pub struct ReadBuf<'a> {
    buf: &'a mut [MaybeUninit<u8>],
    filled: usize,
    initialized: usize,
}
🔬 This is a nightly-only experimental API. (read_buf)
Expand description

A wrapper around a byte buffer that is incrementally filled and initialized.

This type is a sort of “double cursor”. It tracks three regions in the buffer: a region at the beginning of the buffer that has been logically filled with data, a region that has been initialized at some point but not yet logically filled, and a region at the end that is fully uninitialized. The filled region is guaranteed to be a subset of the initialized region.

In summary, the contents of the buffer can be visualized as:

[             capacity              ]
[ filled |         unfilled         ]
[    initialized    | uninitialized ]

Fields

buf: &'a mut [MaybeUninit<u8>]
🔬 This is a nightly-only experimental API. (read_buf)
filled: usize
🔬 This is a nightly-only experimental API. (read_buf)
initialized: usize
🔬 This is a nightly-only experimental API. (read_buf)

Implementations

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

Creates a new ReadBuf from a fully initialized buffer.

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

Creates a new ReadBuf from a fully uninitialized buffer.

Use assume_init if part of the buffer is known to be already initialized.

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

Returns the total capacity of the buffer.

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

Returns a shared reference to the filled portion of the buffer.

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

Returns a mutable reference to the filled portion of the buffer.

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

Returns a shared reference to the initialized portion of the buffer.

This includes the filled portion.

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

Returns a mutable reference to the initialized portion of the buffer.

This includes the filled portion.

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

Returns a mutable reference to the unfilled part of the buffer without ensuring that it has been fully initialized.

Safety

The caller must not de-initialize portions of the buffer that have already been initialized.

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

Returns a mutable reference to the uninitialized part of the buffer.

It is safe to uninitialize any of these bytes.

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

Returns a mutable reference to the unfilled part of the buffer, ensuring it is fully initialized.

Since ReadBuf tracks the region of the buffer that has been initialized, this is effectively “free” after the first use.

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

Returns a mutable reference to the first n bytes of the unfilled part of the buffer, ensuring it is fully initialized.

Panics

Panics if self.remaining() is less than n.

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

Returns the number of bytes at the end of the slice that have not yet been filled.

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

Clears the buffer, resetting the filled region to empty.

The number of initialized bytes is not changed, and the contents of the buffer are not modified.

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

Increases the size of the filled region of the buffer.

The number of initialized bytes is not changed.

Panics

Panics if the filled region of the buffer would become larger than the initialized region.

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

Sets the size of the filled region of the buffer.

The number of initialized bytes is not changed.

Note that this can be used to shrink the filled region of the buffer in addition to growing it (for example, by a Read implementation that compresses data in-place).

Panics

Panics if the filled region of the buffer would become larger than the initialized region.

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

Asserts that the first n unfilled bytes of the buffer are initialized.

ReadBuf assumes that bytes are never de-initialized, so this method does nothing when called with fewer bytes than are already known to be initialized.

Safety

The caller must ensure that the first n unfilled bytes of the buffer have already been initialized.

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

Appends data to the buffer, advancing the written position and possibly also the initialized position.

Panics

Panics if self.remaining() is less than buf.len().

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

Returns the amount of bytes that have been filled.

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

Returns the amount of bytes that have been initialized.

Trait Implementations

Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.