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     /// Constructs a new instance of `FileReader` using a boxed resource.
 561     pub fn new_read_boxed(file: Box<T>) -> Self {
 562         FileReader { file, eof : false }
 563     }
 564     /// Destroys the reader and releases the reader resource for a further use.
 565     pub fn finish(self) -> Box<T> { self.file }
 566 }
 567
 568 impl<T: Read+Seek> ByteIO for FileReader<T> {
 569     fn read_byte(&mut self) -> ByteIOResult<u8> {
 570         let mut byte : [u8; 1] = [0];
 571         let ret = self.file.read(&mut byte);
 572         if ret.is_err() { return Err(ByteIOError::ReadError); }
 573         let sz = ret.unwrap();
 574         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 575         Ok (byte[0])
 576     }
 577
 578     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 579         let b = self.read_byte()?;
 580         self.seek(SeekFrom::Current(-1))?;
 581         Ok(b)
 582     }
 583
 584     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 585         match self.file.read_exact(buf) {
 586             Ok(())  => Ok(buf.len()),
 587             Err(err) => {
 588                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 589                     self.eof = true;
 590                     Err(ByteIOError::EOF)
 591                 } else {
 592                     Err(ByteIOError::ReadError)
 593                 }
 594             },
 595         }
 596     }
 597
 598     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 599         let ret = self.file.read(buf);
 600         if ret.is_err() { return Err(ByteIOError::ReadError); }
 601         let sz = ret.unwrap();
 602         if sz < buf.len() {
 603             if let Err(_err) = self.file.read(&mut buf[sz..][..1]) {
 604                 self.eof = true;
 605             } else {
 606                 return Ok(sz + 1);
 607             }
 608         }
 609         Ok(sz)
 610     }
 611
 612     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 613         let size = self.read_buf(buf)?;
 614         self.seek(SeekFrom::Current(-(size as i64)))?;
 615         Ok(size)
 616     }
 617
 618     #[allow(unused_variables)]
 619     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 620         Err(ByteIOError::NotImplemented)
 621     }
 622
 623     fn tell(&mut self) -> u64 {
 624         self.file.seek(SeekFrom::Current(0)).unwrap()
 625     }
 626
 627     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 628         let res = self.file.seek(pos);
 629         match res {
 630             Ok(r) => Ok(r),
 631             Err(_) => Err(ByteIOError::SeekError),
 632         }
 633     }
 634
 635     fn is_eof(&self) -> bool {
 636         self.eof
 637     }
 638
 639     fn is_seekable(&mut self) -> bool {
 640         true
 641     }
 642
 643     fn size(&mut self) -> i64 {
 644         -1
 645     }
 646
 647     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 648 }
 649
 650
 651 impl<T: Read+Seek> BoundedFileReader<T> {
 652
 653     /// Constructs a new instance of `BoundedFileReader`. The reader pretends that data before `start` and after `end` (if set) does not exist.
 654     pub fn new_read(file: T, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 655         let mut file = Box::new(file);
 656         if let Some(epos) = end {
 657             if start > epos {
 658                 return Err(ByteIOError::WrongRange);
 659             }
 660         }
 661         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 662             return Err(ByteIOError::SeekError);
 663         }
 664         Ok(Self { file, start, end, eof : false })
 665     }
 666     /// 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.
 667     pub fn new_read_boxed(mut file: Box<T>, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 668         if let Some(epos) = end {
 669             if start > epos {
 670                 return Err(ByteIOError::WrongRange);
 671             }
 672         }
 673         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 674             return Err(ByteIOError::SeekError);
 675         }
 676         Ok(Self { file, start, end, eof : false })
 677     }
 678     /// Destroys the reader and releases the reader resource for a further use.
