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     fn write_buf(&mut self, _buf: &[u8]) -> ByteIOResult<()> {
 521         Err(ByteIOError::NotImplemented)
 522     }
 523
 524     fn tell(&mut self) -> u64 {
 525         self.pos as u64
 526     }
 527
 528     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 529         let cur_pos  = self.pos       as i64;
 530         let cur_size = self.buf.len() as i64;
 531         match pos {
 532             SeekFrom::Start(x)   => self.real_seek(x as i64),
 533             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
 534             SeekFrom::End(x)     => self.real_seek(cur_size + x),
 535         }
 536     }
 537
 538     fn is_eof(&self) -> bool {
 539         self.pos >= self.buf.len()
 540     }
 541
 542     fn is_seekable(&mut self) -> bool {
 543         true
 544     }
 545
 546     fn size(&mut self) -> i64 {
 547         self.buf.len() as i64
 548     }
 549
 550     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 551 }
 552
 553 impl<T: Read+Seek> FileReader<T> {
 554
 555     /// Constructs a new instance of `FileReader`.
 556     pub fn new_read(file: T) -> Self {
 557         FileReader { file: Box::new(file), eof : false }
 558     }
 559     /// Constructs a new instance of `FileReader` using a boxed resource.
 560     pub fn new_read_boxed(file: Box<T>) -> Self {
 561         FileReader { file, eof : false }
 562     }
 563     /// Destroys the reader and releases the reader resource for a further use.
 564     pub fn finish(self) -> Box<T> { self.file }
 565 }
 566
 567 impl<T: Read+Seek> ByteIO for FileReader<T> {
 568     fn read_byte(&mut self) -> ByteIOResult<u8> {
 569         let mut byte : [u8; 1] = [0];
 570         let ret = self.file.read(&mut byte);
 571         if ret.is_err() { return Err(ByteIOError::ReadError); }
 572         let sz = ret.unwrap();
 573         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 574         Ok (byte[0])
 575     }
 576
 577     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 578         let b = self.read_byte()?;
 579         self.seek(SeekFrom::Current(-1))?;
 580         Ok(b)
 581     }
 582
 583     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 584         match self.file.read_exact(buf) {
 585             Ok(())  => Ok(buf.len()),
 586             Err(err) => {
 587                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 588                     self.eof = true;
 589                     Err(ByteIOError::EOF)
 590                 } else {
 591                     Err(ByteIOError::ReadError)
 592                 }
 593             },
 594         }
 595     }
 596
 597     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 598         let ret = self.file.read(buf);
 599         if ret.is_err() { return Err(ByteIOError::ReadError); }
 600         let sz = ret.unwrap();
 601         if sz < buf.len() {
 602             if let Err(_err) = self.file.read_exact(&mut buf[sz..][..1]) {
 603                 self.eof = true;
 604                 if sz == 0 {
 605                     return Err(ByteIOError::EOF);
 606                 }
 607             } else {
 608                 return Ok(sz + 1);
 609             }
 610         }
 611         Ok(sz)
 612     }
 613
 614     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 615         let size = self.read_buf(buf)?;
 616         self.seek(SeekFrom::Current(-(size as i64)))?;
 617         Ok(size)
 618     }
 619
 620     fn write_buf(&mut self, _buf: &[u8]) -> ByteIOResult<()> {
 621         Err(ByteIOError::NotImplemented)
 622     }
 623
 624     fn tell(&mut self) -> u64 {
 625         self.file.stream_position().unwrap()
 626     }
 627
 628     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 629         let res = self.file.seek(pos);
 630         match res {
 631             Ok(r) => Ok(r),
 632             Err(_) => Err(ByteIOError::SeekError),
 633         }
 634     }
 635
 636     fn is_eof(&self) -> bool {
 637         self.eof
 638     }
 639
 640     fn is_seekable(&mut self) -> bool {
 641         true
 642     }
 643
 644     fn size(&mut self) -> i64 {
 645         -1
 646     }
 647
 648     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 649 }
 650
 651
 652 impl<T: Read+Seek> BoundedFileReader<T> {
 653
 654     /// Constructs a new instance of `BoundedFileReader`. The reader pretends that data before `start` and after `end` (if set) does not exist.
 655     pub fn new_read(file: T, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 656         let mut file = Box::new(file);
 657         if let Some(epos) = end {
 658             if start > epos {
 659                 return Err(ByteIOError::WrongRange);
 660             }
 661         }
 662         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 663             return Err(ByteIOError::SeekError);
 664         }
 665         Ok(Self { file, start, end, eof : false })
 666     }
 667     /// 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.
