Struct zstd::stream::read::Encoder

pub struct Encoder<'a, R: BufRead> { /* private fields */ }

An encoder that compress input data from another Read.

Implementations

impl<R: Read> Encoder<'static, BufReader<R>>

pub fn new(reader: R, level: i32) -> Result<Self>

Creates a new encoder.

impl<R: BufRead> Encoder<'static, R>

pub fn with_buffer(reader: R, level: i32) -> Result<Self>

Creates a new encoder around a BufRead.

pub fn with_dictionary(reader: R, level: i32, dictionary: &[u8]) -> Result<Self>

Creates a new encoder, using an existing dictionary.

The dictionary must be the same as the one used during compression.

impl<'a, R: BufRead> Encoder<'a, R>

pub fn with_prepared_dictionary<'b>(
    reader: R,
    dictionary: &EncoderDictionary<'b>
) -> Result<Self> where
    'b: 'a, 

Creates a new encoder, using an existing EncoderDictionary.

The dictionary must be the same as the one used during compression.

pub fn recommended_output_size() -> usize

Recommendation for the size of the output buffer.

pub fn get_ref(&self) -> &R

Acquire a reference to the underlying reader.

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

Acquire a mutable reference to the underlying reader.

Note that mutation of the reader may result in surprising results if this encoder is continued to be used.

pub fn finish(self) -> R

Return the inner Read.

Calling finish() is not required after reading a stream - just use it if you need to get the Read back.

pub fn set_parameter(&mut self, parameter: CParameter) -> Result<()>

Sets the given zstd compression parameter.

pub fn set_pledged_src_size(&mut self, size: Option<u64>) -> Result<()>

Sets the expected size of the input.

This affects the compression effectiveness.

It is an error to give an incorrect size (an error will be returned when closing the stream if the size does not match what was pledged).

Giving a None size means the size is unknown (this is the default).

pub fn include_checksum(&mut self, include_checksum: bool) -> Result<()>

Controls whether zstd should include a content checksum at the end of each frame.

pub fn multithread(&mut self, n_workers: u32) -> Result<()>

This is supported on crate feature zstdmt only.

Enables multithreaded compression

• If n_workers == 0 (default), then multithreaded will be disabled.
• If n_workers >= 1, then compression will be done in separate threads.

So even n_workers = 1 may increase performance by separating IO and compression.

Note: This is only available if the zstdmt cargo feature is activated.

pub fn include_dictid(&mut self, include_dictid: bool) -> Result<()>

Enables or disables storing of the dict id.

Defaults to true. If false, the behaviour of decoding with a wrong dictionary is undefined.

pub fn include_contentsize(&mut self, include_contentsize: bool) -> Result<()>

Enables or disabled storing of the contentsize.

Note that this only has an effect if the size is given with set_pledged_src_size.

pub fn long_distance_matching(
    &mut self,
    long_distance_matching: bool
) -> Result<()>

Enables or disables long-distance matching

pub fn window_log(&mut self, log_distance: u32) -> Result<()>

Sets the maximum back-reference distance.

The actual maximum distance is going to be 2^log_distance.

Note that decompression will need to use at least the same setting.

pub fn include_magicbytes(&mut self, include_magicbytes: bool) -> Result<()>

This is supported on crate feature experimental only.

Enables or disable the magic bytes at the beginning of each frame.

If disabled, include_magicbytes must also be called on the decoder.

Only available with the experimental feature.

Note that decompression will need to use the same setting.

Trait Implementations

impl<R: BufRead> Read for Encoder<'_, R>

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_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

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

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> 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, appending them to buf.

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

Read the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>

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

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>

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

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

Creates an adapter which will chain this stream with another.

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

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