Struct IoBufMut 

pub struct IoBufMut { /* private fields */ }

Mutable byte buffer.

The handle stores the first readable byte, readable length, and writable view capacity directly:

before advance:
[ readable len ][ writable cap-len ]
^
ptr

after advance(n):
[ consumed ][ readable len-n ][ writable cap-len ]
             ^
             ptr

advance moves ptr forward and shrinks both len and cap. BufMut writes always begin at ptr + len.

Capacity

The capacity is fixed at construction, and the buffer never grows the way BytesMut does. Every write past capacity() panics, including writes through BufMut methods such as put_slice, so allocate the full expected size up front. Self::default and zero-sized constructions own no storage, so any nonempty write to them panics. remaining_mut() reports the actual writable tail rather than usize::MAX.

Implementations

impl IoBufMut

pub fn with_capacity(capacity: usize) -> Self

Create a buffer whose capacity is exactly capacity bytes.

pub fn with_alignment(capacity: usize, alignment: NonZeroUsize) -> Self

Create a buffer whose allocation is exactly capacity bytes at alignment.

Panics

Panics if capacity is nonzero and alignment is not a power of two, or if capacity rounded up to alignment exceeds isize::MAX.

pub fn zeroed_with_alignment(len: usize, alignment: NonZeroUsize) -> Self

Create a zero-initialized aligned buffer with the given length and alignment.

The allocation is exactly len bytes at alignment, so capacity() == len.

Panics

Panics if len is nonzero and alignment is not a power of two, or if len rounded up to alignment exceeds isize::MAX.

pub fn zeroed(len: usize) -> Self

Create a buffer of len bytes, all initialized to zero.

Unlike Self::with_capacity, the full buffer is immediately readable (len() == capacity() == len), which suits APIs that fill a preallocated buffer such as read_exact.

pub unsafe fn set_len(&mut self, len: usize)

Sets the length of the buffer.

Safety

Caller must ensure all bytes in 0..len are initialized before any read operations.

Panics

Panics if len > capacity().

pub const fn len(&self) -> usize

Number of readable bytes remaining in the buffer.

pub const fn is_empty(&self) -> bool

Whether the buffer has no readable bytes.

pub fn freeze(self) -> IoBuf

Freeze into immutable IoBuf.

The owner moves to the immutable handle without a refcount operation. Freezing allocates only when the spare capacity capacity() - len() is too large to record in the handle (at least 128 KiB on 64-bit targets, 128 bytes on 32-bit targets), and then allocates the owner record that sharing would otherwise allocate. Freezing an empty buffer releases its allocation, so the result holds no memory.

pub const fn capacity(&self) -> usize

Returns how many bytes the buffer can hold, counted from its first readable byte.

pub const fn as_mut_ptr(&mut self) -> *mut u8

Returns an unsafe mutable pointer to the first readable byte.

pub fn truncate(&mut self, len: usize)

Truncates the buffer to len readable bytes.

Has no effect when len is greater than the current length.

pub const fn clear(&mut self)

Clears the buffer, removing all readable data. Existing view capacity is preserved.

Trait Implementations

impl AsMut<[u8]> for IoBufMut

fn as_mut(&mut self) -> &mut [u8]

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsRef<[u8]> for IoBufMut

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl Buf for IoBufMut

fn copy_to_bytes(&mut self, len: usize) -> Bytes

Drains len readable bytes into Bytes.

Draining a nonempty buffer’s full readable length moves the whole buffer into the result without copying. The handle is then empty with zero capacity, whereas BytesMut would keep its spare capacity. A partial or zero-length drain copies the prefix and keeps the handle’s remaining capacity.

fn remaining(&self) -> usize

Returns the number of bytes between the current position and the end of the buffer.