 668     pub fn new_read_boxed(mut file: Box<T>, start: u64, end: Option<u64>) -> ByteIOResult<Self> {
 669         if let Some(epos) = end {
 670             if start > epos {
 671                 return Err(ByteIOError::WrongRange);
 672             }
 673         }
 674         if start > 0 && file.seek(SeekFrom::Start(start)).is_err() {
 675             return Err(ByteIOError::SeekError);
 676         }
 677         Ok(Self { file, start, end, eof : false })
 678     }
 679     /// Destroys the reader and releases the reader resource for a further use.
 680     pub fn finish(self) -> Box<T> { self.file }
 681     fn real_tell(&mut self) -> u64 {
 682         self.file.stream_position().unwrap()
 683     }
 684     fn max_read_len(&mut self, len: usize) -> usize {
 685         if let Some(epos) = self.end {
 686             (len as u64).min(epos - self.real_tell()) as usize
 687         } else {
 688             len
 689         }
 690     }
 691 }
 692
 693 impl<T: Read+Seek> ByteIO for BoundedFileReader<T> {
 694     fn read_byte(&mut self) -> ByteIOResult<u8> {
 695         if let Some(epos) = self.end {
 696             if self.real_tell() >= epos {
 697                 self.eof = true;
 698                 return Err(ByteIOError::EOF);
 699             }
 700         }
 701         let mut byte : [u8; 1] = [0];
 702         let ret = self.file.read(&mut byte);
 703         if ret.is_err() { return Err(ByteIOError::ReadError); }
 704         let sz = ret.unwrap();
 705         if sz == 0 { self.eof = true; return Err(ByteIOError::EOF); }
 706         Ok (byte[0])
 707     }
 708
 709     fn peek_byte(&mut self) -> ByteIOResult<u8> {
 710         let b = self.read_byte()?;
 711         if self.file.seek(SeekFrom::Current(-1)).is_err() {
 712             return Err(ByteIOError::SeekError);
 713         }
 714         Ok(b)
 715     }
 716
 717     fn read_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 718         if let Some(epos) = self.end {
 719             if self.real_tell() >= epos {
 720                 self.eof = true;
 721                 return Err(ByteIOError::EOF);
 722             }
 723         }
 724         let len = self.max_read_len(buf.len());
 725         match self.file.read_exact(&mut buf[..len]) {
 726             Ok(()) if len == buf.len() => Ok(buf.len()),
 727             Ok(()) => {
 728                 self.eof = true;
 729                 Err(ByteIOError::EOF)
 730             },
 731             Err(err) => {
 732                 if err.kind() == std::io::ErrorKind::UnexpectedEof {
 733                     self.eof = true;
 734                     Err(ByteIOError::EOF)
 735                 } else {
 736                     Err(ByteIOError::ReadError)
 737                 }
 738             },
 739         }
 740     }
 741
 742     fn read_buf_some(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 743         if let Some(epos) = self.end {
 744             if self.real_tell() >= epos {
 745                 self.eof = true;
 746                 return Err(ByteIOError::EOF);
 747             }
 748         }
 749         let len = self.max_read_len(buf.len());
 750         let ret = self.file.read(&mut buf[..len]);
 751         if ret.is_err() { return Err(ByteIOError::ReadError); }
 752         let sz = ret.unwrap();
 753         if sz < len {
 754             if let Ok(1) = self.file.read(&mut buf[sz..][..1]) {
 755                 return Ok(sz + 1);
 756             }
 757             self.eof = true;
 758             if sz == 0 {
 759                 return Err(ByteIOError::EOF);
 760             }
 761         }
 762         Ok(sz)
 763     }
 764
 765     fn peek_buf(&mut self, buf: &mut [u8]) -> ByteIOResult<usize> {
 766         let len = self.max_read_len(buf.len());
 767         let size = self.read_buf(&mut buf[..len])?;
 768         if self.file.seek(SeekFrom::Current(-(size as i64))).is_err() {
 769             return Err(ByteIOError::SeekError);
 770         }
 771         Ok(size)
 772     }
 773
 774     fn write_buf(&mut self, _buf: &[u8]) -> ByteIOResult<()> {
 775         Err(ByteIOError::NotImplemented)
 776     }
 777
 778     fn tell(&mut self) -> u64 {
