Struct CountingSource 

pub struct CountingSource<'a, S> { /* private fields */ }

A RangedSource adapter that adds each count its source returns to a caller-owned byte counter.

The counter is borrowed, so it keeps the bytes of the successful reads before a failing one and can accumulate across short-lived adapters. It saturates; reaching u64::MAX would take more reads than any input allows.

A count larger than the destination is passed on uncounted, for the caller’s read helper to reject, unless Self::rejecting_overread makes the adapter reject it first.

Implementations

impl<'a, S> CountingSource<'a, S>

pub fn new(source: &'a mut S, bytes_read: &'a mut u64) -> Self

Count the bytes source returns into bytes_read.

pub fn rejecting_overread(self, reason: &'static str) -> Self

Reject a count larger than the destination as an invalid-input Error with reason.

Trait Implementations

impl<S: RangedSource> RangedSource for CountingSource<'_, S>

fn size(&self) -> u64

fn read_at(&mut self, offset: u64, destination: &mut [u8]) -> Result<usize>