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+#ifndef QPID_RANGESET_H
+#define QPID_RANGESET_H
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+#include "qpid/InlineVector.h"
+#include <boost/iterator/iterator_facade.hpp>
+#include <boost/operators.hpp>
+#include <boost/bind.hpp>
+#include <algorithm>
+#include <numeric>
+
+namespace qpid {
+
+/** A range of values, used in RangeSet.
+ * Range(begin, end) includes begin but excludes end.
+ * Range::makeClosed(first,last) includes both first and last.
+ */
+template <class T>
+class Range {
+ public:
+ static Range makeClosed(const T& first, T last) { return Range(first, ++last); }
+
+ Range() : begin_(), end_() {}
+ explicit Range(const T& t) : begin_(t), end_(t) { ++end_; }
+ Range(const T& b, const T& e) : begin_(b), end_(e) { assert(b <= e); }
+
+ T begin() const { return begin_; }
+ /** End of _open_ range, i.e. !contains(end()) */
+ T end() const { return end_; }
+
+ T first() const { assert(!empty()); return begin_; }
+ /** Last in closed range, i.e. contains(end()) */
+ T last() const { assert(!empty()); T ret=end_; return --ret; }
+
+ void begin(const T& t) { begin_ = t; }
+ void end(const T& t) { end_ = t; }
+ size_t size() const { return end_ - begin_; }
+ bool empty() const { return begin_ == end_; }
+
+ bool contains(const T& x) const { return begin_ <= x && x < end_; }
+ bool contains(const Range& r) const { return begin_ <= r.begin_ && r.end_ <= end_; }
+ bool strictContains(const Range& r) const { return begin_ < r.begin_ && r.end_ < end_; }
+
+ bool operator==(const Range& x) { return begin_ == x.begin_ && end_== x.end_; }
+
+ bool operator<(const T& t) const { return end_ < t; }
+ bool operator<(const Range<T>& r) const { return end_ < r.begin_; }
+
+ /** touching ranges can be merged into a single range. */
+ bool touching(const Range& r) const {
+ return std::max(begin_, r.begin_) <= std::min(end_, r.end_);
+ }
+
+ /** @pre touching */
+ void merge(const Range& r) {
+ assert(touching(r));
+ begin_ = std::min(begin_, r.begin_);
+ end_ = std::max(end_, r.end_);
+ }
+
+ operator bool() const { return !empty(); }
+
+ template <class S> void serialize(S& s) { s(begin_)(end_); }
+
+ private:
+ T begin_, end_;
+};
+
+
+/**
+ * A set implemented as a list of [begin, end) ranges.
+ * T must be LessThanComparable and Incrementable.
+ * RangeSet only provides const iterators.
+ */
+template <class T>
+class RangeSet
+ : boost::additive1<RangeSet<T>,
+ boost::additive2<RangeSet<T>, Range<T>,
+ boost::additive2<RangeSet<T>, T> > >
+{
+ typedef InlineVector<Range<T>, 3> Ranges; // TODO aconway 2008-04-21: what's the optimial inlined value?