 779         self.file.stream_position().unwrap() - self.start
 780     }
 781
 782     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 783         let res = match pos {
 784                 SeekFrom::Start(off) => {
 785                     let dpos = self.start + off;
 786                     if let Some(epos) = self.end {
 787                         if dpos > epos {
 788                             return Err(ByteIOError::WrongRange);
 789                         }
 790                     }
 791                     self.file.seek(SeekFrom::Start(dpos))
 792                 },
 793                 SeekFrom::Current(off) => {
 794                     let dpos = (self.real_tell() as i64) + off;
 795                     let end = self.end.unwrap_or(dpos as u64);
 796                     if dpos < 0 || ((dpos as u64) < self.start) || ((dpos as u64) > end) {
 797                         return Err(ByteIOError::WrongRange);
 798                     }
 799                     self.file.seek(pos)
 800                 },
 801                 SeekFrom::End(off) => {
 802                     if let Some(epos) = self.end {
 803                         let dpos = (epos as i64) + off;
 804                         if dpos < (self.start as i64) || ((dpos as u64) > epos) {
 805                             return Err(ByteIOError::WrongRange);
 806                         }
 807                         self.file.seek(SeekFrom::Start(dpos as u64))
 808                     } else {
 809                         self.file.seek(pos)
 810                     }
 811                 },
 812             };
 813         match res {
 814             Ok(r) => Ok(r),
 815             Err(_) => Err(ByteIOError::SeekError),
 816         }
 817     }
 818
 819     fn is_eof(&self) -> bool {
 820         self.eof
 821     }
 822
 823     fn is_seekable(&mut self) -> bool {
 824         true
 825     }
 826
 827     fn size(&mut self) -> i64 {
 828         -1
 829     }
 830
 831     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
 832 }
 833
 834
 835 /// High-level bytestream writer.
 836 ///
 837 /// 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.
 838 ///
 839 /// # Examples
 840 ///
 841 /// ````
 842 /// use nihav_core::io::byteio::{MemoryWriter,ByteWriter};
 843 /// # use nihav_core::io::byteio::ByteIOResult;
 844 ///
 845 /// # fn foo() -> ByteIOResult<()> {
 846 /// let mut memory = [0u8; 4];
 847 /// let mut mw = MemoryWriter::new_write(&mut memory);
 848 /// let mut bw = ByteWriter::new(&mut mw);
 849 /// let val = bw.write_u16be(42)?; // memory should be [ 0, 42, 0, 0 ]
 850 /// let val = bw.write_u16le(42)?; // memory should be [ 0, 42, 42, 0 ]
 851 /// # Ok(())
 852 /// # }
 853 /// ````
 854 ///
 855 /// [`ByteIO`]: ./trait.ByteIO.html
 856 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 857 #[allow(dead_code)]
 858 pub struct ByteWriter<'a> {
 859     io: &'a mut dyn ByteIO,
 860 }
 861
 862 /// Bytestream writer to memory.
 863 pub struct MemoryWriter<'a> {
 864     buf:      &'a mut [u8],
 865     pos:      usize,
 866 }
 867
 868 /// Bytestream writer to anything implementing `std::io::Write` and `std::io::Seek`.
 869 pub struct FileWriter<T: Write+Seek> {
 870     file:     Box<T>,
 871 }
 872
 873 /// Bytestream writer to memory.
 874 ///
 875 /// Unlike [`MemoryWriter`] which writes to an array of fixed size, `GrowableMemoryWriter` grows output size when output size exceeds capacity.
 876 ///
 877 /// [`MemoryWriter`]: ./struct.MemoryWriter.html
 878 pub struct GrowableMemoryWriter<'a> {
 879     buf:    &'a mut Vec<u8>,
 880     pos:    usize,
 881 }
 882
 883 impl<'a> ByteWriter<'a> {
 884     /// Constructs a new instance of `ByteWriter`.
 885     pub fn new(io: &'a mut dyn ByteIO) -> Self { ByteWriter { io } }
 886
 887     /// Writes byte array to the output.
 888     pub fn write_buf(&mut self, buf: &[u8])  -> ByteIOResult<()> {
 889         self.io.write_buf(buf)
 890     }
 891
 892     /// Writes single byte to the output.
 893     pub fn write_byte(&mut self, val: u8) -> ByteIOResult<()> {
 894         let buf: [u8; 1] = [val];
 895         self.io.write_buf(&buf)
 896     }
 897
 898     /// Writes 16-bit big-endian integer to the output.
