nihav-core/src/io/byteio.rs

   1 //! Bytestream reading/writing functionality.
   2 pub use std::io::SeekFrom;
   3 use std::io::prelude::*;
   4 use std::ptr;
   5
   6 /// A list specifying general bytestream reading and writing errors.
   7 #[derive(Debug)]
   8 pub enum ByteIOError {
   9     /// End of stream.
  10     EOF,
  11     /// Wrong seek position was provided.
  12     WrongRange,
  13     /// Tried to call read() on bytestream writer or write() on bytestream reader.
  14     WrongIOMode,
  15     /// Functionality is not implemented.
  16     NotImplemented,
  17     /// Read error.
  18     ReadError,
  19     /// Write error.
  20     WriteError,
  21     /// Seeking failed.
  22     SeekError,
  23 }
  24
  25 /// A specialised `Result` type for bytestream operations.
  26 pub type ByteIOResult<T> = Result<T, ByteIOError>;
  27
  28 /// Common trait for bytestream operations.
  29 pub trait ByteIO {
  30     /// Reads data into provided buffer. Fails if it cannot fill whole buffer.
  31     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize>;
  32     /// Reads data into provided buffer. Partial read is treated as success.
  33     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize>;
  34     /// Reads data into provided buffer but does not advance read position.
  35     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize>;
  36     /// Reads single byte from the stream.
  37     fn read_byte(&mut self) -> ByteIOResult<u8>;
  38     /// Returns the next byte value in the stream without advancing read position.
  39     fn peek_byte(&mut self) -> ByteIOResult<u8>;
  40     /// Writes buffer to the stream.
  41     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()>;
  42     /// Returns current read or write position.
  43     fn tell(&mut self) -> u64;
  44     /// Seeks to the provided position.
  45     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64>;
  46     /// Tells whether this is end of stream.
  47     fn is_eof(&self) -> bool;
  48     /// Reports whether stream is seekable or not.
  49     fn is_seekable(&mut self) -> bool;
  50     /// Returns stream size or -1 if it is not known.
  51     fn size(&mut self) -> i64;
  52     /// Flushes output if possible.
  53     fn flush(&mut self) -> ByteIOResult<()>;
  54 }
  55
  56 /// High-level bytestream reader.
  57 ///
  58 /// User is supposed to create some reader implementing [`ByteIO`] trait e.g. [`MemoryReader`] and use it to create `ByteReader` which can be used for reading e.g. various integer types.
  59 ///
  60 /// # Examples
  61 ///
  62 /// ````
  63 /// use nihav_core::io::byteio::{MemoryReader,ByteReader};
  64 /// # use nihav_core::io::byteio::ByteIOResult;
  65 ///
  66 /// # fn foo() -> ByteIOResult<()> {
  67 /// let memory: [u8; 4] = [ 0, 42, 42, 0 ];
  68 /// let mut mr = MemoryReader::new_read(&memory);
  69 /// let mut br = ByteReader::new(&mut mr);
  70 /// let val = br.read_u16be()?; // read 16-bit big-endian integer, should be 42
  71 /// let val = br.read_u16le()?; // read 16-bit little-endian integer, should be 42 as well
  72 /// # Ok(())
  73 /// # }
  74 /// ````
  75 ///
  76 /// [`ByteIO`]: ./trait.ByteIO.html
  77 /// [`MemoryReader`]: ./struct.MemoryReader.html
  78 #[allow(dead_code)]
  79 pub struct ByteReader<'a> {
  80     io: &'a mut dyn ByteIO,
  81 }
  82
  83 /// Bytestream reader from memory.
  84 pub struct MemoryReader<'a> {
  85     buf:      &'a [u8],
  86     pos:      usize,
  87 }
  88
  89 /// Bytestream reader from anything implementing `std::io::Read` and `std::io::Seek`.
  90 pub struct FileReader<T: Read+Seek> {
  91     file:     Box<T>,
  92     eof:      bool,
  93 }
  94
  95 /// Bytestream reader from anything implementing `std::io::Read` and `std::io::Seek` that operates only on a part of the input.
  96 pub struct BoundedFileReader<T: Read+Seek> {
  97     file:     Box<T>,
  98     start:    u64,
  99     end:      Option<u64>,
 100     eof:      bool,
 101 }
 102
 103 macro_rules! read_int {
 104     ($s: ident, $inttype: ty, $size: expr, $which: ident) => ({
 105         unsafe {
 106             let mut buf: $inttype = 0;
 107             $s.read_buf(&mut *(&mut buf as *mut $inttype as *mut [u8; $size]))?;
 108             Ok(buf.$which())
 109         }
 110     })
 111 }
 112
 113 macro_rules! peek_int {
 114     ($s: ident, $inttype: ty, $size: expr, $which: ident) => ({
 115         unsafe {
 116             let mut buf: $inttype = 0;
 117             $s.peek_buf(&mut *(&mut buf as *mut $inttype as *mut [u8; $size]))?;
 118             Ok(buf.$which())
 119         }
 120     })
 121 }
 122
 123 macro_rules! read_int_func {
 124     ($s: ident, $inttype: ty, $size: expr, $which: ident) => {
 125 /// Reads integer of certain size and endianness.
 126         pub fn $s(src: &[u8]) -> ByteIOResult<$inttype> {
 127             if src.len() < $size { return Err(ByteIOError::ReadError); }
 128             unsafe {
 129                 let mut buf: $inttype = 0;
 130                 ptr::copy_nonoverlapping(src.as_ptr(), &mut buf as *mut $inttype as *mut u8, std::mem::size_of::<$inttype>());
 131                 Ok(buf.$which())
 132             }
 133         }
 134     }
 135 }
 136
 137 read_int_func!(read_u16be, u16, 2, to_be);
 138 read_int_func!(read_u16le, u16, 2, to_le);
 139 read_int_func!(read_u32be, u32, 4, to_be);
 140 read_int_func!(read_u32le, u32, 4, to_le);
 141 read_int_func!(read_u64be, u64, 8, to_be);
 142 read_int_func!(read_u64le, u64, 8, to_le);
 143
 144 /// Reads 24-bit big-endian integer.