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 a shorter slice (this allows non-continuous internal representation).

fn advance(&mut self, cnt: usize)

Advance the internal cursor of the Buf

fn copy_to_slice(&mut self, dst: &mut [u8])

Copies bytes from self into dst.

fn try_copy_to_slice(&mut self, dst: &mut [u8]) -> Result<(), TryGetError>

Copies bytes from self into dst.

fn chunks_vectored<'a>(&'a self, dst: &mut [IoSlice<'a>]) -> usize

Fills dst with potentially multiple slices starting at self’s current position.

fn has_remaining(&self) -> bool

Returns true if there are any more bytes to consume

fn get_u8(&mut self) -> u8

Gets an unsigned 8 bit integer from self.

fn get_i8(&mut self) -> i8

Gets a signed 8 bit integer from self.

fn get_u16(&mut self) -> u16

Gets an unsigned 16 bit integer from self in big-endian byte order.

fn get_u16_le(&mut self) -> u16

Gets an unsigned 16 bit integer from self in little-endian byte order.

fn get_u16_ne(&mut self) -> u16

Gets an unsigned 16 bit integer from self in native-endian byte order.

fn get_i16(&mut self) -> i16

Gets a signed 16 bit integer from self in big-endian byte order.

fn get_i16_le(&mut self) -> i16

Gets a signed 16 bit integer from self in little-endian byte order.

fn get_i16_ne(&mut self) -> i16

Gets a signed 16 bit integer from self in native-endian byte order.

fn get_u32(&mut self) -> u32

Gets an unsigned 32 bit integer from self in the big-endian byte order.

fn get_u32_le(&mut self) -> u32

Gets an unsigned 32 bit integer from self in the little-endian byte order.

fn get_u32_ne(&mut self) -> u32

Gets an unsigned 32 bit integer from self in native-endian byte order.

fn get_i32(&mut self) -> i32

Gets a signed 32 bit integer from self in big-endian byte order.

fn get_i32_le(&mut self) -> i32

Gets a signed 32 bit integer from self in little-endian byte order.

fn get_i32_ne(&mut self) -> i32

Gets a signed 32 bit integer from self in native-endian byte order.

fn get_u64(&mut self) -> u64

Gets an unsigned 64 bit integer from self in big-endian byte order.

fn get_u64_le(&mut self) -> u64

Gets an unsigned 64 bit integer from self in little-endian byte order.

fn get_u64_ne(&mut self) -> u64

Gets an unsigned 64 bit integer from self in native-endian byte order.

fn get_i64(&mut self) -> i64

Gets a signed 64 bit integer from self in big-endian byte order.

fn get_i64_le(&mut self) -> i64

Gets a signed 64 bit integer from self in little-endian byte order.

fn get_i64_ne(&mut self) -> i64

Gets a signed 64 bit integer from self in native-endian byte order.

fn get_u128(&mut self) -> u128

Gets an unsigned 128 bit integer from self in big-endian byte order.

fn get_u128_le(&mut self) -> u128

Gets an unsigned 128 bit integer from self in little-endian byte order.

fn get_u128_ne(&mut self) -> u128

Gets an unsigned 128 bit integer from self in native-endian byte order.

fn get_i128(&mut self) -> i128

Gets a signed 128 bit integer from self in big-endian byte order.

fn get_i128_le(&mut self) -> i128

Gets a signed 128 bit integer from self in little-endian byte order.

fn get_i128_ne(&mut self) -> i128

Gets a signed 128 bit integer from self in native-endian byte order.

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

Gets an unsigned n-byte integer from self in big-endian byte order.

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

Gets an unsigned n-byte integer from self in little-endian byte order.

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

Gets an unsigned n-byte integer from self in native-endian byte order.

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

Gets a signed n-byte integer from self in big-endian byte order.

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

Gets a signed n-byte integer from self in little-endian byte order.