 899     pub fn write_u16be(&mut self, val: u16) -> ByteIOResult<()> {
 900         let buf: [u8; 2] = [((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 901         self.io.write_buf(&buf)
 902     }
 903
 904     /// Writes 16-bit little-endian integer to the output.
 905     pub fn write_u16le(&mut self, val: u16) -> ByteIOResult<()> {
 906         let buf: [u8; 2] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8];
 907         self.io.write_buf(&buf)
 908     }
 909
 910     /// Writes 24-bit big-endian integer to the output.
 911     pub fn write_u24be(&mut self, val: u32) -> ByteIOResult<()> {
 912         let buf: [u8; 3] = [((val >> 16) & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, (val & 0xFF) as u8];
 913         self.write_buf(&buf)
 914     }
 915
 916     /// Writes 24-bit little-endian integer to the output.
 917     pub fn write_u24le(&mut self, val: u32) -> ByteIOResult<()> {
 918         let buf: [u8; 3] = [(val & 0xFF) as u8, ((val >> 8) & 0xFF) as u8, ((val >> 16) & 0xFF) as u8];
 919         self.write_buf(&buf)
 920     }
 921
 922     /// Writes 32-bit big-endian integer to the output.
 923     pub fn write_u32be(&mut self, val: u32) -> ByteIOResult<()> {
 924         self.write_u16be(((val >> 16) & 0xFFFF) as u16)?;
 925         self.write_u16be((val & 0xFFFF) as u16)
 926     }
 927
 928     /// Writes 32-bit little-endian integer to the output.
 929     pub fn write_u32le(&mut self, val: u32) -> ByteIOResult<()> {
 930         self.write_u16le((val & 0xFFFF) as u16)?;
 931         self.write_u16le(((val >> 16) & 0xFFFF) as u16)
 932     }
 933
 934     /// Writes 64-bit big-endian integer to the output.
 935     pub fn write_u64be(&mut self, val: u64) -> ByteIOResult<()> {
 936         self.write_u32be((val >> 32) as u32)?;
 937         self.write_u32be(val as u32)
 938     }
 939
 940     /// Writes 64-bit little-endian integer to the output.
 941     pub fn write_u64le(&mut self, val: u64) -> ByteIOResult<()> {
 942         self.write_u32le(val as u32)?;
 943         self.write_u32le((val >> 32) as u32)
 944     }
 945
 946     /// Writes 32-bit big-endian floating point number to the output.
 947     pub fn write_f32be(&mut self, val: f32) -> ByteIOResult<()> {
 948         self.write_u32be(val.to_bits())
 949     }
 950
 951     /// Writes 32-bit little-endian floating point number to the output.
 952     pub fn write_f32le(&mut self, val: f32) -> ByteIOResult<()> {
 953         self.write_u32le(val.to_bits())
 954     }
 955
 956     /// Writes 64-bit big-endian floating point number to the output.
 957     pub fn write_f64be(&mut self, val: f64) -> ByteIOResult<()> {
 958         self.write_u64be(val.to_bits())
 959     }
 960
 961     /// Writes 64-bit little-endian floating point number to the output.
 962     pub fn write_f64le(&mut self, val: f64) -> ByteIOResult<()> {
 963         self.write_u64le(val.to_bits())
 964     }
 965
 966     /// Reports the current write position.
 967     pub fn tell(&mut self) -> u64 {
 968         self.io.tell()
 969     }
 970
 971     /// Seeks to the requested position.
 972     pub fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
 973         self.io.seek(pos)
 974     }
 975
 976     /// Reports the amount of bytes the writer can still write (-1 if unknown).
 977     pub fn size_left(&mut self) -> i64 {
 978         let sz = self.io.size();
 979         if sz == -1 { return -1; }
 980         sz - (self.tell() as i64)
 981     }
 982
 983     /// Flushes output stream if possible.
 984     pub fn flush(&mut self) -> ByteIOResult<()> {
 985         self.io.flush()
 986     }
 987 }
 988
 989 impl<'a> MemoryWriter<'a> {
 990
 991     /// Constructs a new instance of `MemoryWriter`.