 679     pub fn finish(self) -> Box<T> { self.file }
 680     fn real_tell(&mut self) -> u64 {
 681         self.file.seek(SeekFrom::Current(0)).unwrap()
 682     }
 683     fn max_read_len(&mut self, len: usize) -> usize {
 684         if let Some(epos) = self.end {
 685             (len as u64).min(epos - self.real_tell()) as usize
 686         } else {
 687             len
 688         }
 689     }
 690 }
 691
 692 impl<T: Read+Seek> ByteIO for BoundedFileReader<T> {
 693     fn read_byte(&mut self) -> ByteIOResult<u8> {
 694         if let Some(epos) = self.end {
 695             if self.real_tell() >= epos {
 696                 self.eof = true;
 697                 return Err(ByteIOError::EOF);
 698             }
 699         }
 700         let mut byte : [u8; 1] = [0];
 701         let ret = self.file.read(&mut byte);
 702         if ret.is_err() { return Err(ByteIOError::ReadError); }
 703         let sz = ret.unwrap();
 704         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 705         Ok (byte[0])
 706     }
 707
 708     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 709         let b = self.read_byte()?;
 710         if self.file.seek(SeekFrom::Current(-1)).is_err() {
 711             return Err(ByteIOError::SeekError);
 712         }
 713         Ok(b)
 714     }
 715
 716     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 717         let len = self.max_read_len(buf.len());
 718         match self.file.read_exact(&mut buf[..len]) {
 719             Ok(()) if len == buf.len() => Ok(buf.len()),
 720             Ok(()) => {
 721                 self.eof = true;
 722                 Err(ByteIOError::EOF)
 723             },
 724             Err(err) => {
 725                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 726                     self.eof = true;
 727                     Err(ByteIOError::EOF)
 728                 } else {
 729                     Err(ByteIOError::ReadError)
 730                 }
 731             },
 732         }
 733     }
 734
 735     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 736         let len = self.max_read_len(buf.len());
 737         let ret = self.file.read(&mut buf[..len]);
 738         if ret.is_err() { return Err(ByteIOError::ReadError); }
 739         let sz = ret.unwrap();
 740         if sz < len {
 741             if let Err(_err) = self.file.read(&mut buf[sz..][..1]) {
 742                 self.eof = true;
 743             } else {
 744                 return Ok(sz + 1);
 745             }
 746         }
 747         Ok(sz)
 748     }
 749
 750     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 751         let len = self.max_read_len(buf.len());
 752         let size = self.read_buf(&mut buf[..len])?;
 753         if self.file.seek(SeekFrom::Current(-(size as i64))).is_err() {
 754             return Err(ByteIOError::SeekError);
 755         }
 756         Ok(size)
 757     }
 758
 759     #[allow(unused_variables)]
 760     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 761         Err(ByteIOError::NotImplemented)
 762     }
 763
 764     fn tell(&mut self) -> u64 {
 765         self.file.seek(SeekFrom::Current(0)).unwrap() - self.start
 766     }
 767
 768     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 769         let res = match pos {
 770                 SeekFrom::Start(off) => {
 771                     let dpos = self.start + off;
 772                     if let Some(epos) = self.end {
 773                         if dpos > epos {
 774                             return Err(ByteIOError::WrongRange);
 775                         }
 776                     }
 777                     self.file.seek(SeekFrom::Start(dpos))
 778                 },
 779                 SeekFrom::Current(off) => {
 780                     let dpos = (self.real_tell() as i64) + off;
 781                     let end = self.end.unwrap_or(dpos as u64);
 782                     if dpos < 0 || ((dpos as u64) < self.start) || ((dpos as u64) > end) {
 783                         return Err(ByteIOError::WrongRange);
 784                     }
 785                     self.file.seek(pos)
 786                 },
 787                 SeekFrom::End(off) => {
 788                     if let Some(epos) = self.end {
 789                         let dpos = (epos as i64) + off;
 790                         if dpos < (self.start as i64) || ((dpos as u64) > epos) {
 791                             return Err(ByteIOError::WrongRange);
 792                         }
 793                         self.file.seek(SeekFrom::Start(dpos as u64))
 794                     } else {
 795                         self.file.seek(pos)
 796                     }
 797                 },
 798             };
 799         match res {
 800             Ok(r) => Ok(r),
 801             Err(_) => Err(ByteIOError::SeekError),
 802         }
 803     }
 804
 805     fn is_eof(&self) -> bool {
 806         self.eof
 807     }
 808
 809     fn is_seekable(&mut self) -> bool {
 810         true
 811     }
 812
 813     fn size(&mut self) -> i64 {
 814         -1
 815     }
 816
 817     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 818 }
 819
 820
 821 /// High-level bytestream writer.