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

Gets a signed n-byte integer from self in native-endian byte order.

fn get_f32(&mut self) -> f32

Gets an IEEE754 single-precision (4 bytes) floating point number from self in big-endian byte order.

fn get_f32_le(&mut self) -> f32

Gets an IEEE754 single-precision (4 bytes) floating point number from self in little-endian byte order.

fn get_f32_ne(&mut self) -> f32

Gets an IEEE754 single-precision (4 bytes) floating point number from self in native-endian byte order.

fn get_f64(&mut self) -> f64

Gets an IEEE754 double-precision (8 bytes) floating point number from self in big-endian byte order.

fn get_f64_le(&mut self) -> f64

Gets an IEEE754 double-precision (8 bytes) floating point number from self in little-endian byte order.

fn get_f64_ne(&mut self) -> f64

Gets an IEEE754 double-precision (8 bytes) floating point number from self in native-endian byte order.

fn try_get_u8(&mut self) -> Result<u8, TryGetError>

Gets an unsigned 8 bit integer from self.

fn try_get_i8(&mut self) -> Result<i8, TryGetError>

Gets a signed 8 bit integer from self.

fn try_get_u16(&mut self) -> Result<u16, TryGetError>

Gets an unsigned 16 bit integer from self in big-endian byte order.

fn try_get_u16_le(&mut self) -> Result<u16, TryGetError>

Gets an unsigned 16 bit integer from self in little-endian byte order.

fn try_get_u16_ne(&mut self) -> Result<u16, TryGetError>

Gets an unsigned 16 bit integer from self in native-endian byte order.

fn try_get_i16(&mut self) -> Result<i16, TryGetError>

Gets a signed 16 bit integer from self in big-endian byte order.

fn try_get_i16_le(&mut self) -> Result<i16, TryGetError>

Gets an signed 16 bit integer from self in little-endian byte order.

fn try_get_i16_ne(&mut self) -> Result<i16, TryGetError>

Gets a signed 16 bit integer from self in native-endian byte order.

fn try_get_u32(&mut self) -> Result<u32, TryGetError>

Gets an unsigned 32 bit integer from self in big-endian byte order.

fn try_get_u32_le(&mut self) -> Result<u32, TryGetError>

Gets an unsigned 32 bit integer from self in little-endian byte order.

fn try_get_u32_ne(&mut self) -> Result<u32, TryGetError>

Gets an unsigned 32 bit integer from self in native-endian byte order.

fn try_get_i32(&mut self) -> Result<i32, TryGetError>

Gets a signed 32 bit integer from self in big-endian byte order.

fn try_get_i32_le(&mut self) -> Result<i32, TryGetError>

Gets a signed 32 bit integer from self in little-endian byte order.

fn try_get_i32_ne(&mut self) -> Result<i32, TryGetError>

Gets a signed 32 bit integer from self in native-endian byte order.

fn try_get_u64(&mut self) -> Result<u64, TryGetError>

Gets an unsigned 64 bit integer from self in big-endian byte order.

fn try_get_u64_le(&mut self) -> Result<u64, TryGetError>

Gets an unsigned 64 bit integer from self in little-endian byte order.

fn try_get_u64_ne(&mut self) -> Result<u64, TryGetError>

Gets an unsigned 64 bit integer from self in native-endian byte order.

fn try_get_i64(&mut self) -> Result<i64, TryGetError>

Gets a signed 64 bit integer from self in big-endian byte order.

fn try_get_i64_le(&mut self) -> Result<i64, TryGetError>

Gets a signed 64 bit integer from self in little-endian byte order.

fn try_get_i64_ne(&mut self) -> Result<i64, TryGetError>

Gets a signed 64 bit integer from self in native-endian byte order.

fn try_get_u128(&mut self) -> Result<u128, TryGetError>

Gets an unsigned 128 bit integer from self in big-endian byte order.

fn try_get_u128_le(&mut self) -> Result<u128, TryGetError>

Gets an unsigned 128 bit integer from self in little-endian byte order.

fn try_get_u128_ne(&mut self) -> Result<u128, TryGetError>

Gets an unsigned 128 bit integer from self in native-endian byte order.

fn try_get_i128(&mut self) -> Result<i128, TryGetError>

Gets a signed 128 bit integer from self in big-endian byte order.

