Struct ZstdEncoder

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

Available on crate features tokio and zstd only.

A zstd encoder, or compressor.

This structure implements an AsyncRead interface and will read uncompressed data from an underlying stream and emit a stream of compressed data.

Implementations

impl<R: AsyncBufRead> ZstdEncoder<R>

pub fn new(inner: R) -> Self

Creates a new encoder which will read uncompressed data from the given stream and emit a compressed stream.

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

Creates a new encoder which will read uncompressed data from the given stream and emit a compressed stream.

pub fn with_quality_and_params( inner: R, 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: R, 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<R> ZstdEncoder<R>

pub fn get_ref(&self) -> &R

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

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

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

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

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

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

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

pub fn into_inner(self) -> R

Consumes this encoder returning the underlying reader.

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<R: AsyncBufRead> AsyncRead for ZstdEncoder<R>

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

Attempts to read from the AsyncRead into buf.

impl<R: AsyncWrite> AsyncWrite for ZstdEncoder<R>

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<()>>

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

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

Initiates or attempts to shut down this writer, returning success when the I/O connection has completely shut down.

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

Like poll_write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

Determines if this writer has an efficient poll_write_vectored implementation.

impl<R: Debug> Debug for ZstdEncoder<R>

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

Formats the value using the given formatter.

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

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