diff options
author | Chih-Hung Hsieh <chh@google.com> | 2020-06-10 20:15:59 -0700 |
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committer | Chih-Hung Hsieh <chh@google.com> | 2020-06-10 20:15:59 -0700 |
commit | 01ae379526218e7f6ca28510b6c06098419b7380 (patch) | |
tree | ded7cfd36c57807924e0b2e62439a8df9f6d32c1 /src/buf | |
parent | 7457df12a2eb70afcfa283968f7d1fadf123b0a1 (diff) | |
download | bytes-01ae379526218e7f6ca28510b6c06098419b7380.tar.gz |
Import bytes-0.5.4
* Add OWNERS and Android.bp
Bug: 143953733
Test: make
Change-Id: Ica69d7252abb1c2967f2c0e11a62d0bd83192fb3
Diffstat (limited to 'src/buf')
-rw-r--r-- | src/buf/buf_impl.rs | 1006 | ||||
-rw-r--r-- | src/buf/buf_mut.rs | 1088 | ||||
-rw-r--r-- | src/buf/ext/chain.rs | 234 | ||||
-rw-r--r-- | src/buf/ext/limit.rs | 77 | ||||
-rw-r--r-- | src/buf/ext/mod.rs | 176 | ||||
-rw-r--r-- | src/buf/ext/reader.rs | 81 | ||||
-rw-r--r-- | src/buf/ext/take.rs | 150 | ||||
-rw-r--r-- | src/buf/ext/writer.rs | 88 | ||||
-rw-r--r-- | src/buf/iter.rs | 133 | ||||
-rw-r--r-- | src/buf/mod.rs | 31 | ||||
-rw-r--r-- | src/buf/vec_deque.rs | 22 |
11 files changed, 3086 insertions, 0 deletions
diff --git a/src/buf/buf_impl.rs b/src/buf/buf_impl.rs new file mode 100644 index 0000000..843db71 --- /dev/null +++ b/src/buf/buf_impl.rs @@ -0,0 +1,1006 @@ +use core::{cmp, ptr, mem}; + +#[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.bytes().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 `bytes`. + /// + /// # 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.bytes(), &b"hello world"[..]); + /// + /// buf.advance(6); + /// + /// assert_eq!(buf.bytes(), &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 `bytes` should return an + /// empty slice. + fn bytes(&self) -> &[u8]; + + /// Fills `dst` with potentially multiple slices starting at `self`'s + /// current position. + /// + /// If the `Buf` is backed by disjoint slices of bytes, `bytes_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 `bytes_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 `bytes_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 bytes_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize { + if dst.is_empty() { + return 0; + } + + if self.has_remaining() { + dst[0] = IoSlice::new(self.bytes()); + 1 + } else { + 0 + } + } + + /// Advance the internal cursor of the Buf + /// + /// The next call to `bytes` 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.bytes(), &b"hello world"[..]); + /// + /// buf.advance(6); + /// + /// assert_eq!(buf.bytes(), &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.bytes(); + 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.bytes()[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.bytes()[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 remaining bytes inside self and returns new instance of `Bytes` + /// + /// # Examples + /// + /// ``` + /// use bytes::Buf; + /// + /// let bytes = (&b"hello world"[..]).to_bytes(); + /// assert_eq!(&bytes[..], &b"hello world"[..]); + /// ``` + fn to_bytes(&mut self) -> crate::Bytes { + use super::BufMut; + let mut ret = crate::BytesMut::with_capacity(self.remaining()); + ret.put(self); + ret.freeze() + } +} + +macro_rules! deref_forward_buf { + () => ( + fn remaining(&self) -> usize { + (**self).remaining() + } + + fn bytes(&self) -> &[u8] { + (**self).bytes() + } + + #[cfg(feature = "std")] + fn bytes_vectored<'b>(&'b self, dst: &mut [IoSlice<'b>]) -> usize { + (**self).bytes_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 to_bytes(&mut self) -> crate::Bytes { + (**self).to_bytes() + } + + ) +} + +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 bytes(&self) -> &[u8] { + self + } + + #[inline] + fn advance(&mut self, cnt: usize) { + *self = &self[cnt..]; + } +} + +impl Buf for Option<[u8; 1]> { + fn remaining(&self) -> usize { + if self.is_some() { + 1 + } else { + 0 + } + } + + fn bytes(&self) -> &[u8] { + self.as_ref().map(AsRef::as_ref) + .unwrap_or(Default::default()) + } + + fn advance(&mut self, cnt: usize) { + if cnt == 0 { + return; + } + + if self.is_none() { + panic!("overflow"); + } else { + assert_eq!(1, cnt); + *self = None; + } + } +} + +#[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 bytes(&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) {} diff --git a/src/buf/buf_mut.rs b/src/buf/buf_mut.rs new file mode 100644 index 0000000..f5ed2a7 --- /dev/null +++ b/src/buf/buf_mut.rs @@ -0,0 +1,1088 @@ +use core::{cmp, mem::{self, MaybeUninit}, ptr, usize}; + +#[cfg(feature = "std")] +use std::fmt; + +use alloc::{vec::Vec, boxed::Box}; + +/// A trait for values that provide sequential write access to bytes. +/// +/// Write bytes to a buffer +/// +/// A buffer stores bytes in memory such that write operations are infallible. +/// The underlying storage may or may not be in contiguous memory. A `BufMut` +/// value is a cursor into the buffer. Writing to `BufMut` advances the cursor +/// position. +/// +/// The simplest `BufMut` is a `Vec<u8>`. +/// +/// ``` +/// use bytes::BufMut; +/// +/// let mut buf = vec![]; +/// +/// buf.put(&b"hello world"[..]); +/// +/// assert_eq!(buf, b"hello world"); +/// ``` +pub trait BufMut { + /// Returns the number of bytes that can be written from the current + /// position until the end of the buffer is reached. + /// + /// This value is greater than or equal to the length of the slice returned + /// by `bytes_mut`. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut dst = [0; 10]; + /// let mut buf = &mut dst[..]; + /// + /// let original_remaining = buf.remaining_mut(); + /// buf.put(&b"hello"[..]); + /// + /// assert_eq!