 992     pub fn new_write(buf: &'a mut [u8]) -> Self {
 993         MemoryWriter { buf, pos: 0 }
 994     }
 995
 996     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
 997         if pos < 0 || (pos as usize) > self.buf.len() {
 998             return Err(ByteIOError::WrongRange)
 999         }
1000         self.pos = pos as usize;
1001         Ok(pos as u64)
1002     }
1003 }
1004
1005 impl<'a> ByteIO for MemoryWriter<'a> {
1006     fn read_byte(&mut self) -> ByteIOResult<u8> {
1007         Err(ByteIOError::NotImplemented)
1008     }
1009
1010     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1011         Err(ByteIOError::NotImplemented)
1012     }
1013
1014     fn read_buf(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1015         Err(ByteIOError::NotImplemented)
1016     }
1017
1018     fn read_buf_some(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1019         Err(ByteIOError::NotImplemented)
1020     }
1021
1022     fn peek_buf(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1023         Err(ByteIOError::NotImplemented)
1024     }
1025
1026     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1027         if self.pos + buf.len() > self.buf.len() { return Err(ByteIOError::WriteError); }
1028         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1029         self.pos += buf.len();
1030         Ok(())
1031     }
1032
1033     fn tell(&mut self) -> u64 {
1034         self.pos as u64
1035     }
1036
1037     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1038         let cur_pos  = self.pos       as i64;
1039         let cur_size = self.buf.len() as i64;
1040         match pos {
1041             SeekFrom::Start(x)   => self.real_seek(x as i64),
1042             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1043             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1044         }
1045     }
1046
1047     fn is_eof(&self) -> bool {
1048         self.pos >= self.buf.len()
1049     }
1050
1051     fn is_seekable(&mut self) -> bool {
1052         true
1053     }
1054
1055     fn size(&mut self) -> i64 {
1056         self.buf.len() as i64
1057     }
1058
1059     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1060 }
1061
1062 impl<'a> GrowableMemoryWriter<'a> {
1063
1064     /// Constructs a new instance of `GrowableMemoryWriter`.
1065     pub fn new_write(buf: &'a mut Vec<u8>) -> Self {
1066         GrowableMemoryWriter { buf, pos: 0 }
1067     }
1068
1069     fn real_seek(&mut self, pos: i64) -> ByteIOResult<u64> {
1070         if pos < 0 || (pos as usize) > self.buf.len() {
1071             return Err(ByteIOError::WrongRange)
1072         }
1073         self.pos = pos as usize;
1074         Ok(pos as u64)
1075     }
1076 }
1077
1078 impl<'a> ByteIO for GrowableMemoryWriter<'a> {
1079     fn read_byte(&mut self) -> ByteIOResult<u8> {
1080         Err(ByteIOError::NotImplemented)
1081     }
1082
1083     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1084         Err(ByteIOError::NotImplemented)
1085     }
1086
1087     fn read_buf(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1088         Err(ByteIOError::NotImplemented)
1089     }
1090
1091     fn read_buf_some(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1092         Err(ByteIOError::NotImplemented)
1093     }
1094
1095     fn peek_buf(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1096         Err(ByteIOError::NotImplemented)
1097     }
1098
1099     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1100         if self.pos + buf.len() > self.buf.len() {
1101             self.buf.resize(self.pos + buf.len(), 0);
1102         }
1103         self.buf[self.pos..][..buf.len()].copy_from_slice(buf);
1104         self.pos += buf.len();
1105         Ok(())
1106     }
1107
1108     fn tell(&mut self) -> u64 {
1109         self.pos as u64
1110     }
1111
1112     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1113         let cur_pos  = self.pos       as i64;
1114         let cur_size = self.buf.len() as i64;
1115         match pos {
1116             SeekFrom::Start(x)   => self.real_seek(x as i64),
1117             SeekFrom::Current(x) => self.real_seek(cur_pos + x),
1118             SeekFrom::End(x)     => self.real_seek(cur_size + x),
1119         }
1120     }
1121
1122     fn is_eof(&self) -> bool {
1123         self.pos >= self.buf.len()
1124     }
1125
1126     fn is_seekable(&mut self) -> bool {
1127         true
1128     }
1129
1130     fn size(&mut self) -> i64 {
1131         self.buf.len() as i64
1132     }
1133
1134     fn flush(&mut self) -> ByteIOResult<()> { Ok(()) }
1135 }
1136
1137 impl<T: Write+Seek> FileWriter<T> {
1138     /// Constructs a new instance of `FileWriter`.
