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1 #![allow(deprecated)]
2 
3 use super::{IntoIter, IterMut, ThreadLocal};
4 use std::fmt;
5 use std::panic::UnwindSafe;
6 use 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")]
13 pub struct CachedThreadLocal<T: Send> {
14     inner: ThreadLocal<T>,
15 }
16 
17 impl<T: Send> Default for CachedThreadLocal<T> {
default() -> CachedThreadLocal<T>18     fn default() -> CachedThreadLocal<T> {
19         CachedThreadLocal::new()
20     }
21 }
22 
23 impl<T: Send> CachedThreadLocal<T> {
24     /// Creates a new empty `CachedThreadLocal`.
25     #[inline]
new() -> CachedThreadLocal<T>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]
get(&self) -> Option<&T>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]
get_or<F>(&self, create: F) -> &T where F: FnOnce() -> T,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]
get_or_try<F, E>(&self, create: F) -> Result<&T, E> where F: FnOnce() -> Result<T, E>,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]
iter_mut(&mut self) -> CachedIterMut<T>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]
clear(&mut self)78     pub fn clear(&mut self) {
79         self.inner.clear();
80     }
81 }
82 
83 impl<T: Send> IntoIterator for CachedThreadLocal<T> {
84     type Item = T;
85     type IntoIter = CachedIntoIter<T>;
86 
into_iter(self) -> CachedIntoIter<T>87     fn into_iter(self) -> CachedIntoIter<T> {
88         CachedIntoIter {
89             inner: self.inner.into_iter(),
90         }
91     }
92 }
93 
94 impl<'a, T: Send + 'a> IntoIterator for &'a mut CachedThreadLocal<T> {
95     type Item = &'a mut T;
96     type IntoIter = CachedIterMut<'a, T>;
97 
into_iter(self) -> CachedIterMut<'a, T>98     fn into_iter(self) -> CachedIterMut<'a, T> {
99         self.iter_mut()
100     }
101 }
102 
103 impl<T: Send + Default> CachedThreadLocal<T> {
104     /// Returns the element for the current thread, or creates a default one if
105     /// it doesn't exist.
get_or_default(&self) -> &T106     pub fn get_or_default(&self) -> &T {
107         self.get_or(T::default)
108     }
109 }
110 
111 impl<T: Send + fmt::Debug> fmt::Debug for CachedThreadLocal<T> {
fmt(&self, f: &mut fmt::Formatter) -> fmt::Result112     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
113         write!(f, "ThreadLocal {{ local_data: {:?} }}", self.get())
114     }
115 }
116 
117 impl<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")]
121 pub struct CachedIterMut<'a, T: Send + 'a> {
122     inner: IterMut<'a, T>,
123 }
124 
125 impl<'a, T: Send + 'a> Iterator for CachedIterMut<'a, T> {
126     type Item = &'a mut T;
127 
128     #[inline]
next(&mut self) -> Option<&'a mut T>129     fn next(&mut self) -> Option<&'a mut T> {
130         self.inner.next()
131     }
132 
133     #[inline]
size_hint(&self) -> (usize, Option<usize>)134     fn size_hint(&self) -> (usize, Option<usize>) {
135         self.inner.size_hint()
136     }
137 }
138 
139 impl<'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")]
143 pub struct CachedIntoIter<T: Send> {
144     inner: IntoIter<T>,
145 }
146 
147 impl<T: Send> Iterator for CachedIntoIter<T> {
148     type Item = T;
149 
150     #[inline]
next(&mut self) -> Option<T>151     fn next(&mut self) -> Option<T> {
152         self.inner.next()
153     }
154 
155     #[inline]
size_hint(&self) -> (usize, Option<usize>)156     fn size_hint(&self) -> (usize, Option<usize>) {
157         self.inner.size_hint()
158     }
159 }
160 
161 impl<T: Send> ExactSizeIterator for CachedIntoIter<T> {}
162