(original_remaining - 5, buf.remaining_mut()); + /// ``` + /// + /// # Implementer notes + /// + /// Implementations of `remaining_mut` should ensure that the return value + /// does not change unless a call is made to `advance_mut` or any other + /// function that is documented to change the `BufMut`'s current position. + fn remaining_mut(&self) -> usize; + + /// Advance the internal cursor of the BufMut + /// + /// The next call to `bytes_mut` will return a slice starting `cnt` bytes + /// further into the underlying buffer. + /// + /// This function is unsafe because there is no guarantee that the bytes + /// being advanced past have been initialized. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = Vec::with_capacity(16); + /// + /// unsafe { + /// // MaybeUninit::as_mut_ptr + /// buf.bytes_mut()[0].as_mut_ptr().write(b'h'); + /// buf.bytes_mut()[1].as_mut_ptr().write(b'e'); + /// + /// buf.advance_mut(2); + /// + /// buf.bytes_mut()[0].as_mut_ptr().write(b'l'); + /// buf.bytes_mut()[1].as_mut_ptr().write(b'l'); + /// buf.bytes_mut()[2].as_mut_ptr().write(b'o'); + /// + /// buf.advance_mut(3); + /// } + /// + /// assert_eq!(5, buf.len()); + /// assert_eq!(buf, b"hello"); + /// ``` + /// + /// # Panics + /// + /// This function **may** panic if `cnt > self.remaining_mut()`. + /// + /// # Implementer notes + /// + /// It is recommended for implementations of `advance_mut` to panic if + /// `cnt > self.remaining_mut()`. If the implementation does not panic, + /// the call must behave as if `cnt == self.remaining_mut()`. + /// + /// A call with `cnt == 0` should never panic and be a no-op. + unsafe fn advance_mut(&mut self, cnt: usize); + + /// Returns true if there is space in `self` for more bytes. + /// + /// This is equivalent to `self.remaining_mut() != 0`. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut dst = [0; 5]; + /// let mut buf = &mut dst[..]; + /// + /// assert!(buf.has_remaining_mut()); + /// + /// buf.put(&b"hello"[..]); + /// + /// assert!(!buf.has_remaining_mut()); + /// ``` + fn has_remaining_mut(&self) -> bool { + self.remaining_mut() > 0 + } + + /// Returns a mutable slice starting at the current BufMut position and of + /// length between 0 and `BufMut::remaining_mut()`. Note that this *can* be shorter than the + /// whole remainder of the buffer (this allows non-continuous implementation). + /// + /// This is a lower level function. Most operations are done with other + /// functions. + /// + /// The returned byte slice may represent uninitialized memory. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = Vec::with_capacity(16); + /// + /// unsafe { + /// // MaybeUninit::as_mut_ptr + /// buf.bytes_mut()[0].as_mut_ptr().write(b'h'); + /// buf.bytes_mut()[1].as_mut_ptr().write(b'e'); + /// + /// buf.advance_mut(2); + /// + /// buf.bytes_mut()[0].as_mut_ptr().write(b'l'); + /// buf.bytes_mut()[1].as_mut_ptr().write(b'l'); + /// buf.bytes_mut()[2].as_mut_ptr().write(b'o'); + /// + /// buf.advance_mut(3); + /// } + /// + /// assert_eq!(5, buf.len()); + /// assert_eq!(buf, b"hello"); + /// ``` + /// + /// # Implementer notes + /// + /// This function should never panic. `bytes_mut` should return an empty + /// slice **if and only if** `remaining_mut` returns 0. In other words, + /// `bytes_mut` returning an empty slice implies that `remaining_mut` will + /// return 0 and `remaining_mut` returning 0 implies that `bytes_mut` will + /// return an empty slice. + fn bytes_mut(&mut self) -> &mut [MaybeUninit<u8>]; + + /// Fills `dst` with potentially multiple mutable slices starting at `self`'s + /// current position. + /// + /// If the `BufMut` is backed by disjoint slices of bytes, `bytes_vectored_mut` + /// enables fetching more than one slice at once. `dst` is a slice of + /// mutable `IoSliceMut` references, enabling the slice to be directly used with + /// [`readv`] without any further conversion. The sum of the lengths of all + /// the buffers in `dst` will be less than or equal to + /// `Buf::remaining_mut()`. + /// + /// The entries in `dst` will be overwritten, but the data **contained** by + /// the slices **will not** be modified. If `bytes_vectored_mut` 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., `BufMut::remaining_mut` returns 0, calls to `bytes_vectored_mut` must + /// return 0 without mutating `dst`. + /// + /// Implementations should also take care to properly handle being called + /// with `dst` being a zero length slice. + /// + /// [`readv`]: http://man7.org/linux/man-pages/man2/readv.2.html + #[cfg(feature = "std")] + fn bytes_vectored_mut<'a>(&'a mut self, dst: &mut [IoSliceMut<'a>]) -> usize { + if dst.is_empty() { + return 0; + } + + if self.has_remaining_mut() { + dst[0] = IoSliceMut::from(self.bytes_mut()); + 1 + } else { + 0 + } + } + + /// Transfer bytes into `self` from `src` and advance the cursor by the + /// number of bytes written. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// + /// buf.put_u8(b'h'); + /// buf.put(&b"ello"[..]); + /// buf.put(&b" world"[..]); + /// + /// assert_eq!(buf, b"hello world"); + /// ``` + /// + /// # Panics + /// + /// Panics if `self` does not have enough capacity to contain `src`. + fn put<T: super::Buf>(&mut self, mut src: T) where Self: Sized { + assert!(self.remaining_mut() >= src.remaining()); + + while src.has_remaining() { + let l; + + unsafe { + let s = src.bytes(); + let d = self.bytes_mut(); + l = cmp::min(s.len(), d.len()); + + ptr::copy_nonoverlapping( + s.as_ptr(), + d.as_mut_ptr() as *mut u8, + l); + } + + src.advance(l); + unsafe { self.advance_mut(l); } + } + } + + /// Transfer bytes into `self` from `src` and advance the cursor by the + /// number of bytes written. + /// + /// `self` must have enough remaining capacity to contain all of `src`. + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut dst = [0; 6]; + /// + /// { + /// let mut buf = &mut dst[..]; + /// buf.put_slice(b"hello"); + /// + /// assert_eq!(1, buf.remaining_mut()); + /// } + /// + /// assert_eq!(b"hello\0", &dst); + /// ``` + fn put_slice(&mut self, src: &[u8]) { + let mut off = 0; + + assert!