[−][src]Trait bytes::Buf

pub trait Buf {
    fn remaining(&self) -> usize;

    fn bytes(&self) -> &[u8];

    fn advance(&mut self, cnt: usize);

    fn bytes_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_i16(&mut self) -> i16 { ... }

    fn get_i16_le(&mut self) -> i16 { ... }

    fn get_u32(&mut self) -> u32 { ... }

    fn get_u32_le(&mut self) -> u32 { ... }

    fn get_i32(&mut self) -> i32 { ... }

    fn get_i32_le(&mut self) -> i32 { ... }

    fn get_u64(&mut self) -> u64 { ... }

    fn get_u64_le(&mut self) -> u64 { ... }

    fn get_i64(&mut self) -> i64 { ... }

    fn get_i64_le(&mut self) -> i64 { ... }

    fn get_u128(&mut self) -> u128 { ... }

    fn get_u128_le(&mut self) -> u128 { ... }

    fn get_i128(&mut self) -> i128 { ... }

    fn get_i128_le(&mut self) -> i128 { ... }

    fn get_uint(&mut self, nbytes: usize) -> u64 { ... }

    fn get_uint_le(&mut self, nbytes: usize) -> u64 { ... }

    fn get_int(&mut self, nbytes: usize) -> i64 { ... }

    fn get_int_le(&mut self, nbytes: usize) -> i64 { ... }

    fn get_f32(&mut self) -> f32 { ... }

    fn get_f32_le(&mut self) -> f32 { ... }

    fn get_f64(&mut self) -> f64 { ... }

    fn get_f64_le(&mut self) -> f64 { ... }

    fn to_bytes(&mut self) -> Bytes { ... }
}

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

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 bytes(&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.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 advance(&mut self, cnt: usize)

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.

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Provided methods

fn bytes_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, 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.

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])

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_u8(&mut self) -> u8

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_i8(&mut self) -> i8

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_u16(&mut self) -> u16

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_le(&mut self) -> u16

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_i16(&mut self) -> i16

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_le(&mut self) -> i16

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_u32(&mut self) -> u32

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_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_i32(&mut self) -> i32

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_le(&mut self) -> i32

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_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

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_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

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_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

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_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

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_uint(&mut self, nbytes: usize) -> u64

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_le(&mut self, nbytes: usize) -> u64

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_int(&mut self, nbytes: usize) -> i64

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_le(&mut self, nbytes: usize) -> i64

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_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

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_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

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 to_bytes(&mut self) -> Bytes

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"[..]);
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Implementations on Foreign Types

impl<T: Buf + ?Sized, '_> Buf for &'_ mut T[src]

impl<T: Buf + ?Sized> Buf for Box<T>[src]

impl<'_> Buf for &'_ [u8][src]

impl Buf for Option<[u8; 1]>[src]

impl<T: AsRef<[u8]>> Buf for Cursor<T>[src]

impl Buf for VecDeque<u8>[src]

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Implementors

impl Buf for Bytes[src]

impl Buf for BytesMut[src]

impl<T, U> Buf for Chain<T, U> where
    T: Buf,
    U: Buf, [src]

impl<T: Buf> Buf for Take<T>[src]

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