--- /dev/null
+#[derive(Debug)]
+pub enum BitReaderMode {
+ BE,
+ LE16,
+ LE32,
+}
+
+#[derive(Debug)]
+pub enum BitReaderError {
+ BitstreamEnd,
+ TooManyBitsRequested,
+}
+
+use self::BitReaderError::*;
+
+type BitReaderResult<T> = Result<T, BitReaderError>;
+
+#[derive(Debug)]
+pub struct BitReader<'a> {
+ cache: u64,
+ bits: u8,
+ pos: usize,
+ end: usize,
+ src: &'a [u8],
+ mode: BitReaderMode,
+}
+
+impl<'a> BitReader<'a> {
+
+ pub fn new(src: &'a [u8], size: usize, mode: BitReaderMode) -> Self {
+ if src.len() < size { panic!("size is less than needed"); }
+ BitReader{ cache: 0, pos: 0, bits: 0, end: size, src: src, mode: mode }
+ }
+
+ pub fn tell(&self) -> usize {
+ self.pos * 8 - (self.bits as usize)
+ }
+
+ pub fn left(&self) -> isize {
+ ((self.end as isize) - (self.pos as isize)) * 8 + (self.bits as isize)
+ }
+
+ fn fill32be(&mut self, src: &[u8]) {
+ let nw = (((src[0] as u32) << 24) |
+ ((src[1] as u32) << 16) |
+ ((src[2] as u32) << 8) |
+ ((src[3] as u32) << 0)) as u64;
+ self.cache |= nw << (32 - self.bits);
+ }
+
+ fn fill32le16(&mut self, src: &[u8], realbits: u8) {
+ let mut nw = (((src[1] as u32) << 24) |
+ ((src[0] as u32) << 16) |
+ ((src[3] as u32) << 8) |
+ ((src[2] as u32) << 0)) as u64;
+ if realbits <= 16 { nw >>= 16; }
+ self.cache |= nw << self.bits;
+ }
+
+ fn fill32le32(&mut self, src: &[u8]) {
+ let nw = (((src[3] as u32) << 24) |
+ ((src[2] as u32) << 16) |
+ ((src[1] as u32) << 8) |
+ ((src[0] as u32) << 0)) as u64;
+ self.cache |= nw << self.bits;
+ }
+
+ fn refill(&mut self) -> BitReaderResult<()> {
+ if self.pos >= self.end { return Err(BitstreamEnd) }
+ while self.bits <= 32 {
+ if self.pos + 4 <= self.end {
+ let buf = &self.src[self.pos..];
+ match self.mode {
+ BitReaderMode::BE => self.fill32be (buf),
+ BitReaderMode::LE16 => self.fill32le16(buf, 32),
+ BitReaderMode::LE32 => self.fill32le32(buf),
+ }
+ self.pos += 4;
+ self.bits += 32;
+ } else {
+ let mut buf: [u8; 4] = [0, 0, 0, 0];
+ let mut newbits: u8 = 0;
+ for i in 0..3 {
+ if self.pos < self.end {
+ buf[i] = self.src[self.pos];
+ self.pos = self.pos + 1;
+ newbits += 8;
+ }
+ }
+ if newbits == 0 { break; }
+ match self.mode {
+ BitReaderMode::BE => self.fill32be (&buf),
+ BitReaderMode::LE16 => self.fill32le16(&buf, newbits),
+ BitReaderMode::LE32 => self.fill32le32(&buf),
+ }
+ self.bits += newbits;
+ }
+ }
+ Ok(())
+ }
+
+ fn read_cache(&mut self, nbits: u8) -> u32 {
+ let res = match self.mode {
+ BitReaderMode::BE => (self.cache as u64) >> (64 - nbits),
+ _ => ((1u64 << nbits) - 1) & self.cache,
+ };
+ res as u32
+ }
+
+ fn skip_cache(&mut self, nbits: u8) {
+ match self.mode {
+ BitReaderMode::BE => self.cache <<= nbits,
+ _ => self.cache >>= nbits,
+ };
+ self.bits -= nbits;
+ }
+
+ fn reset_cache(&mut self) {
+ self.bits = 0;
+ self.cache = 0;
+ }
+
+ pub fn read(&mut self, nbits: u8) -> BitReaderResult<u32> {
