thread_local/
cached.rs

1#![allow(deprecated)]
2
3use super::{IntoIter, IterMut, ThreadLocal};
4use std::fmt;
5use std::panic::UnwindSafe;
6use std::usize;
7
8/// Wrapper around [`ThreadLocal`].
9///
10/// This used to add a fast path for a single thread, however that has been
11/// obsoleted by performance improvements to [`ThreadLocal`] itself.
12#[deprecated(since = "1.1.0", note = "Use `ThreadLocal` instead")]
13pub struct CachedThreadLocal<T: Send> {
14    inner: ThreadLocal<T>,
15}
16
17impl<T: Send> Default for CachedThreadLocal<T> {
18    fn default() -> CachedThreadLocal<T> {
19        CachedThreadLocal::new()
20    }
21}
22
23impl<T: Send> CachedThreadLocal<T> {
24    /// Creates a new empty `CachedThreadLocal`.
25    #[inline]
26    pub fn new() -> CachedThreadLocal<T> {
27        CachedThreadLocal {
28            inner: ThreadLocal::new(),
29        }
30    }
31
32    /// Returns the element for the current thread, if it exists.
33    #[inline]
34    pub fn get(&self) -> Option<&T> {
35        self.inner.get()
36    }
37
38    /// Returns the element for the current thread, or creates it if it doesn't
39    /// exist.
40    #[inline]
41    pub fn get_or<F>(&self, create: F) -> &T
42    where
43        F: FnOnce() -> T,
44    {
45        self.inner.get_or(create)
46    }
47
48    /// Returns the element for the current thread, or creates it if it doesn't
49    /// exist. If `create` fails, that error is returned and no element is
50    /// added.
51    #[inline]
52    pub fn get_or_try<F, E>(&self, create: F) -> Result<&T, E>
53    where
54        F: FnOnce() -> Result<T, E>,
55    {
56        self.inner.get_or_try(create)
57    }
58
59    /// Returns a mutable iterator over the local values of all threads.
60    ///
61    /// Since this call borrows the `ThreadLocal` mutably, this operation can
62    /// be done safely---the mutable borrow statically guarantees no other
63    /// threads are currently accessing their associated values.
64    #[inline]
65    pub fn iter_mut(&mut self) -> CachedIterMut<T> {
66        CachedIterMut {
67            inner: self.inner.iter_mut(),
68        }
69    }
70
71    /// Removes all thread-specific values from the `ThreadLocal`, effectively
72    /// reseting it to its original state.
73    ///
74    /// Since this call borrows the `ThreadLocal` mutably, this operation can
75    /// be done safely---the mutable borrow statically guarantees no other
76    /// threads are currently accessing their associated values.
77    #[inline]
78    pub fn clear(&mut self) {
79        self.inner.clear();
80    }
81}
82
83impl<T: Send> IntoIterator for CachedThreadLocal<T> {
84    type Item = T;
85    type IntoIter = CachedIntoIter<T>;
86
87    fn into_iter(self) -> CachedIntoIter<T> {
88        CachedIntoIter {
89            inner: self.inner.into_iter(),
90        }
91    }
92}
93
94impl<'a, T: Send + 'a> IntoIterator for &'a mut CachedThreadLocal<T> {
95    type Item = &'a mut T;
96    type IntoIter = CachedIterMut<'a, T>;
97
98    fn into_iter(self) -> CachedIterMut<'a, T> {
99        self.iter_mut()
100    }
101}
102
103impl<T: Send + Default> CachedThreadLocal<T> {
104    /// Returns the element for the current thread, or creates a default one if
105    /// it doesn't exist.
106    pub fn get_or_default(&self) -> &T {
107        self.get_or(T::default)
108    }
109}
110
111impl<T: Send + fmt::Debug> fmt::Debug for CachedThreadLocal<T> {
112    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
113        write!(f, "ThreadLocal {{ local_data: {:?} }}", self.get())
114    }
115}
116
117impl<T: Send + UnwindSafe> UnwindSafe for CachedThreadLocal<T> {}
118
119/// Mutable iterator over the contents of a `CachedThreadLocal`.
120#[deprecated(since = "1.1.0", note = "Use `IterMut` instead")]
121pub struct CachedIterMut<'a, T: Send + 'a> {
122    inner: IterMut<'a, T>,
123}
124
125impl<'a, T: Send + 'a> Iterator for CachedIterMut<'a, T> {
126    type Item = &'a mut T;
127
128    #[inline]
129    fn next(&mut self) -> Option<&'a mut T> {
130        self.inner.next()
131    }
132
133    #[inline]
134    fn size_hint(&self) -> (usize, Option<usize>) {
135        self.inner.size_hint()
136    }
137}
138
139impl<'a, T: Send + 'a> ExactSizeIterator for CachedIterMut<'a, T> {}
140
141/// An iterator that moves out of a `CachedThreadLocal`.
142#[deprecated(since = "1.1.0", note = "Use `IntoIter` instead")]
143pub struct CachedIntoIter<T: Send> {
144    inner: IntoIter<T>,
145}
146
147impl<T: Send> Iterator for CachedIntoIter<T> {
148    type Item = T;
149
150    #[inline]
151    fn next(&mut self) -> Option<T> {
152        self.inner.next()
153    }
154
155    #[inline]
156    fn size_hint(&self) -> (usize, Option<usize>) {
157        self.inner.size_hint()
158    }
159}
160
161impl<T: Send> ExactSizeIterator for CachedIntoIter<T> {}
thread_local/cached.rs

thread_local/
cached.rs
