Struct MessageConfig 

#[non_exhaustive]
pub struct MessageConfig { /* private fields */ }

Settings for one direction of a permessage-deflate connection.

Setting	Default	RFC 7692 parameter
window bits	15	server_max_window_bits / client_max_window_bits
context takeover	off	server_no_context_takeover / client_no_context_takeover absent
level	1	(local choice)

Idle connections: without takeover nothing carries over between messages, so an idle connection can drop its engines and build new ones when traffic returns (construction allocates the sizes below once, about a microsecond for a decompressor). With takeover the window is connection state and must be kept; Compressor::wipe and Decompressor::wipe zero it when the connection ends.

Memory per direction: without takeover a Decompressor holds only its decode tables (about 11 KiB, no window); with takeover it adds the window (2^window_bits bytes). A Compressor holds a deflater sized by the window bits (about 270 KiB at 15, under 100 KiB at 9).

Examples

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

let config = MessageConfig::new().with_window_bits(10).with_context_takeover(true).with_level(Level::DEFAULT);
assert_eq!(config.window_bits(), 10);
assert!(config.context_takeover());

Implementations

impl MessageConfig

pub const fn new() -> Self

Window bits 15, no context takeover, level 1.

Examples

use compress_lib::message::MessageConfig;

assert_eq!(MessageConfig::new(), MessageConfig::default());
assert!(!MessageConfig::new().context_takeover());

pub const fn with_window_bits(self, bits: u8) -> Self

Sets the window bits, 8 to 15 (checked when an engine is built).

Examples

assert_eq!(compress_lib::message::MessageConfig::new().with_window_bits(9).window_bits(), 9);

pub const fn with_context_takeover(self, on: bool) -> Self

Keeps the window from one message to the next.

Examples

assert!(compress_lib::message::MessageConfig::new().with_context_takeover(true).context_takeover());

pub const fn with_level(self, level: Level) -> Self

Sets the compression level (the compressor only).

Examples

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

assert_eq!(MessageConfig::new().with_level(Level::BEST).level(), Level::BEST);

pub const fn with_memory(self, memory: MemoryConfig) -> Self

Sizes the compressor’s hash table and symbol buffer (see MemoryConfig); the decompressor is not affected.

Examples

use compress_lib::{deflate::MemoryConfig, message::MessageConfig};

let config = MessageConfig::new().with_memory(MemoryConfig::new().with_hash_bits(10));
assert_eq!(config.memory().hash_bits(), 10);

pub const fn memory(&self) -> MemoryConfig

The compressor’s memory settings.

Examples

assert_eq!(compress_lib::message::MessageConfig::new().memory().hash_bits(), 0);

pub const fn window_bits(&self) -> u8

The window bits.

Examples

assert_eq!(compress_lib::message::MessageConfig::new().window_bits(), 15);

pub const fn context_takeover(&self) -> bool

Whether the window carries over between messages.

Examples

assert!(!compress_lib::message::MessageConfig::new().context_takeover());

pub const fn level(&self) -> Level

The compression level.

Examples

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

assert_eq!(MessageConfig::new().level(), Level::FAST);

Trait Implementations

impl Clone for MessageConfig

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for MessageConfig

impl Debug for MessageConfig

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

Formats the value using the given formatter.

impl Default for MessageConfig

fn default() -> Self

Returns the “default value” for a type.

impl Eq for MessageConfig

impl Hash for MessageConfig

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for MessageConfig

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for MessageConfig