insertion_ordered_{map,set}: add new containers

These are associative map/set structures that are iterable in insertion
order.

src/util/insertion_ordered.h

@@ -0,0 +1,368 @@
+/*
+ * Copyright (c) 2017, Intel Corporation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  * Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef UTIL_INSERTION_ORDERED_H
+#define UTIL_INSERTION_ORDERED_H
+
+/**
+ * \file
+ * \brief Insertion-ordered associative containers (set, map).
+ */
+
+#include "util/operators.h"
+#include "util/unordered.h"
+
+#include <cassert>
+#include <iterator>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include <boost/iterator/iterator_facade.hpp>
+
+namespace ue2 {
+
+namespace insertion_ordered_detail {
+
+// Iterator facade that wraps an underlying iterator, so that we get our
+// own iterator types.
+template<class WrappedIter, class Value>
+class iter_wrapper
+    : public boost::iterator_facade<iter_wrapper<WrappedIter, Value>, Value,
+                                    boost::random_access_traversal_tag> {
+public:
+    iter_wrapper() = default;
+    explicit iter_wrapper(WrappedIter it_in) : it(std::move(it_in)) {}
+
+    // Templated copy-constructor to allow for interoperable iterator and
+    // const_iterator.
+    template<class, class> friend class iter_wrapper;
+
+    template<class OtherIter, class OtherValue>
+    iter_wrapper(iter_wrapper<OtherIter, OtherValue> other,
+                 typename std::enable_if<std::is_convertible<
+                     OtherIter, WrappedIter>::value>::type * = nullptr)
+        : it(std::move(other.it)) {}
+
+    WrappedIter get() const { return it; }
+
+private:
+    friend class boost::iterator_core_access;
+
+    WrappedIter it;
+
+    void increment() { ++it; }
+    void decrement() { --it; }
+    void advance(size_t n) { it += n; }
+    typename std::iterator_traits<WrappedIter>::difference_type
+    distance_to(const iter_wrapper &other) const {
+        return other.it - it;
+    }
+    bool equal(const iter_wrapper &other) const { return it == other.it; }
+    Value &dereference() const { return *it; }
+};
+
+template<class Key, class Element>
+class element_store {
+    std::vector<Element> data;
+    ue2_unordered_map<Key, size_t> map;
+
+public:
+    bool empty() const {
+        return data.empty();
+    }
+
+    size_t size() const {
+        assert(data.size() == map.size());
+        return data.size();
+    }
+
+    void clear() {
+        data.clear();
+        map.clear();
+    }
+
+    void reserve(size_t n) {
+        data.reserve(n);
+        map.reserve(n);
+    }
+
+    // Iteration.
+
+    using const_iterator =
+        iter_wrapper<typename std::vector<Element>::const_iterator,
+                     const Element>;
+    using iterator =
+        iter_wrapper<typename std::vector<Element>::iterator, Element>;
+
+    const_iterator begin() const {
+        return const_iterator(data.begin());
+    }
+
+    const_iterator end() const {
+        return const_iterator(data.end());
+    }
+
+    iterator begin() {
+        return iterator(data.begin());
+    }
+
+    iterator end() {
+        return iterator(data.end());
+    }
+
+    // Search.
+
+    const_iterator find(const Key &key) const {
+        auto map_it = map.find(key);
+        if (map_it == map.end()) {
+            return end();
+        }
+        auto idx = map_it->second;
+        assert(idx < data.size());
+        return begin() + idx;
+    }
+
+    iterator find(const Key &key) {
+        auto map_it = map.find(key);
+        if (map_it == map.end()) {
+            return end();
+        }
+        auto idx = map_it->second;
+        assert(idx < data.size());
+        return begin() + idx;
+    }
+
+    // Insert.
+
+    std::pair<iterator, bool> insert(const Key &key, const Element &element) {
+        const auto idx = data.size();
+        if (map.emplace(key, idx).second) {
+            data.push_back(element);
+            return {begin() + idx, true};
+        }
+        return {end(), false};
+    }
+
+    bool operator==(const element_store &a) const {
+        return data == a.data;
+    }
+
+    bool operator<(const element_store &a) const {
+        return data < a.data;
+    }
+
+    void swap(element_store &a) {
+        using std::swap;
+        swap(data, a.data);
+        swap(map, a.map);
+    }
+};
+