1139     pub fn new_write(file: T) -> Self {
1140         FileWriter { file: Box::new(file) }
1141     }
1142 }
1143
1144 impl<T: Write+Seek> ByteIO for FileWriter<T> {
1145     fn read_byte(&mut self) -> ByteIOResult<u8> {
1146         Err(ByteIOError::NotImplemented)
1147     }
1148
1149     fn peek_byte(&mut self) -> ByteIOResult<u8> {
1150         Err(ByteIOError::NotImplemented)
1151     }
1152
1153     fn read_buf(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1154         Err(ByteIOError::NotImplemented)
1155     }
1156
1157     fn read_buf_some(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1158         Err(ByteIOError::NotImplemented)
1159     }
1160
1161     fn peek_buf(&mut self, _buf: &mut [u8]) -> ByteIOResult<usize> {
1162         Err(ByteIOError::NotImplemented)
1163     }
1164
1165     fn write_buf(&mut self, buf: &[u8]) -> ByteIOResult<()> {
1166         match self.file.write_all(buf) {
1167             Ok(()) => Ok(()),
1168             Err(_) => Err(ByteIOError::WriteError),
1169         }
1170     }
1171
1172     fn tell(&mut self) -> u64 {
1173         self.file.stream_position().unwrap()
1174     }
1175
1176     fn seek(&mut self, pos: SeekFrom) -> ByteIOResult<u64> {
1177         let res = self.file.seek(pos);
1178         match res {
1179             Ok(r) => Ok(r),
1180             Err(_) => Err(ByteIOError::SeekError),
1181         }
1182     }
1183
1184     fn is_eof(&self) -> bool {
1185         false
1186     }
1187
1188     fn is_seekable(&mut self) -> bool {
1189         true
1190     }
1191
1192     fn size(&mut self) -> i64 {
1193         -1
1194     }
1195
1196     fn flush(&mut self) -> ByteIOResult<()> {
1197         match self.file.flush() {
1198             Ok(()) => Ok(()),
1199             Err(_) => Err(ByteIOError::WriteError),
1200         }
1201     }
1202 }
1203
1204 #[cfg(test)]
1205 mod test {
1206     use super::*;
1207     use std::fs::File;
1208
1209     #[test]
1210     fn test_read() {
1211         //const DATA : &'static [u8] = include_bytes!("../../assets/file");
1212         let buf: [u8; 64] = [1; 64];
1213         let mut mr = MemoryReader::new_read(&buf);
1214         let mut reader = ByteReader::new(&mut mr);
1215         assert_eq!(reader.read_byte().unwrap(),  0x01u8);
1216         assert_eq!(reader.read_u16le().unwrap(), 0x0101u16);
1217         assert_eq!(reader.read_u24le().unwrap(), 0x010101u32);
1218         assert_eq!(reader.read_u32le().unwrap(), 0x01010101u32);
1219         assert_eq!(reader.read_u64le().unwrap(), 0x0101010101010101u64);
1220         let mut file = File::open("assets/Misc/MaoMacha.asx").unwrap();
1221         let mut fr = FileReader::new_read(&mut file);
1222         let mut br2 = ByteReader::new(&mut fr);
1223         assert_eq!(br2.read_byte().unwrap(), 0x30);
1224         assert_eq!(br2.read_u24be().unwrap(), 0x26B275);
1225         assert_eq!(br2.read_u24le().unwrap(), 0xCF668E);
1226         assert_eq!(br2.read_u32be().unwrap(), 0x11A6D900);
1227         assert_eq!(br2.read_u32le().unwrap(), 0xCE6200AA);
1228     }
1229     #[test]
1230     fn test_write() {
1231         let mut buf: [u8; 64] = [0; 64];
1232         {
1233             let mut mw = MemoryWriter::new_write(&mut buf);
1234             let mut bw = ByteWriter::new(&mut mw);
1235             bw.write_byte(0x00).unwrap();
1236             bw.write_u16be(0x0102).unwrap();
1237             bw.write_u24be(0x030405).unwrap();
1238             bw.write_u32be(0x06070809).unwrap();
1239             bw.write_u64be(0x0A0B0C0D0E0F1011).unwrap();
1240             bw.write_byte(0x00).unwrap();
1241             bw.write_u16le(0x0201).unwrap();
1242             bw.write_u24le(0x050403).unwrap();
1243             bw.write_u32le(0x09080706).unwrap();
1244             bw.write_u64le(0x11100F0E0D0C0B0A).unwrap();
1245             assert_eq!(bw.size_left(), 28);
1246         }
1247         for i in 0..0x12 {
1248             assert_eq!(buf[(i + 0x00) as usize], i);
1249             assert_eq!(buf[(i + 0x12) as usize], i);
1250         }
1251     }
1252 }