X-Git-Url: https://git.nihav.org/?p=nihav.git;a=blobdiff_plain;f=nihav-core%2Fsrc%2Fcompr%2Fdeflate.rs;h=b1266619b87d5b05228dfd21d1d61904e195bef8;hp=3a3819ef2eb4bea191ed55e7fe985f0c44b1b793;hb=bc23de6bedc2e151caea241b073a65d30f62c134;hpb=9f838842665ed75d8fda65146a8a1268b62160ee diff --git a/nihav-core/src/compr/deflate.rs b/nihav-core/src/compr/deflate.rs index 3a3819e..b126661 100644 --- a/nihav-core/src/compr/deflate.rs +++ b/nihav-core/src/compr/deflate.rs @@ -71,6 +71,7 @@ //! # } //! ``` +use crate::options::NAOptionDefinitionType; use crate::io::byteio::*; use crate::io::bitreader::*; use crate::io::codebook::*; @@ -355,6 +356,14 @@ impl Inflate { self.full_pos += len; Ok(()) } + ///! Sets custom history for decoding an update for already decoded data. + pub fn set_dict(&mut self, dict: &[u8]) { + let len = dict.len().min(self.buf.len()); + let start = dict.len() - len; + self.buf[..len].copy_from_slice(&dict[start..]); + self.bpos = len; + self.full_pos = len; + } ///! Reports whether decoder has finished decoding the input. pub fn is_finished(&self) -> bool { match self.state { @@ -1653,7 +1662,7 @@ impl LZParse for OptimalParser { } dst.reserve(src.len()); - self.trellis.truncate(0); + self.trellis.clear(); self.trellis.reserve(src.len() + 1); for _ in 0..=src.len() { self.trellis.push(TNode::default()); @@ -1721,6 +1730,48 @@ pub enum DeflateMode { Best, } +impl Default for DeflateMode { + fn default() -> Self { DeflateMode::Better } +} + +pub const DEFLATE_MODE_DESCRIPTION: &str = "Deflate compression level."; +///! Deflate option for no compression. +pub const DEFLATE_MODE_NONE: &str = "none"; +///! Deflate option for fast compression. +pub const DEFLATE_MODE_FAST: &str = "fast"; +///! Deflate option for better compression. +pub const DEFLATE_MODE_BETTER: &str = "better"; +///! Deflate option for best compression. +pub const DEFLATE_MODE_BEST: &str = "best"; + +///! All possible option values for deflate compression. +pub const DEFLATE_OPTION_VALUES: NAOptionDefinitionType = NAOptionDefinitionType::String(Some(&[DEFLATE_MODE_NONE, DEFLATE_MODE_FAST, DEFLATE_MODE_BETTER, DEFLATE_MODE_BEST])); + +impl std::str::FromStr for DeflateMode { + type Err = (); + + fn from_str(s: &str) -> Result { + match s { + DEFLATE_MODE_NONE => Ok(DeflateMode::NoCompr), + DEFLATE_MODE_FAST => Ok(DeflateMode::Fast), + DEFLATE_MODE_BETTER => Ok(DeflateMode::Better), + DEFLATE_MODE_BEST => Ok(DeflateMode::Best), + _ => Err(()), + } + } +} + +impl ToString for DeflateMode { + fn to_string(&self) -> String { + match *self { + DeflateMode::NoCompr => DEFLATE_MODE_NONE.to_string(), + DeflateMode::Fast => DEFLATE_MODE_FAST.to_string(), + DeflateMode::Better => DEFLATE_MODE_BETTER.to_string(), + DeflateMode::Best => DEFLATE_MODE_BEST.to_string(), + } + } +} + #[derive(Clone,Copy,Debug,PartialEq)] enum Mode { Copy, @@ -1814,6 +1865,20 @@ impl Deflate { self.write_zlib_footer(wr); } } + ///! Tells the encoder to compress the data it received and flush it. + pub fn compress_flush(&mut self, wr: &mut DeflateWriter) { + if self.ssize > 0 { + self.do_block(wr, false); + } + if (wr.bits & 7) != 0 { + // write zero-length copy block for byte-alignment + wr.write(0, 1); + wr.write(0, 2); + wr.align(); + wr.write(0, 16); + wr.write(0xFFFF, 16); + } + } fn do_block(&mut self, wr: &mut DeflateWriter, final_block: bool) { const CRC_BASE: u32 = 65521; for &b in self.srcbuf[..self.ssize].iter() { @@ -1840,7 +1905,7 @@ impl Deflate { Mode::Fixed => { wr.write(final_block as u16, 1); wr.write(1, 2); - self.tokens.truncate(0); + self.tokens.clear(); self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens); let mut codes = CodeHuff::new(true); codes.make_codes(&self.tokens); @@ -1851,7 +1916,7 @@ impl Deflate { Mode::Dynamic => { wr.write(final_block as u16, 1); wr.write(2, 2); - self.tokens.truncate(0); + self.tokens.clear(); self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens); let mut codes = CodeHuff::new(false); codes.make_codes(&self.tokens);