1 use super::interface;
2 use super::super::alloc::SliceWrapper;
3 use super::histogram::ContextType;
4 use super::input_pair::InputReference;
5 use super::constants::{kSigned3BitContextLookup, kUTF8ContextLookup};
6 use super::interface::LiteralPredictionModeNibble;
7 pub trait IRInterpreter {
inc_local_byte_offset(&mut self, inc:usize)8 fn inc_local_byte_offset(&mut self, inc:usize);
local_byte_offset(&self) -> usize9 fn local_byte_offset(&self) -> usize;
update_block_type(&mut self, new_type: u8, new_stride: u8)10 fn update_block_type(&mut self, new_type: u8, new_stride: u8);
block_type(&self) -> u811 fn block_type(&self) -> u8;
literal_data_at_offset(&self, index: usize) -> u812 fn literal_data_at_offset(&self, index: usize) -> u8;
literal_context_map(&self) -> &[u8]13 fn literal_context_map(&self) -> &[u8];
prediction_mode(&self) -> ::interface::LiteralPredictionModeNibble14 fn prediction_mode(&self) -> ::interface::LiteralPredictionModeNibble;
update_cost(&mut self, stride_prior: [u8;8], stride_byte_offset: usize, selected_bits:u8, cm_prior: usize, literal: u8)15 fn update_cost(&mut self, stride_prior: [u8;8], stride_byte_offset: usize, selected_bits:u8, cm_prior: usize, literal: u8);
16 }
17
18
push_base<'a, Interpreter: IRInterpreter>(xself: &mut Interpreter, val: interface::Command<InputReference<'a>>)19 pub fn push_base<'a,
20 Interpreter: IRInterpreter>(xself: &mut Interpreter,
21 val: interface::Command<InputReference<'a>>) {
22 match val {
23 interface::Command::BlockSwitchCommand(_) |
24 interface::Command::BlockSwitchDistance(_) |
25 interface::Command::PredictionMode(_) => {}
26 interface::Command::Copy(ref copy) => {
27 xself.inc_local_byte_offset(copy.num_bytes as usize);
28 },
29 interface::Command::Dict(ref dict) => {
30 xself.inc_local_byte_offset(dict.final_size as usize);
31 },
32 interface::Command::BlockSwitchLiteral(block_type) => xself.update_block_type(block_type.block_type(),
33 block_type.stride()),
34 interface::Command::Literal(ref lit) => {
35 //let stride = xself.get_stride(xself.local_byte_offset()) as usize;
36 let mut priors= [0u8; 8];
37 for poffset in 0..8 {
38 if xself.local_byte_offset() > poffset {
39 let input_offset = xself.local_byte_offset() - poffset - 1;
40 priors[7 - poffset] = xself.literal_data_at_offset(input_offset);
41 }
42 }
43 let mut cur = 0usize;
44 for literal in lit.data.slice().iter() {
45 let (huffman_table_index, selected_bits) = compute_huffman_table_index_for_context_map(priors[(cur + 7)&7], priors[(cur + 6) &7], xself.literal_context_map(), xself.prediction_mode(), xself.block_type());
46 xself.update_cost(priors, (cur + 7) & 7, selected_bits, huffman_table_index, *literal);
47 priors[cur & 7] = *literal;
48 cur += 1;
49 cur &= 7;
50 }
51 xself.inc_local_byte_offset(lit.data.slice().len());
52 }
53 }
54 }
55
56
57 // not sure why this fails
58 //impl<'a> interface::CommandProcessor<'a> for IRInterpreter {
59 // fn push<Cb: FnMut(&[interface::Command<InputReference>])>(&mut self,
60 // val: interface::Command<InputReference<'a>>,
61 // callback: &mut Cb) {
62 // push_base(self, val, callback)
63 // }
64 //}
65
66
67
compute_huffman_table_index_for_context_map( prev_byte: u8, prev_prev_byte: u8, literal_context_map: &[u8], prediction_mode: LiteralPredictionModeNibble, block_type: u8, ) -> (usize, u8)68 fn compute_huffman_table_index_for_context_map (
69 prev_byte: u8,
70 prev_prev_byte: u8,
71 literal_context_map: &[u8],//interface::PredictionModeContextMap<SliceType>,
72 prediction_mode: LiteralPredictionModeNibble,
73 block_type: u8,
74 ) -> (usize, u8) {
75 let prior = Context(prev_byte, prev_prev_byte, prediction_mode.to_context_enum().unwrap());
76 assert!(prior < 64);
77 let context_map_index = ((block_type as usize)<< 6) | prior as usize;
78 if context_map_index < literal_context_map.len() {
79 (literal_context_map[context_map_index] as usize, prior)
80 } else {
81 (prior as usize, prior)
82 }
83 }
84
Context(p1: u8, p2: u8, mode: ContextType) -> u885 pub fn Context(p1: u8, p2: u8, mode: ContextType) -> u8 {
86 match mode {
87 ContextType::CONTEXT_LSB6 => {
88 return (p1 as (i32) & 0x3fi32) as (u8);
89 }
90 ContextType::CONTEXT_MSB6 => {
91 return (p1 as (i32) >> 2i32) as (u8);
92 }
93 ContextType::CONTEXT_UTF8 => {
94 return (kUTF8ContextLookup[p1 as (usize)] as (i32) |
95 kUTF8ContextLookup[(p2 as (i32) + 256i32) as (usize)] as (i32)) as (u8);
96 }
97 ContextType::CONTEXT_SIGNED => {
98 return ((kSigned3BitContextLookup[p1 as (usize)] as (i32) << 3i32) +
99 kSigned3BitContextLookup[p2 as (usize)] as (i32)) as (u8);
100 }
101 }
102 // 0i32 as (u8)
103 }
104