Struct serde::lib::core::io::BorrowedBuf

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

A borrowed byte buffer which 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 ]

A BorrowedBuf is created around some existing data (or capacity for data) via a unique reference (&mut). The BorrowedBuf can be configured (e.g., using clear or set_init), but cannot be directly written. To write into the buffer, use unfilled to create a BorrowedCursor. The cursor has write-only access to the unfilled portion of the buffer (you can think of it as a write-only iterator).

The lifetime 'data is a bound on the lifetime of the underlying data.

Fields

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

Implementations

🔬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 the length of the filled part of the buffer.

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

Returns the length of the initialized part 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 cursor over the unfilled part of the buffer.

🔬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)

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

BorrowedBuf 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.

Trait Implementations

Formats the value using the given formatter. Read more

Create a new BorrowedBuf from an uninitialized buffer.

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

Converts to this type from the input type.

Create a new BorrowedBuf from a fully initialized slice.

Converts to this type from the input type.

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.