Struct ZstdEncoder

pub struct ZstdEncoder<W> { /* private fields */ }

Available on crate features futures-io and zstd only.

A zstd encoder, or compressor.

This structure implements an AsyncWrite interface and will take in uncompressed data and write it compressed to an underlying stream.

Implementations

impl<W: AsyncWrite> ZstdEncoder<W>

pub fn new(inner: W) -> Self

Creates a new encoder which will take in uncompressed data and write it compressed to the given stream.

pub fn with_quality(inner: W, level: Level) -> Self

Creates a new encoder which will take in uncompressed data and write it compressed to the given stream.

pub fn with_quality_and_params( inner: W, level: Level, params: &[CParameter], ) -> Self

Creates a new encoder, using the specified compression level and parameters, which will read uncompressed data from the given stream and emit a compressed stream.

Panics

Panics if this function is called with a CParameter::nb_workers() parameter and the zstdmt crate feature is not enabled.

pub fn with_dict(inner: W, level: Level, dictionary: &[u8]) -> Result<Self>

Creates a new encoder, using the specified compression level and pre-trained dictionary, which will read uncompressed data from the given stream and emit a compressed stream.

Dictionaries provide better compression ratios for small files, but are required to be present during decompression.

Errors

Returns error when dictionary is not valid.

impl<W> ZstdEncoder<W>

pub fn get_ref(&self) -> &W

Acquires a reference to the underlying writer that this encoder is wrapping.

pub fn get_mut(&mut self) -> &mut W

Acquires a mutable reference to the underlying writer that this encoder is wrapping.

Note that care must be taken to avoid tampering with the state of the writer which may otherwise confuse this encoder.

pub fn get_pin_mut(self: Pin<&mut Self>) -> Pin<&mut W>

Acquires a pinned mutable reference to the underlying writer that this encoder is wrapping.

Note that care must be taken to avoid tampering with the state of the writer which may otherwise confuse this encoder.

pub fn into_inner(self) -> W

Consumes this encoder returning the underlying writer.

Note that this may discard internal state of this encoder, so care should be taken to avoid losing resources when this is called.

Trait Implementations

impl<W: AsyncBufRead> AsyncBufRead for ZstdEncoder<W>

fn poll_fill_buf( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<&[u8]>>

Attempt to return the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(self: Pin<&mut Self>, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to poll_read.

impl<W: AsyncRead> AsyncRead for ZstdEncoder<W>

fn poll_read( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut [u8], ) -> Poll<Result<usize>>

Attempt to read from the AsyncRead into buf.

fn poll_read_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &mut [IoSliceMut<'_>], ) -> Poll<Result<usize>>

Attempt to read from the AsyncRead into bufs using vectored IO operations.

impl<W: AsyncWrite> AsyncWrite for ZstdEncoder<W>

fn poll_write( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize>>

Attempt to write bytes from buf into the object.

fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Attempt to flush the object, ensuring that any buffered data reach their destination.

fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Attempt to close the object.

fn poll_write_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>

Attempt to write bytes from bufs into the object using vectored IO operations.

impl<W: Debug> Debug for ZstdEncoder<W>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'__pin, W> Unpin for ZstdEncoder<W>

where PinnedFieldsOf<__Origin<'__pin, W>>: Unpin,