1 // Copyright (c) 2012 The Bitcoin developers
2 // Distributed under the MIT/X11 software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 #ifndef BITCOIN_MRUSET_H
6 #define BITCOIN_MRUSET_H
12 /** STL-like set container that only keeps the most recent N elements. */
13 template <typename T
> class mruset
18 typedef typename
std::set
<T
>::iterator iterator
;
19 typedef typename
std::set
<T
>::const_iterator const_iterator
;
20 typedef typename
std::set
<T
>::size_type size_type
;
28 mruset(size_type nMaxSizeIn
= 0) { nMaxSize
= nMaxSizeIn
; }
29 iterator
begin() const { return set
.begin(); }
30 iterator
end() const { return set
.end(); }
31 size_type
size() const { return set
.size(); }
32 bool empty() const { return set
.empty(); }
33 iterator
find(const key_type
& k
) const { return set
.find(k
); }
34 size_type
count(const key_type
& k
) const { return set
.count(k
); }
35 bool inline friend operator==(const mruset
<T
>& a
, const mruset
<T
>& b
) { return a
.set
== b
.set
; }
36 bool inline friend operator==(const mruset
<T
>& a
, const std::set
<T
>& b
) { return a
.set
== b
; }
37 bool inline friend operator<(const mruset
<T
>& a
, const mruset
<T
>& b
) { return a
.set
< b
.set
; }
38 std::pair
<iterator
, bool> insert(const key_type
& x
)
40 std::pair
<iterator
, bool> ret
= set
.insert(x
);
43 if (nMaxSize
&& queue
.size() == nMaxSize
)
45 set
.erase(queue
.front());
52 size_type
max_size() const { return nMaxSize
; }
53 size_type
max_size(size_type s
)
56 while (queue
.size() > s
)
58 set
.erase(queue
.front());