//
// Copyright 2016 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
// Wrap one of various unordered map implementations.  The exposed API
// is similar to std::unordered_map but is missing some methods and
// erase(const_iterator) returns nothing.
//
// Wrapping provides a convenient way to switch between implementations.
// The GNU extension (currently) has the best overall performance but
// isn't standard.  Otherwise we use the C++11 standard implementation.

#ifndef PXR_BASE_TF_HASHMAP_H
#define PXR_BASE_TF_HASHMAP_H

#include "pxr/pxr.h"
#include "pxr/base/arch/defines.h"

#if defined(ARCH_HAS_GNU_STL_EXTENSIONS)
#include <ext/hash_map>
#else
#include <unordered_map>
#endif // ARCH_HAS_GNU_STL_EXTENSIONS

PXR_NAMESPACE_OPEN_SCOPE

#if defined(ARCH_HAS_GNU_STL_EXTENSIONS)

template<class Key, class Mapped, class HashFn = __gnu_cxx::hash<Key>,
	 class EqualKey = __gnu_cxx::equal_to<Key>,
         class Alloc = __gnu_cxx::allocator<Mapped> >
class TfHashMap :
    private __gnu_cxx::hash_map<Key, Mapped, HashFn, EqualKey, Alloc> {
    typedef __gnu_cxx::hash_map<Key, Mapped, HashFn, EqualKey, Alloc> _Base;
public:
    typedef typename _Base::key_type key_type;
    typedef typename _Base::mapped_type mapped_type;
    typedef typename _Base::value_type value_type;
    typedef typename _Base::hasher hasher;
    typedef typename _Base::key_equal key_equal;
    typedef typename _Base::size_type size_type;
    typedef typename _Base::difference_type difference_type;
    typedef typename _Base::pointer pointer;
    typedef typename _Base::const_pointer const_pointer;
    typedef typename _Base::reference reference;
    typedef typename _Base::const_reference const_reference;
    typedef typename _Base::iterator iterator;
    typedef typename _Base::const_iterator const_iterator;
    typedef typename _Base::allocator_type allocator_type;
    // No local_iterator nor any methods using them.

    TfHashMap() : _Base() { }
    explicit
    TfHashMap(size_type n, const hasher& hf = hasher(),
              const key_equal& eql = key_equal(),
              const allocator_type& alloc = allocator_type()) :
        _Base(n, hf, eql, alloc) { }
    explicit
    TfHashMap(const allocator_type& alloc) :
        _Base(0, hasher(), key_equal(), alloc) { }
    template<class InputIterator>
    TfHashMap(InputIterator first, InputIterator last,
              size_type n = 0, const hasher& hf = hasher(),
              const key_equal& eql = key_equal(),
              const allocator_type& alloc = allocator_type()) :
        _Base(first, last, n, hf, eql, alloc) { }
    TfHashMap(const TfHashMap& other) : _Base(other) { }

    TfHashMap& operator=(const TfHashMap& rhs) {
        _Base::operator=(rhs);
        return *this;
    }