 145 ///
 146 /// # Example
 147 ///
 148 /// ````
 149 /// use nihav_core::io::byteio::read_u24be;
 150 /// # use nihav_core::io::byteio::ByteIOResult;
 151 ///
 152 /// # fn foo() -> ByteIOResult<()> {
 153 /// let src: [u8; 3] = [ 1, 2, 3];
 154 /// let value = read_u24be(&src)?; // should return 0x010203
 155 /// # Ok(())
 156 /// # }
 157 /// ````
 158 pub fn read_u24be(src: &[u8]) -> ByteIOResult<u32> {
 159     if src.len() < 3 { return Err(ByteIOError::ReadError); }
 160     Ok((u32::from(src[0]) << 16) | (u32::from(src[1]) << 8) | u32::from(src[2]))
 161 }
 162 /// Reads 24-bit little-endian integer.
 163 pub fn read_u24le(src: &[u8]) -> ByteIOResult<u32> {
 164     if src.len() < 3 { return Err(ByteIOError::ReadError); }
 165     Ok((u32::from(src[2]) << 16) | (u32::from(src[1]) << 8) | u32::from(src[0]))
 166 }
 167 /// Reads 32-bit big-endian floating point number.
 168 pub fn read_f32be(src: &[u8]) -> ByteIOResult<f32> { Ok(f32::from_bits(read_u32be(src)?)) }
 169 /// Reads 32-bit little-endian floating point number.
 170 pub fn read_f32le(src: &[u8]) -> ByteIOResult<f32> { Ok(f32::from_bits(read_u32le(src)?)) }
 171 /// Reads 64-bit big-endian floating point number.
 172 pub fn read_f64be(src: &[u8]) -> ByteIOResult<f64> { Ok(f64::from_bits(read_u64be(src)?)) }
 173 /// Reads 64-bit little-endian floating point number.
 174 pub fn read_f64le(src: &[u8]) -> ByteIOResult<f64> { Ok(f64::from_bits(read_u64le(src)?)) }
 175
 176 macro_rules! write_int_func {
 177     ($s: ident, $inttype: ty, $size: expr, $which: ident) => {
 178 /// Writes integer of certain size and endianness into byte buffer.
 179         pub fn $s(dst: &mut [u8], val: $inttype) -> ByteIOResult<()> {
 180             if dst.len() < $size { return Err(ByteIOError::WriteError); }
 181             unsafe {
 182                 let val = val.$which();
 183                 ptr::copy_nonoverlapping(&val as *const $inttype as *const u8, dst.as_mut_ptr(), std::mem::size_of::<$inttype>());
 184             }
 185             Ok(())
 186         }
 187     }
 188 }
 189
 190 write_int_func!(write_u16be, u16, 2, to_be);
 191 write_int_func!(write_u16le, u16, 2, to_le);
 192 write_int_func!(write_u32be, u32, 4, to_be);
 193 write_int_func!(write_u32le, u32, 4, to_le);
 194 write_int_func!(write_u64be, u64, 8, to_be);
 195 write_int_func!(write_u64le, u64, 8, to_le);
 196
 197 /// Writes 24-bit big-endian integer to the provided buffer.
 198 ///
 199 /// # Example
 200 ///
 201 /// ````
 202 /// use nihav_core::io::byteio::write_u24be;
 203 /// # use nihav_core::io::byteio::ByteIOResult;
 204 ///
 205 /// # fn foo() -> ByteIOResult<()> {
 206 /// let mut dst = [0u8; 3];
 207 /// write_u24be(&mut dst, 0x010203)?;
 208 /// // dst should contain [ 1, 2, 3] now
 209 /// # Ok(())
 210 /// # }
 211 /// ````
 212 #[allow(clippy::identity_op)]
 213 pub fn write_u24be(dst: &mut [u8], val: u32) -> ByteIOResult<()> {
 214     if dst.len() < 3 { return Err(ByteIOError::WriteError); }
 215     dst[0] = (val >> 16) as u8;
 216     dst[1] = (val >>  8) as u8;
 217     dst[2] = (val >>  0) as u8;
 218     Ok(())
 219 }
 220 /// Writes 24-bit little-endian integer to the provided buffer.
 221 #[allow(clippy::identity_op)]
 222 pub fn write_u24le(dst: &mut [u8], val: u32) -> ByteIOResult<()> {
 223     if dst.len() < 3 { return Err(ByteIOError::WriteError); }
 224     dst[0] = (val >>  0) as u8;
 225     dst[1] = (val >>  8) as u8;
 226     dst[2] = (val >> 16) as u8;
 227     Ok(())
 228 }
 229 /// Writes 32-bit big-endian floating point number to the provided buffer.
 230 pub fn write_f32be(dst: &mut [u8], val: f32) -> ByteIOResult<()> { write_u32be(dst, val.to_bits()) }
 231 /// Writes 32-bit little-endian floating point number to the provided buffer.
 232 pub fn write_f32le(dst: &mut [u8], val: f32) -> ByteIOResult<()> { write_u32le(dst, val.to_bits()) }
 233 /// Writes 64-bit big-endian floating point number to the provided buffer.
 234 pub fn write_f64be(dst: &mut [u8], val: f64) -> ByteIOResult<()> { write_u64be(dst, val.to_bits()) }
 235 /// Writes 64-bit little-endian floating point number to the provided buffer.
 236 pub fn write_f64le(dst: &mut [u8], val: f64) -> ByteIOResult<()> { write_u64le(dst, val.to_bits()) }
 237
 238 impl<'a> ByteReader<'a> {
 239     /// Constructs a new instance of bytestream reader.
 240     ///
 241     /// # Examples
 242     ///
 243     /// ````
 244     /// use nihav_core::io::byteio::{MemoryReader,ByteReader};
 245     /// # use nihav_core::io::byteio::ByteIOResult;
 246     ///
 247     /// # fn foo() -> ByteIOResult<()> {
 248     /// let memory: [u8; 4] = [ 0, 42, 42, 0 ];
 249     /// let mut mr = MemoryReader::new_read(&memory);
 250     /// let mut br = ByteReader::new(&mut mr);
 251     /// # Ok(())
 252     /// # }
 253     /// ````
 254     pub fn new(io: &'a mut dyn ByteIO) -> Self { ByteReader { io } }
 255
 256     /// Reads data into provided buffer. Partial read is treated as success.
