diff options
Diffstat (limited to 'vendor/bytes/src/buf/buf_impl.rs')
| -rw-r--r-- | vendor/bytes/src/buf/buf_impl.rs | 1071 |
1 files changed, 1071 insertions, 0 deletions
diff --git a/vendor/bytes/src/buf/buf_impl.rs b/vendor/bytes/src/buf/buf_impl.rs new file mode 100644 index 000000000..16ad8a7ee --- /dev/null +++ b/vendor/bytes/src/buf/buf_impl.rs @@ -0,0 +1,1071 @@ +#[cfg(feature = "std")] +use crate::buf::{reader, Reader}; +use crate::buf::{take, Chain, Take}; + +use core::{cmp, mem, ptr}; + +#[cfg(feature = "std")] +use std::io::IoSlice; + +use alloc::boxed::Box; + +macro_rules! buf_get_impl { + ($this:ident, $typ:tt::$conv:tt) => {{ + const SIZE: usize = mem::size_of::<$typ>(); + // try to convert directly from the bytes + // this Option<ret> trick is to avoid keeping a borrow on self + // when advance() is called (mut borrow) and to call bytes() only once + let ret = $this + .chunk() + .get(..SIZE) + .map(|src| unsafe { $typ::$conv(*(src as *const _ as *const [_; SIZE])) }); + + if let Some(ret) = ret { + // if the direct conversion was possible, advance and return + $this.advance(SIZE); + return ret; + } else { + // if not we copy the bytes in a temp buffer then convert + let mut buf = [0; SIZE]; + $this.copy_to_slice(&mut buf); // (do the advance) + return $typ::$conv(buf); + } + }}; + (le => $this:ident, $typ:tt, $len_to_read:expr) => {{ + debug_assert!(mem::size_of::<$typ>() >= $len_to_read); + + // The same trick as above does not improve the best case speed. + // It seems to be linked to the way the method is optimised by the compiler + let mut buf = [0; (mem::size_of::<$typ>())]; + $this.copy_to_slice(&mut buf[..($len_to_read)]); + return $typ::from_le_bytes(buf); + }}; + (be => $this:ident, $typ:tt, $len_to_read:expr) => {{ + debug_assert!(mem::size_of::<$typ>() >= $len_to_read); + + let mut buf = [0; (mem::size_of::<$typ>())]; + $this.copy_to_slice(&mut buf[mem::size_of::<$typ>() - ($len_to_read)..]); + return $typ::from_be_bytes(buf); + }}; +} + +/// Read bytes from a buffer. +/// +/// A buffer stores bytes in memory such that read operations are infallible. +/// The underlying storage may or may not be in contiguous memory. A `Buf` value +/// is a cursor into the buffer. Reading from `Buf` advances the cursor +/// position. It can be thought of as an efficient `Iterator` for collections of +/// bytes. +/// +/// The simplest `Buf` is a `&[u8]`. +/// +/// ``` +/// use bytes::Buf; +/// +/// let mut buf = &b"hello world"[..]; +/// +/// assert_eq!(b'h', buf.get_u8()); +/// assert_eq!(b'e', buf.get_u8()); +/// assert_eq!(b'l', buf.get_u8()); +/// +/// let mut rest = [0; 8]; +/// buf.copy_to_slice(&mut rest); +/// +/// assert_eq!(&rest[..], &b"lo world"[..]); +/// ``` +pub trait Buf { + /// Returns the number of bytes between the current position and the end of + /// the buffer. + /// + /// This value is greater than or equal to the length of the slice returned + /// by `chunk()`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"hello world"[..]; + /// + /// assert_eq!(buf.remaining(), 11); + /// + /// buf.get_u8(); + /// + /// assert_eq!(buf.remaining(), 10); + /// ``` + /// + /// # Implementer notes + /// + /// Implementations of `remaining` should ensure that the return value does + /// not change unless a call is made to `advance` or any other function that + /// is documented to change the `Buf`'s current position. + fn remaining(&self) -> usize; + + /// Returns a slice starting at the current position and of length between 0 + /// and `Buf::remaining()`. Note that this *can* return shorter slice (this allows + /// non-continuous internal representation). + /// + /// This is a lower level function. Most operations are done with other + /// functions. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"hello world"[..]; + /// + /// assert_eq!(buf.chunk(), &b"hello world"[..]); + /// + /// buf.advance(6); + /// + /// assert_eq!