    iterator begin() { return _Base::begin(); }
    const_iterator begin() const { return const_iterator(_Base::begin()); }
    // size_type bucket(const key_type& key) const;
    using _Base::bucket_count;
    size_type bucket_size(size_type n) const { return _Base::elems_in_bucket(n); }
    const_iterator cbegin() const { return const_iterator(_Base::begin()); }
    const_iterator cend() const { return const_iterator(_Base::end()); }
    using _Base::clear;
    using _Base::count;
    using _Base::empty;
    iterator end() { return _Base::end(); }
    const_iterator end() const { return const_iterator(_Base::end()); }
    std::pair<iterator,iterator> equal_range(const key_type& key) {
        return _Base::equal_range(key);
    }
    std::pair<const_iterator,const_iterator> equal_range(const key_type& key) const {
        return _Base::equal_range(key);
    }
    size_type erase(const key_type& key) { return _Base::erase(key); }
    void erase(const_iterator position) {
        _Base::erase(_MakeIterator(position));
    }
    void erase(const_iterator first, const_iterator last) {
        _Base::erase(_MakeIterator(first), _MakeIterator(last));
    }
    iterator find(const key_type& key) { return _Base::find(key); }
    const_iterator find(const key_type& key) const {
        return const_iterator(_Base::find(key));
    }
    using _Base::get_allocator;
    hasher hash_function() const { return _Base::hash_funct(); }
    using _Base::insert;
    iterator insert(const_iterator, const value_type& v) {
        return insert(v).first;
    }
    using _Base::key_eq;
    float load_factor() const {
        return static_cast<float>(static_cast<double>(size()) / bucket_count());
    }
    using _Base::max_bucket_count;
    float max_load_factor() const { return 1.0; }
    // void max_load_factor(float) { }
    using _Base::max_size;
    void rehash(size_type n) { _Base::resize(__gnu_cxx::__stl_next_prime(n)); }
    void reserve(size_type n) { _Base::resize(n); }
    using _Base::size;
    void swap(TfHashMap& other) { _Base::swap(other); }
    mapped_type& operator[](const key_type& k) { return _Base::operator[](k); }

    template<class Key2, class Mapped2, class HashFn2, class EqualKey2, class Alloc2>
    friend bool
    operator==(const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&,
               const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&);

private:
    // _Base::erase() takes an iterator, not a const_iterator.  We happen
    // to know const_iterator and iterator have the same layout.
    static const iterator& _MakeIterator(const const_iterator& i) {
        return reinterpret_cast<const iterator&>(i);
    }
};

template<class Key, class Mapped, class HashFn = __gnu_cxx::hash<Key>,
	 class EqualKey = __gnu_cxx::equal_to<Key>,
         class Alloc = __gnu_cxx::allocator<Mapped> >
class TfHashMultiMap :
    private __gnu_cxx::hash_multimap<Key, Mapped, HashFn, EqualKey, Alloc> {
    typedef __gnu_cxx::hash_multimap<Key, Mapped, HashFn, EqualKey, Alloc> _Base;
public:
    typedef typename _Base::key_type key_type;
    typedef typename _Base::mapped_type mapped_type;
    typedef typename _Base::value_type value_type;
    typedef typename _Base::hasher hasher;
    typedef typename _Base::key_equal key_equal;
    typedef typename _Base::size_type size_type;
    typedef typename _Base::difference_type difference_type;
    typedef typename _Base::pointer pointer;
    typedef typename _Base::const_pointer const_pointer;
    typedef typename _Base::reference reference;
    typedef typename _Base::const_reference const_reference;
    typedef typename _Base::iterator iterator;
    typedef typename _Base::const_iterator const_iterator;
    typedef typename _Base::allocator_type allocator_type;
    // No local_iterator nor any methods using them.

    TfHashMultiMap() : _Base() { }
    explicit
    TfHashMultiMap(size_type n, const hasher& hf = hasher(),
                   const key_equal& eql = key_equal(),
                   const allocator_type& alloc = allocator_type()) :
        _Base(n, hf, eql, alloc) { }
    explicit
    TfHashMultiMap(const allocator_type& alloc) :
        _Base(0, hasher(), key_equal(), alloc) { }
    template<class InputIterator>
    TfHashMultiMap(InputIterator first, InputIterator last,
                   size_type n = 0, const hasher& hf = hasher(),
                   const key_equal& eql = key_equal(),
                   const allocator_type& alloc = allocator_type()) :
        _Base(first, last, n, hf, eql, alloc) { }
    TfHashMultiMap(const TfHashMultiMap& other) : _Base(other) { }

