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use crate::{
deflate::{BlockState, DeflateStream, Strategy},
DeflateFlush,
};
use self::{huff::deflate_huff, rle::deflate_rle, stored::deflate_stored};
mod fast;
mod huff;
mod medium;
mod quick;
mod rle;
mod slow;
mod stored;
#[macro_export]
macro_rules! flush_block {
($stream:expr, $is_last_block:expr) => {
$crate::deflate::flush_block_only($stream, $is_last_block);
if $stream.avail_out == 0 {
return match $is_last_block {
true => BlockState::FinishStarted,
false => BlockState::NeedMore,
};
}
};
}
pub fn run(stream: &mut DeflateStream, flush: DeflateFlush) -> BlockState {
match stream.state.strategy {
_ if stream.state.level == 0 => deflate_stored(stream, flush),
Strategy::HuffmanOnly => deflate_huff(stream, flush),
Strategy::Rle => deflate_rle(stream, flush),
Strategy::Default | Strategy::Filtered | Strategy::Fixed => {
(CONFIGURATION_TABLE[stream.state.level as usize].func)(stream, flush)
}
}
}
type CompressFunc = fn(&mut DeflateStream, flush: DeflateFlush) -> BlockState;
pub struct Config {
pub good_length: u16, /* reduce lazy search above this match length */
pub max_lazy: u16, /* do not perform lazy search above this match length */
pub nice_length: u16, /* quit search above this match length */
pub max_chain: u16,
pub func: CompressFunc,
}
impl Config {
const fn new(
good_length: u16,
max_lazy: u16,
nice_length: u16,
max_chain: u16,
func: CompressFunc,
) -> Self {
Self {
good_length,
max_lazy,
nice_length,
max_chain,
func,
}
}
}
pub const CONFIGURATION_TABLE: [Config; 10] = {
[
Config::new(0, 0, 0, 0, stored::deflate_stored), // 0 /* store only */
Config::new(0, 0, 0, 0, quick::deflate_quick), // 1
Config::new(4, 4, 8, 4, fast::deflate_fast), // 2 /* max speed, no lazy matches */
Config::new(4, 6, 16, 6, medium::deflate_medium), // 3
Config::new(4, 12, 32, 24, medium::deflate_medium), // 4 /* lazy matches */
Config::new(8, 16, 32, 32, medium::deflate_medium), // 5
Config::new(8, 16, 128, 128, medium::deflate_medium), // 6
Config::new(8, 32, 128, 256, slow::deflate_slow), // 7
Config::new(32, 128, 258, 1024, slow::deflate_slow), // 8
Config::new(32, 258, 258, 4096, slow::deflate_slow), // 9 /* max compression */
]
};