT: Holds between 1 and Data::MAXLEN bytes, inclusive.

Implementations

impl Data

pub const MAXLEN_V0: usize = 498usize

The longest allowable body length for a single V0 data cell.

Relay command (1) + ‘Recognized’ (2) + StreamID (2) + Digest (4) + Length (2) = 11

pub const MAXLEN_V1: usize = 488usize

The longest allowable body length for a single V1 data cell.

Tag (16) + Relay command (1) + Length (2) + StreamID (2) = 21

pub const MAXLEN: usize = 498usize

The longest allowable body length for any data cell.

Note that this value is too large to fit into a v1 relay cell; see MAXLEN_V1 if you are making a v1 data cell.

pub fn new(inp: &[u8]) -> Result<Self>

Construct a new data cell.

Returns an error if inp is longer than Data::MAXLEN bytes.

pub fn try_split_from( version: RelayCellFormat, inp: &[u8], ) -> Option<(Self, &[u8])>

Construct a new data cell, taking as many bytes from inp as possible.

Return the data cell, and a slice holding any bytes that wouldn’t fit (if any).

Returns None if the input was empty.

fn new_unchecked(body: Vec<u8>) -> Self

Construct a new data cell from a provided vector of bytes.

The vector must not have more than Data::MAXLEN bytes, and must not be empty.

pub fn max_body_len(format: RelayCellFormat) -> usize

Return the maximum allowable body length for a Data message using the provided format.

Trait Implementations

impl AsRef<[u8]> for Data

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl Body for Data

fn decode_from_reader(r: &mut Reader<'_>) -> Result<Self>

Decode a relay cell body from a provided reader.

fn encode_onto<W: Writer + ?Sized>(self, w: &mut W) -> EncodeResult<()>

Encode the body of this cell into the end of a writer.

impl Clone for Data

fn clone(&self) -> Data

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Data

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

Formats the value using the given formatter.

impl From<Data> for AnyRelayMsg

fn from(m: Data) -> AnyRelayMsg

Converts to this type from the input type.

impl From<Data> for Vec<u8>

fn from(data: Data) -> Vec<u8>

Converts to this type from the input type.

impl HasMemoryCostStructural for Data

fn indirect_memory_cost(&self, et: EnabledToken) -> usize

Memory cost of data stored out-of-line

impl RelayMsg for Data

fn cmd(&self) -> RelayCmd

Return the stream command associated with this message.

fn encode_onto<W: Writer + ?Sized>(self, w: &mut W) -> EncodeResult<()>

Encode the body of this message, not including command or length

fn decode_from_reader(cmd: RelayCmd, r: &mut Reader<'_>) -> Result<Self>

Extract the body of a message with command cmd from reader r.

impl TryFrom<AnyRelayMsg> for Data

type Error = Error

The type returned in the event of a conversion error.

fn try_from(msg: AnyRelayMsg) -> Result<Data>

Performs the conversion.