(buf.chunk(), &b"world"[..]); + /// ``` + /// + /// # Implementer notes + /// + /// This function should never panic. Once the end of the buffer is reached, + /// i.e., `Buf::remaining` returns 0, calls to `chunk()` should return an + /// empty slice. + fn chunk(&self) -> &[u8]; + + /// Fills `dst` with potentially multiple slices starting at `self`'s + /// current position. + /// + /// If the `Buf` is backed by disjoint slices of bytes, `chunk_vectored` enables + /// fetching more than one slice at once. `dst` is a slice of `IoSlice` + /// references, enabling the slice to be directly used with [`writev`] + /// without any further conversion. The sum of the lengths of all the + /// buffers in `dst` will be less than or equal to `Buf::remaining()`. + /// + /// The entries in `dst` will be overwritten, but the data **contained** by + /// the slices **will not** be modified. If `chunk_vectored` does not fill every + /// entry in `dst`, then `dst` is guaranteed to contain all remaining slices + /// in `self. + /// + /// This is a lower level function. Most operations are done with other + /// functions. + /// + /// # Implementer notes + /// + /// This function should never panic. Once the end of the buffer is reached, + /// i.e., `Buf::remaining` returns 0, calls to `chunk_vectored` must return 0 + /// without mutating `dst`. + /// + /// Implementations should also take care to properly handle being called + /// with `dst` being a zero length slice. + /// + /// [`writev`]: http://man7.org/linux/man-pages/man2/readv.2.html + #[cfg(feature = "std")] + fn chunks_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize { + if dst.is_empty() { + return 0; + } + + if self.has_remaining() { + dst[0] = IoSlice::new(self.chunk()); + 1 + } else { + 0 + } + } + + /// Advance the internal cursor of the Buf + /// + /// The next call to `chunk()` will return a slice starting `cnt` bytes + /// further into the underlying buffer. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"hello world"[..]; + /// + /// assert_eq!(buf.chunk(), &b"hello world"[..]); + /// + /// buf.advance(6); + /// + /// assert_eq!(buf.chunk(), &b"world"[..]); + /// ``` + /// + /// # Panics + /// + /// This function **may** panic if `cnt > self.remaining()`. + /// + /// # Implementer notes + /// + /// It is recommended for implementations of `advance` to panic if `cnt > + /// self.remaining()`. If the implementation does not panic, the call must + /// behave as if `cnt == self.remaining()`. + /// + /// A call with `cnt == 0` should never panic and be a no-op. + fn advance(&mut self, cnt: usize); + + /// Returns true if there are any more bytes to consume + /// + /// This is equivalent to `self.remaining() != 0`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"a"[..]; + /// + /// assert!(buf.has_remaining()); + /// + /// buf.get_u8(); + /// + /// assert!(!buf.has_remaining()); + /// ``` + fn has_remaining(&self) -> bool { + self.remaining() > 0 + } + + /// Copies bytes from `self` into `dst`. + /// + /// The cursor is advanced by the number of bytes copied. `self` must have + /// enough remaining bytes to fill `dst`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"hello world"[..]; + /// let mut dst = [0; 5]; + /// + /// buf.copy_to_slice(&mut dst); + /// assert_eq!(&b"hello"[..], &dst); + /// assert_eq!(6, buf.remaining()); + /// ``` + /// + /// # Panics + /// + /// This function panics if `self.remaining() < dst.len()` + fn copy_to_slice(&mut self, dst: &mut [u8]) { + let mut off = 0; + + assert!(self.remaining() >= dst.len()); + + while off < dst.len() { + let cnt; + + unsafe { + let src = self.chunk(); + cnt = cmp::min(src.len(), dst.len() - off); + + ptr::copy_nonoverlapping(src.as_ptr(), dst[off..].as_mut_ptr(), cnt); + + off += cnt; + } + + self.advance(cnt); + } + } + + /// Gets an unsigned 8 bit integer from `self`. + /// + /// The current position is advanced by 1. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08 hello"[..]; + /// assert_eq!(8, buf.get_u8()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is no more remaining data in `self`. + fn get_u8(&mut self) -> u8 { + assert!(self.remaining() >= 1); + let ret = self.chunk()[0]; + self.advance(1); + ret + } + + /// Gets a signed 8 bit integer from `self`. + /// + /// The current position is advanced by 1. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08 hello"[..]; + /// assert_eq!(8, buf.get_i8()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is no more remaining data in `self`. + fn get_i8(&mut self) -> i8 { + assert!(self.remaining() >= 1); + let ret = self.chunk()[0] as i8; + self.advance(1); + ret + } + + /// Gets an unsigned 16 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08\x09 hello"[..]; + /// assert_eq!