Struct parquet::memory::Buffer

pub struct Buffer<T: Clone> { /* fields omitted */ }

A resize-able buffer class with generic member, with optional memory tracker.

Note that a buffer has two attributes: capacity and size: the former is the total number of space reserved for the buffer, while the latter is the actual number of elements. Invariant: capacity >= size. The total allocated bytes for a buffer equals to capacity * sizeof<T>().

Methods

impl<T: Clone> Buffer<T>

pub fn new() -> Self

Creates new empty buffer.

pub fn with_mem_tracker(self, mc: MemTrackerPtr) -> Self

Adds MemTracker for this buffer.

pub fn data(&self) -> &[T]

Returns slice of data in this buffer.

pub fn set_data(&mut self, new_data: Vec<T>)

Sets data for this buffer.

pub fn resize(&mut self, new_size: usize, init_value: T)

Resizes underlying data in place to a new length new_size.

If new_size is less than current length, data is truncated, otherwise, it is extended to new_size with provided default value init_value.

Memory tracker is also updated, if available.

pub fn clear(&mut self)

Clears underlying data.

pub fn reserve(&mut self, additional_capacity: usize)

Reserves capacity additional_capacity for underlying data vector.

Memory tracker is also updated, if available.

pub fn consume(&mut self) -> BufferPtr<T>

Returns BufferPtr with buffer data. Buffer data is reset.

pub fn push(&mut self, value: T)

Adds value to the buffer.

pub fn capacity(&self) -> usize

Returns current capacity for the buffer.

pub fn size(&self) -> usize

Returns current size for the buffer.

pub fn is_mem_tracked(&self) -> bool

Returns true if memory tracker is added to buffer, false otherwise.

pub fn mem_tracker(&self) -> &MemTrackerPtr

Returns memory tracker associated with this buffer. This may panic, if memory tracker is not set, use method above to check if memory tracker is available.

Trait Implementations

impl From<Buffer<u8>> for ByteArray

fn from(buf: ByteBuffer) -> ByteArray

Performs the conversion.

impl AsRef<[u8]> for Buffer<u8>

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

Performs the conversion.

impl<T: Clone> Drop for Buffer<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: Sized + Clone> Index<usize> for Buffer<T>

type Output = T

The returned type after indexing.

fn index(&self, index: usize) -> &T

Performs the indexing (container[index]) operation.

impl<T: Sized + Clone> IndexMut<usize> for Buffer<T>

fn index_mut(&mut self, index: usize) -> &mut T

Performs the mutable indexing (container[index]) operation.

impl Write for Buffer<u8>

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

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

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

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

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.