pub trait Buf {
Show 48 methods
// Required methods
fn remaining(&self) -> usize;
fn chunk(&self) -> &[u8] ⓘ;
fn advance(&mut self, cnt: usize);
// Provided methods
fn chunks_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize { ... }
fn has_remaining(&self) -> bool { ... }
fn copy_to_slice(&mut self, dst: &mut [u8]) { ... }
fn get_u8(&mut self) -> u8 { ... }
fn get_i8(&mut self) -> i8 { ... }
fn get_u16(&mut self) -> u16 { ... }
fn get_u16_le(&mut self) -> u16 { ... }
fn get_u16_ne(&mut self) -> u16 { ... }
fn get_i16(&mut self) -> i16 { ... }
fn get_i16_le(&mut self) -> i16 { ... }
fn get_i16_ne(&mut self) -> i16 { ... }
fn get_u32(&mut self) -> u32 { ... }
fn get_u32_le(&mut self) -> u32 { ... }
fn get_u32_ne(&mut self) -> u32 { ... }
fn get_i32(&mut self) -> i32 { ... }
fn get_i32_le(&mut self) -> i32 { ... }
fn get_i32_ne(&mut self) -> i32 { ... }
fn get_u64(&mut self) -> u64 { ... }
fn get_u64_le(&mut self) -> u64 { ... }
fn get_u64_ne(&mut self) -> u64 { ... }
fn get_i64(&mut self) -> i64 { ... }
fn get_i64_le(&mut self) -> i64 { ... }
fn get_i64_ne(&mut self) -> i64 { ... }
fn get_u128(&mut self) -> u128 { ... }
fn get_u128_le(&mut self) -> u128 { ... }
fn get_u128_ne(&mut self) -> u128 { ... }
fn get_i128(&mut self) -> i128 { ... }
fn get_i128_le(&mut self) -> i128 { ... }
fn get_i128_ne(&mut self) -> i128 { ... }
fn get_uint(&mut self, nbytes: usize) -> u64 { ... }
fn get_uint_le(&mut self, nbytes: usize) -> u64 { ... }
fn get_uint_ne(&mut self, nbytes: usize) -> u64 { ... }
fn get_int(&mut self, nbytes: usize) -> i64 { ... }
fn get_int_le(&mut self, nbytes: usize) -> i64 { ... }
fn get_int_ne(&mut self, nbytes: usize) -> i64 { ... }
fn get_f32(&mut self) -> f32 { ... }
fn get_f32_le(&mut self) -> f32 { ... }
fn get_f32_ne(&mut self) -> f32 { ... }
fn get_f64(&mut self) -> f64 { ... }
fn get_f64_le(&mut self) -> f64 { ... }
fn get_f64_ne(&mut self) -> f64 { ... }
fn copy_to_bytes(&mut self, len: usize) -> Bytes { ... }
fn take(self, limit: usize) -> Take<Self>
where Self: Sized { ... }
fn chain<U>(self, next: U) -> Chain<Self, U>
where U: Buf,
Self: Sized { ... }
fn reader(self) -> Reader<Self> ⓘ
where Self: Sized { ... }
}Expand description
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"[..]);Required Methods§
fn remaining(&self) -> usize
fn remaining(&self) -> usize
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 chunk(&self) -> &[u8] ⓘ
fn chunk(&self) -> &[u8] ⓘ
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 advance(&mut self, cnt: usize)
fn advance(&mut self, cnt: usize)
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.
Provided Methods§
fn chunks_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize
fn chunks_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize
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.
fn has_remaining(&self) -> bool
fn has_remaining(&self) -> bool
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 copy_to_slice(&mut self, dst: &mut [u8])
fn copy_to_slice(&mut self, dst: &mut [u8])
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 get_u16_le(&mut self) -> u16
fn get_u16_le(&mut self) -> u16
fn get_u16_ne(&mut self) -> u16
fn get_u16_ne(&mut self) -> u16
Gets an unsigned 16 bit integer from self in native-endian byte order.
The current position is advanced by 2.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x08\x09 hello",
false => b"\x09\x08 hello",
};
assert_eq!(0x0809, buf.get_u16_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_i16_le(&mut self) -> i16
fn get_i16_le(&mut self) -> i16
fn get_i16_ne(&mut self) -> i16
fn get_i16_ne(&mut self) -> i16
Gets a signed 16 bit integer from self in native-endian byte order.
The current position is advanced by 2.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x08\x09 hello",
false => b"\x09\x08 hello",
};
assert_eq!(0x0809, buf.get_i16_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_u32_le(&mut self) -> u32
fn get_u32_le(&mut self) -> u32
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_ne(&mut self) -> u32
fn get_u32_ne(&mut self) -> u32
Gets an unsigned 32 bit integer from self in native-endian byte order.
The current position is advanced by 4.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x08\x09\xA0\xA1 hello",
false => b"\xA1\xA0\x09\x08 hello",
};
assert_eq!(0x0809A0A1, buf.get_u32_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_i32_le(&mut self) -> i32
fn get_i32_le(&mut self) -> i32
fn get_i32_ne(&mut self) -> i32
fn get_i32_ne(&mut self) -> i32
Gets a signed 32 bit integer from self in native-endian byte order.
