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use std::fs::File;
use std::io::{BufReader, BufWriter};
use std::io::{Read, Write};
use std::io::{ErrorKind, Seek, SeekFrom};
enum AccessMode {
Read(BufReader<File>),
Write(BufWriter<File>),
None,
}
impl AccessMode {
pub fn unwrap(self) -> File {
match self {
Self::Read(reader) => reader.into_inner(),
Self::Write(writer) => writer.into_inner().unwrap(),
Self::None => unreachable!(),
}
}
}
impl Default for AccessMode {
fn default() -> Self {
Self::None
}
}
pub struct BufferedFile {
file: AccessMode,
}
impl BufferedFile {
pub fn new(file: File) -> Self {
Self {
file: AccessMode::Read(BufReader::new(file)),
}
}
pub fn read_byte(&mut self) -> u8 {
let mut buffer = [0u8; 1];
let read_result = match &mut self.file {
AccessMode::Read(reader) => reader.read_exact(&mut buffer),
AccessMode::Write(writer) => {
let address = writer.stream_position().unwrap();
let file = std::mem::take(&mut self.file).unwrap();
let mut reader = BufReader::new(file);
reader.seek(SeekFrom::Start(address)).unwrap();
let read_result = reader.read_exact(&mut buffer);
self.file = AccessMode::Read(reader);
read_result
}
AccessMode::None => unreachable!(),
};
match read_result {
Ok(_) => buffer[0],
Err(error) => match error.kind() {
ErrorKind::UnexpectedEof => 0,
_ => panic!("{error:?}"),
}
}
}
pub fn write_byte(&mut self, byte: u8) {
let mut buffer = [byte; 1];
let write_result = match &mut self.file {
AccessMode::Write(writer) => writer.write_all(&mut buffer),
AccessMode::Read(reader) => {
let address = reader.stream_position().unwrap();
let file = std::mem::take(&mut self.file).unwrap();
let mut writer = BufWriter::new(file);
writer.seek(SeekFrom::Start(address)).unwrap();
let write_result = writer.write_all(&mut buffer);
self.file = AccessMode::Write(writer);
write_result
}
AccessMode::None => unreachable!(),
};
write_result.unwrap();
}
pub fn pointer(&mut self) -> u32 {
let position = match &mut self.file {
AccessMode::Read(reader) => reader.stream_position(),
AccessMode::Write(writer) => writer.stream_position(),
AccessMode::None => unreachable!(),
};
u32::try_from(position.unwrap()).unwrap_or(u32::MAX)
}
pub fn set_pointer(&mut self, pointer: u32) {
let position = SeekFrom::Start(pointer as u64);
match &mut self.file {
AccessMode::Read(reader) => reader.seek(position).unwrap(),
AccessMode::Write(writer) => writer.seek(position).unwrap(),
AccessMode::None => unreachable!(),
};
}
pub fn length(&mut self) -> u32 {
let length = match &mut self.file {
AccessMode::Read(reader) => reader.stream_len(),
AccessMode::Write(writer) => writer.stream_len(),
AccessMode::None => unreachable!(),
};
u32::try_from(length.unwrap()).unwrap_or(u32::MAX)
}
pub fn set_length(&mut self, length: u32) {
match &mut self.file {
AccessMode::Read(_) => {
let file = std::mem::take(&mut self.file).unwrap();
file.set_len(length as u64).unwrap();
self.file = AccessMode::Read(BufReader::new(file));
}
AccessMode::Write(_) => {
let file = std::mem::take(&mut self.file).unwrap();
file.set_len(length as u64).unwrap();
self.file = AccessMode::Read(BufReader::new(file));
}
AccessMode::None => unreachable!(),
};
}
}
|
