Struct TreeClose 

pub struct TreeClose { /* private fields */ }

The signal of a tree being closed, returned by Tree::close and its counterparts.

A tree is closed once nothing of it owns a file of its directory or works in it any more: no tree handle, iterator, snapshot or pin holds it, its table file pool made its last file and the background deleter removed the last file it was handed. From then on the tree writes nothing into its directory, and removing the directory is safe.

The handle keeps nothing open itself, nor do the callbacks registered on it, so it can be held for as long as wanted.

Implementations

impl TreeClose

pub fn on_closed(&self, f: impl FnOnce() + Send + 'static)

Runs f once the tree is closed, on the thread that finished closing it, or at once on this thread if it is closed already. Nothing waits or polls meanwhile: an async caller completes its own oneshot from it.

f runs inside the drop that closed the tree, so it should be short. With std a panic in f is caught and logged, and the other callbacks still run.

Examples

use std::sync::mpsc;

let tree = lsm_tree::Config::new(
    folder.path(),
    lsm_tree::SequenceNumberCounter::default(),
    lsm_tree::SequenceNumberCounter::default(),
)
.open()?;

let (closed, on_closed) = mpsc::channel();
// The receiver may be gone by then: a failed send is nothing to report.
tree.close().on_closed(move || {
    let _ = closed.send(());
});
on_closed.recv()?;
std::fs::remove_dir_all(folder.path())?;

pub fn is_closed(&self) -> bool

Whether the tree is closed.

pub fn wait(&self)

Blocks until the tree is closed.

Blocks for good if the caller itself still holds a tree handle, an iterator, a snapshot or a pin of the tree: drop them first, or use on_closed.

Examples

use lsm_tree::AbstractTree;

let tree = lsm_tree::Config::new(
    folder.path(),
    lsm_tree::SequenceNumberCounter::default(),
    lsm_tree::SequenceNumberCounter::default(),
)
.open()?;
tree.insert("a", "1", 0);
tree.flush_active_memtable(0)?;

tree.close().wait();
std::fs::remove_dir_all(folder.path())?;

pub fn wait_timeout(&self, timeout: Duration) -> bool

Blocks until the tree is closed or timeout passes; whether it is closed.

Returns false at the timeout while anything of the tree is held, the caller’s own handles, iterators, snapshots and pins included.

Trait Implementations

impl Clone for TreeClose

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TreeClose

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

Formats the value using the given formatter.