fn try_get_i128_le(&mut self) -> Result<i128, TryGetError>

Gets a signed 128 bit integer from self in little-endian byte order.

fn try_get_i128_ne(&mut self) -> Result<i128, TryGetError>

Gets a signed 128 bit integer from self in native-endian byte order.

fn try_get_uint(&mut self, nbytes: usize) -> Result<u64, TryGetError>

Gets an unsigned n-byte integer from self in big-endian byte order.

fn try_get_uint_le(&mut self, nbytes: usize) -> Result<u64, TryGetError>

Gets an unsigned n-byte integer from self in little-endian byte order.

fn try_get_uint_ne(&mut self, nbytes: usize) -> Result<u64, TryGetError>

Gets an unsigned n-byte integer from self in native-endian byte order.

fn try_get_int(&mut self, nbytes: usize) -> Result<i64, TryGetError>

Gets a signed n-byte integer from self in big-endian byte order.

fn try_get_int_le(&mut self, nbytes: usize) -> Result<i64, TryGetError>

Gets a signed n-byte integer from self in little-endian byte order.

fn try_get_int_ne(&mut self, nbytes: usize) -> Result<i64, TryGetError>

Gets a signed n-byte integer from self in native-endian byte order.

fn try_get_f32(&mut self) -> Result<f32, TryGetError>

Gets an IEEE754 single-precision (4 bytes) floating point number from self in big-endian byte order.

fn try_get_f32_le(&mut self) -> Result<f32, TryGetError>

Gets an IEEE754 single-precision (4 bytes) floating point number from self in little-endian byte order.

fn try_get_f32_ne(&mut self) -> Result<f32, TryGetError>

Gets an IEEE754 single-precision (4 bytes) floating point number from self in native-endian byte order.

fn try_get_f64(&mut self) -> Result<f64, TryGetError>

Gets an IEEE754 double-precision (8 bytes) floating point number from self in big-endian byte order.

fn try_get_f64_le(&mut self) -> Result<f64, TryGetError>

Gets an IEEE754 double-precision (8 bytes) floating point number from self in little-endian byte order.

fn try_get_f64_ne(&mut self) -> Result<f64, TryGetError>

Gets an IEEE754 double-precision (8 bytes) floating point number from self in native-endian byte order.

fn take(self, limit: usize) -> Take<Self>

where Self: Sized,

Creates an adaptor which will read at most limit bytes from self.

fn chain<U>(self, next: U) -> Chain<Self, U>

where U: Buf, Self: Sized,

Creates an adaptor which will chain this buffer with another.

fn reader(self) -> Reader<Self>

where Self: Sized,

Creates an adaptor which implements the Read trait for self.

impl BufMut for IoBufMut

fn remaining_mut(&self) -> usize

Returns the number of bytes that can be written from the current position until the end of the buffer is reached.

unsafe fn advance_mut(&mut self, cnt: usize)

Advance the internal cursor of the BufMut

fn chunk_mut(&mut self) -> &mut UninitSlice

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).

fn put_slice(&mut self, src: &[u8])

Transfer bytes into self from src and advance the cursor by the number of bytes written.

fn put_bytes(&mut self, val: u8, cnt: usize)

Put cnt bytes val into self.

fn put<T: Buf>(&mut self, src: T)

where Self: Sized,

Transfer bytes into self from src and advance the cursor by the number of bytes written.

fn has_remaining_mut(&self) -> bool

Returns true if there is space in self for more bytes.

fn put_u8(&mut self, n: u8)

Writes an unsigned 8 bit integer to self.

fn put_i8(&mut self, n: i8)

Writes a signed 8 bit integer to self.

fn put_u16(&mut self, n: u16)

Writes an unsigned 16 bit integer to self in big-endian byte order.

fn put_u16_le(&mut self, n: u16)

Writes an unsigned 16 bit integer to self in little-endian byte order.

fn put_u16_ne(&mut self, n: u16)

Writes an unsigned 16 bit integer to self in native-endian byte order.

fn put_i16(&mut self, n: i16)

