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_exact(&mut buf[sz..][..1]) {
 604                 self.eof = true;
 605                 if sz == 0 {
 606                     return Err(ByteIOError::EOF);
 607                 }
 608             } else {
 609                 return Ok(sz + 1);
 610             }
 611         }
 612         Ok(sz)
 613     }
 614
 615     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 616         let size = self.read_buf(buf)?;
 617         self.seek(SeekFrom::Current(-(size as i64)))?;
 618         Ok(size)
 619     }
 620
 621     #[allow(unused_variables)]
 622     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 623         Err(ByteIOError::NotImplemented)
 624     }
 625
 626     fn tell(&mut self) -> u64 {
 627         self.file.seek(SeekFrom::Current(0)).unwrap()
 628     }
 629
 630     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 631         let res = self.file.seek(pos);
 632         match res {
 633             Ok(r) => Ok(r),
 634             Err(_) => Err(ByteIOError::SeekError),
 635         }
 636     }
 637
 638     fn is_eof(&self) -> bool {
 639         self.eof
 640     }
 641
 642     fn is_seekable(&mut self) -> bool {
 643         true
 644     }
 645
 646     fn size(&mut self) -> i64 {
 647         -1
 648     }
 649
 650     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 651 }
 652
 653
 654 impl<T: Read+Seek> BoundedFileReader<T> {
 655
 656     /// Constructs a new instance of `BoundedFileReader`. The reader pretends that data before `start` and after `end` (if set) does not exist.
 657     pub fn new_read(file: T, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 658         let mut file = Box::new(file);
 659         if let Some(epos) = end {
 660             if start > epos {
 661                 return Err(ByteIOError::WrongRange);
 662             }
 663         }
 664         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 665             return Err(ByteIOError::SeekError);
 666         }
 667         Ok(Self { file, start, end, eof : false })
 668     }
 669     /// 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.
 670     pub fn new_read_boxed(mut file: Box<T>, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 671         if let Some(epos) = end {
 672             if start > epos {
 673                 return Err(ByteIOError::WrongRange);
 674             }
 675         }
 676         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 677             return Err(ByteIOError::SeekError);
 678         }
 679         Ok(Self { file, start, end, eof : false })
 680     }
 681     /// Destroys the reader and releases the reader resource for a further use.
 682     pub fn finish(self) -> Box<T> { self.file }
 683     fn real_tell(&mut self) -> u64 {
 684         self.file.seek(SeekFrom::Current(0)).unwrap()
 685     }
 686     fn max_read_len(&mut self, len: usize) -> usize {
 687         if let Some(epos) = self.end {
 688             (len as u64).min(epos - self.real_tell()) as usize
 689         } else {
 690             len
 691         }
 692     }
 693 }
 694
 695 impl<T: Read+Seek> ByteIO for BoundedFileReader<T> {
 696     fn read_byte(&mut self) -> ByteIOResult<u8> {
 697         if let Some(epos) = self.end {
 698             if self.real_tell() >= epos {
 699                 self.eof = true;
 700                 return Err(ByteIOError::EOF);
 701             }
 702         }
 703         let mut byte : [u8; 1] = [0];
 704         let ret = self.file.read(&mut byte);
 705         if ret.is_err() { return Err(ByteIOError::ReadError); }
 706         let sz = ret.unwrap();
 707         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 708         Ok (byte[0])
 709     }
 710
 711     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 712         let b = self.read_byte()?;
 713         if self.file.seek(SeekFrom::Current(-1)).is_err() {
 714             return Err(ByteIOError::SeekError);
 715         }
 716         Ok(b)
 717     }
 718
 719     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 720         let len = self.max_read_len(buf.len());
 721         match self.file.read_exact(&mut buf[..len]) {
 722             Ok(()) if len == buf.len() => Ok(buf.len()),
 723             Ok(()) => {
 724                 self.eof = true;
 725                 Err(ByteIOError::EOF)
 726             },
 727             Err(err) => {
 728                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 729                     self.eof = true;
 730                     Err(ByteIOError::EOF)
 731                 } else {
 732                     Err(ByteIOError::ReadError)
 733                 }
 734             },
 735         }
 736     }
 737
