Struct CompressorWriter

pub struct CompressorWriter<W>
where
    W: Write,
{ /* private fields */ }

Wraps a writer and compresses its output.

CompressorWriter<W> wraps a writer and adds brotli compression to the output. It is critical to finish the compression stream, otherwise decompression will not be successful. Dropping will attempt to finish the compression stream, any errors that might arise however will be ignored. Calling into_inner ensures that the compression stream is finished.

Calling flush will not only flush the underlying writer, but also flush all of its compression stream. This will lead to a slight decrease of compression quality, as output will be forced to be flushed as is and not compressed till the block is finished.

Examples

Let’s compress some text file named text.txt and write the output to test.brotli:

use std::fs::File;
use std::io;

use brotlic::CompressorWriter;

let mut input = File::open("test.txt")?; // test.txt is uncompressed
let mut output = File::create("test.brotli")?;
let mut compressed_output = CompressorWriter::new(output);

io::copy(&mut input, &mut compressed_output)?;

To decompress it again, use DecompressorWriter.

Implementations

impl<W> CompressorWriter<W>

where W: Write,

pub fn new(inner: W) -> CompressorWriter<W>

Creates a new CompressorWriter<W> with a newly created encoder.

Panics

Panics if the encoder fails to be allocated or initialized

pub fn with_encoder(encoder: BrotliEncoder, inner: W) -> CompressorWriter<W>

Creates a new CompressorWriter<W> with a specified encoder.

Examples

use brotlic::{BrotliEncoderOptions, CompressorWriter, Quality, WindowSize};

let encoder = BrotliEncoderOptions::new()
    .quality(Quality::new(4)?)
    .window_size(WindowSize::new(16)?)
    .build()?;

let underlying_storage = Vec::new();
let writer = CompressorWriter::with_encoder(encoder, underlying_storage);

pub fn get_ref(&self) -> &W

Gets a reference to the underlying writer

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

Gets a mutable reference to the underlying writer.

It is inadvisable to directly write to the underlying writer.

pub fn into_inner(self) -> Result<W, IntoInnerError<CompressorWriter<W>>>

Unwraps this CompressorWriter<W>, returning the underlying writer.

The compression stream is finished before returning the writer.

Errors

An Err will be returned if an error occurs while finishing the compression stream.

pub fn into_parts(self) -> (W, Result<BrotliEncoder, WriterPanicked>)

Disassembles this CompressorWriter<W>, returning the underlying writer and encoder.

If the underlying writer panicked, it is not known what portion of the data was written. In this case, we return WriterPanicked to get the encoder back. It is worth noting that the compression stream is not finished and hence cannot be successfully decompressed. To obtain the writer once the compression stream is finished, use into_inner.

into_parts makes no attempt to finish the compression stream and cannot fail.

Trait Implementations

impl<W> Debug for CompressorWriter<W>

where W: Debug + Write,

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

Formats the value using the given formatter.

impl<W> Drop for CompressorWriter<W>

where W: Write,

fn drop(&mut self)

Executes the destructor for this type.

impl<W> Write for CompressorWriter<W>

where W: Write,

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

Writes a buffer into this writer, returning how many bytes were written.

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

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

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

fn is_write_vectored(&self) -> bool

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

Determines if this Writer has an efficient write_vectored implementation.

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

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

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

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.