 257     pub fn read_buf(&mut self, buf: &mut [u8])  -> ByteIOResult<usize> {
 258         self.io.read_buf(buf)
 259     }
 260
 261     /// Reads data into provided buffer. Partial read is treated as success.
 262     pub fn read_buf_some(&mut self, buf: &mut [u8])  -> ByteIOResult<usize> {
 263         self.io.read_buf_some(buf)
 264     }
 265
 266     /// Reads data into provided buffer but does not advance read position.
 267     pub fn peek_buf(&mut self, buf: &mut [u8])  -> ByteIOResult<usize> {
 268         self.io.peek_buf(buf)
 269     }
 270
 271     /// Reads single byte from the stream.
 272     pub fn read_byte(&mut self) -> ByteIOResult<u8> {
 273         self.io.read_byte()
 274     }
 275
 276     /// Returns the next byte value in the stream without advancing read position.
 277     pub fn peek_byte(&mut self) -> ByteIOResult<u8> {
 278         self.io.peek_byte()
 279     }
 280
 281     /// Reads four-byte array from the stream.
 282     pub fn read_tag(&mut self)  -> ByteIOResult<[u8; 4]> {
 283         let mut buf = [0u8; 4];
 284         self.io.read_buf(&mut buf)?;
 285         Ok(buf)
 286     }
 287
 288     /// Reads four-byte array from the stream without advancing read position.
 289     pub fn peek_tag(&mut self)  -> ByteIOResult<[u8; 4]> {
 290         let mut buf = [0u8; 4];
 291         self.io.peek_buf(&mut buf)?;
 292         Ok(buf)
 293     }
 294
 295     /// Reads 16-bit big-endian integer from the stream.
 296     pub fn read_u16be(&mut self) -> ByteIOResult<u16> {
 297         read_int!(self, u16, 2, to_be)
 298     }
 299
 300     /// Reads 16-bit big-endian integer from the stream without advancing read position.
 301     pub fn peek_u16be(&mut self) -> ByteIOResult<u16> {
 302         peek_int!(self, u16, 2, to_be)
 303     }
 304
 305     /// Reads 24-bit big-endian integer from the stream.
 306     pub fn read_u24be(&mut self) -> ByteIOResult<u32> {
 307         let p16 = self.read_u16be()?;
 308         let p8 = self.read_byte()?;
 309         Ok((u32::from(p16) << 8) | u32::from(p8))
 310     }
 311
 312     /// Reads 24-bit big-endian integer from the stream without advancing read position.
 313     pub fn peek_u24be(&mut self) -> ByteIOResult<u32> {
 314         let mut src: [u8; 3] = [0; 3];
 315         self.peek_buf(&mut src)?;
 316         Ok((u32::from(src[0]) << 16) | (u32::from(src[1]) << 8) | u32::from(src[2]))
 317     }
 318
 319     /// Reads 32-bit big-endian integer from the stream.
 320     pub fn read_u32be(&mut self) -> ByteIOResult<u32> {
 321         read_int!(self, u32, 4, to_be)
 322     }
 323
 324     /// Reads 32-bit big-endian integer from the stream without advancing read position.
 325     pub fn peek_u32be(&mut self) -> ByteIOResult<u32> {
 326         peek_int!(self, u32, 4, to_be)
 327     }
 328
 329     /// Reads 64-bit big-endian integer from the stream.
 330     pub fn read_u64be(&mut self) -> ByteIOResult<u64> {
 331         read_int!(self, u64, 8, to_be)
 332     }
 333
 334     /// Reads 64-bit big-endian integer from the stream without advancing read position.
 335     pub fn peek_u64be(&mut self) -> ByteIOResult<u64> {
 336         peek_int!(self, u64, 8, to_be)
 337     }
 338
 339     /// Reads 32-bit big-endian floating point number from the stream.
 340     pub fn read_f32be(&mut self) -> ByteIOResult<f32> {
 341         Ok(f32::from_bits(self.read_u32be()?))
 342     }
 343
 344     /// Reads 32-bit big-endian floating point number from the stream without advancing read position.
 345     pub fn peek_f32be(&mut self) -> ByteIOResult<f32> {
 346         Ok(f32::from_bits(self.peek_u32be()?))
 347     }
 348
 349     /// Reads 64-bit big-endian floating point number from the stream.
 350     pub fn read_f64be(&mut self) -> ByteIOResult<f64> {
 351         Ok(f64::from_bits(self.read_u64be()?))
 352     }
 353
 354     /// Reads 64-bit big-endian floating point number from the stream without advancing read position.
 355     pub fn peek_f64be(&mut self) -> ByteIOResult<f64> {
 356         Ok(f64::from_bits(self.peek_u64be()?))
 357     }
 358
 359     /// Reads 16-bit little-endian integer from the stream.
 360     pub fn read_u16le(&mut self) -> ByteIOResult<u16> {
 361         read_int!(self, u16, 2, to_le)
 362     }
 363
 364     /// Reads 16-bit little-endian integer from the stream without advancing read position.
 365     pub fn peek_u16le(&mut self) -> ByteIOResult<u16> {
 366         peek_int!(self, u16, 2, to_le)
 367     }
 368
 369     /// Reads 24-bit little-endian integer from the stream.
 370     pub fn read_u24le(&mut self) -> ByteIOResult<u32> {
 371         let p8 = self.read_byte()?;
 372         let p16 = self.read_u16le()?;
 373         Ok((u32::from(p16) << 8) | u32::from(p8))
 374     }
 375
 376     /// Reads 24-bit little-endian integer from the stream without advancing read position.