    TfHashMultiMap& operator=(const TfHashMultiMap& rhs) {
        _Base::operator=(rhs);
        return *this;
    }

    iterator begin() { return _Base::begin(); }
    const_iterator begin() const { return const_iterator(_Base::begin()); }
    // size_type bucket(const key_type& key) const;
    using _Base::bucket_count;
    size_type bucket_size(size_type n) const { return _Base::elems_in_bucket(n); }
    const_iterator cbegin() const { return const_iterator(_Base::begin()); }
    const_iterator cend() const { return const_iterator(_Base::end()); }
    using _Base::clear;
    using _Base::count;
    using _Base::empty;
    iterator end() { return _Base::end(); }
    const_iterator end() const { return const_iterator(_Base::end()); }
    std::pair<iterator,iterator> equal_range(const key_type& key) {
        return _Base::equal_range(key);
    }
    std::pair<const_iterator,const_iterator> equal_range(const key_type& key) const {
        return _Base::equal_range(key);
    }
    size_type erase(const key_type& key) { return _Base::erase(key); }
    void erase(const_iterator position) {
        _Base::erase(_MakeIterator(position));
    }
    void erase(const_iterator first, const_iterator last) {
        _Base::erase(_MakeIterator(first), _MakeIterator(last));
    }
    iterator find(const key_type& key) { return _Base::find(key); }
    const_iterator find(const key_type& key) const {
        return const_iterator(_Base::find(key));
    }
    using _Base::get_allocator;
    hasher hash_function() const { return _Base::hash_funct(); }
    using _Base::insert;
    iterator insert(const_iterator, const value_type& v) {
        return insert(v).first;
    }
    using _Base::key_eq;
    float load_factor() const {
        return static_cast<float>(static_cast<double>(size()) / bucket_count());
    }
    using _Base::max_bucket_count;
    float max_load_factor() const { return 1.0; }
    // void max_load_factor(float) { }
    using _Base::max_size;
    void rehash(size_type n) { _Base::resize(__gnu_cxx::__stl_next_prime(n)); }
    void reserve(size_type n) { _Base::resize(n); }
    using _Base::size;
    void swap(TfHashMultiMap& other) { _Base::swap(other); }
    mapped_type& operator[](const key_type& k) { return _Base::operator[](k); }

    template<class Key2, class Mapped2, class HashFn2, class EqualKey2, class Alloc2>
    friend bool
    operator==(const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&,
               const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&);

private:
    // _Base::erase() takes an iterator, not a const_iterator.  We happen
    // to know const_iterator and iterator have the same layout.
    static const iterator& _MakeIterator(const const_iterator& i) {
        return reinterpret_cast<const iterator&>(i);
    }
};

#else

template<class Key, class Mapped, class HashFn = std::hash<Key>,
	 class EqualKey = std::equal_to<Key>,
         class Alloc = std::allocator<std::pair<const Key, Mapped> > >
class TfHashMap :
    private std::unordered_map<Key, Mapped, HashFn, EqualKey, Alloc> {
    typedef std::unordered_map<Key, Mapped, HashFn, EqualKey, Alloc> _Base;
public:
    typedef typename _Base::key_type key_type;
    typedef typename _Base::mapped_type mapped_type;
    typedef typename _Base::value_type value_type;
    typedef typename _Base::hasher hasher;
    typedef typename _Base::key_equal key_equal;
    typedef typename _Base::size_type size_type;
    typedef typename _Base::difference_type difference_type;
    typedef typename _Base::pointer pointer;
    typedef typename _Base::const_pointer const_pointer;
    typedef typename _Base::reference reference;
    typedef typename _Base::const_reference const_reference;
    typedef typename _Base::iterator iterator;
    typedef typename _Base::const_iterator const_iterator;
    typedef typename _Base::allocator_type allocator_type;
    // No local_iterator nor any methods using them.