 822 ///
 823 /// 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.
 824 ///
 825 /// # Examples
 826 ///
 827 /// ````
 828 /// use nihav_core::io::byteio::{MemoryWriter,ByteWriter};
 829 /// # use nihav_core::io::byteio::ByteIOResult;
 830 ///
 831 /// # fn foo() -> ByteIOResult<()> {
 832 /// let mut memory = [0u8; 4];
 833 /// let mut mw = MemoryWriter::new_write(&mut memory);
 834 /// let mut bw = ByteWriter::new(&mut mw);
 835 /// let val = bw.write_u16be(42)?; // memory should be [ 0, 42, 0, 0 ]
 836 /// let val = bw.write_u16le(42)?; // memory should be [ 0, 42, 42, 0 ]
 837 /// # Ok(())
 838 /// # }
 839 /// ````
 840 ///
 841 /// [`ByteIO`]: ./trait.ByteIO.html
 842 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 843 #[allow(dead_code)]
 844 pub struct ByteWriter<'a> {
 845     io: &'a mut dyn ByteIO,
 846 }
 847
 848 /// Bytestream writer to memory.
 849 pub struct MemoryWriter<'a> {
 850     buf:      &'a mut [u8],
 851     pos:      usize,
 852 }
 853
 854 /// Bytestream writer to anything implementing `std::io::Write` and `std::io::Seek`.
 855 pub struct FileWriter<T: Write+Seek> {
 856     file:     Box<T>,
 857 }
 858
 859 /// Bytestream writer to memory.
 860 ///
 861 /// Unlike [`MemoryWriter`] which writes to an array of fixed size, `GrowableMemoryWriter` grows output size when output size exceeds capacity.
 862 ///
 863 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 864 pub struct GrowableMemoryWriter<'a> {
 865     buf:    &'a mut Vec<u8>,
 866     pos:    usize,
 867 }
 868
 869 impl<'a> ByteWriter<'a> {
 870     /// Constructs a new instance of `ByteWriter`.
 871     pub fn new(io: &'a mut dyn ByteIO) -> Self { ByteWriter { io } }
 872
 873     /// Writes byte array to the output.
 874     pub fn write_buf(&mut self, buf: &[u8])  -> ByteIOResult<()> {
 875         self.io.write_buf(buf)
 876     }
 877
 878     /// Writes single byte to the output.
 879     pub fn write_byte(&mut self, val: u8) -> ByteIOResult<()> {
 880         let buf: [u8; 1] = [val];
 881         self.io.write_buf(&buf)
 882     }
 883
 884     /// Writes 16-bit big-endian integer to the output.
 885     pub fn write_u16be(&mut self, val: u16) -> ByteIOResult<()> {
 886         let buf: [u8; 2] = [((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 887         self.io.write_buf(&buf)
 888     }
 889
 890     /// Writes 16-bit little-endian integer to the output.
 891     pub fn write_u16le(&mut self, val: u16) -> ByteIOResult<()> {
 892         let buf: [u8; 2] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8];
 893         self.io.write_buf(&buf)
 894     }
 895
 896     /// Writes 24-bit big-endian integer to the output.
 897     pub fn write_u24be(&mut self, val: u32) -> ByteIOResult<()> {
 898         let buf: [u8; 3] = [((val >> 16) & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 899         self.write_buf(&buf)
 900     }
 901
 902     /// Writes 24-bit little-endian integer to the output.
 903     pub fn write_u24le(&mut self, val: u32) -> ByteIOResult<()> {
 904         let buf: [u8; 3] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, ((val >> 16) & 0xFF) as u8];
 905         self.write_buf(&buf)
 906     }
 907
 908     /// Writes 32-bit big-endian integer to the output.
