Struct ZstdWriter 

pub struct ZstdWriter<'dict, W>
where
    W: Write,
{ /* private fields */ }

A writer that writes a compressed zstd stream to the underlying writer.

The underlying writer W must implement the following traits:

• std::io::Write

For async support, see crate::AsyncZstdWriter.

Construction

Create a builder using ZstdWriter::builder. See ZstdWriterBuilder for builder options. Call ZstdWriterBuilder::build to build the ZstdWriter instance.

let mut writer = zstd_framed::ZstdWriter::builder(compressed_file)
    .with_compression_level(3) // Set custom compression level
    .with_seek_table(1024 * 1024) // Write zstd seekable format table
    .build()?;

// ...

writer.shutdown()?; // Optional, will shut down automatically on drop

Writing multiple frames

To allow for efficient seeking (e.g. when using ZstdReaderBuilder::with_seek_table), you can write multiple zstd frames to the underlying writer. If the .with_seek_table() option is given during construction, multiple frames will be created automatically to fit within the given max_frame_size.

Alternatively, you can use ZstdWriter::finish_frame() to explicitly split the underlying stream into multiple frames. .finish_frame() can be used even when not using the .with_seek_table() option (but note the seek table will only be written when using .with_seek_table()).

Clean shutdown

To ensure the writer shuts down cleanly (including flushing any in-memory buffers and writing the seek table if enabled with .with_seek_table()), you can explicitly call the ZstdWriter::shutdown method. This method will also be called automatically on drop, but errors will be ignored.

Implementations

impl<W> ZstdWriter<'_, W>

where W: Write,

pub fn builder(writer: W) -> ZstdWriterBuilder<W>

Create a new zstd writer that writes a compressed zstd stream to the underlying writer.

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

Explicitly finish the current zstd frame. If more data is written, a new frame will be started.

When using ZstdWriterBuilder::with_seek_table, the just-finished frame will be reflected in the resulting seek table.

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

Cleanly shut down the zstd stream. This will flush internal buffers, finish writing any partially-written frames, and write the seek table when using ZstdWriterBuilder::with_seek_table.

This method will be called automatically on drop, although any errors will be ignored.

Trait Implementations

impl<W> Drop for ZstdWriter<'_, W>

where W: Write,

fn drop(&mut self)

Executes the destructor for this type.

impl<W> Write for ZstdWriter<'_, W>

where W: Write,

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

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.