(self.remaining_mut() >= src.len(), "buffer overflow; remaining = {}; src = {}", self.remaining_mut(), src.len()); + + while off < src.len() { + let cnt; + + unsafe { + let dst = self.bytes_mut(); + cnt = cmp::min(dst.len(), src.len() - off); + + ptr::copy_nonoverlapping( + src[off..].as_ptr(), + dst.as_mut_ptr() as *mut u8, + cnt); + + off += cnt; + + } + + unsafe { self.advance_mut(cnt); } + } + } + + /// Writes an unsigned 8 bit integer to `self`. + /// + /// The current position is advanced by 1. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u8(0x01); + /// assert_eq!(buf, b"\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u8(&mut self, n: u8) { + let src = [n]; + self.put_slice(&src); + } + + /// Writes a signed 8 bit integer to `self`. + /// + /// The current position is advanced by 1. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i8(0x01); + /// assert_eq!(buf, b"\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i8(&mut self, n: i8) { + let src = [n as u8]; + self.put_slice(&src) + } + + /// Writes an unsigned 16 bit integer to `self` in big-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u16(0x0809); + /// assert_eq!(buf, b"\x08\x09"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u16(&mut self, n: u16) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes an unsigned 16 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u16_le(0x0809); + /// assert_eq!(buf, b"\x09\x08"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u16_le(&mut self, n: u16) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes a signed 16 bit integer to `self` in big-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i16(0x0809); + /// assert_eq!(buf, b"\x08\x09"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i16(&mut self, n: i16) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes a signed 16 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 2. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i16_le(0x0809); + /// assert_eq!(buf, b"\x09\x08"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i16_le(&mut self, n: i16) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes an unsigned 32 bit integer to `self` in big-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u32(0x0809A0A1); + /// assert_eq!(buf, b"\x08\x09\xA0\xA1"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u32(&mut self, n: u32) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes an unsigned 32 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u32_le(0x0809A0A1); + /// assert_eq!(buf, b"\xA1\xA0\x09\x08"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u32_le(&mut self, n: u32) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes a signed 32 bit integer to `self` in big-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i32(0x0809A0A1); + /// assert_eq!(buf, b"\x08\x09\xA0\xA1"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i32(&mut self, n: i32) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes a signed 32 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i32_le(0x0809A0A1); + /// assert_eq!(buf, b"\xA1\xA0\x09\x08"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i32_le(&mut self, n: i32) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes an unsigned 64 bit integer to `self` in the big-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u64(0x0102030405060708); + /// assert_eq!(buf, b"\x01\x02\x03\x04\x05\x06\x07\x08"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u64(&mut self, n: u64) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes an unsigned 64 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u64_le(0x0102030405060708); + /// assert_eq!(buf, b"\x08\x07\x06\x05\x04\x03\x02\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u64_le(&mut self, n: u64) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes a signed 64 bit integer to `self` in the big-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i64(0x0102030405060708); + /// assert_eq!(buf, b"\x01\x02\x03\x04\x05\x06\x07\x08"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i64(&mut self, n: i64) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes a signed 64 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i64_le(0x0102030405060708); + /// assert_eq!(buf, b"\x08\x07\x06\x05\x04\x03\x02\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i64_le(&mut self, n: i64) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes an unsigned 128 bit integer to `self` in the big-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u128(0x01020304050607080910111213141516); + /// assert_eq!(buf, b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u128(&mut self, n: u128) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes an unsigned 128 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_u128_le(0x01020304050607080910111213141516); + /// assert_eq!(buf, b"\x16\x15\x14\x13\x12\x11\x10\x09\x08\x07\x06\x05\x04\x03\x02\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_u128_le(&mut self, n: u128) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes a signed 128 bit integer to `self` in the big-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i128(0x01020304050607080910111213141516); + /// assert_eq!(buf, b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i128(&mut self, n: i128) { + self.put_slice(&n.to_be_bytes()) + } + + /// Writes a signed 128 bit integer to `self` in little-endian byte order. + /// + /// The current position is advanced by 16. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_i128_le(0x01020304050607080910111213141516); + /// assert_eq!(buf, b"\x16\x15\x14\x13\x12\x11\x10\x09\x08\x07\x06\x05\x04\x03\x02\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_i128_le(&mut self, n: i128) { + self.put_slice(&n.to_le_bytes()) + } + + /// Writes an unsigned n-byte integer to `self` in big-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_uint(0x010203, 3); + /// assert_eq!