 738     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 739         let len = self.max_read_len(buf.len());
 740         let ret = self.file.read(&mut buf[..len]);
 741         if ret.is_err() { return Err(ByteIOError::ReadError); }
 742         let sz = ret.unwrap();
 743         if sz < len {
 744             if let Err(_err) = self.file.read(&mut buf[sz..][..1]) {
 745                 self.eof = true;
 746             } else {
 747                 return Ok(sz + 1);
 748             }
 749         }
 750         Ok(sz)
 751     }
 752
 753     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 754         let len = self.max_read_len(buf.len());
 755         let size = self.read_buf(&mut buf[..len])?;
 756         if self.file.seek(SeekFrom::Current(-(size as i64))).is_err() {
 757             return Err(ByteIOError::SeekError);
 758         }
 759         Ok(size)
 760     }
 761
 762     #[allow(unused_variables)]
 763     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
 764         Err(ByteIOError::NotImplemented)
 765     }
 766
 767     fn tell(&mut self) -> u64 {
 768         self.file.seek(SeekFrom::Current(0)).unwrap() - self.start
 769     }
 770
 771     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 772         let res = match pos {
 773                 SeekFrom::Start(off) => {
 774                     let dpos = self.start + off;
 775                     if let Some(epos) = self.end {
 776                         if dpos > epos {
 777                             return Err(ByteIOError::WrongRange);
 778                         }
 779                     }
 780                     self.file.seek(SeekFrom::Start(dpos))
 781                 },
 782                 SeekFrom::Current(off) => {
 783                     let dpos = (self.real_tell() as i64) + off;
 784                     let end = self.end.unwrap_or(dpos as u64);
 785                     if dpos < 0 || ((dpos as u64) < self.start) || ((dpos as u64) > end) {
 786                         return Err(ByteIOError::WrongRange);
 787                     }
 788                     self.file.seek(pos)
 789                 },
 790                 SeekFrom::End(off) => {
 791                     if let Some(epos) = self.end {
 792                         let dpos = (epos as i64) + off;
 793                         if dpos < (self.start as i64) || ((dpos as u64) > epos) {
 794                             return Err(ByteIOError::WrongRange);
 795                         }
 796                         self.file.seek(SeekFrom::Start(dpos as u64))
 797                     } else {
 798                         self.file.seek(pos)
 799                     }
 800                 },
 801             };
 802         match res {
 803             Ok(r) => Ok(r),
 804             Err(_) => Err(ByteIOError::SeekError),
 805         }
 806     }
 807
 808     fn is_eof(&self) -> bool {
 809         self.eof
 810     }
 811
 812     fn is_seekable(&mut self) -> bool {
 813         true
 814     }
 815
 816     fn size(&mut self) -> i64 {
 817         -1
 818     }
 819
 820     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 821 }
 822
 823
 824 /// High-level bytestream writer.
 825 ///
 826 /// 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.
 827 ///
 828 /// # Examples
 829 ///
 830 /// ````
 831 /// use nihav_core::io::byteio::{MemoryWriter,ByteWriter};
 832 /// # use nihav_core::io::byteio::ByteIOResult;
 833 ///
 834 /// # fn foo() -> ByteIOResult<()> {
 835 /// let mut memory = [0u8; 4];
 836 /// let mut mw = MemoryWriter::new_write(&mut memory);
 837 /// let mut bw = ByteWriter::new(&mut mw);
 838 /// let val = bw.write_u16be(42)?; // memory should be [ 0, 42, 0, 0 ]
 839 /// let val = bw.write_u16le(42)?; // memory should be [ 0, 42, 42, 0 ]
 840 /// # Ok(())
 841 /// # }
 842 /// ````
 843 ///
 844 /// [`ByteIO`]: ./trait.ByteIO.html
 845 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 846 #[allow(dead_code)]
 847 pub struct ByteWriter<'a> {
 848     io: &'a mut dyn ByteIO,
 849 }
 850
 851 /// Bytestream writer to memory.
 852 pub struct MemoryWriter<'a> {
 853     buf:      &'a mut [u8],
 854     pos:      usize,
 855 }
 856
 857 /// Bytestream writer to anything implementing `std::io::Write` and `std::io::Seek`.
 858 pub struct FileWriter<T: Write+Seek> {
 859     file:     Box<T>,
 860 }
 861
 862 /// Bytestream writer to memory.
 863 ///
 864 /// Unlike [`MemoryWriter`] which writes to an array of fixed size, `GrowableMemoryWriter` grows output size when output size exceeds capacity.
 865 ///
 866 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 867 pub struct GrowableMemoryWriter<'a> {
 868     buf:    &'a mut Vec<u8>,
 869     pos:    usize,
 870 }
 871
 872 impl<'a> ByteWriter<'a> {
 873     /// Constructs a new instance of `ByteWriter`.