(0x0809, buf.get_u16()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u16(&mut self) -> u16 { + buf_get_impl!(self, u16::from_be_bytes); + } + + /// Gets an unsigned 16 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x09\x08 hello"[..]; + /// assert_eq!(0x0809, buf.get_u16_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u16_le(&mut self) -> u16 { + buf_get_impl!(self, u16::from_le_bytes); + } + + /// Gets a signed 16 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08\x09 hello"[..]; + /// assert_eq!(0x0809, buf.get_i16()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i16(&mut self) -> i16 { + buf_get_impl!(self, i16::from_be_bytes); + } + + /// Gets a signed 16 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x09\x08 hello"[..]; + /// assert_eq!(0x0809, buf.get_i16_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i16_le(&mut self) -> i16 { + buf_get_impl!(self, i16::from_le_bytes); + } + + /// Gets an unsigned 32 bit integer from `self` in the big-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08\x09\xA0\xA1 hello"[..]; + /// assert_eq!(0x0809A0A1, buf.get_u32()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u32(&mut self) -> u32 { + buf_get_impl!(self, u32::from_be_bytes); + } + + /// Gets an unsigned 32 bit integer from `self` in the little-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\xA1\xA0\x09\x08 hello"[..]; + /// assert_eq!(0x0809A0A1, buf.get_u32_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u32_le(&mut self) -> u32 { + buf_get_impl!(self, u32::from_le_bytes); + } + + /// Gets a signed 32 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08\x09\xA0\xA1 hello"[..]; + /// assert_eq!(0x0809A0A1, buf.get_i32()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i32(&mut self) -> i32 { + buf_get_impl!(self, i32::from_be_bytes); + } + + /// Gets a signed 32 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\xA1\xA0\x09\x08 hello"[..]; + /// assert_eq!(0x0809A0A1, buf.get_i32_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i32_le(&mut self) -> i32 { + buf_get_impl!(self, i32::from_le_bytes); + } + + /// Gets an unsigned 64 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x01\x02\x03\x04\x05\x06\x07\x08 hello"[..]; + /// assert_eq!(0x0102030405060708, buf.get_u64()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u64(&mut self) -> u64 { + buf_get_impl!(self, u64::from_be_bytes); + } + + /// Gets an unsigned 64 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08\x07\x06\x05\x04\x03\x02\x01 hello"[..]; + /// assert_eq!(0x0102030405060708, buf.get_u64_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u64_le(&mut self) -> u64 { + buf_get_impl!(self, u64::from_le_bytes); + } + + /// Gets a signed 64 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x01\x02\x03\x04\x05\x06\x07\x08 hello"[..]; + /// assert_eq!(0x0102030405060708, buf.get_i64()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i64(&mut self) -> i64 { + buf_get_impl!(self, i64::from_be_bytes); + } + + /// Gets a signed 64 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x08\x07\x06\x05\x04\x03\x02\x01 hello"[..]; + /// assert_eq!(0x0102030405060708, buf.get_i64_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i64_le(&mut self) -> i64 { + buf_get_impl!(self, i64::from_le_bytes); + } + + /// Gets an unsigned 128 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16 hello"[..]; + /// assert_eq!(0x01020304050607080910111213141516, buf.get_u128()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u128(&mut self) -> u128 { + buf_get_impl!(self, u128::from_be_bytes); + } + + /// Gets an unsigned 128 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x16\x15\x14\x13\x12\x11\x10\x09\x08\x07\x06\x05\x04\x03\x02\x01 hello"[..]; + /// assert_eq!(0x01020304050607080910111213141516, buf.get_u128_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_u128_le(&mut self) -> u128 { + buf_get_impl!(self, u128::from_le_bytes); + } + + /// Gets a signed 128 bit integer from `self` in big-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16 hello"[..]; + /// assert_eq!(0x01020304050607080910111213141516, buf.get_i128()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i128(&mut self) -> i128 { + buf_get_impl!(self, i128::from_be_bytes); + } + + /// Gets a signed 128 bit integer from `self` in little-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x16\x15\x14\x13\x12\x11\x10\x09\x08\x07\x06\x05\x04\x03\x02\x01 hello"[..]; + /// assert_eq!