Trait PooledIterator

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pub trait PooledIterator {
    type Item;

    // Required methods
    fn next(&mut self) -> Option<Self::Item>;
    fn try_next(&mut self) -> Result<Option<Self::Item>, OutOfBuffers>;
    fn buffer_pool_size(&self) -> usize;
    fn available_buffers(&self) -> usize;
}

Expand description

A PooledIterator is similar to a lending iterator (which can lend one item at a time), but can make use of a buffer pool to lend out multiple items at a time.

Implementations may or may not be threadsafe. Even if an implementation is threadsafe, items newly-added to the backing collection of the iterator may or may not be seen immediately by other threads.

Required Associated Types§

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type Item

The item of this iterator, which likely has a nontrivial drop implementation that returns a buffer to the iterator’s buffer pool.

Required Methods§

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fn next(&mut self) -> Option<Self::Item>

Move the iterator one position forwards, and return the entry at that position. Returns None if the iterator was at the last entry.

May need to wait for a buffer to become available.

§Potential Panics or Deadlocks

If self.buffer_pool_size() == 0, then this method may panic or deadlock.

Source

fn try_next(&mut self) -> Result<Option<Self::Item>, OutOfBuffers>

If a buffer is available, move the iterator one position forwards, and return the entry at that position. Returns Ok(None) if the iterator was at the last entry.