merge.hpp in passenger-6.0.8

- old
+ new

@@ -17,14 +17,267 @@
 #include <boost/move/detail/iterator_traits.hpp>
 #include <boost/move/detail/destruct_n.hpp>
 #include <boost/move/algo/predicate.hpp>
 #include <boost/move/detail/iterator_to_raw_pointer.hpp>
 #include <boost/assert.hpp>
+#include <cstddef>
 
 namespace boost {
 namespace movelib {
 
+template<class T, class RandRawIt = T*, class SizeType = typename iterator_traits<RandRawIt>::size_type>
+class adaptive_xbuf
+{
+   adaptive_xbuf(const adaptive_xbuf &);
+   adaptive_xbuf & operator=(const adaptive_xbuf &);
+
+   #if !defined(UINTPTR_MAX)
+   typedef std::size_t uintptr_t;
+   #endif
+
+   public:
+   typedef RandRawIt iterator;
+   typedef SizeType  size_type;
+
+   adaptive_xbuf()
+      : m_ptr(), m_size(0), m_capacity(0)
+   {}
+
+   adaptive_xbuf(RandRawIt raw_memory, size_type capacity)
+      : m_ptr(raw_memory), m_size(0), m_capacity(capacity)
+   {}
+
+   template<class RandIt>
+   void move_assign(RandIt first, size_type n)
+   {
+      if(n <= m_size){
+         boost::move(first, first+n, m_ptr);
+         size_type size = m_size;
+         while(size-- != n){
+            m_ptr[size].~T();
+         }
+         m_size = n;
+      }
+      else{
+         RandRawIt result = boost::move(first, first+m_size, m_ptr);
+         boost::uninitialized_move(first+m_size, first+n, result);
+         m_size = n;
+      }
+   }
+
+   template<class RandIt>
+   void push_back(RandIt first, size_type n)
+   {
+      BOOST_ASSERT(m_capacity - m_size >= n);
+      boost::uninitialized_move(first, first+n, m_ptr+m_size);
+      m_size += n;
+   }
+
+   template<class RandIt>
+   iterator add(RandIt it)
+   {
+      BOOST_ASSERT(m_size < m_capacity);
+      RandRawIt p_ret = m_ptr + m_size;
+      ::new(&*p_ret) T(::boost::move(*it));
+      ++m_size;
+      return p_ret;
+   }
+
+   template<class RandIt>
+   void insert(iterator pos, RandIt it)
+   {
+      if(pos == (m_ptr + m_size)){
+         this->add(it);
+      }
+      else{
+         this->add(m_ptr+m_size-1);
+         //m_size updated
+         boost::move_backward(pos, m_ptr+m_size-2, m_ptr+m_size-1);
+         *pos = boost::move(*it);
+      }
+   }
+
+   void set_size(size_type size)
+   {
+      m_size = size;
+   }
+
+   void shrink_to_fit(size_type const size)
+   {
+      if(m_size > size){
+         for(size_type szt_i = size; szt_i != m_size; ++szt_i){
+            m_ptr[szt_i].~T();
+         }
+         m_size = size;
+      }
+   }
+
+   void initialize_until(size_type const size, T &t)
+   {
+      BOOST_ASSERT(m_size < m_capacity);
+      if(m_size < size){
+         BOOST_TRY
+         {
+            ::new((void*)&m_ptr[m_size]) T(::boost::move(t));
+            ++m_size;
+            for(; m_size != size; ++m_size){
+               ::new((void*)&m_ptr[m_size]) T(::boost::move(m_ptr[m_size-1]));
+            }
+            t = ::boost::move(m_ptr[m_size-1]);
+         }
+         BOOST_CATCH(...)
+         {
+            while(m_size)
+            {