(0x01020304050607080910111213141516, buf.get_i128_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_i128_le(&mut self) -> i128 { + buf_get_impl!(self, i128::from_le_bytes); + } + + /// Gets an unsigned n-byte integer from `self` in big-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x01\x02\x03 hello"[..]; + /// assert_eq!(0x010203, buf.get_uint(3)); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_uint(&mut self, nbytes: usize) -> u64 { + buf_get_impl!(be => self, u64, nbytes); + } + + /// Gets an unsigned n-byte integer from `self` in little-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x03\x02\x01 hello"[..]; + /// assert_eq!(0x010203, buf.get_uint_le(3)); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_uint_le(&mut self, nbytes: usize) -> u64 { + buf_get_impl!(le => self, u64, nbytes); + } + + /// Gets a signed n-byte integer from `self` in big-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x01\x02\x03 hello"[..]; + /// assert_eq!(0x010203, buf.get_int(3)); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_int(&mut self, nbytes: usize) -> i64 { + buf_get_impl!(be => self, i64, nbytes); + } + + /// Gets a signed n-byte integer from `self` in little-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x03\x02\x01 hello"[..]; + /// assert_eq!(0x010203, buf.get_int_le(3)); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_int_le(&mut self, nbytes: usize) -> i64 { + buf_get_impl!(le => self, i64, nbytes); + } + + /// Gets an IEEE754 single-precision (4 bytes) floating point number from + /// `self` in big-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x3F\x99\x99\x9A hello"[..]; + /// assert_eq!(1.2f32, buf.get_f32()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_f32(&mut self) -> f32 { + f32::from_bits(Self::get_u32(self)) + } + + /// Gets an IEEE754 single-precision (4 bytes) floating point number from + /// `self` in little-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x9A\x99\x99\x3F hello"[..]; + /// assert_eq!(1.2f32, buf.get_f32_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_f32_le(&mut self) -> f32 { + f32::from_bits(Self::get_u32_le(self)) + } + + /// Gets an IEEE754 double-precision (8 bytes) floating point number from + /// `self` in big-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x3F\xF3\x33\x33\x33\x33\x33\x33 hello"[..]; + /// assert_eq!(1.2f64, buf.get_f64()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_f64(&mut self) -> f64 { + f64::from_bits(Self::get_u64(self)) + } + + /// Gets an IEEE754 double-precision (8 bytes) floating point number from + /// `self` in little-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut buf = &b"\x33\x33\x33\x33\x33\x33\xF3\x3F hello"[..]; + /// assert_eq!(1.2f64, buf.get_f64_le()); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining data in `self`. + fn get_f64_le(&mut self) -> f64 { + f64::from_bits(Self::get_u64_le(self)) + } + + /// Consumes `len` bytes inside self and returns new instance of `Bytes` + /// with this data. + /// + /// This function may be optimized by the underlying type to avoid actual + /// copies. For example, `Bytes` implementation will do a shallow copy + /// (ref-count increment). + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let bytes = (&b"hello world"[..]).copy_to_bytes(5); + /// assert_eq!(&bytes[..], &b"hello"[..]); + /// ``` + fn copy_to_bytes(&mut self, len: usize) -> crate::Bytes { + use super::BufMut; + + assert!(len <= self.remaining(), "`len` greater than remaining"); + + let mut ret = crate::BytesMut::with_capacity(len); + ret.put(self.take(len)); + ret.freeze() + } + + /// Creates an adaptor which will read at most `limit` bytes from `self`. + /// + /// This function returns a new instance of `Buf` which will read at most + /// `limit` bytes. + /// + /// # Examples + /// + /// ``` + /// use bytes::{Buf, BufMut}; + /// + /// let mut buf = b"hello world"[..].take(5); + /// let mut dst = vec![]; + /// + /// dst.put(&mut buf); + /// assert_eq!(dst, b"hello"); + /// + /// let mut buf = buf.into_inner(); + /// dst.clear(); + /// dst.put(&mut buf); + /// assert_eq!