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Move util::persistent_list to layout
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parent
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commit
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4 changed files with 2 additions and 2 deletions
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@ -58,7 +58,6 @@ pub mod linked_list;
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#[cfg(feature = "non-geckolib")]
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pub mod non_geckolib;
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pub mod opts;
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pub mod persistent_list;
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pub mod prefs;
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pub mod print_tree;
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pub mod range;
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@ -1,92 +0,0 @@
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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//! A persistent, thread-safe singly-linked list.
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use std::sync::Arc;
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pub struct PersistentList<T> {
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head: PersistentListLink<T>,
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length: usize,
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}
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struct PersistentListEntry<T> {
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value: T,
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next: PersistentListLink<T>,
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}
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type PersistentListLink<T> = Option<Arc<PersistentListEntry<T>>>;
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impl<T> PersistentList<T> where T: Send + Sync {
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#[inline]
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pub fn new() -> PersistentList<T> {
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PersistentList {
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head: None,
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length: 0,
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}
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}
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#[inline]
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pub fn len(&self) -> usize {
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self.length
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}
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#[inline]
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pub fn front(&self) -> Option<&T> {
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self.head.as_ref().map(|head| &head.value)
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}
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#[inline]
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pub fn prepend_elem(&self, value: T) -> PersistentList<T> {
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PersistentList {
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head: Some(Arc::new(PersistentListEntry {
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value: value,
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next: self.head.clone(),
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})),
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length: self.length + 1,
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}
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}
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#[inline]
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pub fn iter(&self) -> PersistentListIterator<T> {
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// This could clone (and would not need the lifetime if it did), but then it would incur
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// atomic operations on every call to `.next()`. Bad.
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PersistentListIterator {
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entry: self.head.as_ref().map(|head| &**head),
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}
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}
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}
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impl<T> Clone for PersistentList<T> where T: Send + Sync {
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fn clone(&self) -> PersistentList<T> {
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// This establishes the persistent nature of this list: we can clone a list by just cloning
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// its head.
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PersistentList {
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head: self.head.clone(),
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length: self.length,
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}
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}
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}
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pub struct PersistentListIterator<'a,T> where T: 'a + Send + Sync {
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entry: Option<&'a PersistentListEntry<T>>,
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}
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impl<'a, T> Iterator for PersistentListIterator<'a, T> where T: Send + Sync + 'static {
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type Item = &'a T;
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#[inline]
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fn next(&mut self) -> Option<&'a T> {
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let entry = match self.entry {
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None => return None,
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Some(entry) => entry,
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};
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let value = &entry.value;
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self.entry = match entry.next {
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None => None,
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Some(ref entry) => Some(&**entry),
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};
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Some(value)
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}
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}
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