Struct Decompressor 

pub struct Decompressor { /* private fields */ }

Decompresses permessage-deflate messages.

The output budget is checked per output chunk while inflating, never after, so a compressed bomb stops at the budget; the error is ErrorKind::OutputLimit (WebSocket close code 1009). Undecodable data is any other kind (close code 1007).

Examples

use compress_lib::{ErrorKind, message::{Decompressor, MessageConfig}};

let mut rx = Decompressor::new(MessageConfig::new())?;
let mut text = Vec::new();
rx.decompress_message(&[0xF2, 0x48, 0xCD, 0xC9, 0xC9, 0x07, 0x00], &mut text, 1024)?;
assert_eq!(text, b"Hello");
let err = rx.decompress_message(&[0xF2, 0x48, 0xCD, 0xC9, 0xC9, 0x07, 0x00], &mut Vec::new(), 4).unwrap_err();
assert_eq!(err.kind(), ErrorKind::OutputLimit);

Implementations

impl Decompressor

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

A decompressor for one direction of a connection.

Errors

ErrorKind::InvalidWindowBits outside 8 to 15.

Examples

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

assert!(Decompressor::new(MessageConfig::new().with_window_bits(8)).is_ok());

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

Decompresses one whole message payload, appending to out, with at most max bytes of output. Returns the bytes appended.

Errors

OutputLimit past max; TrailingData for nonzero bytes after a final block; UnexpectedEnd when the message, with the 00 00 FF FF tail appended, does not end on a block boundary (a block cut short, or a sender that left the tail in place); any decoding error. After an error the decompressor is reset (the connection should be failed anyway).

Examples

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

let mut rx = Decompressor::new(MessageConfig::new())?;
let mut out = Vec::new();
assert_eq!(rx.decompress_message(&[0x00], &mut out, 16)?, 0); // empty message

pub fn decompress_fragment( &mut self, fragment: &[u8], last: bool, out: &mut Vec<u8>, max: usize, ) -> Result<usize, Error>

Decompresses one frame of a message, appending to out; last marks the final frame. Every fragment of a message must append to the same vector, untouched in between: the vector is the message’s history. max caps the whole message. Returns the bytes appended by this fragment.

Errors

As decompress_message, plus InvalidState when out was changed between fragments.

Examples

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

let payload = [0xF2, 0x48, 0xCD, 0xC9, 0xC9, 0x07, 0x00];
let mut rx = Decompressor::new(MessageConfig::new())?;
let mut out = Vec::new();
rx.decompress_fragment(&payload[..3], false, &mut out, 1024)?;
rx.decompress_fragment(&payload[3..], true, &mut out, 1024)?;
assert_eq!(out, b"Hello");

pub fn wipe(&mut self)

Zeroes the decompressor’s window and decode tables and forgets any open message, keeping the allocations; see Inflater::wipe. The message vectors are the caller’s to wipe.

Examples

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

let mut rx = Decompressor::new(MessageConfig::new().with_context_takeover(true))?;
rx.wipe();

pub fn reset(&mut self)

Forgets the window and any open message.

Examples

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

let mut rx = Decompressor::new(MessageConfig::new())?;
rx.reset();

pub fn memory_in_use(&self) -> usize

Heap bytes held: the decode tables, plus the window with takeover.

Examples

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

let lean = Decompressor::new(MessageConfig::new())?;
let takeover = Decompressor::new(MessageConfig::new().with_context_takeover(true))?;
assert!(lean.memory_in_use() + 32 * 1024 <= takeover.memory_in_use());

Trait Implementations

impl Debug for Decompressor

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

Formats the value using the given formatter.