(buf, b"\x01\x02\x03"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_uint(&mut self, n: u64, nbytes: usize) { + self.put_slice(&n.to_be_bytes()[mem::size_of_val(&n) - nbytes..]); + } + + /// Writes an unsigned n-byte integer to `self` in the little-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_uint_le(0x010203, 3); + /// assert_eq!(buf, b"\x03\x02\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_uint_le(&mut self, n: u64, nbytes: usize) { + self.put_slice(&n.to_le_bytes()[0..nbytes]); + } + + /// Writes a signed n-byte integer to `self` in big-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_int(0x010203, 3); + /// assert_eq!(buf, b"\x01\x02\x03"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_int(&mut self, n: i64, nbytes: usize) { + self.put_slice(&n.to_be_bytes()[mem::size_of_val(&n) - nbytes..]); + } + + /// Writes a signed n-byte integer to `self` in little-endian byte order. + /// + /// The current position is advanced by `nbytes`. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_int_le(0x010203, 3); + /// assert_eq!(buf, b"\x03\x02\x01"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_int_le(&mut self, n: i64, nbytes: usize) { + self.put_slice(&n.to_le_bytes()[0..nbytes]); + } + + /// Writes an IEEE754 single-precision (4 bytes) floating point number to + /// `self` in big-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_f32(1.2f32); + /// assert_eq!(buf, b"\x3F\x99\x99\x9A"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_f32(&mut self, n: f32) { + self.put_u32(n.to_bits()); + } + + /// Writes an IEEE754 single-precision (4 bytes) floating point number to + /// `self` in little-endian byte order. + /// + /// The current position is advanced by 4. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_f32_le(1.2f32); + /// assert_eq!(buf, b"\x9A\x99\x99\x3F"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_f32_le(&mut self, n: f32) { + self.put_u32_le(n.to_bits()); + } + + /// Writes an IEEE754 double-precision (8 bytes) floating point number to + /// `self` in big-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_f64(1.2f64); + /// assert_eq!(buf, b"\x3F\xF3\x33\x33\x33\x33\x33\x33"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_f64(&mut self, n: f64) { + self.put_u64(n.to_bits()); + } + + /// Writes an IEEE754 double-precision (8 bytes) floating point number to + /// `self` in little-endian byte order. + /// + /// The current position is advanced by 8. + /// + /// # Examples + /// + /// ``` + /// use bytes::BufMut; + /// + /// let mut buf = vec![]; + /// buf.put_f64_le(1.2f64); + /// assert_eq!(buf, b"\x33\x33\x33\x33\x33\x33\xF3\x3F"); + /// ``` + /// + /// # Panics + /// + /// This function panics if there is not enough remaining capacity in + /// `self`. + fn put_f64_le(&mut self, n: f64) { + self.put_u64_le(n.to_bits()); + } +} + +macro_rules! deref_forward_bufmut { + () => ( + fn remaining_mut(&self) -> usize { + (**self).remaining_mut() + } + + fn bytes_mut(&mut self) -> &mut [MaybeUninit<u8>] { + (**self).bytes_mut() + } + + #[cfg(feature = "std")] + fn bytes_vectored_mut<'b>(&'b mut self, dst: &mut [IoSliceMut<'b>]) -> usize { + (**self).bytes_vectored_mut(dst) + } + + unsafe fn advance_mut(&mut self, cnt: usize) { + (**self).advance_mut(cnt) + } + + fn put_slice(&mut self, src: &[u8]) { + (**self).put_slice(src) + } + + fn put_u8(&mut self, n: u8) { + (**self).put_u8(n) + } + + fn put_i8(&mut self, n: i8) { + (**self).put_i8(n) + } + + fn put_u16(&mut self, n: u16) { + (**self).put_u16(n) + } + + fn put_u16_le(&mut self, n: u16) { + (**self).put_u16_le(n) + } + + fn put_i16(&mut self, n: i16) { + (**self).put_i16(n) + } + + fn put_i16_le(&mut self, n: i16) { + (**self).put_i16_le(n) + } + + fn put_u32(&mut self, n: u32) { + (**self).put_u32(n) + } + + fn put_u32_le(&mut self, n: u32) { + (**self).put_u32_le(n) + } + + fn put_i32(&mut self, n: i32) { + (**self).put_i32(n) + } + + fn put_i32_le(&mut self, n: i32) { + (**self).put_i32_le(n) + } + + fn put_u64(&mut self, n: u64) { + (**self).put_u64(n) + } + + fn put_u64_le(&mut self, n: u64) { + (**self).put_u64_le(n) + } + + fn put_i64(&mut self, n: i64) { + (**self).put_i64(n) + } + + fn put_i64_le(&mut self, n: i64) { + (**self).put_i64_le(n) + } + ) +} + +impl<T: BufMut + ?Sized> BufMut for &mut T { + deref_forward_bufmut!(); +} + +impl<T: BufMut + ?Sized> BufMut for Box<T> { + deref_forward_bufmut!(); +} + +impl BufMut for &mut [u8] { + #[inline] + fn remaining_mut(&self) -> usize { + self.len() + } + + #[inline] + fn bytes_mut(&mut self) -> &mut [MaybeUninit<u8>] { + // MaybeUninit is repr(transparent), so safe to transmute + unsafe { mem::transmute(&mut **self) } + } + + #[inline] + unsafe fn advance_mut(&mut self, cnt: usize) { + // Lifetime dance taken from `impl Write for &mut [u8]`. + let (_, b) = core::mem::replace(self, &mut []).split_at_mut(cnt); + *self = b; + } +} + +impl BufMut for Vec<u8> { + #[inline] + fn remaining_mut(&self) -> usize { + usize::MAX - self.len() + } + + #[inline] + unsafe fn advance_mut(&mut self, cnt: usize) { + let len = self.len(); + let remaining = self.capacity() - len; + if cnt > remaining { + // Reserve additional capacity, and ensure that the total length + // will not overflow usize. + self.reserve(cnt); + } + + self.set_len(len + cnt); + } + + #[inline] + fn bytes_mut(&mut self) -> &mut [MaybeUninit<u8>] { + use core::slice; + + if self.capacity() == self.len() { + self.reserve(64); // Grow the vec + } + + let cap = self.capacity(); + let len = self.len(); + + let ptr = self.as_mut_ptr() as *mut MaybeUninit<u8>; + unsafe { + &mut slice::from_raw_parts_mut(ptr, cap)[len..] + } + } + + // Specialize these methods so they can skip checking `remaining_mut` + // and `advance_mut`. + + fn put<T: super::Buf>(&mut self, mut src: T) where Self: Sized { + // In case the src isn't contiguous, reserve upfront + self.reserve(src.remaining()); + + while src.has_remaining() { + let l; + + // a block to contain the src.bytes() borrow + { + let s = src.bytes(); + l = s.len(); + self.extend_from_slice(s); + } + + src.advance(l); + } + } + + fn put_slice(&mut self, src: &[u8]) { + self.extend_from_slice(src); + } +} + +// The existence of this function makes the compiler catch if the BufMut +// trait is "object-safe" or not. +fn _assert_trait_object(_b: &dyn BufMut) {} + +// ===== impl IoSliceMut ===== + +/// A buffer type used for `readv`. +/// +/// This is a wrapper around an `std::io::IoSliceMut`, but does not expose +/// the inner bytes in a safe API, as they may point at uninitialized memory. +/// +/// This is `repr(transparent)` of the `std::io::IoSliceMut`, so it is valid to +/// transmute them. However, as the memory might be uninitialized, care must be +/// taken to not *read* the internal bytes, only *write* to them. +#[repr(transparent)] +#[cfg(feature = "std")] +pub struct IoSliceMut<'a>(std::io::IoSliceMut<'a>); + +#[cfg(feature = "std")] +impl fmt::Debug for IoSliceMut<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("IoSliceMut") + .field("len", &self.0.len()) + .finish() + } +} + +#[cfg(feature = "std")] +impl<'a> From<&'a mut [u8]> for IoSliceMut<'a> { + fn from(buf: &'a mut [u8]) -> IoSliceMut<'a> { + IoSliceMut(std::io::IoSliceMut::new(buf)) + } +} + +#[cfg(feature = "std")] +impl<'a> From<&'a mut [MaybeUninit<u8>]> for IoSliceMut<'a> { + fn from(buf: &'a mut [MaybeUninit<u8>]) -> IoSliceMut<'a> { + IoSliceMut(std::io::IoSliceMut::new(unsafe { + // We don't look at the contents, and `std::io::IoSliceMut` + // doesn't either. + mem::transmute::<&'a mut [MaybeUninit<u8>], &'a mut [u8]>(buf) + })) + } +} diff --git a/src/buf/ext/chain.rs b/src/buf/ext/chain.rs new file mode 100644 index 0000000..a1ec597 --- /dev/null +++ b/src/buf/ext/chain.rs @@ -0,0 +1,234 @@ +use crate::{Buf, BufMut}; +use crate::buf::IntoIter; + +use core::mem::MaybeUninit; + +#[cfg(feature = "std")] +use std::io::{IoSlice}; +#[cfg(feature = "std")] +use crate::buf::IoSliceMut; + +/// A `Chain` sequences two buffers. +/// +/// `Chain` is an adapter that links two underlying buffers and provides a +/// continuous view across both buffers. It is able to sequence either immutable +/// buffers ([`Buf`] values) or mutable buffers ([`BufMut`] values). +/// +/// This struct is generally created by calling [`Buf::chain`]. Please see that +/// function's documentation for more detail. +/// +/// # Examples +/// +/// ``` +/// use bytes::{Bytes, Buf, buf::BufExt}; +/// +/// let mut buf = (&b"hello "[..]) +/// .chain(&b"world"[..]); +/// +/// let full: Bytes = buf.to_bytes(); +/// assert_eq!(full[..], b"hello world"[..]); +/// ``` +/// +/// [`Buf::chain`]: trait.Buf.html#method.chain +/// [`Buf`]: trait.Buf.html +/// [`BufMut`]: trait.BufMut.html +#[derive(Debug)] +pub struct Chain<T, U> { + a: T, + b: U, +} + +impl<T, U> Chain<T, U> { + /// Creates a new `Chain` sequencing the provided values. + pub fn new(a: T, b: U) -> Chain<T, U> { + Chain { + a, + b, + } + } + + /// Gets a reference to the first underlying `Buf`. + /// + /// # Examples + /// + /// ``` + /// use bytes::buf::BufExt; + /// + /// let buf = (&b"hello"[..]) + /// .chain(&b"world"[..]); + /// + /// assert_eq!(buf.first_ref()[..], b"hello"[..]); + /// ``` + pub fn first_ref(&self) -> &T { + &self.a + } + + /// Gets a mutable reference to the first underlying `Buf`. + /// + /// # Examples + /// + /// ``` + /// use bytes::{Buf, buf::BufExt}; + /// + /// let mut buf = (&b"hello"[..]) + /// .chain(&b"world"[..]); + /// + /// buf.first_mut().advance(1); + /// + /// let full = buf.to_bytes(); + /// assert_eq!(full, b"elloworld"[..]); + /// ``` + pub fn first_mut(&mut self) -> &mut T { + &mut self.a + } + + /// Gets a reference to the last underlying `Buf`. + /// + /// # Examples + /// + /// ``` + /// use bytes::buf::BufExt; + /// + /// let buf = (&b"hello"[..]) + /// .chain(&b"world"[..]); + /// + /// assert_eq!(buf.last_ref()[..], b"world"[..]); + /// ``` + pub fn last_ref(&self) -> &U { + &self.b + } + + /// Gets a mutable reference to the last underlying `Buf`. + /// + /// # Examples + /// + /// ``` + /// use bytes::{Buf, buf::BufExt}; + /// + /// let mut buf = (&b"hello "[..]) + /// .chain(&b"world"[..]); + /// + /// buf.last_mut().advance(1); + /// + /// let full = buf.to_bytes(); + /// assert_eq!(full, b"hello orld"[..]); + /// ``` + pub fn last_mut(&mut self) -> &mut U { + &mut self.b + } + + /// Consumes this `Chain`, returning the underlying values. + /// + /// # Examples + /// + /// ``` + /// use bytes::buf::BufExt; + /// + /// let chain = (&b"hello"[..]) + /// .chain(&b"world"[..]); + /// + /// let (first, last) = chain.into_inner(); + /// assert_eq!(first[..], b"hello"[..]); + /// assert_eq!(last[..], b"world"[..]); + /// ``` + pub fn into_inner(self) -> (T, U) { + (self.a, self.b) + } +} + +impl<T, U> Buf for Chain<T, U> + where T: Buf, + U: Buf, +{ + fn remaining(&self) -> usize { + self.a.remaining() + self.b.remaining() + } + + fn bytes(&self) -> &[u8] { + if self.a.has_remaining() { + self.a.bytes() + } else { + self.b.bytes() + } + } + + fn advance(&mut self, mut cnt: usize) { + let a_rem = self.a.remaining(); + + if a_rem != 0 { + if a_rem >= cnt { + self.a.advance(cnt); + return; + } + + // Consume what is left of a + self.a.advance(a_rem); + + cnt -= a_rem; + } + + self.b.advance(cnt); + } + + #[cfg(feature = "std")] + fn bytes_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize { + let mut n = self.a.bytes_vectored(dst); + n += self.b.bytes_vectored(&mut dst[n..]); + n + } +} + +impl<T, U> BufMut for Chain<T, U> + where T: BufMut, + U: BufMut, +{ + fn remaining_mut(&self) -> usize { + self.a.remaining_mut() + self.b.remaining_mut() + } + + fn bytes_mut(&mut self) -> &mut [MaybeUninit<u8>] { + if self.a.has_remaining_mut() { + self.a.bytes_mut() + } else { + self.b.bytes_mut() + } + } + + unsafe fn advance_mut(&mut self, mut cnt: usize) { + let a_rem = self.a.remaining_mut(); + + if a_rem != 0 { + if a_rem >= cnt { + self.a.advance_mut(cnt); + return; + } + + // Consume what is left of a + self.a.advance_mut(a_rem); + + cnt -= a_rem; + } + + self.b.advance_mut(cnt); + } + + #[cfg(feature = "std")] + fn bytes_vectored_mut<'a>(&'a mut self, dst: &mut [IoSliceMut<'a>]) -> usize { + let mut n = self.a.bytes_vectored_mut(dst); + n += self.b.bytes_vectored_mut(&mut dst[n..]); + n + } +} + +impl<T, U> IntoIterator for Chain<T, U> +where + T: Buf, + U: Buf, +{ + type Item = u8; + type IntoIter = IntoIter<Chain<T, U>>; + + fn into_iter(self) -> Self::IntoIter { + IntoIter::new(self) + } +} diff --git a/src/buf/ext/limit.rs b/src/buf/ext/limit.rs new file mode 100644 index 0000000..f86e011 --- /dev/null +++ b/src/buf/ext/limit.rs @@ -0,0 +1,77 @@ +use crate::BufMut; + +use core::{cmp, mem::MaybeUninit}; + +/// A `BufMut` adapter which limits the amount of bytes that can be written +/// to an underlying buffer. +#[derive(Debug)] +pub struct Limit<T> { + inner: T, + limit: usize, +} + +pub(super) fn new<T>(inner: T, limit: usize) -> Limit<T> { + Limit { + inner, + limit, + } +} + +impl<T> Limit<T> { + /// Consumes this `Limit`, returning the underlying value. + pub fn into_inner(self) -> T { + self.inner + } + + /// Gets a reference to the underlying `BufMut`. + /// + /// It is inadvisable to directly write to the underlying `BufMut`. + pub fn get_ref(&self) -> &T { + &self.inner + } + + /// Gets a mutable reference to the underlying `BufMut`. + /// + /// It is inadvisable to directly write to the underlying `BufMut`. + pub fn get_mut(&mut self) -> &mut T { + &mut self.inner + } + + /// Returns the maximum number of bytes that can be written + /// + /// # Note + /// + /// If the inner `BufMut` has fewer bytes than indicated by this method then + /// that is the actual number of available bytes. + pub fn limit(&self) -> usize { + self.limit + } + + /// Sets the maximum number of bytes that can be written. + /// + /// # Note + /// + /// If the inner `BufMut` has fewer bytes than `lim` then that is the actual + /// number of available bytes. + pub fn set_limit(&mut self, lim: usize) { + self.limit = lim + } +} + +impl<T: BufMut> BufMut for Limit<T> { + fn remaining_mut(&self) -> usize { + cmp::min(self.inner.remaining_mut(), self.limit) + } + + fn bytes_mut(&mut self) -> &mut [MaybeUninit<u8>] { + let bytes = self.inner.bytes_mut(); + let end = cmp::min(bytes.len(), self.limit); + &mut bytes[..end] + } + + unsafe fn advance_mut(&mut self, cnt: usize) { + assert!(cnt <= self.limit); + self.inner.advance_mut(cnt); + self.limit -= cnt; + } +} diff --git a/src/buf/ext/mod.rs b/src/buf/ext/mod.rs new file mode 100644 index 0000000..7b0bdab --- /dev/null +++ b/src/buf/ext/mod.rs @@ -0,0 +1,176 @@ +//! Extra utilities for `Buf` and `BufMut` types. + +use super::{Buf, BufMut}; + +mod chain; +mod limit; +#[cfg(feature = "std")] +mod reader; +mod take; +#[cfg(feature = "std")] +mod writer; + +pub use self::limit::Limit; +pub use self::take::Take; +pub use self::chain::Chain; + +#[cfg(feature = "std")] +pub use self::{reader::Reader, writer::Writer}; + +/// Extra methods for implementations of `Buf`. +pub trait BufExt: Buf { + /// 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, buf::BufExt}; + /// + /// 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, buf::BufExt}; + /// + /// let mut chain = b"hello "[..].chain(&b"world"[..]); + /// + /// let full = chain.to_bytes(); + /// assert_eq!(full.bytes(), 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::{Buf, Bytes, buf::BufExt}; + /// 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) + } +} + +impl<B: Buf + ?Sized> BufExt for B {} + +/// Extra methods for implementations of `BufMut`. +pub trait BufMutExt: BufMut { + /// Creates an adaptor which can write at most `limit` bytes to `self`. + /// + /// # Examples + /// + /// ``` + /// use bytes::{BufMut, buf::BufMutExt}; + /// + /// let arr = &mut [0u8; 128][..]; + /// assert_eq!(arr.remaining_mut(), 128); + /// + /// let dst = arr.limit(10); + /// assert_eq!(dst.remaining_mut(), 10); + /// ``` + fn limit(self, limit: usize) -> Limit<Self> + where Self: Sized + { + limit::new(self, limit) + } + + /// Creates an adaptor which implements the `Write` trait for `self`. + /// + /// This function returns a new value which implements `Write` by adapting + /// the `Write` trait functions to the `BufMut` trait functions. Given that + /// `BufMut` operations are infallible, none of the `Write` functions will + /// return with `Err`. + /// + /// # Examples + /// + /// ``` + /// use bytes::{BufMut, buf::BufMutExt}; + /// use std::io::Write; + /// + /// let mut buf = vec![].writer(); + /// + /// let num = buf.write(&b"hello world"[..]).unwrap(); + /// assert_eq!(11, num); + /// + /// let buf = buf.into_inner(); + /// + /// assert_eq!(*buf, b"hello world"[..]); + /// ``` + #[cfg(feature = "std")] + fn writer(self) -> Writer<Self> where Self: Sized { + writer::new(self) + } + + /// Creates an adapter which will chain this buffer with another. + /// + /// The returned `BufMut` instance will first write to all bytes from + /// `self`. Afterwards, it will write to `next`. + /// + /// # Examples + /// + /// ``` + /// use bytes::{BufMut, buf::BufMutExt}; + /// + /// let mut a = [0u8; 5]; + /// let mut b = [0u8; 6]; + /// + /// let mut chain = (&mut a[..]).chain_mut(&mut b[..]); + /// + /// chain.put_slice(b"hello world"); + /// + /// assert_eq!(&a[..], b"hello"); + /// assert_eq!