+               --m_size;
+               m_ptr[m_size].~T();
+            }
+         }
+         BOOST_CATCH_END
+      }
+   }
+
+   private:
+   template<class RIt>
+   static bool is_raw_ptr(RIt)
+   {
+      return false;
+   }
+
+   static bool is_raw_ptr(T*)
+   {
+      return true;
+   }
+
+   public:
+   template<class U>
+   bool supports_aligned_trailing(size_type size, size_type trail_count) const
+   {
+      if(this->is_raw_ptr(this->data()) && m_capacity){
+         uintptr_t u_addr_sz = uintptr_t(&*(this->data()+size));
+         uintptr_t u_addr_cp = uintptr_t(&*(this->data()+this->capacity()));
+         u_addr_sz = ((u_addr_sz + sizeof(U)-1)/sizeof(U))*sizeof(U);
+         return (u_addr_cp >= u_addr_sz) && ((u_addr_cp - u_addr_sz)/sizeof(U) >= trail_count);
+      }
+      return false;
+   }
+
+   template<class U>
+   U *aligned_trailing() const
+   {
+      return this->aligned_trailing<U>(this->size());
+   }
+
+   template<class U>
+   U *aligned_trailing(size_type pos) const
+   {
+      uintptr_t u_addr = uintptr_t(&*(this->data()+pos));
+      u_addr = ((u_addr + sizeof(U)-1)/sizeof(U))*sizeof(U);
+      return (U*)u_addr;
+   }
+
+   ~adaptive_xbuf()
+   {
+      this->clear();
+   }
+
+   size_type capacity() const
+   {  return m_capacity;   }
+
+   iterator data() const
+   {  return m_ptr;   }
+
+   iterator begin() const
+   {  return m_ptr;   }
+
+   iterator end() const
+   {  return m_ptr+m_size;   }
+
+   size_type size() const
+   {  return m_size;   }
+
+   bool empty() const
+   {  return !m_size;   }
+
+   void clear()
+   {
+      this->shrink_to_fit(0u);
+   }
+
+   private:
+   RandRawIt m_ptr;
+   size_type m_size;
+   size_type m_capacity;
+};
+
+template<class Iterator, class SizeType, class Op>
+class range_xbuf
+{
+   range_xbuf(const range_xbuf &);
+   range_xbuf & operator=(const range_xbuf &);
+
+   public:
+   typedef SizeType size_type;
+   typedef Iterator iterator;
+
+   range_xbuf(Iterator first, Iterator last)
+      : m_first(first), m_last(first), m_cap(last)
+   {}
+
+   template<class RandIt>
+   void move_assign(RandIt first, size_type n)
+   {
+      BOOST_ASSERT(size_type(n) <= size_type(m_cap-m_first));
+      m_last = Op()(forward_t(), first, first+n, m_first);
+   }
+
+   ~range_xbuf()
+   {}
+
+   size_type capacity() const
+   {  return m_cap-m_first;   }
+
+   Iterator data() const
+   {  return m_first;   }
+
+   Iterator end() const
+   {  return m_last;   }
+
+   size_type size() const
+   {  return m_last-m_first;   }
+
+   bool empty() const
+   {  return m_first == m_last;   }
+
+   void clear()
+   {
+      m_last = m_first;
+   }
+
+   template<class RandIt>
+   iterator add(RandIt it)
+   {
+      Iterator pos(m_last);
+      *pos = boost::move(*it);
+      ++m_last;
+      return pos;
+   }
+
+   void set_size(size_type size)
+   {
+      m_last  = m_first;
+      m_last += size;
+   }
+
+   private:
+   Iterator const m_first;
+   Iterator m_last;
+   Iterator const m_cap;
+};
+
+
+
 // @cond
 