 377     pub fn peek_u24le(&mut self) -> ByteIOResult<u32> {
 378         let mut src: [u8; 3] = [0; 3];
 379         self.peek_buf(&mut src)?;
 380         Ok(u32::from(src[0]) | (u32::from(src[1]) << 8) | (u32::from(src[2]) << 16))
 381     }
 382
 383     /// Reads 32-bit little-endian integer from the stream.
 384     pub fn read_u32le(&mut self) -> ByteIOResult<u32> {
 385         read_int!(self, u32, 4, to_le)
 386     }
 387
 388     /// Reads 32-bit little-endian integer from the stream without advancing read position.
 389     pub fn peek_u32le(&mut self) -> ByteIOResult<u32> {
 390         peek_int!(self, u32, 4, to_le)
 391     }
 392
 393     /// Reads 64-bit little-endian integer from the stream.
 394     pub fn read_u64le(&mut self) -> ByteIOResult<u64> {
 395         read_int!(self, u64, 8, to_le)
 396     }
 397
 398     /// Reads 64-bit little-endian integer from the stream without advancing read position.
 399     pub fn peek_u64le(&mut self) -> ByteIOResult<u64> {
 400         peek_int!(self, u64, 8, to_le)
 401     }
 402
 403     /// Reads 32-bit little-endian floating point number from the stream.
 404     pub fn read_f32le(&mut self) -> ByteIOResult<f32> {
 405         Ok(f32::from_bits(self.read_u32le()?))
 406     }
 407
 408     /// Reads 32-bit little-endian floating point number from the stream without advancing read position.
 409     pub fn peek_f32le(&mut self) -> ByteIOResult<f32> {
 410         Ok(f32::from_bits(self.peek_u32le()?))
 411     }
 412
 413     /// Reads 64-bit little-endian floating point number from the stream.
 414     pub fn read_f64le(&mut self) -> ByteIOResult<f64> {
 415         Ok(f64::from_bits(self.read_u64le()?))
 416     }
 417
 418     /// Reads 64-bit little-endian floating point number from the stream without advancing read position.
 419     pub fn peek_f64le(&mut self) -> ByteIOResult<f64> {
 420         Ok(f64::from_bits(self.peek_u64le()?))
 421     }
 422
 423     /// Skips requested number of bytes.
 424     pub fn read_skip(&mut self, len: usize) -> ByteIOResult<()> {
 425         if self.io.is_seekable() {
 426             self.io.seek(SeekFrom::Current(len as i64))?;
 427         } else {
 428             let mut ssize = len;
 429             let mut buf : [u8; 16] = [0; 16];
 430             let bref = &mut buf;
 431             while ssize > bref.len() {
 432                 self.io.read_buf(bref)?;
 433                 ssize -= bref.len();
 434             }
 435             while ssize > 0 {
 436                 self.io.read_byte()?;
 437                 ssize -= 1;
 438             }
 439         }
 440         Ok(())
 441     }
 442
 443     /// Returns current read position.
 444     pub fn tell(&mut self) -> u64 {
 445         self.io.tell()
 446     }
 447
 448     /// Seeks to the provided position.
 449     pub fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 450         self.io.seek(pos)
 451     }
 452
 453     /// Tells whether this is end of stream.
 454     pub fn is_eof(&self) -> bool {
 455         self.io.is_eof()
 456     }
 457
 458     /// Returns stream size or -1 if it is not known.
 459     pub fn size(&mut self) -> i64 {
 460         self.io.size()
 461     }
 462
 463     /// Reports number of bytes left in the stream.
 464     pub fn left(&mut self) -> i64 {
 465         let size = self.io.size();
 466         if size == -1 { return -1; }
 467         size - (self.io.tell() as i64)
 468     }
 469 }
 470
 471 impl<'a> MemoryReader<'a> {
 472     /// Constructs a new instance of `MemoryReader`.
 473     pub fn new_read(buf: &'a [u8]) -> Self {
 474         MemoryReader { buf, pos: 0 }
 475     }
 476
 477     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
 478         if pos < 0 || (pos as usize) > self.buf.len() {
 479             return Err(ByteIOError::WrongRange);
 480         }
 481         self.pos = pos as usize;
 482         Ok(pos as u64)
 483     }
 484 }
 485
 486 impl<'a> ByteIO for MemoryReader<'a> {
 487     fn read_byte(&mut self) -> ByteIOResult<u8> {
 488         if self.is_eof() { return Err(ByteIOError::EOF); }
 489         let res = self.buf[self.pos];
 490         self.pos += 1;
 491         Ok(res)
 492     }
 493
 494     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 495         if self.is_eof() { return Err(ByteIOError::EOF); }
 496         Ok(self.buf[self.pos])
 497     }
 498
 499     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 500         let copy_size = if self.buf.len() - self.pos < buf.len() { self.buf.len() - self.pos } else { buf.len() };
 501         if copy_size == 0 { return Err(ByteIOError::EOF); }
 502         let dst = &mut buf[0..copy_size];
 503         dst.copy_from_slice(&self.buf[self.pos..][..copy_size]);
 504         Ok(copy_size)
 505     }
 506
 507     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 508         let read_size = self.peek_buf(buf)?;
 509         if read_size < buf.len() { return Err(ByteIOError::EOF); }
 510         self.pos += read_size;
 511         Ok(read_size)
 512     }
 513
 514     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 515         let read_size = self.peek_buf(buf)?;
 516         self.pos += read_size;
 517         Ok(read_size)
 518     }
 519
 520     #[allow(unused_variables)]
 521     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 522         Err(ByteIOError::NotImplemented)
 523     }
 524
 525     fn tell(&mut self) -> u64 {
 526         self.pos as u64
 527     }
 528
 529     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 530         let cur_pos  = self.pos       as i64;
 531         let cur_size = self.buf.len() as i64;
 532         match pos {
 533             SeekFrom::Start(x)   => self.real_seek(x as i64),
 534             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
 535             SeekFrom::End(x)     => self.real_seek(cur_size + x),
 536         }
 537     }
 538
 539     fn is_eof(&self) -> bool {
 540         self.pos >= self.buf.len()
 541     }
 542
 543     fn is_seekable(&mut self) -> bool {
 544         true
 545     }
 546
 547     fn size(&mut self) -> i64 {
 548         self.buf.len() as i64
 549     }
 550
 551     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 552 }
 553
 554 impl<T: Read+Seek> FileReader<T> {
 555
 556     /// Constructs a new instance of `FileReader`.
