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use std::io::{Read, Write};
use crate::error::{DecodeError, EncodeError};
use byteorder::{ReadBytesExt, BigEndian, WriteBytesExt};
use std::convert::TryFrom;
use crate::ll::marker::Marker;
pub fn read_size_8<T: Read>(reader: &mut T) -> Result<usize, DecodeError> {
let u = reader.read_u8()?;
TryFrom::try_from(u).or(Err(DecodeError::CannotReadSizeInfo))
}
pub fn read_size_16<T: Read>(reader: &mut T) -> Result<usize, DecodeError> {
let u = reader.read_u16::<BigEndian>()?;
TryFrom::try_from(u).or(Err(DecodeError::CannotReadSizeInfo))
}
pub fn read_size_32<T: Read>(reader: &mut T) -> Result<usize, DecodeError> {
let u = reader.read_i32::<BigEndian>()?;
TryFrom::try_from(u).or(Err(DecodeError::CannotReadSizeInfo))
}
pub fn read_dict_size<T: Read>(marker: Marker, reader: &mut T) -> Result<usize, DecodeError> {
match marker {
Marker::TinyDictionary(u) => Ok(u),
Marker::Dictionary8 => read_size_8(reader),
Marker::Dictionary16 => read_size_16(reader),
Marker::Dictionary32 => read_size_32(reader),
_ => Err(DecodeError::UnexpectedMarker(marker))
}
}
pub fn read_list_size<T: Read>(marker: Marker, reader: &mut T) -> Result<usize, DecodeError> {
match marker {
Marker::TinyList(u) => Ok(u),
Marker::List8 => read_size_8(reader),
Marker::List16 => read_size_16(reader),
Marker::List32 => read_size_32(reader),
_ => Err(DecodeError::UnexpectedMarker(marker))
}
}
pub fn read_string_size<T: Read>(marker: Marker, reader: &mut T) -> Result<usize, DecodeError> {
match marker {
Marker::TinyString(u) => Ok(u),
Marker::String8 => read_size_8(reader),
Marker::String16 => read_size_16(reader),
Marker::String32 => read_size_32(reader),
_ => Err(DecodeError::UnexpectedMarker(marker))
}
}
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum Length {
Tiny(u8),
Bit8(u8),
Bit16(u16),
Bit32(i32),
}
impl Length {
pub fn marker(self, tiny_marker: fn(usize) -> Marker, marker8: Marker, marker16: Marker, marker32: Marker) -> Marker {
match self {
Length::Tiny(u) => tiny_marker(u as usize),
Length::Bit8(_) => marker8,
Length::Bit16(_) => marker16,
Length::Bit32(_) => marker32,
}
}
pub fn from_usize(size: usize) -> Option<Length> {
if size <= 0x0F {
Some(Length::Tiny(size as u8))
} else if let Ok(i) = TryFrom::try_from(size) {
Some(Length::Bit8(i))
} else if let Ok(i) = TryFrom::try_from(size) {
Some(Length::Bit16(i))
} else if let Ok(i) = TryFrom::try_from(size) {
Some(Length::Bit32(i))
} else {
None
}
}
pub fn into_usize(self) -> usize {
match self {
Length::Tiny(u) => u as usize,
Length::Bit8(u) => u as usize,
Length::Bit16(u) => u as usize,
Length::Bit32(i) =>
TryFrom::try_from(i).expect(&format!("Cannot read usize out of {}", i))
}
}
pub fn encode<T: Write>(self, mut writer: T) -> Result<usize, EncodeError> {
match self {
Length::Tiny(_) => Ok(0),
Length::Bit8(size) => {
writer.write_u8(size)?;
Ok(1)
},
Length::Bit16(size) => {
writer.write_u16::<BigEndian>(size)?;
Ok(2)
},
Length::Bit32(size) => {
writer.write_i32::<BigEndian>(size)?;
Ok(4)
}
}
}
}