Struct CountingWriter

pub struct CountingWriter<W> {
    wtr: W,
    cnt: u64,
    summer: CheckSummer,
}

Wraps any writer that counts and checksums bytes written.

Fields

wtr: W

cnt: u64

summer: CheckSummer

Implementations

impl<W: Write> CountingWriter<W>

pub fn new(wtr: W) -> CountingWriter<W>

Wrap the given writer with a counter.

pub fn count(&self) -> u64

Return the total number of bytes written to the underlying writer.

The count returned is the sum of all counts resulting from a call to write.

pub fn masked_checksum(&self) -> u32

Returns the masked CRC32C checksum of the bytes written so far.

This “masked” checksum is the same one used by the Snappy frame format. Masking is supposed to make the checksum robust with respect to data that contains the checksum itself.

pub fn into_inner(self) -> W

Unwrap the counting writer and return the inner writer.

pub fn get_ref(&self) -> &W

Gets a reference to the underlying writer.

Trait Implementations

impl<W: Write> Write for CountingWriter<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.