+} // namespace insertion_ordered_detail
+
+template<class Key, class Value>
+class insertion_ordered_map
+    : public totally_ordered<insertion_ordered_map<Key, Value>> {
+public:
+    using key_type = Key;
+    using mapped_type = Value;
+    using value_type = std::pair<const Key, Value>;
+
+private:
+    using store_type = insertion_ordered_detail::element_store<Key, value_type>;
+    store_type store;
+
+public:
+    using const_iterator = typename store_type::const_iterator;
+    using iterator = typename store_type::iterator;
+
+    insertion_ordered_map() = default;
+
+    template<class Iter>
+    insertion_ordered_map(Iter it, Iter it_end) {
+        insert(it, it_end);
+    }
+
+    explicit insertion_ordered_map(std::initializer_list<value_type> init) {
+        insert(init.begin(), init.end());
+    }
+
+    const_iterator begin() const { return store.begin(); }
+    const_iterator end() const { return store.end(); }
+    iterator begin() { return store.begin(); }
+    iterator end() { return store.end(); }
+
+    const_iterator find(const Key &key) const {
+        return store.find(key);
+    }
+
+    iterator find(const Key &key) {
+        return store.find(key);
+    }
+
+    std::pair<iterator, bool> insert(const std::pair<const Key, Value> &p) {
+        return store.insert(p.first, p);
+    }
+
+    template<class Iter>
+    void insert(Iter it, Iter it_end) {
+        for (; it != it_end; ++it) {
+            insert(*it);
+        }
+    }
+
+    Value &operator[](const Key &key) {
+        auto it = find(key);
+        if (it == end()) {
+            it = insert({key, Value{}}).first;
+        }
+        return it->second;
+    }
+
+    const Value &at(const Key &key) const {
+        return find(key)->second;
+    }
+
+    Value &at(const Key &key) {
+        return find(key)->second;
+    }
+
+    bool empty() const {
+        return store.empty();
+    }
+
+    size_t size() const {
+        return store.size();
+    }
+
+    void clear() {
+        store.clear();
+    }
+
+    void reserve(size_t n) {
+        store.reserve(n);
+    }
+
+    bool operator==(const insertion_ordered_map &a) const {
+        return store == a.store;
+    }
+
+    bool operator<(const insertion_ordered_map &a) const {
+        return store < a.store;
+    }
+
+    void swap(insertion_ordered_map &a) {
+        store.swap(a.store);
+    }
+
+    friend void swap(insertion_ordered_map &a, insertion_ordered_map &b) {
+        a.swap(b);
+    }
+};
+
+template<class Key>
+class insertion_ordered_set
+    : public totally_ordered<insertion_ordered_set<Key>> {
+public:
+    using key_type = Key;
+    using value_type = Key;
+
+private:
+    using store_type = insertion_ordered_detail::element_store<Key, value_type>;
+    store_type store;
+
+public:
+    using const_iterator = typename store_type::const_iterator;
+    using iterator = typename store_type::iterator;
+
+    insertion_ordered_set() = default;
+
+    template<class Iter>
+        insertion_ordered_set(Iter it, Iter it_end) {
+        insert(it, it_end);
+    }
+
+    explicit insertion_ordered_set(std::initializer_list<value_type> init) {
+        insert(init.begin(), init.end());
+    }
+
+    const_iterator begin() const { return store.begin(); }
+    const_iterator end() const { return store.end(); }
+
+    const_iterator find(const Key &key) const {
+        return store.find(key);
+    }
+
+    std::pair<iterator, bool> insert(const Key &key) {
+        return store.insert(key, key);
+    }
+
+    template<class Iter>
+    void insert(Iter it, Iter it_end) {
+        for (; it != it_end; ++it) {
+            insert(*it);
+        }
+    }
+
+    bool empty() const {
+        return store.empty();
+    }
+
+    size_t size() const {
+        return store.size();
+    }
+
+    void clear() {
+        store.clear();
+    }
+
+    void reserve(size_t n) {
+        store.reserve(n);
+    }
+
+    bool operator==(const insertion_ordered_set &a) const {
+        return store == a.store;
+    }
+
+    bool operator<(const insertion_ordered_set &a) const {
+        return store < a.store;
+    }
+
+    void swap(insertion_ordered_set &a) {
+        store.swap(a.store);
+    }
+
+    friend void swap(insertion_ordered_set &a, insertion_ordered_set &b) {
+        a.swap(b);
+    }
+};
+
+} // namespace ue2
+
+#endif // UTIL_INSERTION_ORDERED_H