Struct flate2::write::DeflateDecoder

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pub struct DeflateDecoder<W: Write> { /* private fields */ }
Expand description

A DEFLATE decoder, or decompressor.

This structure implements a Write and will emit a stream of decompressed data when fed a stream of compressed data.

After decoding a single member of the DEFLATE data this writer will return the number of bytes up to to the end of the DEFLATE member and subsequent writes will return Ok(0) allowing the caller to handle any data following the DEFLATE member.

§Examples

use std::io::prelude::*;
use std::io;
use flate2::write::DeflateDecoder;

// Uncompresses a Deflate Encoded vector of bytes and returns a string or error
// Here Vec<u8> implements Write
fn decode_writer(bytes: Vec<u8>) -> io::Result<String> {
   let mut writer = Vec::new();
   let mut deflater = DeflateDecoder::new(writer);
   deflater.write_all(&bytes[..])?;
   writer = deflater.finish()?;
   let return_string = String::from_utf8(writer).expect("String parsing error");
   Ok(return_string)
}

Implementations§

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impl<W: Write> DeflateDecoder<W>

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pub fn new(w: W) -> DeflateDecoder<W>

Creates a new decoder which will write uncompressed data to the stream.

When this encoder is dropped or unwrapped the final pieces of data will be flushed.

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pub fn get_ref(&self) -> &W

Acquires a reference to the underlying writer.

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

Acquires a mutable reference to the underlying writer.

Note that mutating the output/input state of the stream may corrupt this object, so care must be taken when using this method.

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pub fn reset(&mut self, w: W) -> Result<W>

Resets the state of this decoder entirely, swapping out the output stream for another.

This function will finish encoding the current stream into the current output stream before swapping out the two output streams.

This will then reset the internal state of this decoder and replace the output stream with the one provided, returning the previous output stream. Future data written to this decoder will be decompressed into the output stream w.

§Errors

This function will perform I/O to finish the stream, and if that I/O returns an error then that will be returned from this function.

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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 finish the stream, returning any errors which happen.

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

Consumes this encoder, flushing the output stream.

This will flush the underlying data stream and then return the contained writer if the flush succeeded.

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.

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pub fn total_in(&self) -> u64

Returns the number of bytes that the decompressor has consumed for decompression.

Note that this will likely be smaller than the number of bytes successfully written to this stream due to internal buffering.

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pub fn total_out(&self) -> u64

Returns the number of bytes that the decompressor has written to its output stream.

Trait Implementations§

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

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

Formats the value using the given formatter. Read more
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impl<W: Read + Write> Read for DeflateDecoder<W>

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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. Read more
1.36.0 · source§

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

Like read, except that it reads into a slice of buffers. Read more
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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. Read more
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fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf. Read more
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fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf. Read more
1.6.0 · source§

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

Read the exact number of bytes required to fill buf. Read more
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fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)
Pull some bytes from this source into the specified buffer. Read more
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fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)
Read the exact number of bytes required to fill cursor. Read more
1.0.0 · source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Creates a “by reference” adaptor for this instance of Read. Read more
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fn bytes(self) -> Bytes<Self>
where Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more
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fn chain<R>(self, next: R) -> Chain<Self, R>
where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another. Read more
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fn take(self, limit: u64) -> Take<Self>
where Self: Sized,

Creates an adapter which will read at most limit bytes from it. Read more
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impl<W: Write> Write for DeflateDecoder<W>

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

Write a buffer into this writer, returning how many bytes were written. Read more
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fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
1.36.0 · source§

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

Like write, except that it writes from a slice of buffers. Read more
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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. Read more
1.0.0 · source§

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

Attempts to write an entire buffer into this writer. Read more
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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. Read more
1.0.0 · source§

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

Writes a formatted string into this writer, returning any error encountered. Read more
1.0.0 · source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

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

Auto Trait Implementations§

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impl<W> Freeze for DeflateDecoder<W>
where W: Freeze,

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impl<W> RefUnwindSafe for DeflateDecoder<W>
where W: RefUnwindSafe,

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impl<W> Send for DeflateDecoder<W>
where W: Send,

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impl<W> Sync for DeflateDecoder<W>
where W: Sync,

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impl<W> Unpin for DeflateDecoder<W>
where W: Unpin,

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impl<W> UnwindSafe for DeflateDecoder<W>
where W: UnwindSafe,

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.