(&b[..], b" world"); + /// ``` + fn chain_mut<U: BufMut>(self, next: U) -> Chain<Self, U> + where Self: Sized + { + Chain::new(self, next) + } +} + +impl<B: BufMut + ?Sized> BufMutExt for B {} diff --git a/src/buf/ext/reader.rs b/src/buf/ext/reader.rs new file mode 100644 index 0000000..e38103b --- /dev/null +++ b/src/buf/ext/reader.rs @@ -0,0 +1,81 @@ +use crate::{Buf}; + +use std::{cmp, io}; + +/// A `Buf` adapter which implements `io::Read` for the inner value. +/// +/// This struct is generally created by calling `reader()` on `Buf`. See +/// documentation of [`reader()`](trait.Buf.html#method.reader) for more +/// details. +#[derive(Debug)] +pub struct Reader<B> { + buf: B, +} + +pub fn new<B>(buf: B) -> Reader<B> { + Reader { buf } +} + +impl<B: Buf> Reader<B> { + /// Gets a reference to the underlying `Buf`. + /// + /// It is inadvisable to directly read from the underlying `Buf`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::buf::BufExt; + /// + /// let mut buf = b"hello world".reader(); + /// + /// assert_eq!(b"hello world", buf.get_ref()); + /// ``` + pub fn get_ref(&self) -> &B { + &self.buf + } + + /// Gets a mutable reference to the underlying `Buf`. + /// + /// It is inadvisable to directly read from the underlying `Buf`. + pub fn get_mut(&mut self) -> &mut B { + &mut self.buf + } + + /// Consumes this `Reader`, returning the underlying value. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, buf::BufExt}; + /// use std::io; + /// + /// let mut buf = b"hello world".reader(); + /// let mut dst = vec![]; + /// + /// io::copy(&mut buf, &mut dst).unwrap(); + /// + /// let buf = buf.into_inner(); + /// assert_eq!(0, buf.remaining()); + /// ``` + pub fn into_inner(self) -> B { + self.buf + } +} + +impl<B: Buf + Sized> io::Read for Reader<B> { + fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> { + let len = cmp::min(self.buf.remaining(), dst.len()); + + Buf::copy_to_slice(&mut self.buf, &mut dst[0..len]); + Ok(len) + } +} + +impl<B: Buf + Sized> io::BufRead for Reader<B> { + fn fill_buf(&mut self) -> io::Result<&[u8]> { + Ok(self.buf.bytes()) + } + fn consume(&mut self, amt: usize) { + self.buf.advance(amt) + } +} diff --git a/src/buf/ext/take.rs b/src/buf/ext/take.rs new file mode 100644 index 0000000..6fc4ffc --- /dev/null +++ b/src/buf/ext/take.rs @@ -0,0 +1,150 @@ +use crate::Buf; + +use core::cmp; + +/// A `Buf` adapter which limits the bytes read from an underlying buffer. +/// +/// This struct is generally created by calling `take()` on `Buf`. See +/// documentation of [`take()`](trait.Buf.html#method.take) for more details. +#[derive(Debug)] +pub struct Take<T> { + inner: T, + limit: usize, +} + +pub fn new<T>(inner: T, limit: usize) -> Take<T> { + Take { + inner, + limit, + } +} + +impl<T> Take<T> { + /// Consumes this `Take`, returning the underlying value. + /// + /// # Examples + /// + /// ```rust + /// use bytes::buf::{Buf, BufMut, BufExt}; + /// + /// let mut buf = b"hello world".take(2); + /// let mut dst = vec![]; + /// + /// dst.put(&mut buf); + /// assert_eq!(*dst, b"he"[..]); + /// + /// let mut buf = buf.into_inner(); + /// + /// dst.clear(); + /// dst.put(&mut buf); + /// assert_eq!(*dst, b"llo world"[..]); + /// ``` + pub fn into_inner(self) -> T { + self.inner + } + + /// Gets a reference to the underlying `Buf`. + /// + /// It is inadvisable to directly read from the underlying `Buf`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, buf::BufExt}; + /// + /// let mut buf = b"hello world".take(2); + /// + /// assert_eq!(11, buf.get_ref().remaining()); + /// ``` + pub fn get_ref(&self) -> &T { + &self.inner + } + + /// Gets a mutable reference to the underlying `Buf`. + /// + /// It is inadvisable to directly read from the underlying `Buf`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, BufMut, buf::BufExt}; + /// + /// let mut buf = b"hello world".take(2); + /// let mut dst = vec![]; + /// + /// buf.get_mut().advance(2); + /// + /// dst.put(&mut buf); + /// assert_eq!(*dst, b"ll"[..]); + /// ``` + pub fn get_mut(&mut self) -> &mut T { + &mut self.inner + } + + /// Returns the maximum number of bytes that can be read. + /// + /// # Note + /// + /// If the inner `Buf` has fewer bytes than indicated by this method then + /// that is the actual number of available bytes. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, buf::BufExt}; + /// + /// let mut buf = b"hello world".take(2); + /// + /// assert_eq!(2, buf.limit()); + /// assert_eq!(b'h', buf.get_u8()); + /// assert_eq!(1, buf.limit()); + /// ``` + pub fn limit(&self) -> usize { + self.limit + } + + /// Sets the maximum number of bytes that can be read. + /// + /// # Note + /// + /// If the inner `Buf` has fewer bytes than `lim` then that is the actual + /// number of available bytes. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, BufMut, buf::BufExt}; + /// + /// let mut buf = b"hello world".take(2); + /// let mut dst = vec![]; + /// + /// dst.put(&mut buf); + /// assert_eq!(*dst, b"he"[..]); + /// + /// dst.clear(); + /// + /// buf.set_limit(3); + /// dst.put(&mut buf); + /// assert_eq!(*dst, b"llo"[..]); + /// ``` + pub fn set_limit(&mut self, lim: usize) { + self.limit = lim + } +} + +impl<T: Buf> Buf for Take<T> { + fn remaining(&self) -> usize { + cmp::min(self.inner.remaining(), self.limit) + } + + fn bytes(&self) -> &[u8] { + let bytes = self.inner.bytes(); + &bytes[..cmp::min(bytes.len(), self.limit)] + } + + fn advance(&mut self, cnt: usize) { + assert!(cnt <= self.limit); + self.inner.advance(cnt); + self.limit -= cnt; + } +} diff --git a/src/buf/ext/writer.rs b/src/buf/ext/writer.rs new file mode 100644 index 0000000..1418418 --- /dev/null +++ b/src/buf/ext/writer.rs @@ -0,0 +1,88 @@ +use crate::BufMut; + +use std::{cmp, io}; + +/// A `BufMut` adapter which implements `io::Write` for the inner value. +/// +/// This struct is generally created by calling `writer()` on `BufMut`. See +/// documentation of [`writer()`](trait.BufMut.html#method.writer) for more +/// details. +#[derive(Debug)] +pub struct Writer<B> { + buf: B, +} + +pub fn new<B>(buf: B) -> Writer<B> { + Writer { buf } +} + +impl<B: BufMut> Writer<B> { + /// Gets a reference to the underlying `BufMut`. + /// + /// It is inadvisable to directly write to the underlying `BufMut`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::buf::BufMutExt; + /// + /// let mut buf = Vec::with_capacity(1024).writer(); + /// + /// assert_eq!