Writes a signed 16 bit integer to self in big-endian byte order.

fn put_i16_le(&mut self, n: i16)

Writes a signed 16 bit integer to self in little-endian byte order.

fn put_i16_ne(&mut self, n: i16)

Writes a signed 16 bit integer to self in native-endian byte order.

fn put_u32(&mut self, n: u32)

Writes an unsigned 32 bit integer to self in big-endian byte order.

fn put_u32_le(&mut self, n: u32)

Writes an unsigned 32 bit integer to self in little-endian byte order.

fn put_u32_ne(&mut self, n: u32)

Writes an unsigned 32 bit integer to self in native-endian byte order.

fn put_i32(&mut self, n: i32)

Writes a signed 32 bit integer to self in big-endian byte order.

fn put_i32_le(&mut self, n: i32)

Writes a signed 32 bit integer to self in little-endian byte order.

fn put_i32_ne(&mut self, n: i32)

Writes a signed 32 bit integer to self in native-endian byte order.

fn put_u64(&mut self, n: u64)

Writes an unsigned 64 bit integer to self in the big-endian byte order.

fn put_u64_le(&mut self, n: u64)

Writes an unsigned 64 bit integer to self in little-endian byte order.

fn put_u64_ne(&mut self, n: u64)

Writes an unsigned 64 bit integer to self in native-endian byte order.

fn put_i64(&mut self, n: i64)

Writes a signed 64 bit integer to self in the big-endian byte order.

fn put_i64_le(&mut self, n: i64)

Writes a signed 64 bit integer to self in little-endian byte order.

fn put_i64_ne(&mut self, n: i64)

Writes a signed 64 bit integer to self in native-endian byte order.

fn put_u128(&mut self, n: u128)

Writes an unsigned 128 bit integer to self in the big-endian byte order.

fn put_u128_le(&mut self, n: u128)

Writes an unsigned 128 bit integer to self in little-endian byte order.

fn put_u128_ne(&mut self, n: u128)

Writes an unsigned 128 bit integer to self in native-endian byte order.

fn put_i128(&mut self, n: i128)

Writes a signed 128 bit integer to self in the big-endian byte order.

fn put_i128_le(&mut self, n: i128)

Writes a signed 128 bit integer to self in little-endian byte order.

fn put_i128_ne(&mut self, n: i128)

Writes a signed 128 bit integer to self in native-endian byte order.

fn put_uint(&mut self, n: u64, nbytes: usize)

Writes an unsigned n-byte integer to self in big-endian byte order.

fn put_uint_le(&mut self, n: u64, nbytes: usize)

Writes an unsigned n-byte integer to self in the little-endian byte order.

fn put_uint_ne(&mut self, n: u64, nbytes: usize)

Writes an unsigned n-byte integer to self in the native-endian byte order.

fn put_int(&mut self, n: i64, nbytes: usize)

Writes low nbytes of a signed integer to self in big-endian byte order.

fn put_int_le(&mut self, n: i64, nbytes: usize)

Writes low nbytes of a signed integer to self in little-endian byte order.

fn put_int_ne(&mut self, n: i64, nbytes: usize)

Writes low nbytes of a signed integer to self in native-endian byte order.

fn put_f32(&mut self, n: f32)

Writes an IEEE754 single-precision (4 bytes) floating point number to self in big-endian byte order.

fn put_f32_le(&mut self, n: f32)

Writes an IEEE754 single-precision (4 bytes) floating point number to self in little-endian byte order.

fn put_f32_ne(&mut self, n: f32)

Writes an IEEE754 single-precision (4 bytes) floating point number to self in native-endian byte order.

fn put_f64(&mut self, n: f64)

Writes an IEEE754 double-precision (8 bytes) floating point number to self in big-endian byte order.

fn put_f64_le(&mut self, n: f64)

Writes an IEEE754 double-precision (8 bytes) floating point number to self in little-endian byte order.

fn put_f64_ne(&mut self, n: f64)

