Merge support for emplace for compilers with rvalue references and variadic templates arguments, and better use of C++0x allocators.

Merged revisions 44058-44075,44078-44084,44086-44108,44110-44365,44367,44369-44414,44416-44419,44421-44457,44467-44469,44471-44511,44513-44535,44537-44737 via svnmerge from https://svn.boost.org/svn/boost/branches/unordered/trunk ................ r44467 | danieljames | 2008-04-16 18:35:56 +0100 (Wed, 16 Apr 2008) | 2 lines Add C++-0x support to the test allocators. ................ r44468 | danieljames | 2008-04-16 18:36:06 +0100 (Wed, 16 Apr 2008) | 2 lines Add a C++-0x node_constructor. ................ r44469 | danieljames | 2008-04-16 18:36:16 +0100 (Wed, 16 Apr 2008) | 2 lines C++-0x constructor for node. ................ r44516 | danieljames | 2008-04-17 21:41:48 +0100 (Thu, 17 Apr 2008) | 16 lines Merge in my work so far on implementing emplace for compilers with variadic template & rvalue references. Merged revisions 44059-44062 via svnmerge from https://svn.boost.org/svn/boost/branches/unordered/dev ........ r44059 | danieljames | 2008-04-05 17:41:25 +0100 (Sat, 05 Apr 2008) | 1 line First stab at implementing emplace - only for compilers with variadic template & rvalue references. ........ r44062 | danieljames | 2008-04-05 19:12:09 +0100 (Sat, 05 Apr 2008) | 1 line Better variable template arguments, need to add proper support to BoostBook. ........ ................ r44616 | danieljames | 2008-04-20 13:30:19 +0100 (Sun, 20 Apr 2008) | 1 line Merge with trunk, fixes tabs. ................ r44618 | danieljames | 2008-04-20 13:42:38 +0100 (Sun, 20 Apr 2008) | 2 lines Some extra compile tests. ................ r44619 | danieljames | 2008-04-20 13:42:50 +0100 (Sun, 20 Apr 2008) | 2 lines Fix an error message. ................ r44703 | danieljames | 2008-04-21 20:19:50 +0100 (Mon, 21 Apr 2008) | 15 lines Merge latest changes from trunk. Merged revisions 44616-44702 via svnmerge from https://svn.boost.org/svn/boost/trunk ........ r44650 | danieljames | 2008-04-20 22:08:57 +0100 (Sun, 20 Apr 2008) | 1 line Update an include. ........ r44697 | danieljames | 2008-04-21 16:55:40 +0100 (Mon, 21 Apr 2008) | 1 line Factor out the code for choosing the bucket count, and which bucket that hash values map to make it easier to experiment with alternative policies. ........ ................ r44733 | danieljames | 2008-04-23 07:55:43 +0100 (Wed, 23 Apr 2008) | 2 lines Remove 'reserve_extra'. ................ r44734 | danieljames | 2008-04-23 07:55:55 +0100 (Wed, 23 Apr 2008) | 2 lines More unnecessary copy tests - showing some weakness in the emplace implementation. ................ r44735 | danieljames | 2008-04-23 07:56:06 +0100 (Wed, 23 Apr 2008) | 2 lines More tests. ................ r44736 | danieljames | 2008-04-23 07:56:19 +0100 (Wed, 23 Apr 2008) | 2 lines Comment out a test which requires a C++0x std::pair. ................ r44737 | danieljames | 2008-04-23 07:56:35 +0100 (Wed, 23 Apr 2008) | 2 lines Avoid creating unnecessary copies in unordered_set::emplace and unordered_map::emplace. ................ [SVN r44738]
2026-05-04 11:44:19 +02:00 · 2008-04-23 07:09:58 +00:00
parent c56213442d
commit 94932ae026
12 changed files with 978 additions and 64 deletions
@@ -32,6 +32,13 @@

 #include <boost/mpl/aux_/config/eti.hpp>

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/mpl/not.hpp>
+#endif
+
 #if BOOST_WORKAROUND(__BORLANDC__, <= 0x0582)
 #define BOOST_UNORDERED_BORLAND_BOOL(x) (bool)(x)
 #else
@@ -108,15 +108,114 @@ namespace boost {
            struct node : node_base
            {
            public:
+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+                template <typename... Args>
+                node(Args&&... args)
+                    : node_base(), value_(std::forward<Args>(args)...) {}
+#else
                node(value_type const& v) : node_base(), value_(v) {}
+#endif

                value_type value_;
            };