 /*
 template<typename Unsigned>
 inline Unsigned gcd(Unsigned x, Unsigned y)
@@ -254,10 +507,49 @@
    (RandIt first1, RandIt last1, RandIt last2, RandIt buf_last, Compare comp)
 {
    op_merge_right(first1, last1, last2, buf_last, comp, swap_op());
 }
 
+///////////////////////////////////////////////////////////////////////////////
+//
+//                            BUFFERED MERGE
+//
+///////////////////////////////////////////////////////////////////////////////
+template<class RandIt, class Compare, class Op, class Buf>
+void op_buffered_merge
+      ( RandIt first, RandIt const middle, RandIt last
+      , Compare comp, Op op
+      , Buf &xbuf)
+{
+   if(first != middle && middle != last && comp(*middle, middle[-1])){
+      typedef typename iterator_traits<RandIt>::size_type   size_type;
+      size_type const len1 = size_type(middle-first);
+      size_type const len2 = size_type(last-middle);
+      if(len1 <= len2){
+         first = boost::movelib::upper_bound(first, middle, *middle, comp);
+         xbuf.move_assign(first, size_type(middle-first));
+         op_merge_with_right_placed
+            (xbuf.data(), xbuf.end(), first, middle, last, comp, op);
+      }
+      else{
+         last = boost::movelib::lower_bound(middle, last, middle[-1], comp);
+         xbuf.move_assign(middle, size_type(last-middle));
+         op_merge_with_left_placed
+            (first, middle, last, xbuf.data(), xbuf.end(), comp, op);
+      }
+   }
+}
+
+template<class RandIt, class Compare, class XBuf>
+void buffered_merge
+      ( RandIt first, RandIt const middle, RandIt last
+      , Compare comp
+      , XBuf &xbuf)
+{
+   op_buffered_merge(first, middle, last, comp, move_op(), xbuf);
+}
+
 //Complexity: min(len1,len2)^2 + max(len1,len2)
 template<class RandIt, class Compare>
 void merge_bufferless_ON2(RandIt first, RandIt middle, RandIt last, Compare comp)
 {
    if((middle - first) < (last - middle)){
@@ -287,15 +579,18 @@
          } while(middle != last && !comp(last[-1], *p));
       }
    }
 }
 
-static const std::size_t MergeBufferlessONLogNRotationThreshold = 32;
+static const std::size_t MergeBufferlessONLogNRotationThreshold = 16u;
 
-template <class RandIt, class Distance, class Compare>
+template <class RandIt, class Compare>
 void merge_bufferless_ONlogN_recursive
-   (RandIt first, RandIt middle, RandIt last, Distance len1, Distance len2, Compare comp)
+   ( RandIt first, RandIt middle, RandIt last
+   , typename iterator_traits<RandIt>::size_type len1
+   , typename iterator_traits<RandIt>::size_type len2
+   , Compare comp)
 {
    typedef typename iterator_traits<RandIt>::size_type size_type;
 
    while(1) {
       //trivial cases
@@ -315,12 +610,12 @@
          return;
       }
 
       RandIt first_cut = first;
       RandIt second_cut = middle;
-      Distance len11 = 0;
-      Distance len22 = 0;
+      size_type len11 = 0;
+      size_type len22 = 0;
       if (len1 > len2) {
          len11 = len1 / 2;
          first_cut +=  len11;
          second_cut = boost::movelib::lower_bound(middle, last, *first_cut, comp);
          len22 = size_type(second_cut - middle);
@@ -332,34 +627,36 @@
          len11 = size_type(first_cut - first);
       }
       RandIt new_middle = rotate_gcd(first_cut, middle, second_cut);
 
       //Avoid one recursive call doing a manual tail call elimination on the biggest range
-      const Distance len_internal = len11+len22;
+      const size_type len_internal = len11+len22;
       if( len_internal < (len1 + len2 - len_internal) ) {
-         merge_bufferless_ONlogN_recursive(first,      first_cut,  new_middle, len11,        len22,        comp);
+         merge_bufferless_ONlogN_recursive(first, first_cut,  new_middle, len11, len22,        comp);
          first = new_middle;
          middle = second_cut;
          len1 -= len11;
          len2 -= len22;
       }
       else {
-         merge_bufferless_ONlogN_recursive(new_middle, second_cut, last,       len1 - len11, len2 - len22, comp);
+         merge_bufferless_ONlogN_recursive(new_middle, second_cut, last, len1 - len11, len2 - len22, comp);
          middle = first_cut;
          last = new_middle;
          len1 = len11;
          len2 = len22;
       }
    }
 }
 