 909     pub fn write_u32be(&mut self, val: u32) -> ByteIOResult<()> {
 910         self.write_u16be(((val >> 16) & 0xFFFF) as u16)?;
 911         self.write_u16be((val & 0xFFFF) as u16)
 912     }
 913
 914     /// Writes 32-bit little-endian integer to the output.
 915     pub fn write_u32le(&mut self, val: u32) -> ByteIOResult<()> {
 916         self.write_u16le((val & 0xFFFF) as u16)?;
 917         self.write_u16le(((val >> 16) & 0xFFFF) as u16)
 918     }
 919
 920     /// Writes 64-bit big-endian integer to the output.
 921     pub fn write_u64be(&mut self, val: u64) -> ByteIOResult<()> {
 922         self.write_u32be((val >> 32) as u32)?;
 923         self.write_u32be(val as u32)
 924     }
 925
 926     /// Writes 64-bit little-endian integer to the output.
 927     pub fn write_u64le(&mut self, val: u64) -> ByteIOResult<()> {
 928         self.write_u32le(val as u32)?;
 929         self.write_u32le((val >> 32) as u32)
 930     }
 931
 932     /// Writes 32-bit big-endian floating point number to the output.
 933     pub fn write_f32be(&mut self, val: f32) -> ByteIOResult<()> {
 934         self.write_u32be(val.to_bits())
 935     }
 936
 937     /// Writes 32-bit little-endian floating point number to the output.
 938     pub fn write_f32le(&mut self, val: f32) -> ByteIOResult<()> {
 939         self.write_u32le(val.to_bits())
 940     }
 941
 942     /// Writes 64-bit big-endian floating point number to the output.
 943     pub fn write_f64be(&mut self, val: f64) -> ByteIOResult<()> {
 944         self.write_u64be(val.to_bits())
 945     }
 946
 947     /// Writes 64-bit little-endian floating point number to the output.
 948     pub fn write_f64le(&mut self, val: f64) -> ByteIOResult<()> {
 949         self.write_u64le(val.to_bits())
 950     }
 951
 952     /// Reports the current write position.
 953     pub fn tell(&mut self) -> u64 {
 954         self.io.tell()
 955     }
 956
 957     /// Seeks to the requested position.
 958     pub fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 959         self.io.seek(pos)
 960     }
 961
 962     /// Reports the amount of bytes the writer can still write (-1 if unknown).
 963     pub fn size_left(&mut self) -> i64 {
 964         let sz = self.io.size();
 965         if sz == -1 { return -1; }
 966         sz - (self.tell() as i64)
 967     }
 968
 969     /// Flushes output stream if possible.
 970     pub fn flush(&mut self) -> ByteIOResult<()> {
 971         self.io.flush()
 972     }
 973 }
 974
 975 impl<'a> MemoryWriter<'a> {
 976
 977     /// Constructs a new instance of `MemoryWriter`.
