/*
- * Copyright (c) 2012 ARM Limited
+ * Copyright (c) 2012, 2018 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
#ifndef __BASE_ADDR_RANGE_MAP_HH__
#define __BASE_ADDR_RANGE_MAP_HH__
+#include <cstddef>
+#include <functional>
+#include <list>
#include <map>
#include <utility>
#include "base/addr_range.hh"
+#include "base/types.hh"
/**
* The AddrRangeMap uses an STL map to implement an interval tree for
* address decoding. The value stored is a template type and can be
* e.g. a port identifier, or a pointer.
*/
-template <typename V>
+template <typename V, int max_cache_size=0>
class AddrRangeMap
{
private:
typedef std::map<AddrRange, V> RangeMap;
- RangeMap tree;
public:
typedef typename RangeMap::iterator iterator;
typedef typename RangeMap::const_iterator const_iterator;
+ /**
+ * Find entry that contains the given address range
+ *
+ * Searches through the ranges in the address map and returns an
+ * iterator to the entry which range is a superset of the input
+ * address range. Returns end() if none found.
+ *
+ * @param r An input address range
+ * @return An iterator that contains the input address range
+ */
const_iterator
- find(const AddrRange &r) const
- {
- const_iterator i;
-
- i = tree.upper_bound(r);
-
- if (i == tree.begin()) {
- if (i->first.start <= r.end && i->first.end >= r.start)
- return i;
- else
- // Nothing could match, so return end()
- return tree.end();
- }
-
- --i;
-
- if (i->first.start <= r.end && i->first.end >= r.start)
- return i;
-
- return tree.end();
- }
-
- iterator
- find(const AddrRange &r)
+ contains(const AddrRange &r) const
{
- iterator i;
-
- i = tree.upper_bound(r);
-
- if (i == tree.begin()) {
- if (i->first.start <= r.end && i->first.end >= r.start)
- return i;
- else
- // Nothing could match, so return end()
- return tree.end();
- }
-
- --i;
-
- if (i->first.start <= r.end && i->first.end >= r.start)
- return i;
-
- return tree.end();
+ return find(r, [r](const AddrRange r1) { return r.isSubset(r1); });
}
+ /**
+ * Find entry that contains the given address
+ *
+ * Searches through the ranges in the address map and returns an
+ * iterator to the entry which range is a superset of the input
+ * address. Returns end() if none found.
+ *
+ * @param r An input address
+ * @return An iterator that contains the input address
+ */
const_iterator
- find(const Addr &r) const
+ contains(Addr r) const
{
- return find(RangeSize(r, 1));
+ return contains(RangeSize(r, 1));
}
- iterator
- find(const Addr &r)
- {
- return find(RangeSize(r, 1));
- }
-
- bool
- intersect(const AddrRange &r)
+ /**
+ * Find entry that intersects with the given address range
+ *
+ * Searches through the ranges in the address map and returns an
+ * iterator to the first entry which range intersects with the
+ * input address.
+ *
+ * @param r An input address
+ * @return An iterator that intersects with the input address range
+ */
+ const_iterator
+ intersects(const AddrRange &r) const
{
- iterator i;
- i = find(r);
- if (i != tree.end())
- return true;
- return false;
+ return find(r, [r](const AddrRange r1) { return r.intersects(r1); });
}
- iterator
+ const_iterator
insert(const AddrRange &r, const V& d)
{
- if (intersect(r))
+ if (intersects(r) != end())
return tree.end();
return tree.insert(std::make_pair(r, d)).first;
}
- std::size_t
- erase(Addr k)
- {
- return tree.erase(k);
- }
-
void
erase(iterator p)
{
+ cache.remove(p);
tree.erase(p);
}
void
erase(iterator p, iterator q)
{
+ for (auto it = p; it != q; it++) {
+ cache.remove(p);
+ }
tree.erase(p,q);
}
void
clear()
{
+ cache.erase(cache.begin(), cache.end());
tree.erase(tree.begin(), tree.end());
}
{
return tree.empty();
}
+
+ private:
+ /**
+ * Add an address range map entry to the cache.
+ *
+ * @param it Iterator to the entry in the address range map
+ */
+ void
+ addNewEntryToCache(const_iterator it) const
+ {
+ if (max_cache_size != 0) {
+ // If there's a cache, add this element to it.
+ if (cache.size() >= max_cache_size) {
+ // If the cache is full, move the last element to the
+ // front and overwrite it with the new value. This
+ // avoids creating or destroying elements of the list.
+ auto last = cache.end();
+ last--;
+ *last = it;
+ if (max_cache_size > 1)
+ cache.splice(cache.begin(), cache, last);
+ } else {
+ cache.push_front(it);
+ }
+ }
+ }
+
+ /**
+ * Find entry that satisfies a condition on an address range
+ *
+ * Searches through the ranges in the address map and returns an
+ * iterator to the entry that satisfies the input conidition on
+ * the input address range. Returns end() if none found.
+ *
+ * @param r An input address range
+ * @param f A condition on an address range
+ * @return An iterator that contains the input address range
+ */
+ const_iterator
+ find(const AddrRange &r, std::function<bool(const AddrRange)> cond) const
+ {
+ // Check the cache first
+ for (auto c = cache.begin(); c != cache.end(); c++) {
+ auto it = *c;
+ if (cond(it->first)) {
+ // If this entry matches, promote it to the front
+ // of the cache and return it.
+ cache.splice(cache.begin(), cache, c);
+ return it;
+ }
+ }
+
+ const_iterator next = tree.upper_bound(r);
+ if (next != end() && cond(next->first)) {
+ addNewEntryToCache(next);
+ return next;
+ }
+ if (next == begin())
+ return end();
+ next--;
+
+ const_iterator i;
+ do {
+ i = next;
+ if (cond(i->first)) {
+ addNewEntryToCache(i);
+ return i;
+ }
+ // Keep looking if the next range merges with the current one.
+ } while (next != begin() &&
+ (--next)->first.mergesWith(i->first));
+
+ return end();
+ }
+
+ RangeMap tree;
+
+ /**
+ * A list of iterator that correspond to the max_cache_size most
+ * recently used entries in the address range map. This mainly
+ * used to optimize lookups. The elements in the list should
+ * always be valid iterators of the tree.
+ */
+ mutable std::list<const_iterator> cache;
};
#endif //__BASE_ADDR_RANGE_MAP_HH__
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