+ if nbits > 32 { return Err(TooManyBitsRequested) }
+ if self.bits < nbits {
+ if let Err(err) = self.refill() { return Err(err) }
+ if self.bits < nbits { return Err(BitstreamEnd) }
+ }
+ let res = self.read_cache(nbits);
+ self.skip_cache(nbits);
+ Ok(res as u32)
+ }
+
+ pub fn peek(&mut self, nbits: u8) -> u32 {
+ if nbits > 32 { return 0 }
+ if self.bits < nbits { let _ = self.refill(); }
+ self.read_cache(nbits)
+ }
+
+ pub fn skip(&mut self, nbits: u32) -> BitReaderResult<()> {
+ if self.bits as u32 >= nbits {
+ self.skip_cache(nbits as u8);
+ return Ok(());
+ }
+ let mut skip_bits = nbits - (self.bits as u32);
+ self.reset_cache();
+ self.pos += ((skip_bits / 32) * 4) as usize;
+ skip_bits = skip_bits & 0x1F;
+ self.refill()?;
+ if skip_bits > 0 {
+ self.skip_cache(skip_bits as u8);
+ }
+ Ok(())
+ }
+
+ pub fn seek(&mut self, nbits: u32) -> BitReaderResult<()> {
+ if ((nbits + 7) >> 3) as usize > self.end { return Err(TooManyBitsRequested); }
+ self.reset_cache();
+ self.pos = ((nbits / 32) * 4) as usize;
+ self.skip(nbits & 0x1F)
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use super::*;
+
+ #[test]
+ fn br_works() {
+ const DATA: [u8; 18] = [0b00011011; 18];
+ let src = &DATA;
+ let mut br = BitReader::new(src, src.len(), BitReaderMode::LE16);
+
+ for _ in 0..8 {
+ assert_eq!(br.read(16).unwrap(), 0x1B1B);
+ }
+ }
+}
--- /dev/null
+use std::io::SeekFrom;
+use std::fs::File;
+use std::io::prelude::*;
+
+#[derive(Debug)]
+pub enum ByteIOError {
+ EOF,
+ WrongRange,
+ WrongIOMode,
+ NotImplemented,
+ ReadError,
+ WriteError,
+ SeekError,
+}
+
+type ByteIOResult<T> = Result<T, ByteIOError>;
+
+pub trait ByteIO {
+ fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize>;
+ fn read_byte(&mut self) -> ByteIOResult<u8>;
+ fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<usize>;
+ fn tell(&mut self) -> u64;
+ fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64>;
+ fn is_eof(&mut self) -> bool;
+ fn is_seekable(&mut self) -> bool;
+}
+
+#[allow(dead_code)]
+pub struct ByteReader<'a> {
+ io: &'a mut ByteIO,
+}
+
+pub struct MemoryReader<'a> {
+ buf: &'a [u8],
+ size: usize,
+ pos: usize,
+ do_write: bool,
+}
+
+pub struct FileReader<'a> {
+ file: &'a File,
+ eof: bool,
+}
+
+macro_rules! read_int {
+ ($s: ident, $inttype: ty, $size: expr, $which: ident) => ({
+ let mut buf = [0; $size];
+ try!($s.read_buf(&mut buf));
+ unsafe {
+ Ok((*(buf.as_ptr() as *const $inttype)).$which())
+ }
+ })
+}
+
+impl<'a> ByteReader<'a> {
+ pub fn new(io: &'a mut ByteIO) -> ByteReader { ByteReader { io: io } }
+
+ pub fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
+ self.io.read_buf(buf)
+ }
+
+ pub fn read_byte(&mut self) -> ByteIOResult<u8> {
+ self.io.read_byte()
+ }
+
+ pub fn read_u16be(&mut self) -> ByteIOResult<u16> {
+ read_int!(self, u16, 2, to_be)
+ }
+