 978     pub fn new_write(buf: &'a mut [u8]) -> Self {
 979         MemoryWriter { buf, pos: 0 }
 980     }
 981
 982     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
 983         if pos < 0 || (pos as usize) > self.buf.len() {
 984             return Err(ByteIOError::WrongRange)
 985         }
 986         self.pos = pos as usize;
 987         Ok(pos as u64)
 988     }
 989 }
 990
 991 impl<'a> ByteIO for MemoryWriter<'a> {
 992     #[allow(unused_variables)]
 993     fn read_byte(&mut self) -> ByteIOResult<u8> {
 994         Err(ByteIOError::NotImplemented)
 995     }
 996
 997     #[allow(unused_variables)]
 998     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 999         Err(ByteIOError::NotImplemented)
1000     }
1001
1002     #[allow(unused_variables)]
1003     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1004         Err(ByteIOError::NotImplemented)
1005     }
1006
1007     #[allow(unused_variables)]
1008     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1009         Err(ByteIOError::NotImplemented)
1010     }
1011
1012     #[allow(unused_variables)]
1013     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1014         Err(ByteIOError::NotImplemented)
1015     }
1016
1017     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1018         if self.pos + buf.len() > self.buf.len() { return Err(ByteIOError::WriteError); }
1019         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1020         self.pos += buf.len();
1021         Ok(())
1022     }
1023
1024     fn tell(&mut self) -> u64 {
1025         self.pos as u64
1026     }
1027
1028     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1029         let cur_pos  = self.pos       as i64;
1030         let cur_size = self.buf.len() as i64;
1031         match pos {
1032             SeekFrom::Start(x)   => self.real_seek(x as i64),
1033             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1034             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1035         }
1036     }
1037
1038     fn is_eof(&self) -> bool {
1039         self.pos >= self.buf.len()
1040     }
1041
1042     fn is_seekable(&mut self) -> bool {
1043         true
1044     }
1045
1046     fn size(&mut self) -> i64 {
1047         self.buf.len() as i64
1048     }
1049
1050     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1051 }
1052
1053 impl<'a> GrowableMemoryWriter<'a> {
1054
1055     /// Constructs a new instance of `GrowableMemoryWriter`.
1056     pub fn new_write(buf: &'a mut Vec<u8>) -> Self {
1057         GrowableMemoryWriter { buf, pos: 0 }
1058     }
1059
1060     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
1061         if pos < 0 || (pos as usize) > self.buf.len() {
1062             return Err(ByteIOError::WrongRange)
1063         }
1064         self.pos = pos as usize;
1065         Ok(pos as u64)
1066     }
1067 }
1068
1069 impl<'a> ByteIO for GrowableMemoryWriter<'a> {
1070     #[allow(unused_variables)]
1071     fn read_byte(&mut self) -> ByteIOResult<u8> {
1072         Err(ByteIOError::NotImplemented)
1073     }
1074
1075     #[allow(unused_variables)]
1076     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1077         Err(ByteIOError::NotImplemented)
1078     }
1079
1080     #[allow(unused_variables)]
1081     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1082         Err(ByteIOError::NotImplemented)
1083     }
1084
1085     #[allow(unused_variables)]
1086     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1087         Err(ByteIOError::NotImplemented)
1088     }
1089
1090     #[allow(unused_variables)]
1091     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1092         Err(ByteIOError::NotImplemented)
1093     }
1094
1095     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1096         if self.pos + buf.len() > self.buf.len() {
1097             self.buf.resize(self.pos + buf.len(), 0);
1098         }
1099         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1100         self.pos += buf.len();
1101         Ok(())
1102     }
1103
1104     fn tell(&mut self) -> u64 {
1105         self.pos as u64
1106     }
1107
1108     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1109         let cur_pos  = self.pos       as i64;
1110         let cur_size = self.buf.len() as i64;
1111         match pos {
1112             SeekFrom::Start(x)   => self.real_seek(x as i64),
1113             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1114             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1115         }
1116     }
1117
1118     fn is_eof(&self) -> bool {
1119         self.pos >= self.buf.len()
1120     }
1121
1122     fn is_seekable(&mut self) -> bool {
1123         true
1124     }
1125
1126     fn size(&mut self) -> i64 {
1127         self.buf.len() as i64
1128     }
1129
1130     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1131 }
1132
1133 impl<T: Write+Seek> FileWriter<T> {
1134     /// Constructs a new instance of `FileWriter`.