 874     pub fn new(io: &'a mut dyn ByteIO) -> Self { ByteWriter { io } }
 875
 876     /// Writes byte array to the output.
 877     pub fn write_buf(&mut self, buf: &[u8])  -> ByteIOResult<()> {
 878         self.io.write_buf(buf)
 879     }
 880
 881     /// Writes single byte to the output.
 882     pub fn write_byte(&mut self, val: u8) -> ByteIOResult<()> {
 883         let buf: [u8; 1] = [val];
 884         self.io.write_buf(&buf)
 885     }
 886
 887     /// Writes 16-bit big-endian integer to the output.
 888     pub fn write_u16be(&mut self, val: u16) -> ByteIOResult<()> {
 889         let buf: [u8; 2] = [((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 890         self.io.write_buf(&buf)
 891     }
 892
 893     /// Writes 16-bit little-endian integer to the output.
 894     pub fn write_u16le(&mut self, val: u16) -> ByteIOResult<()> {
 895         let buf: [u8; 2] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8];
 896         self.io.write_buf(&buf)
 897     }
 898
 899     /// Writes 24-bit big-endian integer to the output.
 900     pub fn write_u24be(&mut self, val: u32) -> ByteIOResult<()> {
 901         let buf: [u8; 3] = [((val >> 16) & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 902         self.write_buf(&buf)
 903     }
 904
 905     /// Writes 24-bit little-endian integer to the output.
 906     pub fn write_u24le(&mut self, val: u32) -> ByteIOResult<()> {
 907         let buf: [u8; 3] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, ((val >> 16) & 0xFF) as u8];
 908         self.write_buf(&buf)
 909     }
 910
 911     /// Writes 32-bit big-endian integer to the output.
 912     pub fn write_u32be(&mut self, val: u32) -> ByteIOResult<()> {
 913         self.write_u16be(((val >> 16) & 0xFFFF) as u16)?;
 914         self.write_u16be((val & 0xFFFF) as u16)
 915     }
 916
 917     /// Writes 32-bit little-endian integer to the output.
 918     pub fn write_u32le(&mut self, val: u32) -> ByteIOResult<()> {
 919         self.write_u16le((val & 0xFFFF) as u16)?;
 920         self.write_u16le(((val >> 16) & 0xFFFF) as u16)
 921     }
 922
 923     /// Writes 64-bit big-endian integer to the output.
 924     pub fn write_u64be(&mut self, val: u64) -> ByteIOResult<()> {
 925         self.write_u32be((val >> 32) as u32)?;
 926         self.write_u32be(val as u32)
 927     }
 928
 929     /// Writes 64-bit little-endian integer to the output.
 930     pub fn write_u64le(&mut self, val: u64) -> ByteIOResult<()> {
 931         self.write_u32le(val as u32)?;
 932         self.write_u32le((val >> 32) as u32)
 933     }
 934
 935     /// Writes 32-bit big-endian floating point number to the output.
 936     pub fn write_f32be(&mut self, val: f32) -> ByteIOResult<()> {
 937         self.write_u32be(val.to_bits())
 938     }
 939
 940     /// Writes 32-bit little-endian floating point number to the output.
 941     pub fn write_f32le(&mut self, val: f32) -> ByteIOResult<()> {
 942         self.write_u32le(val.to_bits())
 943     }
 944
 945     /// Writes 64-bit big-endian floating point number to the output.
 946     pub fn write_f64be(&mut self, val: f64) -> ByteIOResult<()> {
 947         self.write_u64be(val.to_bits())
 948     }
 949
 950     /// Writes 64-bit little-endian floating point number to the output.
 951     pub fn write_f64le(&mut self, val: f64) -> ByteIOResult<()> {
 952         self.write_u64le(val.to_bits())
 953     }
 954
 955     /// Reports the current write position.
 956     pub fn tell(&mut self) -> u64 {
 957         self.io.tell()
 958     }
 959
 960     /// Seeks to the requested position.
 961     pub fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 962         self.io.seek(pos)
 963     }
 964
 965     /// Reports the amount of bytes the writer can still write (-1 if unknown).
 966     pub fn size_left(&mut self) -> i64 {
 967         let sz = self.io.size();
 968         if sz == -1 { return -1; }
 969         sz - (self.tell() as i64)
 970     }
 971
 972     /// Flushes output stream if possible.
 973     pub fn flush(&mut self) -> ByteIOResult<()> {
 974         self.io.flush()
 975     }
 976 }
 977
 978 impl<'a> MemoryWriter<'a> {
 979
 980     /// Constructs a new instance of `MemoryWriter`.
