Struct circbuf::CircBuf

pub struct CircBuf { /* fields omitted */ }

Circular Buffer

A growable circular buffer for use with bytes.

Methods

impl CircBuf

fn new() -> Self

Create a new CircBuf. The default size of the buffer is DEFAULT_CAPACITY bytes.

fn with_capacity(cap: usize) -> Result<Self, CircBufError>

Create a new CircBuf with a size of cap bytes. The capacity will be rounded up to the nearest power of two greater than or equal to cap. If the nearest power of two overflows usize, return CircBufError::Overflow, else return the buffer.

fn cap(&self) -> usize

Get the capacity of the buffer. This value is equal to one less than the length of the underlying buffer because we cannot let the write cursor to ever circle back to being equal with the read cursor.

fn len(&self) -> usize

Get the number of bytes stored in the buffer.

fn avail(&self) -> usize

Get the number of bytes available in the buffer.

fn is_empty(&self) -> bool

Get a bool indicating whether the buffer is empty or not.

fn is_full(&self) -> bool

Get a bool indicating whether the buffer is full or not.

fn find_from_index(&self, val: u8, index: usize) -> Option<usize>

Find the first occurence of val in the buffer starting from index. If val exists in the buffer return the index of the first occurence of val else return None.

fn find(&self, val: u8) -> Option<usize>

Find the first occurence of val in the buffer. If val exists in the buffer return the index of the first occurence of val else return None. A convenience method for find_from_index with 0 as the index.

fn peek(&self) -> Result<u8, CircBufError>

Get the next byte to be read from the buffer without removing it from it the buffer. Returns the byte if the buffer is not empty, else returns a BufEmpty error.

fn get(&mut self) -> Result<u8, CircBufError>

Get the next byte to be read from the buffer and remove it from it the buffer. Returns the byte if the buffer is not empty, else returns a BufEmpty error.

fn put(&mut self, val: u8) -> Result<(), CircBufError>

Put val into the buffer. Returns a BufFull error if the buffer is full, else returns an empty tuple ().

fn advance_read(&mut self, num: usize)

Advance the buffer's read cursor num bytes.

fn advance_write(&mut self, num: usize)

Advance the buffer's write cursor num bytes.

fn clear(&mut self)

Clear the buffer.

fn grow_with_factor(&mut self, factor: usize) -> Result<(), CircBufError>

Grow the size of the buffer by factor. The size of the buffer will be rounded up to the nearest power of two that is greater than or equal to the the current size of the buffer multiplied by factor. If the size of the buffer will overflow usize then CircBufError::Overflow will be returned else an empty tuple () will be returned.

fn grow(&mut self) -> Result<(), CircBufError>

Grow the size of the buffer. The buffer will be expanded by a factor of DEFAULT_SIZE_MULTIPLIER. If the size of the buffer will overflow usize then CircBufError::Overflow will be returned else an empty tuple () will be returned.

fn get_avail_upto_size(&mut self, size: usize) -> [&mut [u8]; 2]

Return an array that contains two mutable slices which point to the available bytes in the buffer. The combined lengths of the slices will be the minimum of size and self.avail(). If the available bytes in the buffer are contiguous then the second slice will be of size zero. Otherwise, the first slice will point to the bytes available at the end of the buffer and the second slice will point to the bytes available at the start of the buffer. The array can be used for vector IO.

fn get_bytes_upto_size(&mut self, size: usize) -> [&[u8]; 2]

Return an array that contains two slices which point to the bytes that have been written to the buffer. The combined lengths of the slices will be the minimum of size and self.len(). If the bytes are contiguous then the second slice will be of size zero. Otherwise, the first slice will point to the bytes at the end of the buffer and the second slice will point to the bytes available at the start of the buffer.

fn get_avail(&mut self) -> [&mut [u8]; 2]

Return an array that contains two slices which point to the bytes that are available in the buffer. A convenience method for get_avail_upto_size with size equal to self.avail() so all bytes written available in buffer will be returned.

fn get_bytes(&mut self) -> [&[u8]; 2]

Return an array that contains two slices which point to the bytes that have been written to the buffer. A convenience method for get_bytes_upto_size with size equal to self.len() so all bytes written to the buffer will be returned.

Trait Implementations

impl Debug for CircBuf

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Read for CircBuf

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

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

fn chars(self) -> Chars<Self>

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

the semantics of a partial read/write of where errors happen is currently unclear and may change

Transforms this Read instance to an Iterator over chars.

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adaptor which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

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

impl Write for CircBuf

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

Write a buffer into this object, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Clear the buffer by setting the read and write pointers to 0.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this write.

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Write.