+
+ public:
+
+ class iterator : public boost::iterator_facade<
+ iterator,
+ const T,
+ boost::forward_traversal_tag>
+ {
+ public:
+ iterator() : ranges(), iter(), value() {}
+
+ private:
+ typedef typename Ranges::const_iterator RangesIter;
+ iterator(const Ranges& r, const RangesIter& i, const T& t)
+ : ranges(&r), iter(i), value(t) {}
+
+ void increment();
+ bool equal(const iterator& i) const;
+ const T& dereference() const { return value; }
+
+ const Ranges* ranges;
+ RangesIter iter;
+ T value;
+
+ friend class RangeSet<T>;
+ friend class boost::iterator_core_access;
+ };
+
+ typedef iterator const_iterator;
+
+ RangeSet() {}
+ explicit RangeSet(const Range<T>& r) { *this += r; }
+ RangeSet(const T& a, const T& b) { *this += Range<T>(a,b); }
+
+ bool contiguous() const { return ranges.size() <= 1; }
+
+ bool contains(const T& t) const;
+ bool contains(const Range<T>&) const;
+
+ /**@pre contiguous() */
+ Range<T> toRange() const;
+
+ bool operator==(const RangeSet<T>&) const;
+
+ void addRange (const Range<T>&);
+ void addSet (const RangeSet<T>&);
+
+ RangeSet<T>& operator+=(const T& t) { return *this += Range<T>(t); }
+ RangeSet<T>& operator+=(const Range<T>& r) { addRange(r); return *this; }
+ RangeSet<T>& operator+=(const RangeSet<T>& s) { addSet(s); return *this; }
+
+ void removeRange (const Range<T>&);
+ void removeSet (const RangeSet<T>&);
+
+ RangeSet<T>& operator-=(const T& t) { return *this -= Range<T>(t); }
+ RangeSet<T>& operator-=(const Range<T>& r) { removeRange(r); return *this; }
+ RangeSet<T>& operator-=(const RangeSet<T>& s) { removeSet(s); return *this; }
+
+ T front() const { return ranges.front().begin(); }
+ T back() const { return ranges.back().end(); }
+
+ // Iterate over elements in the set.
+ iterator begin() const;
+ iterator end() const;
+
+ // Iterate over ranges in the set.
+ typedef typename Ranges::const_iterator RangeIterator;
+ RangeIterator rangesBegin() const { return ranges.begin(); }
+ RangeIterator rangesEnd() const { return ranges.end(); }
+ size_t rangesSize() const { return ranges.size(); }
+
+ // The difference between the start and end of this range set
+ uint32_t span() const;
+
+ size_t size() const;
+ bool empty() const { return ranges.empty(); }
+ void clear() { ranges.clear(); }
+
+ /** Return the largest contiguous range containing x.
+ * Returns the empty range [x,x) if x is not in the set.
+ */
+ Range<T> rangeContaining(const T&) const;
+
+ template <class S> void serialize(S& s) { s.split(*this); s(ranges.begin(), ranges.end()); }
+ template <class S> void encode(S& s) const { s(uint16_t(ranges.size()*sizeof(Range<T>))); }
+ template <class S> void decode(S& s) { uint16_t sz; s(sz); ranges.resize(sz/sizeof(Range<T>)); }
+
+ private:
+ static size_t accumulateSize(size_t s, const Range<T>& r) { return s+r.size(); }
+ Ranges ranges;
+
+ template <class U> friend std::ostream& operator<<(std::ostream& o, const RangeSet<U>& r);
+
+ friend class iterator;
+};
+
+template <class T>
+std::ostream& operator<<(std::ostream& o, const Range<T>& r) {
+ return o << "[" << r.begin() << "," << r.end() << ")";
+}
+
+template <class T>
+std::ostream& operator<<(std::ostream& o, const RangeSet<T>& rs) {
+ std::ostream_iterator<Range<T> > i(o, " ");
+ o << "{ ";
+ std::copy(rs.ranges.begin(), rs.ranges.end(), i);
+ return o << "}";
+}
+
+template <class T>
+bool RangeSet<T>::contains(const T& t) const {
+ typename Ranges::const_iterator i =
+ std::lower_bound(ranges.begin(), ranges.end(), Range<T>(t));
