Struct Compressor 

pub struct Compressor { /* private fields */ }

Compresses messages for permessage-deflate.

Examples

use compress_lib::message::{Compressor, MessageConfig};

let mut tx = Compressor::new(MessageConfig::new())?;
let mut wire = Vec::new();
tx.compress_message(b"Hello", &mut wire)?;
assert_eq!(wire, [0xF2, 0x48, 0xCD, 0xC9, 0xC9, 0x07, 0x00]); // RFC 7692 7.2.3.1

Implementations

impl Compressor

pub fn new(config: MessageConfig) -> Result<Self, Error>

A compressor for one direction of a connection.

Errors

ErrorKind::InvalidWindowBits outside 8 to 15.

Examples

use compress_lib::message::{Compressor, MessageConfig};

assert!(Compressor::new(MessageConfig::new().with_window_bits(8)).is_ok());
assert!(Compressor::new(MessageConfig::new().with_window_bits(16)).is_err());

pub fn compress_message( &mut self, message: &[u8], out: &mut Vec<u8>, ) -> Result<usize, Error>

Compresses one message, appending the payload (without the trailing 00 00 FF FF) to out. Returns the payload length. An empty message compresses to the single byte 00.

The payload can be longer than the message for incompressible data; the WebSocket layer may then send the message uncompressed instead (with takeover the compressor’s window has advanced either way, so call reset and tell the peer, or keep sending compressed).

Errors

ErrorKind::AllocationFailed when out cannot grow.

Examples

use compress_lib::message::{Compressor, MessageConfig};

let mut tx = Compressor::new(MessageConfig::new())?;
let mut wire = Vec::new();
assert_eq!(tx.compress_message(b"", &mut wire)?, 1);
assert_eq!(wire, [0x00]);

pub fn wipe(&mut self)

Zeroes the compressor’s window, hash chains, and buffers (they hold plaintext of earlier messages), keeping the allocations; see Deflater::wipe for what “zeroes” can promise without unsafe.

Examples

use compress_lib::message::{Compressor, MessageConfig};

let mut tx = Compressor::new(MessageConfig::new().with_context_takeover(true))?;
tx.compress_message(b"token=secret", &mut Vec::new())?;
tx.wipe();

pub fn reset(&mut self)

Forgets the window (for a connection that restarts its context).

Examples

use compress_lib::message::{Compressor, MessageConfig};

let mut tx = Compressor::new(MessageConfig::new().with_context_takeover(true))?;
tx.reset();

pub fn memory_in_use(&self) -> usize

Heap bytes held.

Examples

use compress_lib::message::{Compressor, MessageConfig};

let small = Compressor::new(MessageConfig::new().with_window_bits(9))?;
let big = Compressor::new(MessageConfig::new())?;
assert!(small.memory_in_use() < big.memory_in_use());

Trait Implementations

impl Debug for Compressor

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

Formats the value using the given formatter.