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+
+            // allocators
+            //
+            // Stores all the allocators that we're going to need.
+
+            struct allocators
+            {
+                node_allocator node_alloc_;
+                bucket_allocator bucket_alloc_;
+
+                allocators(value_allocator const& a)
+                    : node_alloc_(a), bucket_alloc_(a)
+                {}
+
+                void destroy(link_ptr ptr)
+                {
+                    node_ptr n(node_alloc_.address(*static_cast<node*>(&*ptr)));
+                    node_alloc_.destroy(n);
+                    node_alloc_.deallocate(n, 1);
+                }
+
+                void swap(allocators& x)
+                {
+                    unordered_detail::hash_swap(node_alloc_, x.node_alloc_);
+                    unordered_detail::hash_swap(bucket_alloc_, x.bucket_alloc_);
+                }
+
+                bool operator==(allocators const& x)
+                {
+                    return node_alloc_ == x.node_alloc_;
+                }
+            };
+
            // node_constructor
            //
            // Used to construct nodes in an exception safe manner.

+            class node_constructor
+            {
+                allocators& allocators_;
+
+                node_ptr node_;
+                bool node_constructed_;
+
+            public:
+
+                node_constructor(allocators& a)
+                    : allocators_(a),
+                    node_(), node_constructed_(false)
+                {
+                }
+
+                ~node_constructor()
+                {
+                    if (node_) {
+                        if (node_constructed_)
+                            allocators_.node_alloc_.destroy(node_);
+                        allocators_.node_alloc_.deallocate(node_, 1);
+                    }
+                }
+
+                template <typename... Args>
+                void construct(Args&&... args)
+                {
+                    BOOST_ASSERT(!node_);
+                    node_constructed_ = false;
+
+                    node_ = allocators_.node_alloc_.allocate(1);
+                    allocators_.node_alloc_.construct(node_, std::forward<Args>(args)...);
+                    node_constructed_ = true;
+                }
+
+                node_ptr get() const
+                {
+                    BOOST_ASSERT(node_);
+                    return node_;
+                }
+
+                // no throw
+                link_ptr release()
+                {
+                    node_ptr p = node_;
+                    unordered_detail::reset(node_);
+                    return link_ptr(allocators_.bucket_alloc_.address(*p));
+                }
+
+            private:
+                node_constructor(node_constructor const&);
+                node_constructor& operator=(node_constructor const&);
+            };
+#else
+
+            // allocators
+            //
+            // Stores all the allocators that we're going to need.
+
            struct allocators
            {
                node_allocator node_alloc_;
@@ -151,6 +250,10 @@ namespace boost {
                }
            };

+            // node_constructor
+            //
+            // Used to construct nodes in an exception safe manner.
+
            class node_constructor
            {
                allocators& allocators_;
@@ -201,6 +304,27 @@ namespace boost {
                    value_constructed_ = true;
                }

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+                template <typename... Args>
+                void construct(Args&&... args)
+                {
+                    BOOST_ASSERT(!node_);
+                    value_constructed_ = false;
+                    node_base_constructed_ = false;
+
+                    node_ = allocators_.node_alloc_.allocate(1);
+
+                    allocators_.node_base_alloc_.construct(
+                            allocators_.node_base_alloc_.address(*node_),
+                            node_base());
+                    node_base_constructed_ = true;
+
+                    allocators_.value_alloc_.construct(
+                            allocators_.value_alloc_.address(node_->value_), std::forward<Args>(args)...);
+                    value_constructed_ = true;
+                }
+#endif
+
                node_ptr get() const
                {
                    BOOST_ASSERT(node_);
@@ -219,6 +343,7 @@ namespace boost {
                node_constructor(node_constructor const&);
                node_constructor& operator=(node_constructor const&);
            };
+#endif

            // Methods for navigating groups of elements with equal keys.