(dst, b" world"); + /// ``` + fn take(self, limit: usize) -> Take<Self> + where + Self: Sized, + { + take::new(self, limit) + } + + /// Creates an adaptor which will chain this buffer with another. + /// + /// The returned `Buf` instance will first consume all bytes from `self`. + /// Afterwards the output is equivalent to the output of next. + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let mut chain = b"hello "[..].chain(&b"world"[..]); + /// + /// let full = chain.copy_to_bytes(11); + /// assert_eq!(full.chunk(), b"hello world"); + /// ``` + fn chain<U: Buf>(self, next: U) -> Chain<Self, U> + where + Self: Sized, + { + Chain::new(self, next) + } + + /// Creates an adaptor which implements the `Read` trait for `self`. + /// + /// This function returns a new value which implements `Read` by adapting + /// the `Read` trait functions to the `Buf` trait functions. Given that + /// `Buf` operations are infallible, none of the `Read` functions will + /// return with `Err`. + /// + /// # Examples + /// + /// ``` + /// use bytes::{Bytes, Buf}; + /// use std::io::Read; + /// + /// let buf = Bytes::from("hello world"); + /// + /// let mut reader = buf.reader(); + /// let mut dst = [0; 1024]; + /// + /// let num = reader.read(&mut dst).unwrap(); + /// + /// assert_eq!(11, num); + /// assert_eq!(&dst[..11], &b"hello world"[..]); + /// ``` + #[cfg(feature = "std")] + fn reader(self) -> Reader<Self> + where + Self: Sized, + { + reader::new(self) + } +} + +macro_rules! deref_forward_buf { + () => { + fn remaining(&self) -> usize { + (**self).remaining() + } + + fn chunk(&self) -> &[u8] { + (**self).chunk() + } + + #[cfg(feature = "std")] + fn chunks_vectored<'b>(&'b self, dst: &mut [IoSlice<'b>]) -> usize { + (**self).chunks_vectored(dst) + } + + fn advance(&mut self, cnt: usize) { + (**self).advance(cnt) + } + + fn has_remaining(&self) -> bool { + (**self).has_remaining() + } + + fn copy_to_slice(&mut self, dst: &mut [u8]) { + (**self).copy_to_slice(dst) + } + + fn get_u8(&mut self) -> u8 { + (**self).get_u8() + } + + fn get_i8(&mut self) -> i8 { + (**self).get_i8() + } + + fn get_u16(&mut self) -> u16 { + (**self).get_u16() + } + + fn get_u16_le(&mut self) -> u16 { + (**self).get_u16_le() + } + + fn get_i16(&mut self) -> i16 { + (**self).get_i16() + } + + fn get_i16_le(&mut self) -> i16 { + (**self).get_i16_le() + } + + fn get_u32(&mut self) -> u32 { + (**self).get_u32() + } + + fn get_u32_le(&mut self) -> u32 { + (**self).get_u32_le() + } + + fn get_i32(&mut self) -> i32 { + (**self).get_i32() + } + + fn get_i32_le(&mut self) -> i32 { + (**self).get_i32_le() + } + + fn get_u64(&mut self) -> u64 { + (**self).get_u64() + } + + fn get_u64_le(&mut self) -> u64 { + (**self).get_u64_le() + } + + fn get_i64(&mut self) -> i64 { + (**self).get_i64() + } + + fn get_i64_le(&mut self) -> i64 { + (**self).get_i64_le() + } + + fn get_uint(&mut self, nbytes: usize) -> u64 { + (**self).get_uint(nbytes) + } + + fn get_uint_le(&mut self, nbytes: usize) -> u64 { + (**self).get_uint_le(nbytes) + } + + fn get_int(&mut self, nbytes: usize) -> i64 { + (**self).get_int(nbytes) + } + + fn get_int_le(&mut self, nbytes: usize) -> i64 { + (**self).get_int_le(nbytes) + } + + fn copy_to_bytes(&mut self, len: usize) -> crate::Bytes { + (**self).copy_to_bytes(len) + } + }; +} + +impl<T: Buf + ?Sized> Buf for &mut T { + deref_forward_buf!(); +} + +impl<T: Buf + ?Sized> Buf for Box<T> { + deref_forward_buf!(); +} + +impl Buf for &[u8] { + #[inline] + fn remaining(&self) -> usize { + self.len() + } + + #[inline] + fn chunk(&self) -> &[u8] { + self + } + + #[inline] + fn advance(&mut self, cnt: usize) { + *self = &self[cnt..]; + } +} + +#[cfg(feature = "std")] +impl<T: AsRef<[u8]>> Buf for std::io::Cursor<T> { + fn remaining(&self) -> usize { + let len = self.get_ref().as_ref().len(); + let pos = self.position(); + + if pos >= len as u64 { + return 0; + } + + len - pos as usize + } + + fn chunk(&self) -> &[u8] { + let len = self.get_ref().as_ref().len(); + let pos = self.position(); + + if pos >= len as u64 { + return &[]; + } + + &self.get_ref().as_ref()[pos as usize..] + } + + fn advance(&mut self, cnt: usize) { + let pos = (self.position() as usize) + .checked_add(cnt) + .expect("overflow"); + + assert!(pos <= self.get_ref().as_ref().len()); + self.set_position(pos as u64); + } +} + +// The existence of this function makes the compiler catch if the Buf +// trait is "object-safe" or not. +fn _assert_trait_object(_b: &dyn Buf) {} |