Struct GzEncoder 

pub struct GzEncoder<W: Write> { /* private fields */ }

A gzip streaming encoder

This structure exposes a Write interface that will emit compressed data to the underlying writer W.

Examples

use std::io::prelude::*;
use flate2::Compression;
use flate2::write::GzEncoder;

// Vec<u8> implements Write to print the compressed bytes of sample string

let mut e = GzEncoder::new(Vec::new(), Compression::default());
e.write_all(b"Hello World").unwrap();
println!("{:?}", e.finish().unwrap());

Implementations

impl<W: Write> GzEncoder<W>

pub fn new(w: W, level: Compression) -> GzEncoder<W>

Creates a new encoder which will use the given compression level.

The encoder is not configured specially for the emitted header. For header configuration, see the GzBuilder type.

The data written to the returned encoder will be compressed and then written to the stream w.

pub fn get_ref(&self) -> &W

Acquires a reference to the underlying writer.

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

Acquires a mutable reference to the underlying writer.

The underlying writer may be mutated or replaced as long as this preserves the bytes and ordering of the logical output stream. Concatenate output from each writer to reconstruct the complete stream.

Replacing the writer does not require flush. Call it first when all input accepted so far must be decodable without output from later writes. This inserts a sync-flush point and changes the output bitstream. This is useful before applying std::mem::take to get_mut when forwarding the stream incrementally.

To start a new stream, call finish and create a new encoder; replacing the writer does not reset it.

pub fn try_finish(&mut self) -> Result<()>

Attempt to finish this output stream, writing out final chunks of data.

Note that this function can only be used once data has finished being written to the output stream. After this function is called then further calls to write may result in a panic.

Panics

Attempts to write data to this stream may result in a panic after this function is called.

Errors

This function will perform I/O to complete this stream, and any I/O errors which occur will be returned from this function.

pub fn finish(self) -> Result<W>

Finish encoding this stream, returning the underlying writer once the encoding is done.

Note that this function may not be suitable to call in a situation where the underlying stream is an asynchronous I/O stream. To finish a stream the try_finish (or shutdown) method should be used instead. To re-acquire ownership of a stream it is safe to call this method after try_finish or shutdown has returned Ok.

Errors

This function will perform I/O to complete this stream, and any I/O errors which occur will be returned from this function.

Trait Implementations

impl<W: Debug + Write> Debug for GzEncoder<W>

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

Formats the value using the given formatter.

impl<W: Write> Drop for GzEncoder<W>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

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

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl<R: Read + Write> Read for GzEncoder<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>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

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

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_, u8>) -> 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, cursor: BorrowedCursor<'_, u8>, ) -> Result<(), Error>

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

Reads the exact number of bytes required to fill cursor.

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

where Self: Sized,

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

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

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

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

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

where Self: Sized,

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

fn read_array<const N: usize>(&mut self) -> Result<[u8; N], Error>

where Self: Sized,

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

Read and return a fixed array of bytes from this source.

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

where T: FromEndianBytes, Self: Sized,

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

Read and return a type (e.g. an integer) in little-endian order.

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

where T: FromEndianBytes, Self: Sized,

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

Read and return a type (e.g. an integer) in big-endian order.

impl<W: Write> Write for GzEncoder<W>

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

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

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

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.