Struct zstd::stream::Encoder

pub struct Encoder<W: Write> { /* fields omitted */ }

An encoder that compress and forward data to another writer.

This allows to compress a stream of data (good for files or heavy network stream).

Don't forget to call finish() before dropping it!

Note: The zstd library has its own internal input buffer (~128kb).

Methods

impl<W: Write> Encoder<W>

fn new(writer: W, level: i32) -> Result<Self>

Creates a new encoder.

level: compression level (1-21).

A level of 0 uses zstd's default (currently 3).

fn with_dictionary(writer: W, level: i32, dictionary: &[u8]) -> Result<Self>

Creates a new encoder, using an existing dictionary.

(Provides better compression ratio for small files, but requires the dictionary to be present during decompression.)

A level of 0 uses zstd's default (currently 3).

fn auto_finish(self) -> AutoFinishEncoder<W>

Returns a wrapper around self that will finish the stream on drop.

Panic

Panics on drop if an error happens when finishing the stream.

fn on_finish<F: 'static + FnMut(Result<W>)>(self, f: F) -> AutoFinishEncoder<W>

Returns an encoder that will finish the stream on drop.

Calls the given callback with the result from finish().

fn get_ref(&self) -> &W

Acquires a reference to the underlying writer.

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

Acquires a mutable reference to the underlying writer.

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

fn finish(self) -> Result<W>

Required: Finishes the stream.

You need to finish the stream when you're done writing, either with this method or with try_finish(self).

This returns the inner writer in case you need it.

To get back self in case an error happened, use try_finish.

Note: If you don't want (or can't) call finish() manually after writing your data, consider using auto_finish() to get an AutoFinishEncoder.

fn try_finish(self) -> Result<W, (Self, Error)>

Required: Attempts to finish the stream.

You need to finish the stream when you're done writing, either with this method or with finish(self).

This returns the inner writer if the finish was successful, or the object plus an error if it wasn't.

write on this object will panic after try_finish has been called, even if it fails.

fn recommended_input_size() -> usize

Return a recommendation for the size of data to write at once.

Trait Implementations

impl<W: Write> Write for Encoder<W>

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

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

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

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.