Struct ChunkVecBuffer

pub(crate) struct ChunkVecBuffer {
    prefix_used: usize,
    chunks: VecDeque<Vec<u8>>,
    limit: Option<usize>,
}

This is a byte buffer that is built from a deque of byte vectors.

This avoids extra copies when appending a new byte vector, at the expense of more complexity when reading out.

Fields

prefix_used: usize

How many bytes have been consumed in the first chunk.

Invariant: zero if chunks.is_empty() Invariant: 0 <= prefix_used < chunks[0].len()

chunks: VecDeque<Vec<u8>>

limit: Option<usize>

The total upper limit (in bytes) of this object.

Implementations

impl ChunkVecBuffer

pub(crate) fn new(limit: Option<usize>) -> Self

pub(crate) fn set_limit(&mut self, new_limit: Option<usize>)

Sets the upper limit on how many bytes this object can store.

Setting a lower limit than the currently stored data is not an error.

A None limit is interpreted as no limit.

pub(crate) fn is_empty(&self) -> bool

If we’re empty

pub(crate) fn len(&self) -> usize

How many bytes we’re storing

pub(crate) fn apply_limit(&self, len: usize) -> usize

For a proposed append of len bytes, how many bytes should we actually append to adhere to the currently set limit?

pub(crate) fn append(&mut self, bytes: Vec<u8>) -> usize

Take and append the given bytes.

pub(crate) fn pop(&mut self) -> Option<Vec<u8>>

Take one of the chunks from this object.

This function returns None if the object is_empty.

pub(crate) fn peek(&self) -> Option<&[u8]>

Inspect the first chunk from this object.

impl ChunkVecBuffer

pub(crate) fn is_full(&self) -> bool

pub(crate) fn append_limited_copy( &mut self, payload: OutboundChunks<'_>, ) -> usize

Append a copy of bytes, perhaps a prefix if we’re near the limit.

pub(crate) fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Read data out of this object, writing it into buf and returning how many bytes were written there.

pub(crate) fn consume_first_chunk(&mut self, used: usize)

fn consume(&mut self, used: usize)

pub(crate) fn write_to(&mut self, wr: &mut dyn Write) -> Result<usize>

Read data out of this object, passing it wr

pub(crate) fn chunk(&self) -> Option<&[u8]>

Returns the first contiguous chunk of data, or None if empty.