@@ -1251,9 +1376,9 @@ namespace boost {
            // accessors

            // no throw
-            value_allocator get_allocator() const
+            node_allocator get_allocator() const
            {
-                return data_.allocators_.value_alloc_;
+                return data_.allocators_.node_alloc_;
            }

            // no throw
@@ -1356,26 +1481,6 @@ namespace boost {
                return need_to_reserve;
            }

-            // basic exception safety
-            //
-            // This version of reserve is called when inserting a range
-            // into a container with equivalent keys, it creates more buckets
-            // if the resulting load factor would be over 80% of the load
-            // factor. This is to try to avoid excessive rehashes.
-            bool reserve_extra(size_type n)
-            {
-                using namespace std;
-
-                bool need_to_reserve = n >= max_load_;
-                // throws - basic:
-                if (need_to_reserve) {
-                    rehash_impl(double_to_size_t(floor(
-                        n / (double) mlf_ * 1.25)) + 1);
-                }
-                BOOST_ASSERT(n < max_load_ || n > max_size());
-                return need_to_reserve;
-            }
-
        public:

            // no throw
@@ -1422,6 +1527,41 @@ namespace boost {
                return v.first;
            }

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+            struct no_key {};
+
+            template <typename Arg1, typename... Args>
+            static typename boost::enable_if<
+                boost::mpl::and_<
+                    boost::mpl::not_<boost::is_same<key_type, value_type> >,
+                    boost::is_same<Arg1, key_type>
+                >,
+                key_type>::type const& extract_key(Arg1 const& k, Args const&...)
+            {
+                return k;
+            }
+
+            template <typename First, typename Second>
+            static typename boost::enable_if<
+                boost::mpl::and_<
+                    boost::mpl::not_<boost::is_same<key_type, value_type> >,
+                    boost::is_same<key_type,
+                        typename boost::remove_const<
+                            typename boost::remove_reference<First>::type
+                        >::type>
+                >,
+                key_type>::type const& extract_key(std::pair<First, Second> const& v)
+            {
+                return v.first;
+            }
+
+            template <typename... Args>
+            static no_key extract_key(Args const&...)
+            {
+                return no_key();
+            }
+#endif
+
        public:

            // if hash function throws, basic exception safety
@@ -1526,16 +1666,70 @@ namespace boost {
            // strong otherwise
            iterator_base insert(value_type const& v)
            {
-                key_type const& k = extract_key(v);
-                size_type hash_value = hash_function()(k);
-                bucket_ptr bucket = data_.bucket_ptr_from_hash(hash_value);
-                link_ptr position = find_iterator(bucket, k);
-
                // Create the node before rehashing in case it throws an
                // exception (need strong safety in such a case).
                node_constructor a(data_.allocators_);
                a.construct(v);

+                return insert_impl(a);
+            }
+
+            // Insert (equivalent key containers)
+
+            // if hash function throws, basic exception safety
+            // strong otherwise
+            iterator_base insert_hint(iterator_base const& it, value_type const& v)
+            {
+                // Create the node before rehashing in case it throws an
+                // exception (need strong safety in such a case).
+                node_constructor a(data_.allocators_);
+                a.construct(v);
+
+                return insert_hint_impl(it, a);
+            }
+
+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+            // Insert (equivalent key containers)
+            // (I'm using an overloaded insert for both 'insert' and 'emplace')
+
+            // if hash function throws, basic exception safety
+            // strong otherwise
+            template <class... Args>
+            iterator_base insert(Args&&... args)
+            {
+                // Create the node before rehashing in case it throws an
+                // exception (need strong safety in such a case).
+                node_constructor a(data_.allocators_);
+                a.construct(std::forward<Args>(args)...);
+
+                return insert_impl(a);
+            }
+
+            // Insert (equivalent key containers)
+            // (I'm using an overloaded insert for both 'insert' and 'emplace')
+
+            // if hash function throws, basic exception safety
+            // strong otherwise
+            template <class... Args>
+            iterator_base insert_hint(iterator_base const& it, Args&&... args)
+            {
+                // Create the node before rehashing in case it throws an
+                // exception (need strong safety in such a case).
+                node_constructor a(data_.allocators_);
+                a.construct(std::forward<Args>(args)...);
+
+                return insert_hint_impl(it, a);
+            }
+
+#endif
+
+            iterator_base insert_impl(node_constructor& a)
+            {
+                key_type const& k = extract_key(a.get()->value_);
+                size_type hash_value = hash_function()(k);
+                bucket_ptr bucket = data_.bucket_ptr_from_hash(hash_value);
+                link_ptr position = find_iterator(bucket, k);
+
                // reserve has basic exception safety if the hash function
                // throws, strong otherwise.
                if(reserve(size() + 1))
@@ -1550,17 +1744,13 @@ namespace boost {
                );
            }