(1024, buf.get_ref().capacity()); + /// ``` + pub fn get_ref(&self) -> &B { + &self.buf + } + + /// Gets a mutable reference to the underlying `BufMut`. + /// + /// It is inadvisable to directly write to the underlying `BufMut`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::buf::BufMutExt; + /// + /// let mut buf = vec![].writer(); + /// + /// buf.get_mut().reserve(1024); + /// + /// assert_eq!(1024, buf.get_ref().capacity()); + /// ``` + pub fn get_mut(&mut self) -> &mut B { + &mut self.buf + } + + /// Consumes this `Writer`, returning the underlying value. + /// + /// # Examples + /// + /// ```rust + /// use bytes::buf::BufMutExt; + /// use std::io; + /// + /// let mut buf = vec![].writer(); + /// let mut src = &b"hello world"[..]; + /// + /// io::copy(&mut src, &mut buf).unwrap(); + /// + /// let buf = buf.into_inner(); + /// assert_eq!(*buf, b"hello world"[..]); + /// ``` + pub fn into_inner(self) -> B { + self.buf + } +} + +impl<B: BufMut + Sized> io::Write for Writer<B> { + fn write(&mut self, src: &[u8]) -> io::Result<usize> { + let n = cmp::min(self.buf.remaining_mut(), src.len()); + + self.buf.put(&src[0..n]); + Ok(n) + } + + fn flush(&mut self) -> io::Result<()> { + Ok(()) + } +} diff --git a/src/buf/iter.rs b/src/buf/iter.rs new file mode 100644 index 0000000..1af421a --- /dev/null +++ b/src/buf/iter.rs @@ -0,0 +1,133 @@ +use crate::Buf; + +/// Iterator over the bytes contained by the buffer. +/// +/// This struct is created by the [`iter`] method on [`Buf`]. +/// +/// # Examples +/// +/// Basic usage: +/// +/// ``` +/// use bytes::{Buf, Bytes}; +/// +/// let buf = Bytes::from(&b"abc"[..]); +/// let mut iter = buf.into_iter(); +/// +/// assert_eq!(iter.next(), Some(b'a')); +/// assert_eq!(iter.next(), Some(b'b')); +/// assert_eq!(iter.next(), Some(b'c')); +/// assert_eq!(iter.next(), None); +/// ``` +/// +/// [`iter`]: trait.Buf.html#method.iter +/// [`Buf`]: trait.Buf.html +#[derive(Debug)] +pub struct IntoIter<T> { + inner: T, +} + +impl<T> IntoIter<T> { + /// Creates an iterator over the bytes contained by the buffer. + /// + /// # Examples + /// + /// ``` + /// use bytes::{Buf, Bytes}; + /// use bytes::buf::IntoIter; + /// + /// let buf = Bytes::from_static(b"abc"); + /// let mut iter = IntoIter::new(buf); + /// + /// assert_eq!(iter.next(), Some(b'a')); + /// assert_eq!(iter.next(), Some(b'b')); + /// assert_eq!(iter.next(), Some(b'c')); + /// assert_eq!(iter.next(), None); + /// ``` + pub fn new(inner: T) -> IntoIter<T> { + IntoIter { inner } + } + /// Consumes this `IntoIter`, returning the underlying value. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, Bytes}; + /// + /// let buf = Bytes::from(&b"abc"[..]); + /// let mut iter = buf.into_iter(); + /// + /// assert_eq!(iter.next(), Some(b'a')); + /// + /// let buf = iter.into_inner(); + /// assert_eq!(2, buf.remaining()); + /// ``` + pub fn into_inner(self) -> T { + self.inner + } + + /// Gets a reference to the underlying `Buf`. + /// + /// It is inadvisable to directly read from the underlying `Buf`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, Bytes}; + /// + /// let buf = Bytes::from(&b"abc"[..]); + /// let mut iter = buf.into_iter(); + /// + /// assert_eq!(iter.next(), Some(b'a')); + /// + /// assert_eq!(2, iter.get_ref().remaining()); + /// ``` + pub fn get_ref(&self) -> &T { + &self.inner + } + + /// Gets a mutable reference to the underlying `Buf`. + /// + /// It is inadvisable to directly read from the underlying `Buf`. + /// + /// # Examples + /// + /// ```rust + /// use bytes::{Buf, BytesMut}; + /// + /// let buf = BytesMut::from(&b"abc"[..]); + /// let mut iter = buf.into_iter(); + /// + /// assert_eq!(iter.next(), Some(b'a')); + /// + /// iter.get_mut().advance(1); + /// + /// assert_eq!(iter.next(), Some(b'c')); + /// ``` + pub fn get_mut(&mut self) -> &mut T { + &mut self.inner + } +} + + +impl<T: Buf> Iterator for IntoIter<T> { + type Item = u8; + + fn next(&mut self) -> Option<u8> { + if !self.inner.has_remaining() { + return None; + } + + let b = self.inner.bytes()[0]; + self.inner.advance(1); + + Some(b) + } + + fn size_hint(&self) -> (usize, Option<usize>) { + let rem = self.inner.remaining(); + (rem, Some(rem)) + } +} + +impl<T: Buf> ExactSizeIterator for IntoIter<T> { } diff --git a/src/buf/mod.rs b/src/buf/mod.rs new file mode 100644 index 0000000..d4538f2 --- /dev/null +++ b/src/buf/mod.rs @@ -0,0 +1,31 @@ +//! Utilities for working with buffers. +//! +//! A buffer is any structure that contains a sequence of bytes. The bytes may +//! or may not be stored in contiguous memory. This module contains traits used +//! to abstract over buffers as well as utilities for working with buffer types. +//! +//! # `Buf`, `BufMut` +//! +//! These are the two foundational traits for abstractly working with buffers. +//! They can be thought as iterators for byte structures. They offer additional +//! performance over `Iterator` by providing an API optimized for byte slices. +//! +//! See [`Buf`] and [`BufMut`] for more details. +//! +//! [rope]: https://en.wikipedia.org/wiki/Rope_(data_structure) +//! [`Buf`]: trait.Buf.html +//! [`BufMut`]: trait.BufMut.html + +mod buf_impl; +mod buf_mut; +pub mod ext; +mod iter; +mod vec_deque; + +pub use self::buf_impl::Buf; +pub use self::buf_mut::BufMut; +pub use self::ext::{BufExt, BufMutExt}; +#[cfg(feature = "std")] +pub use self::buf_mut::IoSliceMut; +pub use self::iter::IntoIter; + diff --git a/src/buf/vec_deque.rs b/src/buf/vec_deque.rs new file mode 100644 index 0000000..195e689 --- /dev/null +++ b/src/buf/vec_deque.rs @@ -0,0 +1,22 @@ +use alloc::collections::VecDeque; + +use super::Buf; + +impl Buf for VecDeque<u8> { + fn remaining(&self) -> usize { + self.len() + } + + fn bytes(&self) -> &[u8] { + let (s1, s2) = self.as_slices(); + if s1.is_empty() { + s2 + } else { + s1 + } + } + + fn advance(&mut self, cnt: usize) { + self.drain(..cnt); + } +} |