+ return i != ranges.end() && i->contains(t);
+}
+
+template <class T>
+bool RangeSet<T>::contains(const Range<T>& r) const {
+ typename Ranges::const_iterator i =
+ std::lower_bound(ranges.begin(), ranges.end(), r);
+ return i != ranges.end() && i->contains(r);
+}
+
+template <class T> void RangeSet<T>::addRange(const Range<T>& r) {
+ if (r.empty()) return;
+ typename Ranges::iterator i =
+ std::lower_bound(ranges.begin(), ranges.end(), r);
+ if (i == ranges.end() || !i->touching(r))
+ ranges.insert(i, r);
+ else {
+ i->merge(r);
+ typename Ranges::iterator j = i;
+ if (++j != ranges.end() && i->touching(*j)) {
+ i->merge(*j);
+ ranges.erase(j);
+ }
+ }
+}
+
+
+template <class T> void RangeSet<T>::addSet(const RangeSet<T>& s) {
+ typedef RangeSet<T>& (RangeSet<T>::*RangeSetRangeOp)(const Range<T>&);
+ std::for_each(s.ranges.begin(), s.ranges.end(),
+ boost::bind((RangeSetRangeOp)&RangeSet<T>::operator+=, this, _1));
+}
+
+template <class T> void RangeSet<T>::removeRange(const Range<T>& r) {
+ if (r.empty()) return;
+ typename Ranges::iterator i,j;
+ i = std::lower_bound(ranges.begin(), ranges.end(), r);
+ if (i == ranges.end() || i->begin() >= r.end())
+ return; // Outside of set
+ if (*i == r) // Erase i
+ ranges.erase(i);
+ else if (i->strictContains(r)) { // Split i
+ Range<T> i1(i->begin(), r.begin());
+ Range<T> i2(r.end(), i->end());
+ *i = i2;
+ ranges.insert(i, i1);
+ } else {
+ if (i->begin() < r.begin()) { // Truncate i
+ i->end(r.begin());
+ ++i;
+ }
+ for (j = i; j != ranges.end() && r.contains(*j); ++j)
+ ; // Ranges to erase.
+ if (j != ranges.end() && j->end() > r.end())
+ j->begin(r.end()); // Truncate j
+ ranges.erase(i,j);
+ }
+}
+
+template <class T> void RangeSet<T>::removeSet(const RangeSet<T>& r) {
+ std::for_each(
+ r.ranges.begin(), r.ranges.end(),
+ boost::bind(&RangeSet<T>::removeRange, this, _1));
+}
+
+template <class T> Range<T> RangeSet<T>::toRange() const {
+ assert(contiguous());
+ return empty() ? Range<T>() : ranges.front();
+}
+
+template <class T> void RangeSet<T>::iterator::increment() {
+ assert(ranges && iter != ranges->end());
+ if (!iter->contains(++value)) {
+ ++iter;
+ if (iter == ranges->end())
+ *this=iterator(); // end() iterator
+ else
+ value=iter->begin();
+ }
+}
+
+template <class T> bool RangeSet<T>::operator==(const RangeSet<T>& r) const {
+ return ranges.size() == r.ranges.size() && std::equal(ranges.begin(), ranges.end(), r.ranges.begin());
+}
+
+template <class T> typename RangeSet<T>::iterator RangeSet<T>::begin() const {
+ return empty() ? end() : iterator(ranges, ranges.begin(), front());
+}
+
+template <class T> typename RangeSet<T>::iterator RangeSet<T>::end() const {
+ return iterator();
+}
+
+template <class T> bool RangeSet<T>::iterator::equal(const iterator& i) const {
+ return ranges==i.ranges && (ranges==0 || value==i.value);
+}
+
+template <class T> Range<T> RangeSet<T>::rangeContaining(const T& t) const {
+ typename Ranges::const_iterator i =
+ std::lower_bound(ranges.begin(), ranges.end(), Range<T>(t));
+ return (i != ranges.end() && i->contains(t)) ? *i : Range<T>(t,t);
+}
+
+template <class T> uint32_t RangeSet<T>::span() const {
+ if (ranges.empty()) return 0;
+ return ranges.back().last() - ranges.front().first();
+}
+
+template <class T> size_t RangeSet<T>::size() const {
+ return std::accumulate(rangesBegin(), rangesEnd(), 0, &RangeSet<T>::accumulateSize);
+}
+
+} // namespace qpid
+
+
+#endif /*!QPID_RANGESET_H*/