 557     pub fn new_read(file: T) -> Self {
 558         FileReader { file: Box::new(file), eof : false }
 559     }
 560 }
 561
 562 impl<T: Read+Seek> ByteIO for FileReader<T> {
 563     fn read_byte(&mut self) -> ByteIOResult<u8> {
 564         let mut byte : [u8; 1] = [0];
 565         let ret = self.file.read(&mut byte);
 566         if ret.is_err() { return Err(ByteIOError::ReadError); }
 567         let sz = ret.unwrap();
 568         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 569         Ok (byte[0])
 570     }
 571
 572     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 573         let b = self.read_byte()?;
 574         self.seek(SeekFrom::Current(-1))?;
 575         Ok(b)
 576     }
 577
 578     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 579         match self.file.read_exact(buf) {
 580             Ok(())  => Ok(buf.len()),
 581             Err(err) => {
 582                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 583                     self.eof = true;
 584                     Err(ByteIOError::EOF)
 585                 } else {
 586                     Err(ByteIOError::ReadError)
 587                 }
 588             },
 589         }
 590     }
 591
 592     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 593         let ret = self.file.read(buf);
 594         if ret.is_err() { return Err(ByteIOError::ReadError); }
 595         let sz = ret.unwrap();
 596         if sz < buf.len() {
 597             if let Err(_err) = self.file.read(&mut buf[sz..][..1]) {
 598                 self.eof = true;
 599             } else {
 600                 return Ok(sz + 1);
 601             }
 602         }
 603         Ok(sz)
 604     }
 605
 606     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 607         let size = self.read_buf(buf)?;
 608         self.seek(SeekFrom::Current(-(size as i64)))?;
 609         Ok(size)
 610     }
 611
 612     #[allow(unused_variables)]
 613     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 614         Err(ByteIOError::NotImplemented)
 615     }
 616
 617     fn tell(&mut self) -> u64 {
 618         self.file.seek(SeekFrom::Current(0)).unwrap()
 619     }
 620
 621     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 622         let res = self.file.seek(pos);
 623         match res {
 624             Ok(r) => Ok(r),
 625             Err(_) => Err(ByteIOError::SeekError),
 626         }
 627     }
 628
 629     fn is_eof(&self) -> bool {
 630         self.eof
 631     }
 632
 633     fn is_seekable(&mut self) -> bool {
 634         true
 635     }
 636
 637     fn size(&mut self) -> i64 {
 638         -1
 639     }
 640
 641     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 642 }
 643
 644
 645 impl<T: Read+Seek> BoundedFileReader<T> {
 646
 647     /// Constructs a new instance of `BoundedFileReader`. The reader pretends that data before `start` and after `end` (if set) does not exist.
 648     pub fn new_read(file: T, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 649         let mut file = Box::new(file);
 650         if let Some(epos) = end {
 651             if start > epos {
 652                 return Err(ByteIOError::WrongRange);
 653             }
 654         }
 655         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 656             return Err(ByteIOError::SeekError);
 657         }
 658         Ok(Self { file, start, end, eof : false })
 659     }
 660     /// Constructs a new instance of `BoundedFileReader` using a boxed resource. The reader pretends that data before `start` and after `end` (if set) does not exist.
 661     pub fn new_read_boxed(mut file: Box<T>, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 662         if let Some(epos) = end {
 663             if start > epos {
 664                 return Err(ByteIOError::WrongRange);
 665             }
 666         }
 667         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 668             return Err(ByteIOError::SeekError);
 669         }
 670         Ok(Self { file, start, end, eof : false })
 671     }
 672     /// Destroys the reader and releases the reader resource for a further use.
 673     pub fn finish(self) -> Box<T> { self.file }
 674     fn real_tell(&mut self) -> u64 {
 675         self.file.seek(SeekFrom::Current(0)).unwrap()
 676     }
 677     fn max_read_len(&mut self, len: usize) -> usize {
 678         if let Some(epos) = self.end {
 679             (len as u64).min(epos - self.real_tell()) as usize
 680         } else {
 681             len
 682         }
 683     }
 684 }
 685
 686 impl<T: Read+Seek> ByteIO for BoundedFileReader<T> {
 687     fn read_byte(&mut self) -> ByteIOResult<u8> {
 688         if let Some(epos) = self.end {
 689             if self.real_tell() >= epos {
 690                 self.eof = true;
 691                 return Err(ByteIOError::EOF);
 692             }
 693         }
 694         let mut byte : [u8; 1] = [0];
 695         let ret = self.file.read(&mut byte);
 696         if ret.is_err() { return Err(ByteIOError::ReadError); }
 697         let sz = ret.unwrap();
 698         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 699         Ok (byte[0])
 700     }
 701
 702     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 703         let b = self.read_byte()?;
 704         if self.file.seek(SeekFrom::Current(-1)).is_err() {
 705             return Err(ByteIOError::SeekError);
 706         }
 707         Ok(b)
 708     }
 709
 710     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 711         let len = self.max_read_len(buf.len());
 712         match self.file.read_exact(&mut buf[..len]) {
 713             Ok(()) if len == buf.len() => Ok(buf.len()),
 714             Ok(()) => {
 715                 self.eof = true;
 716                 Err(ByteIOError::EOF)
 717             },
 718             Err(err) => {
 719                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 720                     self.eof = true;
 721                     Err(ByteIOError::EOF)
 722                 } else {
 723                     Err(ByteIOError::ReadError)
 724                 }
 725             },
 726         }
 727     }
 728
