openharmony/third_party_rust_nom
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Create the big endian uint parsers (8, 16, 32, 64 bits)

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This commit is contained in:
Geoffroy Couprie 2015-02-17 23:25:17 +01:00
parent 1b4f270544
commit d863278e93
2 changed files with 42 additions and 9 deletions
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36
src/nom.rs
View File

@ -726,6 +726,42 @@ macro_rules! take_until_either_and_leave(
)
);
pub fn be_u8(i: &[u8]) -> IResult<&[u8], u8> {
if i.len() < 1 {
Incomplete(0)
} else {
Done(&i[1..], i[0])
}
}
pub fn be_u16(i: &[u8]) -> IResult<&[u8], u16> {
if i.len() < 2 {
Incomplete(0)
} else {
let res = ((i[0] as u16) << 8) + i[1] as u16;
Done(&i[2..], res)
}
}
pub fn be_u32(i: &[u8]) -> IResult<&[u8], u32> {
if i.len() < 4 {
Incomplete(0)
} else {
let res = ((i[0] as u32) << 24) + ((i[1] as u32) << 16) + ((i[2] as u32) << 8) + i[3] as u32;
Done(&i[4..], res)
}
}
pub fn be_u64(i: &[u8]) -> IResult<&[u8], u64> {
if i.len() < 8 {
Incomplete(0)
} else {
let res = ((i[0] as u64) << 56) + ((i[1] as u64) << 48) + ((i[2] as u64) << 40) + ((i[3] as u64) << 32) +
((i[4] as u64) << 24) + ((i[5] as u64) << 16) + ((i[6] as u64) << 8) + i[7] as u64;
Done(&i[8..], res)
}
}
#[cfg(test)]
mod tests {
use super::*;

15
tests/mp4.rs
View File

@ -1,26 +1,23 @@
#[macro_use]
extern crate nom;
use nom::{HexDisplay,IResult,FlatMap,FlatMapOpt,Functor,Producer,ProducerState,FileProducer};
use nom::{HexDisplay,IResult,FlatMap,FlatMapOpt,Functor,Producer,ProducerState,FileProducer,be_u8,be_u32,be_u64};
use nom::IResult::*;
use std::str;
fn mp4_box(input:&[u8]) -> IResult<&[u8], &[u8]> {
take!(offset_parser 4);
match offset_parser(input) {
Done(i, offset_bytes) => {
let offset:u32 = (offset_bytes[3] as u32) + (offset_bytes[2] as u32) * 0x100 + (offset_bytes[1] as u32) * 0x10000 + (offset_bytes[0] as u32) * 0x1000000;
match be_u32(input) {
Done(i, offset) => {
let sz: usize = offset as usize;
//println!("box size: {} -> {} (input: {})", offset_bytes.to_hex(8), sz, i.len());
if i.len() >= sz - 4 {
return Done(&i[(sz-4)..], &i[0..(sz-4)])
} else {
return Incomplete(1234)
}
},
e => e
}
Error(e) => Error(e),
Incomplete(e) => Incomplete(e)
}
}