    TfHashMap() : _Base() { }
    explicit
    TfHashMap(size_type n, const hasher& hf = hasher(),
              const key_equal& eql = key_equal(),
              const allocator_type& alloc = allocator_type()) :
        _Base(n, hf, eql, alloc) { }
    explicit
    TfHashMap(const allocator_type& alloc) : _Base(alloc) { }
    template<class InputIterator>
    TfHashMap(InputIterator first, InputIterator last,
              size_type n = 0, const hasher& hf = hasher(),
              const key_equal& eql = key_equal(),
              const allocator_type& alloc = allocator_type()) :
        _Base(first, last, n, hf, eql, alloc) { }
    TfHashMap(const TfHashMap& other) : _Base(other) { }

    TfHashMap& operator=(const TfHashMap& rhs) {
        _Base::operator=(rhs);
        return *this;
    }

    iterator begin() { return _Base::begin(); }
    const_iterator begin() const { return _Base::begin(); }
    // using _Base::bucket;
    using _Base::bucket_count;
    using _Base::bucket_size;
    const_iterator cbegin() const { return _Base::cbegin(); }
    const_iterator cend() const { return _Base::cend(); }
    using _Base::clear;
    using _Base::count;
    using _Base::empty;
    iterator end() { return _Base::end(); }
    const_iterator end() const { return _Base::end(); }
    using _Base::equal_range;
    size_type erase(const key_type& key) { return _Base::erase(key); }
    void erase(const_iterator position) { _Base::erase(position); }
    void erase(const_iterator first, const_iterator last) {
        _Base::erase(first, last);
    }
    using _Base::find;
    using _Base::get_allocator;
    using _Base::hash_function;
    std::pair<iterator, bool> insert(const value_type& v) {
        return _Base::insert(v);
    }
    iterator insert(const_iterator hint, const value_type& v) {
        return _Base::insert(hint, v);
    }
    template<class InputIterator>
    void insert(InputIterator first, InputIterator last) {
        _Base::insert(first, last);
    }
    using _Base::key_eq;
    using _Base::load_factor;
    using _Base::max_bucket_count;
    using _Base::max_load_factor;
    // using _Base::max_load_factor;
    using _Base::max_size;
    using _Base::rehash;
    using _Base::reserve;
    using _Base::size;
    void swap(TfHashMap& other) { _Base::swap(other); }
    mapped_type& operator[](const key_type& k) { return _Base::operator[](k); }

    template<class Key2, class Mapped2, class HashFn2, class EqualKey2, class Alloc2>
    friend bool
    operator==(const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&,
               const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&);
};

template<class Key, class Mapped, class HashFn = std::hash<Key>,
	 class EqualKey = std::equal_to<Key>,
         class Alloc = std::allocator<std::pair<const Key, Mapped> > >
class TfHashMultiMap :
    private std::unordered_map<Key, Mapped, HashFn, EqualKey, Alloc> {
    typedef std::unordered_map<Key, Mapped, HashFn, EqualKey, Alloc> _Base;
public:
    typedef typename _Base::key_type key_type;
    typedef typename _Base::mapped_type mapped_type;
    typedef typename _Base::value_type value_type;
    typedef typename _Base::hasher hasher;
    typedef typename _Base::key_equal key_equal;
    typedef typename _Base::size_type size_type;
    typedef typename _Base::difference_type difference_type;
    typedef typename _Base::pointer pointer;
    typedef typename _Base::const_pointer const_pointer;
    typedef typename _Base::reference reference;
    typedef typename _Base::const_reference const_reference;
    typedef typename _Base::iterator iterator;
    typedef typename _Base::const_iterator const_iterator;
    typedef typename _Base::allocator_type allocator_type;
    // No local_iterator nor any methods using them.