 729     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 730         let len = self.max_read_len(buf.len());
 731         let ret = self.file.read(&mut buf[..len]);
 732         if ret.is_err() { return Err(ByteIOError::ReadError); }
 733         let sz = ret.unwrap();
 734         if sz < len {
 735             if let Err(_err) = self.file.read(&mut buf[sz..][..1]) {
 736                 self.eof = true;
 737             } else {
 738                 return Ok(sz + 1);
 739             }
 740         }
 741         Ok(sz)
 742     }
 743
 744     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 745         let len = self.max_read_len(buf.len());
 746         let size = self.read_buf(&mut buf[..len])?;
 747         if self.file.seek(SeekFrom::Current(-(size as i64))).is_err() {
 748             return Err(ByteIOError::SeekError);
 749         }
 750         Ok(size)
 751     }
 752
 753     #[allow(unused_variables)]
 754     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 755         Err(ByteIOError::NotImplemented)
 756     }
 757
 758     fn tell(&mut self) -> u64 {
 759         self.file.seek(SeekFrom::Current(0)).unwrap() - self.start
 760     }
 761
 762     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 763         let res = match pos {
 764                 SeekFrom::Start(off) => {
 765                     let dpos = self.start + off;
 766                     if let Some(epos) = self.end {
 767                         if dpos > epos {
 768                             return Err(ByteIOError::WrongRange);
 769                         }
 770                     }
 771                     self.file.seek(SeekFrom::Start(dpos))
 772                 },
 773                 SeekFrom::Current(off) => {
 774                     let dpos = (self.real_tell() as i64) + off;
 775                     let end = self.end.unwrap_or(dpos as u64);
 776                     if dpos < 0 || ((dpos as u64) < self.start) || ((dpos as u64) > end) {
 777                         return Err(ByteIOError::WrongRange);
 778                     }
 779                     self.file.seek(pos)
 780                 },
 781                 SeekFrom::End(off) => {
 782                     if let Some(epos) = self.end {
 783                         let dpos = (epos as i64) + off;
 784                         if dpos < (self.start as i64) || ((dpos as u64) > epos) {
 785                             return Err(ByteIOError::WrongRange);
 786                         }
 787                         self.file.seek(SeekFrom::Start(dpos as u64))
 788                     } else {
 789                         self.file.seek(pos)
 790                     }
 791                 },
 792             };
 793         match res {
 794             Ok(r) => Ok(r),
 795             Err(_) => Err(ByteIOError::SeekError),
 796         }
 797     }
 798
 799     fn is_eof(&self) -> bool {
 800         self.eof
 801     }
 802
 803     fn is_seekable(&mut self) -> bool {
 804         true
 805     }
 806
 807     fn size(&mut self) -> i64 {
 808         -1
 809     }
 810
 811     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 812 }
 813
 814
 815 /// High-level bytestream writer.
 816 ///
 817 /// User is supposed to create some writer implementing [`ByteIO`] trait e.g. [`MemoryWriter`] and use it to create `ByteWriter` which can be used for writing e.g. various integer types.
 818 ///
 819 /// # Examples
 820 ///
 821 /// ````
 822 /// use nihav_core::io::byteio::{MemoryWriter,ByteWriter};
 823 /// # use nihav_core::io::byteio::ByteIOResult;
 824 ///
 825 /// # fn foo() -> ByteIOResult<()> {
 826 /// let mut memory = [0u8; 4];
 827 /// let mut mw = MemoryWriter::new_write(&mut memory);
 828 /// let mut bw = ByteWriter::new(&mut mw);
 829 /// let val = bw.write_u16be(42)?; // memory should be [ 0, 42, 0, 0 ]
 830 /// let val = bw.write_u16le(42)?; // memory should be [ 0, 42, 42, 0 ]
 831 /// # Ok(())
 832 /// # }
 833 /// ````
 834 ///
 835 /// [`ByteIO`]: ./trait.ByteIO.html
 836 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 837 #[allow(dead_code)]
 838 pub struct ByteWriter<'a> {
 839     io: &'a mut dyn ByteIO,
 840 }
 841
 842 /// Bytestream writer to memory.
 843 pub struct MemoryWriter<'a> {
 844     buf:      &'a mut [u8],
 845     pos:      usize,
 846 }
 847
 848 /// Bytestream writer to anything implementing `std::io::Write` and `std::io::Seek`.
 849 pub struct FileWriter<T: Write+Seek> {
 850     file:     Box<T>,
 851 }
 852
 853 /// Bytestream writer to memory.
 854 ///
 855 /// Unlike [`MemoryWriter`] which writes to an array of fixed size, `GrowableMemoryWriter` grows output size when output size exceeds capacity.
 856 ///
 857 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 858 pub struct GrowableMemoryWriter<'a> {
 859     buf:    &'a mut Vec<u8>,
 860     pos:    usize,
 861 }
 862
 863 impl<'a> ByteWriter<'a> {
 864     /// Constructs a new instance of `ByteWriter`.
 865     pub fn new(io: &'a mut dyn ByteIO) -> Self { ByteWriter { io } }
 866
 867     /// Writes byte array to the output.
 868     pub fn write_buf(&mut self, buf: &[u8])  -> ByteIOResult<()> {
 869         self.io.write_buf(buf)
 870     }
 871
 872     /// Writes single byte to the output.
 873     pub fn write_byte(&mut self, val: u8) -> ByteIOResult<()> {
 874         let buf: [u8; 1] = [val];
 875         self.io.write_buf(&buf)
 876     }
 877
 878     /// Writes 16-bit big-endian integer to the output.
 879     pub fn write_u16be(&mut self, val: u16) -> ByteIOResult<()> {
 880         let buf: [u8; 2] = [((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 881         self.io.write_buf(&buf)
 882     }
 883
 884     /// Writes 16-bit little-endian integer to the output.
 885     pub fn write_u16le(&mut self, val: u16) -> ByteIOResult<()> {
 886         let buf: [u8; 2] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8];
 887         self.io.write_buf(&buf)
 888     }
 889
 890     /// Writes 24-bit big-endian integer to the output.
 891     pub fn write_u24be(&mut self, val: u32) -> ByteIOResult<()> {
 892         let buf: [u8; 3] = [((val >> 16) & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 893         self.write_buf(&buf)
 894     }
 895
 896     /// Writes 24-bit little-endian integer to the output.