1135     pub fn new_write(file: T) -> Self {
1136         FileWriter { file: Box::new(file) }
1137     }
1138 }
1139
1140 impl<T: Write+Seek> ByteIO for FileWriter<T> {
1141     #[allow(unused_variables)]
1142     fn read_byte(&mut self) -> ByteIOResult<u8> {
1143         Err(ByteIOError::NotImplemented)
1144     }
1145
1146     #[allow(unused_variables)]
1147     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1148         Err(ByteIOError::NotImplemented)
1149     }
1150
1151     #[allow(unused_variables)]
1152     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1153         Err(ByteIOError::NotImplemented)
1154     }
1155
1156     #[allow(unused_variables)]
1157     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1158         Err(ByteIOError::NotImplemented)
1159     }
1160
1161     #[allow(unused_variables)]
1162     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1163         Err(ByteIOError::NotImplemented)
1164     }
1165
1166     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1167         match self.file.write_all(buf) {
1168             Ok(()) => Ok(()),
1169             Err(_) => Err(ByteIOError::WriteError),
1170         }
1171     }
1172
1173     fn tell(&mut self) -> u64 {
1174         self.file.seek(SeekFrom::Current(0)).unwrap()
1175     }
1176
1177     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1178         let res = self.file.seek(pos);
1179         match res {
1180             Ok(r) => Ok(r),
1181             Err(_) => Err(ByteIOError::SeekError),
1182         }
1183     }
1184
1185     fn is_eof(&self) -> bool {
1186         false
1187     }
1188
1189     fn is_seekable(&mut self) -> bool {
1190         true
1191     }
1192
1193     fn size(&mut self) -> i64 {
1194         -1
1195     }
1196
1197     fn flush(&mut self) -> ByteIOResult<()> {
1198         match self.file.flush() {
1199             Ok(()) => Ok(()),
1200             Err(_) => Err(ByteIOError::WriteError),
1201         }
1202     }
1203 }
1204
1205 #[cfg(test)]
1206 mod test {
1207     use super::*;
1208     use std::fs::File;
1209
1210     #[test]
1211     fn test_read() {
1212         //const DATA : &'static [u8] = include_bytes!("../../assets/file");
1213         let buf: [u8; 64] = [1; 64];
1214         let mut mr = MemoryReader::new_read(&buf);
1215         let mut reader = ByteReader::new(&mut mr);
1216         assert_eq!(reader.read_byte().unwrap(),  0x01u8);
1217         assert_eq!(reader.read_u16le().unwrap(), 0x0101u16);
1218         assert_eq!(reader.read_u24le().unwrap(), 0x010101u32);
1219         assert_eq!(reader.read_u32le().unwrap(), 0x01010101u32);
1220         assert_eq!(reader.read_u64le().unwrap(), 0x0101010101010101u64);
1221         let mut file = File::open("assets/Misc/MaoMacha.asx").unwrap();
1222         let mut fr = FileReader::new_read(&mut file);
1223         let mut br2 = ByteReader::new(&mut fr);
1224         assert_eq!(br2.read_byte().unwrap(), 0x30);
1225         assert_eq!(br2.read_u24be().unwrap(), 0x26B275);
1226         assert_eq!(br2.read_u24le().unwrap(), 0xCF668E);
1227         assert_eq!(br2.read_u32be().unwrap(), 0x11A6D900);
1228         assert_eq!(br2.read_u32le().unwrap(), 0xCE6200AA);
1229     }
1230     #[test]
1231     fn test_write() {
1232         let mut buf: [u8; 64] = [0; 64];
1233         {
1234             let mut mw = MemoryWriter::new_write(&mut buf);
1235             let mut bw = ByteWriter::new(&mut mw);
1236             bw.write_byte(0x00).unwrap();
1237             bw.write_u16be(0x0102).unwrap();
1238             bw.write_u24be(0x030405).unwrap();
1239             bw.write_u32be(0x06070809).unwrap();
1240             bw.write_u64be(0x0A0B0C0D0E0F1011).unwrap();
1241             bw.write_byte(0x00).unwrap();
1242             bw.write_u16le(0x0201).unwrap();
1243             bw.write_u24le(0x050403).unwrap();
1244             bw.write_u32le(0x09080706).unwrap();
1245             bw.write_u64le(0x11100F0E0D0C0B0A).unwrap();
1246             assert_eq!(bw.size_left(), 28);
1247         }
1248         for i in 0..0x12 {
1249             assert_eq!(buf[(i + 0x00) as usize], i);
1250             assert_eq!(buf[(i + 0x12) as usize], i);
1251         }
1252     }
1253 }