    TfHashMultiMap() : _Base() { }
    explicit
    TfHashMultiMap(size_type n, const hasher& hf = hasher(),
                   const key_equal& eql = key_equal(),
                   const allocator_type& alloc = allocator_type()) :
        _Base(n, hf, eql, alloc) { }
    explicit
    TfHashMultiMap(const allocator_type& alloc) : _Base(alloc) { }
    template<class InputIterator>
    TfHashMultiMap(InputIterator first, InputIterator last,
                   size_type n = 0, const hasher& hf = hasher(),
                   const key_equal& eql = key_equal(),
                   const allocator_type& alloc = allocator_type()) :
        _Base(first, last, n, hf, eql, alloc) { }
    TfHashMultiMap(const TfHashMultiMap& other) : _Base(other) { }

    TfHashMultiMap& operator=(const TfHashMultiMap& rhs) {
        _Base::operator=(rhs);
        return *this;
    }

    iterator begin() { return _Base::begin(); }
    const_iterator begin() const { return _Base::begin(); }
    // using _Base::bucket;
    using _Base::bucket_count;
    using _Base::bucket_size;
    const_iterator cbegin() const { return _Base::cbegin(); }
    const_iterator cend() const { return _Base::cend(); }
    using _Base::clear;
    using _Base::count;
    using _Base::empty;
    iterator end() { return _Base::end(); }
    const_iterator end() const { return _Base::end(); }
    using _Base::equal_range;
    size_type erase(const key_type& key) { return _Base::erase(key); }
    void erase(const_iterator position) { _Base::erase(position); }
    void erase(const_iterator first, const_iterator last) {
        _Base::erase(first, last);
    }
    using _Base::find;
    using _Base::get_allocator;
    using _Base::hash_function;
    std::pair<iterator, bool> insert(const value_type& v) {
        return _Base::insert(v);
    }
    iterator insert(const_iterator hint, const value_type& v) {
        return _Base::insert(hint, v);
    }
    template<class InputIterator>
    void insert(InputIterator first, InputIterator last) {
        _Base::insert(first, last);
    }
    using _Base::key_eq;
    using _Base::load_factor;
    using _Base::max_bucket_count;
    using _Base::max_load_factor;
    // using _Base::max_load_factor;
    using _Base::max_size;
    using _Base::rehash;
    using _Base::reserve;
    using _Base::size;
    void swap(TfHashMultiMap& other) { _Base::swap(other); }
    mapped_type& operator[](const key_type& k) { return _Base::operator[](k); }

    template<class Key2, class Mapped2, class HashFn2, class EqualKey2, class Alloc2>
    friend bool
    operator==(const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&,
               const TfHashMap<Key2, Mapped2, HashFn2, EqualKey2, Alloc2>&);
};

#endif // ARCH_HAS_GNU_STL_EXTENSIONS

template<class Key, class Mapped, class HashFn, class EqualKey, class Alloc>
inline void
swap(TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>& lhs,
     TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>& rhs)
{
    lhs.swap(rhs);
}

template<class Key, class Mapped, class HashFn, class EqualKey, class Alloc>
inline bool
operator==(const TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>& lhs,
           const TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>& rhs)
{
    typedef typename TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>::_Base _Base;
    return static_cast<const _Base&>(lhs) == static_cast<const _Base&>(rhs);
}

template<class Key, class Mapped, class HashFn, class EqualKey, class Alloc>
inline bool
operator!=(const TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>& lhs,
           const TfHashMap<Key, Mapped, HashFn, EqualKey, Alloc>& rhs)
{
    return !(lhs == rhs);
}

template<class Key, class Mapped, class HashFn, class EqualKey, class Alloc>
inline void
swap(TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>& lhs,
     TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>& rhs)
{
    lhs.swap(rhs);
}

template<class Key, class Mapped, class HashFn, class EqualKey, class Alloc>
inline bool
operator==(const TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>& lhs,
           const TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>& rhs)
{
    typedef typename TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>::_Base _Base;
    return static_cast<const _Base&>(lhs) == static_cast<const _Base&>(rhs);
}

template<class Key, class Mapped, class HashFn, class EqualKey, class Alloc>
inline bool
operator!=(const TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>& lhs,
           const TfHashMultiMap<Key, Mapped, HashFn, EqualKey, Alloc>& rhs)
{
    return !(lhs == rhs);
}

PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_BASE_TF_HASHMAP_H