 897     pub fn write_u24le(&mut self, val: u32) -> ByteIOResult<()> {
 898         let buf: [u8; 3] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, ((val >> 16) & 0xFF) as u8];
 899         self.write_buf(&buf)
 900     }
 901
 902     /// Writes 32-bit big-endian integer to the output.
 903     pub fn write_u32be(&mut self, val: u32) -> ByteIOResult<()> {
 904         self.write_u16be(((val >> 16) & 0xFFFF) as u16)?;
 905         self.write_u16be((val & 0xFFFF) as u16)
 906     }
 907
 908     /// Writes 32-bit little-endian integer to the output.
 909     pub fn write_u32le(&mut self, val: u32) -> ByteIOResult<()> {
 910         self.write_u16le((val & 0xFFFF) as u16)?;
 911         self.write_u16le(((val >> 16) & 0xFFFF) as u16)
 912     }
 913
 914     /// Writes 64-bit big-endian integer to the output.
 915     pub fn write_u64be(&mut self, val: u64) -> ByteIOResult<()> {
 916         self.write_u32be((val >> 32) as u32)?;
 917         self.write_u32be(val as u32)
 918     }
 919
 920     /// Writes 64-bit little-endian integer to the output.
 921     pub fn write_u64le(&mut self, val: u64) -> ByteIOResult<()> {
 922         self.write_u32le(val as u32)?;
 923         self.write_u32le((val >> 32) as u32)
 924     }
 925
 926     /// Writes 32-bit big-endian floating point number to the output.
 927     pub fn write_f32be(&mut self, val: f32) -> ByteIOResult<()> {
 928         self.write_u32be(val.to_bits())
 929     }
 930
 931     /// Writes 32-bit little-endian floating point number to the output.
 932     pub fn write_f32le(&mut self, val: f32) -> ByteIOResult<()> {
 933         self.write_u32le(val.to_bits())
 934     }
 935
 936     /// Writes 64-bit big-endian floating point number to the output.
 937     pub fn write_f64be(&mut self, val: f64) -> ByteIOResult<()> {
 938         self.write_u64be(val.to_bits())
 939     }
 940
 941     /// Writes 64-bit little-endian floating point number to the output.
 942     pub fn write_f64le(&mut self, val: f64) -> ByteIOResult<()> {
 943         self.write_u64le(val.to_bits())
 944     }
 945
 946     /// Reports the current write position.
 947     pub fn tell(&mut self) -> u64 {
 948         self.io.tell()
 949     }
 950
 951     /// Seeks to the requested position.
 952     pub fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 953         self.io.seek(pos)
 954     }
 955
 956     /// Reports the amount of bytes the writer can still write (-1 if unknown).
 957     pub fn size_left(&mut self) -> i64 {
 958         let sz = self.io.size();
 959         if sz == -1 { return -1; }
 960         sz - (self.tell() as i64)
 961     }
 962
 963     /// Flushes output stream if possible.
 964     pub fn flush(&mut self) -> ByteIOResult<()> {
 965         self.io.flush()
 966     }
 967 }
 968
 969 impl<'a> MemoryWriter<'a> {
 970
 971     /// Constructs a new instance of `MemoryWriter`.
 972     pub fn new_write(buf: &'a mut [u8]) -> Self {
 973         MemoryWriter { buf, pos: 0 }
 974     }
 975
 976     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
 977         if pos < 0 || (pos as usize) > self.buf.len() {
 978             return Err(ByteIOError::WrongRange)
 979         }
 980         self.pos = pos as usize;
 981         Ok(pos as u64)
 982     }
 983 }
 984
 985 impl<'a> ByteIO for MemoryWriter<'a> {
 986     #[allow(unused_variables)]
 987     fn read_byte(&mut self) -> ByteIOResult<u8> {
 988         Err(ByteIOError::NotImplemented)
 989     }
 990
 991     #[allow(unused_variables)]
 992     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 993         Err(ByteIOError::NotImplemented)
 994     }
 995
 996     #[allow(unused_variables)]
 997     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 998         Err(ByteIOError::NotImplemented)
 999     }
1000
1001     #[allow(unused_variables)]
1002     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1003         Err(ByteIOError::NotImplemented)
1004     }
1005
1006     #[allow(unused_variables)]
1007     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1008         Err(ByteIOError::NotImplemented)
1009     }
1010
1011     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1012         if self.pos + buf.len() > self.buf.len() { return Err(ByteIOError::WriteError); }
1013         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1014         self.pos += buf.len();
1015         Ok(())
1016     }
1017
1018     fn tell(&mut self) -> u64 {
1019         self.pos as u64
1020     }
1021
1022     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1023         let cur_pos  = self.pos       as i64;
1024         let cur_size = self.buf.len() as i64;
1025         match pos {
1026             SeekFrom::Start(x)   => self.real_seek(x as i64),
1027             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1028             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1029         }
1030     }
1031
1032     fn is_eof(&self) -> bool {
1033         self.pos >= self.buf.len()
1034     }
1035
1036     fn is_seekable(&mut self) -> bool {
1037         true
1038     }
1039
1040     fn size(&mut self) -> i64 {
1041         self.buf.len() as i64
1042     }
1043
1044     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1045 }
1046
1047 impl<'a> GrowableMemoryWriter<'a> {
1048
1049     /// Constructs a new instance of `GrowableMemoryWriter`.
