Struct Chunk

pub struct Chunk<'a> { /* private fields */ }

A chunk of compressed data.

A chunk is a thin wrapper around CowVec<u8>, with some additional metadata, and the creation of a Chunk through the Self::from_compressed is very cheap.

Implementations

impl<'a> Chunk<'a>

pub fn from_compressed(bytes: CowVec<'a, u8>) -> Result<Self, Error>

Create a new Chunk from a compressed bytes buffer.

pub fn as_bytes(&self) -> &[u8]

Get a reference to the underlying bytes buffer.

pub fn into_bytes(self) -> CowVec<'a, u8>

Convert the chunk into a bytes buffer.

pub fn get_dparams(&self) -> DParams

Get the current decompression parameters.

pub fn set_dparams(&self, params: DParams) -> Result<(), Error>

Set the decompression parameters.

pub fn decompress(&self) -> Result<Vec<u8>, Error>

Decompress the whole chunk into a new allocated bytes vector.

For decompressing the data into an already allocated buffer, create a Decoder (with other params or Self::get_dparams) and use Decoder::decompress_into.

pub fn nbytes(&self) -> usize

Get the number of bytes in the uncompressed data.

pub fn typesize(&self) -> usize

Get the size of each item in the chunk.

pub fn items_num(&self) -> usize

Get the number of items in the chunk.

pub fn item(&self, idx: usize) -> Result<Vec<u8>, Error>

Get an item at the specified index.

Each item is typesize (as provided during encoding) bytes long, and the index is zero-based.

Note that the returned vector may not be aligned to the original data type’s alignment, and the caller should ensure that the alignment is correct before transmuting it to original type. If the alignment does not match the original data type, the bytes should be copied to a new aligned allocation before transmuting, otherwise undefined behavior may occur. Alternatively, the caller can use Self::item_into and provide an already aligned destination buffer.

pub fn item_into( &self, idx: usize, dst: &mut [MaybeUninit<u8>], ) -> Result<usize, Error>

Get an item at the specified index and copy it into the provided destination buffer.

Each item is typesize (as provided during encoding) bytes long, and the index is zero-based.

Note that if the destination buffer is not aligned to the original data type’s alignment, the caller should not transmute the decompressed data to original type, as this may lead to undefined behavior.

pub fn items(&self, idx: Range<usize>) -> Result<Vec<u8>, Error>

Get a range of items specified by the index range.

Each item is typesize (as provided during encoding) bytes long, and the index is zero-based.

Note that the returned vector may not be aligned to the original data type’s alignment, and the caller should ensure that the alignment is correct before transmuting it to original type. If the alignment does not match the original data type, the bytes should be copied to a new aligned allocation before transmuting, otherwise undefined behavior may occur. Alternatively, the caller can use Self::items_into and provide an already aligned destination buffer.

pub fn items_into( &self, idx: Range<usize>, dst: &mut [MaybeUninit<u8>], ) -> Result<usize, Error>

Get a range of items specified by the index range and copy them into the provided destination buffer.

Each item is typesize (as provided during encoding) bytes long, and the index is zero-based.

Note that if the destination buffer is not aligned to the original data type’s alignment, the caller should not transmute the decompressed data to original type, as this may lead to undefined behavior.

pub fn shallow_clone(&self) -> Chunk<'_>

Create a shallow clone of the chunk without re-allocating the internal buffer.

Trait Implementations

impl Clone for Chunk<'_>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.