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Diffstat (limited to 'vendor/zune-inflate/src/encoder.rs')
| -rw-r--r-- | vendor/zune-inflate/src/encoder.rs | 217 |
1 files changed, 0 insertions, 217 deletions
diff --git a/vendor/zune-inflate/src/encoder.rs b/vendor/zune-inflate/src/encoder.rs deleted file mode 100644 index f53f599..0000000 --- a/vendor/zune-inflate/src/encoder.rs +++ /dev/null @@ -1,217 +0,0 @@ -/* - * Copyright (c) 2023. - * - * This software is free software; You can redistribute it or modify it under terms of the MIT, Apache License or Zlib license - */ - -use alloc::vec; -use alloc::vec::Vec; - -use crate::constants::DEFLATE_BLOCKTYPE_UNCOMPRESSED; - -mod fast_match_finder; - -const _SEQ_LENGTH_SHIFT: u32 = 23; - -const _SEQ_LITRUNLEN_MASK: u32 = (1_u32 << _SEQ_LENGTH_SHIFT) - 1; - -pub(crate) struct _Sequence -{ - /* - * Bits 0..22: the number of literals in this run. This may be 0 and - * can be at most MAX_BLOCK_LENGTH. The literals are not stored - * explicitly in this structure; instead, they are read directly from - * the uncompressed data. - * - * Bits 23..31: the length of the match which follows the literals, or 0 - * if this literal run was the last in the block, so there is no match - * which follows it. - */ - litrunlen_and_length: u32 -} - -#[derive(Debug, Copy, Clone)] -pub enum DeflateEncodingStrategy -{ - NoCompression -} - -impl DeflateEncodingStrategy -{ - #[allow(dead_code)] - fn to_level(self) -> u8 - { - match self - { - Self::NoCompression => 0 - } - } -} - -pub struct DeflateEncodingOptions -{ - strategy: DeflateEncodingStrategy -} - -impl Default for DeflateEncodingOptions -{ - fn default() -> Self - { - DeflateEncodingOptions { - strategy: DeflateEncodingStrategy::NoCompression - } - } -} - -/// A simple Deflate Encoder. -/// -/// Not yet complete -pub struct DeflateEncoder<'a> -{ - data: &'a [u8], - options: DeflateEncodingOptions, - output_position: usize, - input_position: usize, - output: Vec<u8> -} - -impl<'a> DeflateEncoder<'a> -{ - /// Create a new deflate encoder. - /// - /// The - pub fn new(data: &'a [u8]) -> DeflateEncoder<'a> - { - DeflateEncoder::new_with_options(data, DeflateEncodingOptions::default()) - } - pub fn new_with_options(data: &'a [u8], options: DeflateEncodingOptions) -> DeflateEncoder<'a> - { - let length = data.len() + 1024; - let out_array = vec![0; length]; - - DeflateEncoder { - data, - options, - output_position: 0, - input_position: 0, - output: out_array - } - } - - #[cfg(feature = "zlib")] - fn write_zlib_header(&mut self) - { - const ZLIB_CM_DEFLATE: u16 = 8; - const ZLIB_CINFO_32K_WINDOW: u16 = 7; - - let level_hint = self.options.strategy.to_level(); - - let mut hdr = (ZLIB_CM_DEFLATE << 8) | (ZLIB_CINFO_32K_WINDOW << 12); - - hdr |= u16::from(level_hint) << 6; - hdr |= 31 - (hdr % 31); - - self.output[self.output_position..self.output_position + 2] - .copy_from_slice(&hdr.to_be_bytes()); - } - /// Encode a deflate data block with no compression - /// - /// # Argument - /// - `bytes`: number of bytes to compress from input as non-compressed - /// bytes - fn encode_no_compression(&mut self, bytes: usize) - { - let final_position = self.input_position + bytes; - - /* - * If the input is zero-length, we still must output a block in order - * for the output to be a valid DEFLATE stream. Handle this case - * specially to avoid potentially passing NULL to memcpy() below. - */ - if self.data.is_empty() - { - /* BFINAL and BTYPE */ - self.output[self.output_position] = (1 | (DEFLATE_BLOCKTYPE_UNCOMPRESSED << 1)) as u8; - self.output_position += 1; - /* LEN and NLEN */ - let num: u32 = 0xFFFF0000; - self.output[self.output_position..self.output_position + 4] - .copy_from_slice(&num.to_le_bytes()); - self.output_position += 4; - return; - } - loop - { - let mut bfinal = 0; - let mut len = usize::from(u16::MAX); - - if final_position - self.input_position <= usize::from(u16::MAX) - { - bfinal = 1; - len = final_position - self.input_position; - } - /* - * Output BFINAL and BTYPE. The stream is already byte-aligned - * here, so this step always requires outputting exactly 1 byte. - */ - self.output[self.output_position] = - (bfinal | (DEFLATE_BLOCKTYPE_UNCOMPRESSED << 1)) as u8; - - self.output_position += 1; - // output len and nlen - let len_u16 = len as u16; - - self.output[self.output_position..self.output_position + 2] - .copy_from_slice(&len_u16.to_le_bytes()); - self.output_position += 2; - - self.output[self.output_position..self.output_position + 2] - .copy_from_slice(&(!len_u16).to_le_bytes()); - self.output_position += 2; - - // copy from input to output - self.output[self.output_position..self.output_position + len] - .copy_from_slice(&self.data[self.input_position..self.input_position + len]); - self.output_position += len; - self.input_position += len; - - if self.input_position == final_position - { - break; - } - } - } - - /// Encode a deflate stream - pub fn encode_deflate(&mut self) - { - match self.options.strategy - { - DeflateEncodingStrategy::NoCompression => - { - self.encode_no_compression(self.data.len()); - } - } - } - - #[cfg(feature = "zlib")] - pub fn encode_zlib(&mut self) -> Vec<u8> - { - let extra = 40 * ((self.data.len() + 41) / 40); - self.output = vec![0_u8; self.data.len() + extra]; - self.write_zlib_header(); - self.output_position = 2; - - self.encode_deflate(); - - // add adler hash - let hash = crate::utils::calc_adler_hash(self.data); - self.output[self.output_position..self.output_position + 4] - .copy_from_slice(&hash.to_be_bytes()); - self.output_position += 4; - - self.output.truncate(self.output_position); - - core::mem::take(&mut self.output) - } -} |