1050     pub fn new_write(buf: &'a mut Vec<u8>) -> Self {
1051         GrowableMemoryWriter { buf, pos: 0 }
1052     }
1053
1054     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
1055         if pos < 0 || (pos as usize) > self.buf.len() {
1056             return Err(ByteIOError::WrongRange)
1057         }
1058         self.pos = pos as usize;
1059         Ok(pos as u64)
1060     }
1061 }
1062
1063 impl<'a> ByteIO for GrowableMemoryWriter<'a> {
1064     #[allow(unused_variables)]
1065     fn read_byte(&mut self) -> ByteIOResult<u8> {
1066         Err(ByteIOError::NotImplemented)
1067     }
1068
1069     #[allow(unused_variables)]
1070     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1071         Err(ByteIOError::NotImplemented)
1072     }
1073
1074     #[allow(unused_variables)]
1075     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1076         Err(ByteIOError::NotImplemented)
1077     }
1078
1079     #[allow(unused_variables)]
1080     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1081         Err(ByteIOError::NotImplemented)
1082     }
1083
1084     #[allow(unused_variables)]
1085     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1086         Err(ByteIOError::NotImplemented)
1087     }
1088
1089     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1090         if self.pos + buf.len() > self.buf.len() {
1091             self.buf.resize(self.pos + buf.len(), 0);
1092         }
1093         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1094         self.pos += buf.len();
1095         Ok(())
1096     }
1097
1098     fn tell(&mut self) -> u64 {
1099         self.pos as u64
1100     }
1101
1102     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1103         let cur_pos  = self.pos       as i64;
1104         let cur_size = self.buf.len() as i64;
1105         match pos {
1106             SeekFrom::Start(x)   => self.real_seek(x as i64),
1107             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1108             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1109         }
1110     }
1111
1112     fn is_eof(&self) -> bool {
1113         self.pos >= self.buf.len()
1114     }
1115
1116     fn is_seekable(&mut self) -> bool {
1117         true
1118     }
1119
1120     fn size(&mut self) -> i64 {
1121         self.buf.len() as i64
1122     }
1123
1124     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1125 }
1126
1127 impl<T: Write+Seek> FileWriter<T> {
1128     /// Constructs a new instance of `FileWriter`.
1129     pub fn new_write(file: T) -> Self {
1130         FileWriter { file: Box::new(file) }
1131     }
1132 }
1133
1134 impl<T: Write+Seek> ByteIO for FileWriter<T> {
1135     #[allow(unused_variables)]
1136     fn read_byte(&mut self) -> ByteIOResult<u8> {
1137         Err(ByteIOError::NotImplemented)
1138     }
1139
1140     #[allow(unused_variables)]
1141     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1142         Err(ByteIOError::NotImplemented)
1143     }
1144
1145     #[allow(unused_variables)]
1146     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1147         Err(ByteIOError::NotImplemented)
1148     }
1149
1150     #[allow(unused_variables)]
1151     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1152         Err(ByteIOError::NotImplemented)
1153     }
1154
1155     #[allow(unused_variables)]
1156     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1157         Err(ByteIOError::NotImplemented)
1158     }
1159
1160     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1161         match self.file.write_all(buf) {
1162             Ok(()) => Ok(()),
1163             Err(_) => Err(ByteIOError::WriteError),
1164         }
1165     }
1166
1167     fn tell(&mut self) -> u64 {
1168         self.file.seek(SeekFrom::Current(0)).unwrap()
1169     }
1170
1171     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1172         let res = self.file.seek(pos);
1173         match res {
1174             Ok(r) => Ok(r),
1175             Err(_) => Err(ByteIOError::SeekError),
1176         }
1177     }
1178
1179     fn is_eof(&self) -> bool {
1180         false
1181     }
1182
1183     fn is_seekable(&mut self) -> bool {
1184         true
1185     }
1186
1187     fn size(&mut self) -> i64 {
1188         -1
1189     }
1190
1191     fn flush(&mut self) -> ByteIOResult<()> {
1192         match self.file.flush() {
1193             Ok(()) => Ok(()),
1194             Err(_) => Err(ByteIOError::WriteError),
1195         }
1196     }
1197 }
1198
1199 #[cfg(test)]
1200 mod test {
1201     use super::*;
1202     use std::fs::File;
1203
1204     #[test]
1205     fn test_read() {
1206         //const DATA : &'static [u8] = include_bytes!("../../assets/file");
1207         let buf: [u8; 64] = [1; 64];
1208         let mut mr = MemoryReader::new_read(&buf);
1209         let mut reader = ByteReader::new(&mut mr);
1210         assert_eq!(reader.read_byte().unwrap(),  0x01u8);
1211         assert_eq!(reader.read_u16le().unwrap(), 0x0101u16);
1212         assert_eq!(reader.read_u24le().unwrap(), 0x010101u32);
1213         assert_eq!(reader.read_u32le().unwrap(), 0x01010101u32);
1214         assert_eq!(reader.read_u64le().unwrap(), 0x0101010101010101u64);
1215         let mut file = File::open("assets/Misc/MaoMacha.asx").unwrap();
1216         let mut fr = FileReader::new_read(&mut file);
1217         let mut br2 = ByteReader::new(&mut fr);
1218         assert_eq!(br2.read_byte().unwrap(), 0x30);
1219         assert_eq!(br2.read_u24be().unwrap(), 0x26B275);
1220         assert_eq!(br2.read_u24le().unwrap(), 0xCF668E);
1221         assert_eq!(br2.read_u32be().unwrap(), 0x11A6D900);
1222         assert_eq!(br2.read_u32le().unwrap(), 0xCE6200AA);
1223     }
1224     #[test]
1225     fn test_write() {
1226         let mut buf: [u8; 64] = [0; 64];
1227         {
1228             let mut mw = MemoryWriter::new_write(&mut buf);
1229             let mut bw = ByteWriter::new(&mut mw);
1230             bw.write_byte(0x00).unwrap();
1231             bw.write_u16be(0x0102).unwrap();
1232             bw.write_u24be(0x030405).unwrap();
1233             bw.write_u32be(0x06070809).unwrap();
1234             bw.write_u64be(0x0A0B0C0D0E0F1011).unwrap();
1235             bw.write_byte(0x00).unwrap();
1236             bw.write_u16le(0x0201).unwrap();
1237             bw.write_u24le(0x050403).unwrap();
1238             bw.write_u32le(0x09080706).unwrap();
1239             bw.write_u64le(0x11100F0E0D0C0B0A).unwrap();
1240             assert_eq!(bw.size_left(), 28);
1241         }
1242         for i in 0..0x12 {
1243             assert_eq!(buf[(i + 0x00) as usize], i);
1244             assert_eq!(buf[(i + 0x12) as usize], i);
1245         }
1246     }
1247 }