-            // Insert (equivalent key containers)
-
-            // if hash function throws, basic exception safety
-            // strong otherwise
-            iterator_base insert_hint(iterator_base const& it, value_type const& v)
+            iterator_base insert_hint_impl(iterator_base const& it, node_constructor& a)
            {
                // equal can throw, but with no effects
-                if (it == data_.end() || !equal(extract_key(v), *it)) {
+                if (it == data_.end() || !equal(extract_key(a.get()->value_), *it)) {
                    // Use the standard insert if the iterator doesn't point
                    // to a matching key.
-                    return insert(v);
+                    return insert_impl(a);
                }
                else {
                    // Find the first node in the group - so that the node
@@ -1570,15 +1760,10 @@ namespace boost {
                    while(data_.prev_in_group(start)->next_ == start)
                        start = data_.prev_in_group(start);

-                    // Create the node before rehashing in case it throws an
-                    // exception (need strong safety in such a case).
-                    node_constructor a(data_.allocators_);
-                    a.construct(v);
-
                    // reserve has basic exception safety if the hash function
                    // throws, strong otherwise.
                    bucket_ptr base = reserve(size() + 1) ?
-                        get_bucket(extract_key(v)) : it.bucket_;
+                        get_bucket(extract_key(a.get()->value_)) : it.bucket_;

                    // Nothing after this point can throw

@@ -1602,7 +1787,7 @@ namespace boost {
                }
                else {
                    // Only require basic exception safety here
-                    reserve_extra(size() + distance);
+                    reserve(size() + distance);
                    node_constructor a(data_.allocators_);

                    for (; i != j; ++i) {
@@ -1729,6 +1914,104 @@ namespace boost {
                    return insert(v).first;
            }

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+            // Insert (unique keys)
+            // (I'm using an overloaded insert for both 'insert' and 'emplace')
+            //
+            // TODO:
+            // For sets: create a local key without creating the node?
+            // For maps: use the first argument as the key.
+
+            // if hash function throws, basic exception safety
+            // strong otherwise
+            template<typename... Args>
+            std::pair<iterator_base, bool> insert(Args&&... args)
+            {
+                return insert_impl(
+                    extract_key(std::forward<Args>(args)...),
+                    std::forward<Args>(args)...);
+            }
+
+            template<typename... Args>
+            std::pair<iterator_base, bool> insert_impl(key_type const& k, Args&&... args)
+            {
+                // No side effects in this initial code
+                size_type hash_value = hash_function()(k);
+                bucket_ptr bucket = data_.bucket_ptr_from_hash(hash_value);
+                link_ptr pos = find_iterator(bucket, k);
+
+                if (BOOST_UNORDERED_BORLAND_BOOL(pos)) {
+                    // Found an existing key, return it (no throw).
+                    return std::pair<iterator_base, bool>(
+                        iterator_base(bucket, pos), false);
+
+                } else {
+                    // Doesn't already exist, add to bucket.
+                    // Side effects only in this block.
+
+                    // Create the node before rehashing in case it throws an
+                    // exception (need strong safety in such a case).
+                    node_constructor a(data_.allocators_);
+                    a.construct(std::forward<Args>(args)...);
+
+                    // reserve has basic exception safety if the hash function
+                    // throws, strong otherwise.
+                    if(reserve(size() + 1))
+                        bucket = data_.bucket_ptr_from_hash(hash_value);
+
+                    // Nothing after this point can throw.
+
+                    link_ptr n = data_.link_node_in_bucket(a, bucket);
+
+                    return std::pair<iterator_base, bool>(
+                        iterator_base(bucket, n), true);
+                }
+            }
+
+            template<typename... Args>
+            std::pair<iterator_base, bool> insert_impl(no_key, Args&&... args)
+            {
+                // Construct the node regardless - in order to get the key.
+                // It will be discarded if it isn't used
+                node_constructor a(data_.allocators_);
+                a.construct(std::forward<Args>(args)...);
+
+                // No side effects in this initial code
+                key_type const& k = extract_key(a.get()->value_);
+                size_type hash_value = hash_function()(k);
+                bucket_ptr bucket = data_.bucket_ptr_from_hash(hash_value);
+                link_ptr pos = find_iterator(bucket, k);
+                
+                if (BOOST_UNORDERED_BORLAND_BOOL(pos)) {
+                    // Found an existing key, return it (no throw).
+                    return std::pair<iterator_base, bool>(
+                        iterator_base(bucket, pos), false);
+                } else {
+                    // reserve has basic exception safety if the hash function
+                    // throws, strong otherwise.
+                    if(reserve(size() + 1))
+                        bucket = data_.bucket_ptr_from_hash(hash_value);
+
+                    // Nothing after this point can throw.
+
+                    return std::pair<iterator_base, bool>(iterator_base(bucket,
+                        data_.link_node_in_bucket(a, bucket)), true);
+                }
+            }
+
+            // Insert (unique keys)
+            // (I'm using an overloaded insert for both 'insert' and 'emplace')
+
+            // if hash function throws, basic exception safety
+            // strong otherwise
+            template<typename... Args>
+            iterator_base insert_hint(iterator_base const& it, Args&&... args)
+            {
+                // Life is complicated - just call the normal implementation.
+                return insert(std::forward<Args>(args)...).first;
+            }
+#endif
+
            // Insert from iterators (unique keys)