The current position is advanced by 4.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x08\x09\xA0\xA1 hello",
false => b"\xA1\xA0\x09\x08 hello",
};
assert_eq!(0x0809A0A1, buf.get_i32_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_u64(&mut self) -> u64
fn get_u64(&mut self) -> u64
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_le(&mut self) -> u64
fn get_u64_le(&mut self) -> u64
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_ne(&mut self) -> u64
fn get_u64_ne(&mut self) -> u64
Gets an unsigned 64 bit integer from self in native-endian byte order.
The current position is advanced by 8.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x01\x02\x03\x04\x05\x06\x07\x08 hello",
false => b"\x08\x07\x06\x05\x04\x03\x02\x01 hello",
};
assert_eq!(0x0102030405060708, buf.get_u64_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_i64(&mut self) -> i64
fn get_i64(&mut self) -> i64
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_le(&mut self) -> i64
fn get_i64_le(&mut self) -> i64
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_ne(&mut self) -> i64
fn get_i64_ne(&mut self) -> i64
Gets a signed 64 bit integer from self in native-endian byte order.
The current position is advanced by 8.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x01\x02\x03\x04\x05\x06\x07\x08 hello",
false => b"\x08\x07\x06\x05\x04\x03\x02\x01 hello",
};
assert_eq!(0x0102030405060708, buf.get_i64_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_u128(&mut self) -> u128
fn get_u128(&mut self) -> u128
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_le(&mut self) -> u128
fn get_u128_le(&mut self) -> u128
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_ne(&mut self) -> u128
fn get_u128_ne(&mut self) -> u128
Gets an unsigned 128 bit integer from self in native-endian byte order.
The current position is advanced by 16.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16 hello",
false => b"\x16\x15\x14\x13\x12\x11\x10\x09\x08\x07\x06\x05\x04\x03\x02\x01 hello",
};
assert_eq!(0x01020304050607080910111213141516, buf.get_u128_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_i128(&mut self) -> i128
fn get_i128(&mut self) -> i128
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_le(&mut self) -> i128
fn get_i128_le(&mut self) -> i128
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_ne(&mut self) -> i128
fn get_i128_ne(&mut self) -> i128
Gets a signed 128 bit integer from self in native-endian byte order.
The current position is advanced by 16.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16 hello",
false => b"\x16\x15\x14\x13\x12\x11\x10\x09\x08\x07\x06\x05\x04\x03\x02\x01 hello",
};
assert_eq!(0x01020304050607080910111213141516, buf.get_i128_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_uint_le(&mut self, nbytes: usize) -> u64
fn get_uint_le(&mut self, nbytes: usize) -> u64
fn get_uint_ne(&mut self, nbytes: usize) -> u64
fn get_uint_ne(&mut self, nbytes: usize) -> u64
Gets an unsigned n-byte integer from self in native-endian byte order.
The current position is advanced by nbytes.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x01\x02\x03 hello",
false => b"\x03\x02\x01 hello",
};
assert_eq!(0x010203, buf.get_uint_ne(3));Panics
This function panics if there is not enough remaining data in self.
fn get_int_le(&mut self, nbytes: usize) -> i64
fn get_int_le(&mut self, nbytes: usize) -> i64
fn get_int_ne(&mut self, nbytes: usize) -> i64
fn get_int_ne(&mut self, nbytes: usize) -> i64
Gets a signed n-byte integer from self in native-endian byte order.
The current position is advanced by nbytes.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x01\x02\x03 hello",
false => b"\x03\x02\x01 hello",
};
assert_eq!(0x010203, buf.get_int_ne(3));Panics
This function panics if there is not enough remaining data in self.
fn get_f32(&mut self) -> f32
fn get_f32(&mut self) -> f32
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_le(&mut self) -> f32
fn get_f32_le(&mut self) -> f32
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_ne(&mut self) -> f32
fn get_f32_ne(&mut self) -> f32
Gets an IEEE754 single-precision (4 bytes) floating point number from
self in native-endian byte order.
The current position is advanced by 4.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x3F\x99\x99\x9A hello",
false => b"\x9A\x99\x99\x3F hello",
};
assert_eq!(1.2f32, buf.get_f32_ne());Panics
This function panics if there is not enough remaining data in self.
fn get_f64(&mut self) -> f64
fn get_f64(&mut self) -> f64
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_le(&mut self) -> f64
fn get_f64_le(&mut self) -> f64
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_ne(&mut self) -> f64
fn get_f64_ne(&mut self) -> f64
Gets an IEEE754 double-precision (8 bytes) floating point number from
self in native-endian byte order.
The current position is advanced by 8.
Examples
use bytes::Buf;
let mut buf: &[u8] = match cfg!(target_endian = "big") {
true => b"\x3F\xF3\x33\x33\x33\x33\x33\x33 hello",
false => b"\x33\x33\x33\x33\x33\x33\xF3\x3F hello",
};
assert_eq!(1.2f64, buf.get_f64_ne());Panics
This function panics if there is not enough remaining data in self.
fn copy_to_bytes(&mut self, len: usize) -> Bytes
fn copy_to_bytes(&mut self, len: usize) -> Bytes
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 take(self, limit: usize) -> Take<Self>where
Self: Sized,
fn take(self, limit: usize) -> Take<Self>where Self: Sized,
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 chain<U>(self, next: U) -> Chain<Self, U>where
U: Buf,
Self: Sized,
fn chain<U>(self, next: U) -> Chain<Self, U>where U: Buf, Self: Sized,
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 reader(self) -> Reader<Self> ⓘwhere
Self: Sized,
fn reader(self) -> Reader<Self> ⓘwhere Self: Sized,
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"[..]);