 981     pub fn new_write(buf: &'a mut [u8]) -> Self {
 982         MemoryWriter { buf, pos: 0 }
 983     }
 984
 985     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
 986         if pos < 0 || (pos as usize) > self.buf.len() {
 987             return Err(ByteIOError::WrongRange)
 988         }
 989         self.pos = pos as usize;
 990         Ok(pos as u64)
 991     }
 992 }
 993
 994 impl<'a> ByteIO for MemoryWriter<'a> {
 995     #[allow(unused_variables)]
 996     fn read_byte(&mut self) -> ByteIOResult<u8> {
 997         Err(ByteIOError::NotImplemented)
 998     }
 999
1000     #[allow(unused_variables)]
1001     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1002         Err(ByteIOError::NotImplemented)
1003     }
1004
1005     #[allow(unused_variables)]
1006     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1007         Err(ByteIOError::NotImplemented)
1008     }
1009
1010     #[allow(unused_variables)]
1011     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1012         Err(ByteIOError::NotImplemented)
1013     }
1014
1015     #[allow(unused_variables)]
1016     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1017         Err(ByteIOError::NotImplemented)
1018     }
1019
1020     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1021         if self.pos + buf.len() > self.buf.len() { return Err(ByteIOError::WriteError); }
1022         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1023         self.pos += buf.len();
1024         Ok(())
1025     }
1026
1027     fn tell(&mut self) -> u64 {
1028         self.pos as u64
1029     }
1030
1031     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1032         let cur_pos  = self.pos       as i64;
1033         let cur_size = self.buf.len() as i64;
1034         match pos {
1035             SeekFrom::Start(x)   => self.real_seek(x as i64),
1036             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1037             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1038         }
1039     }
1040
1041     fn is_eof(&self) -> bool {
1042         self.pos >= self.buf.len()
1043     }
1044
1045     fn is_seekable(&mut self) -> bool {
1046         true
1047     }
1048
1049     fn size(&mut self) -> i64 {
1050         self.buf.len() as i64
1051     }
1052
1053     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1054 }
1055
1056 impl<'a> GrowableMemoryWriter<'a> {
1057
1058     /// Constructs a new instance of `GrowableMemoryWriter`.
1059     pub fn new_write(buf: &'a mut Vec<u8>) -> Self {
1060         GrowableMemoryWriter { buf, pos: 0 }
1061     }
1062
1063     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
1064         if pos < 0 || (pos as usize) > self.buf.len() {
1065             return Err(ByteIOError::WrongRange)
1066         }
1067         self.pos = pos as usize;
1068         Ok(pos as u64)
1069     }
1070 }
1071
1072 impl<'a> ByteIO for GrowableMemoryWriter<'a> {
1073     #[allow(unused_variables)]
1074     fn read_byte(&mut self) -> ByteIOResult<u8> {
1075         Err(ByteIOError::NotImplemented)
1076     }
1077
1078     #[allow(unused_variables)]
1079     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1080         Err(ByteIOError::NotImplemented)
1081     }
1082
1083     #[allow(unused_variables)]
1084     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1085         Err(ByteIOError::NotImplemented)
1086     }
1087
1088     #[allow(unused_variables)]
1089     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1090         Err(ByteIOError::NotImplemented)
1091     }
1092
1093     #[allow(unused_variables)]
1094     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1095         Err(ByteIOError::NotImplemented)
1096     }
1097
1098     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1099         if self.pos + buf.len() > self.buf.len() {
1100             self.buf.resize(self.pos + buf.len(), 0);
1101         }
1102         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1103         self.pos += buf.len();
1104         Ok(())
1105     }
1106
1107     fn tell(&mut self) -> u64 {
1108         self.pos as u64
1109     }
1110
1111     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1112         let cur_pos  = self.pos       as i64;
1113         let cur_size = self.buf.len() as i64;
1114         match pos {
1115             SeekFrom::Start(x)   => self.real_seek(x as i64),
1116             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1117             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1118         }
1119     }
1120
1121     fn is_eof(&self) -> bool {
1122         self.pos >= self.buf.len()
1123     }
1124
1125     fn is_seekable(&mut self) -> bool {
1126         true
1127     }
1128
1129     fn size(&mut self) -> i64 {
1130         self.buf.len() as i64
1131     }
1132
1133     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1134 }
1135
1136 impl<T: Write+Seek> FileWriter<T> {
1137     /// Constructs a new instance of `FileWriter`.