+ pub fn read_u24be(&mut self) -> ByteIOResult<u32> {
+ let p16 = self.read_u16be();
+ if let Err(e) = p16 { return Err(e); }
+ let p8 = self.read_byte();
+ if let Err(e) = p8 { return Err(e); }
+ Ok(((p16.unwrap() as u32) << 8) | (p8.unwrap() as u32))
+ }
+
+ pub fn read_u32be(&mut self) -> ByteIOResult<u32> {
+ read_int!(self, u32, 4, to_be)
+ }
+
+ pub fn read_u64be(&mut self) -> ByteIOResult<u64> {
+ read_int!(self, u64, 8, to_be)
+ }
+
+ pub fn read_u16le(&mut self) -> ByteIOResult<u16> {
+ read_int!(self, u16, 2, to_le)
+ }
+
+ pub fn read_u24le(&mut self) -> ByteIOResult<u32> {
+ let p8 = self.read_byte();
+ if let Err(e) = p8 { return Err(e); }
+ let p16 = self.read_u16le();
+ if let Err(e) = p16 { return Err(e); }
+ Ok(((p16.unwrap() as u32) << 8) | (p8.unwrap() as u32))
+ }
+
+ pub fn read_u32le(&mut self) -> ByteIOResult<u32> {
+ read_int!(self, u32, 4, to_le)
+ }
+
+ pub fn read_u64le(&mut self) -> ByteIOResult<u64> {
+ read_int!(self, u64, 8, to_le)
+ }
+
+ pub fn read_skip(&mut self, len: usize) -> ByteIOResult<u64> {
+ if self.io.is_seekable() {
+ self.io.seek(SeekFrom::Current(len as i64))?;
+ } else {
+ let mut ssize = len;
+ let mut buf : [u8; 16] = [0; 16];
+ let mut bref = &mut buf;
+ while ssize > bref.len() {
+ self.io.read_buf(bref)?;
+ ssize -= bref.len();
+ }
+ while ssize > 0 {
+ self.io.read_byte()?;
+ ssize = ssize - 1;
+ }
+ }
+ Ok(self.tell())
+ }
+
+ pub fn tell(&mut self) -> u64 {
+ self.io.tell()
+ }
+
+ pub fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
+ self.io.seek(pos)
+ }
+
+ pub fn is_eof(&mut self) -> bool {
+ self.io.is_eof()
+ }
+}
+
+impl<'a> MemoryReader<'a> {
+
+ pub fn new_read(buf: &'a [u8]) -> Self {
+ MemoryReader { buf: buf, size: buf.len(), pos: 0, do_write: false }
+ }
+
+ fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
+ if pos < 0 || (pos as usize) > self.size {
+ return Err(ByteIOError::WrongRange)
+ }
+ self.pos = pos as usize;
+ Ok(pos as u64)
+ }
+
+ fn check_read_perm(&self) -> ByteIOResult<()> {
+ if self.do_write {
+ Err(ByteIOError::WrongIOMode)
+ } else {
+ Ok(())
+ }
+ }
+
+ fn check_write_perm(&self) -> ByteIOResult<()> {
+ if !self.do_write {
+ Err(ByteIOError::WrongIOMode)
+ } else {
+ Ok(())
+ }
+ }
+}
+
+impl<'a> ByteIO for MemoryReader<'a> {
+ fn read_byte(&mut self) -> ByteIOResult<u8> {
+ self.check_read_perm()?;
+ if self.is_eof() { return Err(ByteIOError::EOF); }
+ let res = self.buf[self.pos];
+ self.pos = self.pos + 1;
+ Ok(res)
+ }
+
+ fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
+ self.check_read_perm()?;
+ let copy_size = if self.size - self.pos < buf.len() { self.size } else { buf.len() };
+ if copy_size == 0 { return Err(ByteIOError::EOF); }
+ for i in 0..copy_size {
+ buf[i] = self.buf[self.pos + i];
+ }
+ self.pos += copy_size;
+ Ok(copy_size)
+ }
+
+ #[allow(unused_variables)]
+ fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<usize> {
+ self.check_write_perm()?;
+ Err(ByteIOError::NotImplemented)
+ }
+
+ fn tell(&mut self) -> u64 {
+ self.pos as u64
+ }
+
+ fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
+ let cur_pos = self.pos as i64;
+ let cur_size = self.size as i64;
+ match pos {
+ SeekFrom::Start(x) => self.real_seek(x as i64),
+ SeekFrom::Current(x) => self.real_seek(cur_pos + x),
+ SeekFrom::End(x) => self.real_seek(cur_size + x),
+ }
+ }
+
+ fn is_eof(&mut self) -> bool {
+ self.pos >= self.size
+ }
+
+ fn is_seekable(&mut self) -> bool {
+ true
+ }
+}
+
+impl<'a> FileReader<'a> {
+
+ pub fn new_read(file: &'a mut File) -> Self {
+ FileReader { file: file, eof : false }
+ }
+}
+
+impl<'a> ByteIO for FileReader<'a> {
+ fn read_byte(&mut self) -> ByteIOResult<u8> {
+ let mut byte : [u8; 1] = [0];
+ let err = self.file.read(&mut byte);
+ if let Err(_) = err { return Err(ByteIOError::ReadError); }
+ let sz = err.unwrap();
+ if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
+ Ok (byte[0])
+ }
+
+ fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
+ let res = self.file.read(buf);
+ if let Err(_) = res { return Err(ByteIOError::ReadError); }
+ let sz = res.unwrap();
+ if sz < buf.len() { self.eof = true; }
+ Ok(sz)
+ }
+
+ #[allow(unused_variables)]
+ fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<usize> {
+ Err(ByteIOError::NotImplemented)
+ }
+
+ fn tell(&mut self) -> u64 {
+ self.file.seek(SeekFrom::Current(0)).unwrap()
+ }
+
+ fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
+ let res = self.file.seek(pos);
+ match res {
+ Ok(r) => Ok(r),
+ Err(_) => Err(ByteIOError::SeekError),
+ }
+ }
+
+ fn is_eof(&mut self) -> bool {
+ self.eof
+ }
+
+ fn is_seekable(&mut self) -> bool {
+ true
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use super::*;
+ use std::fs::File;
+
+ #[test]
+ fn test_read() {
+ //const DATA : &'static [u8] = include_bytes!("../../assets/file");
+ let buf: [u8; 64] = [1; 64];
+ let mut mr = MemoryReader::new_read(&buf);
+ let mut reader = ByteReader::new(&mut mr);
+ assert_eq!(reader.read_byte().unwrap(), 0x01u8);
+ assert_eq!(reader.read_u16le().unwrap(), 0x0101u16);
+ assert_eq!(reader.read_u24le().unwrap(), 0x010101u32);
+ assert_eq!(reader.read_u32le().unwrap(), 0x01010101u32);
+ assert_eq!(reader.read_u64le().unwrap(), 0x0101010101010101u64);
+ let mut file = File::open("assets/MaoMacha.asx").unwrap();
+ let mut fr = FileReader::new_read(&mut file);
+ let mut br2 = ByteReader::new(&mut fr);
+ assert_eq!(br2.read_byte().unwrap(), 0x30);
+ assert_eq!(br2.read_u24be().unwrap(), 0x26B275);
+ assert_eq!(br2.read_u24le().unwrap(), 0xCF668E);
+ assert_eq!(br2.read_u32be().unwrap(), 0x11A6D900);
+ assert_eq!(br2.read_u32le().unwrap(), 0xCE6200AA);
+ }
+ #[test]
+ fn test_write() {
+ }
+}
projects / nihav.git / commitdiff