            template <typename I>
@@ -199,6 +199,21 @@ namespace boost

        // modifiers

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+        template <class... Args>
+        std::pair<iterator, bool> emplace(Args&&... args)
+        {
+            return boost::unordered_detail::pair_cast<iterator, bool>(
+                base.insert(std::forward<Args>(args)...));
+        }
+
+        template <class... Args>
+        iterator emplace(const_iterator hint, Args&&... args)
+        {
+            return iterator(base.insert_hint(get(hint), std::forward<Args>(args)...));
+        }
+#endif
+
        std::pair<iterator, bool> insert(const value_type& obj)
        {
            return boost::unordered_detail::pair_cast<iterator, bool>(
@@ -553,6 +568,20 @@ namespace boost

        // modifiers

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+        template <class... Args>
+        iterator emplace(Args&&... args)
+        {
+            return iterator(base.insert(std::forward<Args>(args)...));
+        }
+
+        template <class... Args>
+        iterator emplace(const_iterator hint, Args&&... args)
+        {
+            return iterator(base.insert_hint(get(hint), std::forward<Args>(args)...));
+        }
+#endif
+
        iterator insert(const value_type& obj)
        {
            return iterator(base.insert(obj));
@@ -196,6 +196,22 @@ namespace boost

        // modifiers

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+        template <class... Args>
+        std::pair<iterator, bool> emplace(Args&&... args)
+        {
+            return boost::unordered_detail::pair_cast<iterator, bool>(
+                base.insert(std::forward<Args>(args)...));
+        }
+
+        template <class... Args>
+        iterator emplace(const_iterator hint, Args&&... args)
+        {
+            return iterator(
+                base.insert_hint(get(hint), std::forward<Args>(args)...));
+        }
+#endif
+
        std::pair<iterator, bool> insert(const value_type& obj)
        {
            return boost::unordered_detail::pair_cast<iterator, bool>(
@@ -520,6 +536,20 @@ namespace boost

        // modifiers

+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
+        template <class... Args>
+        iterator emplace(Args&&... args)
+        {
+            return iterator(base.insert(std::forward<Args>(args)...));
+        }
+
+        template <class... Args>
+        iterator emplace(const_iterator hint, Args&&... args)
+        {
+            return iterator(base.insert_hint(get(hint), std::forward<Args>(args)...));
+        }
+#endif
+
        iterator insert(const value_type& obj)
        {
            return iterator(base.insert(obj));