1138     pub fn new_write(file: T) -> Self {
1139         FileWriter { file: Box::new(file) }
1140     }
1141 }
1142
1143 impl<T: Write+Seek> ByteIO for FileWriter<T> {
1144     #[allow(unused_variables)]
1145     fn read_byte(&mut self) -> ByteIOResult<u8> {
1146         Err(ByteIOError::NotImplemented)
1147     }
1148
1149     #[allow(unused_variables)]
1150     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1151         Err(ByteIOError::NotImplemented)
1152     }
1153
1154     #[allow(unused_variables)]
1155     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1156         Err(ByteIOError::NotImplemented)
1157     }
1158
1159     #[allow(unused_variables)]
1160     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1161         Err(ByteIOError::NotImplemented)
1162     }
1163
1164     #[allow(unused_variables)]
1165     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
1166         Err(ByteIOError::NotImplemented)
1167     }
1168
1169     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1170         match self.file.write_all(buf) {
1171             Ok(()) => Ok(()),
1172             Err(_) => Err(ByteIOError::WriteError),
1173         }
1174     }
1175
1176     fn tell(&mut self) -> u64 {
1177         self.file.seek(SeekFrom::Current(0)).unwrap()
1178     }
1179
1180     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1181         let res = self.file.seek(pos);
1182         match res {
1183             Ok(r) => Ok(r),
1184             Err(_) => Err(ByteIOError::SeekError),
1185         }
1186     }
1187
1188     fn is_eof(&self) -> bool {
1189         false
1190     }
1191
1192     fn is_seekable(&mut self) -> bool {
1193         true
1194     }
1195
1196     fn size(&mut self) -> i64 {
1197         -1
1198     }
1199
1200     fn flush(&mut self) -> ByteIOResult<()> {
1201         match self.file.flush() {
1202             Ok(()) => Ok(()),
1203             Err(_) => Err(ByteIOError::WriteError),
1204         }
1205     }
1206 }
1207
1208 #[cfg(test)]
1209 mod test {
1210     use super::*;
1211     use std::fs::File;
1212
1213     #[test]
1214     fn test_read() {
1215         //const DATA : &'static [u8] = include_bytes!("../../assets/file");
1216         let buf: [u8; 64] = [1; 64];
1217         let mut mr = MemoryReader::new_read(&buf);
1218         let mut reader = ByteReader::new(&mut mr);
1219         assert_eq!(reader.read_byte().unwrap(),  0x01u8);
1220         assert_eq!(reader.read_u16le().unwrap(), 0x0101u16);
1221         assert_eq!(reader.read_u24le().unwrap(), 0x010101u32);
1222         assert_eq!(reader.read_u32le().unwrap(), 0x01010101u32);
1223         assert_eq!(reader.read_u64le().unwrap(), 0x0101010101010101u64);
1224         let mut file = File::open("assets/Misc/MaoMacha.asx").unwrap();
1225         let mut fr = FileReader::new_read(&mut file);
1226         let mut br2 = ByteReader::new(&mut fr);
1227         assert_eq!(br2.read_byte().unwrap(), 0x30);
1228         assert_eq!(br2.read_u24be().unwrap(), 0x26B275);
1229         assert_eq!(br2.read_u24le().unwrap(), 0xCF668E);
1230         assert_eq!(br2.read_u32be().unwrap(), 0x11A6D900);
1231         assert_eq!(br2.read_u32le().unwrap(), 0xCE6200AA);
1232     }
1233     #[test]
1234     fn test_write() {
1235         let mut buf: [u8; 64] = [0; 64];
1236         {
1237             let mut mw = MemoryWriter::new_write(&mut buf);
1238             let mut bw = ByteWriter::new(&mut mw);
1239             bw.write_byte(0x00).unwrap();
1240             bw.write_u16be(0x0102).unwrap();
1241             bw.write_u24be(0x030405).unwrap();
1242             bw.write_u32be(0x06070809).unwrap();
1243             bw.write_u64be(0x0A0B0C0D0E0F1011).unwrap();
1244             bw.write_byte(0x00).unwrap();
1245             bw.write_u16le(0x0201).unwrap();
1246             bw.write_u24le(0x050403).unwrap();
1247             bw.write_u32le(0x09080706).unwrap();
1248             bw.write_u64le(0x11100F0E0D0C0B0A).unwrap();
1249             assert_eq!(bw.size_left(), 28);
1250         }
1251         for i in 0..0x12 {
1252             assert_eq!(buf[(i + 0x00) as usize], i);
1253             assert_eq!(buf[(i + 0x12) as usize], i);
1254         }
1255     }
1256 }