Writes an IEEE754 double-precision (8 bytes) floating point number to self in native-endian byte order.

fn limit(self, limit: usize) -> Limit<Self>

where Self: Sized,

Creates an adaptor which can write at most limit bytes to self.

fn writer(self) -> Writer<Self>

where Self: Sized,

Creates an adaptor which implements the Write trait for self.

fn chain_mut<U>(self, next: U) -> Chain<Self, U>

where U: BufMut, Self: Sized,

Creates an adapter which will chain this buffer with another.

impl Debug for IoBufMut

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for IoBufMut

fn default() -> Self

Returns the “default value” for a type.

impl Drop for IoBufMut

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl<const N: usize> From<&[u8; N]> for IoBufMut

Create a mutable buffer by copying the array.

fn from(array: &[u8; N]) -> Self

Converts to this type from the input type.

impl From<&[u8]> for IoBufMut

Create a mutable buffer by copying the slice.

fn from(slice: &[u8]) -> Self

Converts to this type from the input type.

impl From<Bytes> for IoBufMut

Convert Bytes into an IoBufMut.

When no other handle shares an allocation the Bytes owns (one that came from a Vec<u8>, Box<[u8]>, or BytesMut), the buffer reuses that whole allocation and moves the readable bytes to its front. Otherwise, including for 'static slices and Bytes::from_owner storage, it copies the readable bytes into an allocation of exactly their length.

fn from(bytes: Bytes) -> Self

Converts to this type from the input type.

impl From<BytesMut> for IoBufMut

Convert a BytesMut into an IoBufMut.

When no other handle shares the allocation, the buffer reuses it and moves the readable bytes to its front. Otherwise it copies the readable bytes into a new allocation. Either way the capacity is at least bytes.capacity().

fn from(bytes: BytesMut) -> Self

Converts to this type from the input type.

impl From<IoBuf> for IoBufMut

Convert an IoBuf into an IoBufMut, without copying when IoBuf::try_into_mut succeeds and copying the readable bytes otherwise.

fn from(buf: IoBuf) -> Self

Converts to this type from the input type.

impl From<IoBufMut> for IoBuf

Convert IoBufMut into an IoBuf without copying (via IoBufMut::freeze).

fn from(buf: IoBufMut) -> Self

Converts to this type from the input type.

impl From<IoBufMut> for IoBufs

Zero-copy: freezes the buffer and wraps it as the single chunk.

fn from(buf: IoBufMut) -> Self

Converts to this type from the input type.

impl From<IoBufMut> for IoBufsMut

Zero-copy: wraps the buffer as the single chunk.

fn from(buf: IoBufMut) -> Self

Converts to this type from the input type.

impl From<Vec<u8>> for IoBufMut

Convert a Vec<u8> into an IoBufMut without copying.

The buffer adopts the vec’s allocation, with the vec’s contents as its readable bytes and vec.capacity() as its capacity. A vec without an allocation becomes an empty buffer.

fn from(vec: Vec<u8>) -> Self

Converts to this type from the input type.

impl<const N: usize> From<[u8; N]> for IoBufMut

Create a mutable buffer by copying the array.

fn from(array: [u8; N]) -> Self

Converts to this type from the input type.

impl FromIterator<IoBufMut> for IoBufsMut

Zero-copy: collects the chunks, dropping zero-capacity ones.

fn from_iter<T: IntoIterator<Item = IoBufMut>>(bufs: T) -> Self

Creates a value from an iterator.

impl Input for IoBufMut

type Buf = IoBuf

The buffer used by the decoder.

impl<const N: usize> PartialEq<&[u8; N]> for IoBufMut

fn eq(&self, other: &&[u8; N]) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialEq<&[u8]> for IoBufMut

fn eq(&self, other: &&[u8]) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<const N: usize> PartialEq<[u8; N]> for IoBufMut

fn eq(&self, other: &[u8; N]) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialEq<[u8]> for IoBufMut

fn eq(&self, other: &[u8]) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Send for IoBufMut

impl Sync for IoBufMut