+
 //Complexity: NlogN
 template<class RandIt, class Compare>
 void merge_bufferless_ONlogN(RandIt first, RandIt middle, RandIt last, Compare comp)
 {
+   typedef typename iterator_traits<RandIt>::size_type size_type;
    merge_bufferless_ONlogN_recursive
-      (first, middle, last, middle - first, last - middle, comp); 
+      (first, middle, last, size_type(middle - first), size_type(last - middle), comp);
 }
 
 template<class RandIt, class Compare>
 void merge_bufferless(RandIt first, RandIt middle, RandIt last, Compare comp)
 {
@@ -439,11 +736,11 @@
    // Remaining [first, last) already in the correct place
 }
 
 // @endcond
 
-// [irst, last) are already in the right part of the destination range.
+// [first, last) are already in the right part of the destination range.
 template <class Compare, class BidirIterator, class BidirOutIterator>
 void merge_with_left_placed
    ( BidirOutIterator const first, BidirOutIterator last, BidirOutIterator dest_last
    , BidirIterator const r_first, BidirIterator r_last
    , Compare comp)
@@ -544,9 +841,139 @@
    }
    d.release();
    merge_with_right_placed(first, last, original_r_first, r_first, r_last, comp);
 }
 */
+
+
+/// This is a helper function for the merge routines.
+template<typename BidirectionalIterator1, typename BidirectionalIterator2>
+   BidirectionalIterator1
+   rotate_adaptive(BidirectionalIterator1 first,
+      BidirectionalIterator1 middle,
+      BidirectionalIterator1 last,
+      typename iterator_traits<BidirectionalIterator1>::size_type len1,
+      typename iterator_traits<BidirectionalIterator1>::size_type len2,
+      BidirectionalIterator2 buffer,
+      typename iterator_traits<BidirectionalIterator1>::size_type buffer_size)
+{
+   if (len1 > len2 && len2 <= buffer_size)
+   {
+      if(len2) //Protect against self-move ranges
+      {
+         BidirectionalIterator2 buffer_end = boost::move(middle, last, buffer);
+         boost::move_backward(first, middle, last);
+         return boost::move(buffer, buffer_end, first);
+      }
+      else
+         return first;
+   }
+   else if (len1 <= buffer_size)
+   {
+      if(len1) //Protect against self-move ranges
+      {
+         BidirectionalIterator2 buffer_end = boost::move(first, middle, buffer);
+         BidirectionalIterator1 ret = boost::move(middle, last, first);
+         boost::move(buffer, buffer_end, ret);
+         return ret;
+      }
+      else
+         return last;
+   }
+   else
+      return rotate_gcd(first, middle, last);
+}
+
+template<typename BidirectionalIterator,
+   typename Pointer, typename Compare>
+   void merge_adaptive_ONlogN_recursive
+   (BidirectionalIterator first,
+      BidirectionalIterator middle,
+      BidirectionalIterator last,
+      typename iterator_traits<BidirectionalIterator>::size_type len1,
+      typename iterator_traits<BidirectionalIterator>::size_type len2,
+      Pointer buffer,
+      typename iterator_traits<BidirectionalIterator>::size_type buffer_size,
+      Compare comp)
+{
+   typedef typename iterator_traits<BidirectionalIterator>::size_type size_type;
+   //trivial cases
+   if (!len2 || !len1) {
+      return;
+   }
+   else if (len1 <= buffer_size || len2 <= buffer_size)
+   {
+      range_xbuf<Pointer, size_type, move_op> rxbuf(buffer, buffer + buffer_size);
+      buffered_merge(first, middle, last, comp, rxbuf);
+   }
+   else if (size_type(len1 + len2) == 2u) {
+      if (comp(*middle, *first))
+         adl_move_swap(*first, *middle);
+      return;
+   }
+   else if (size_type(len1 + len2) < MergeBufferlessONLogNRotationThreshold) {
+      merge_bufferless_ON2(first, middle, last, comp);
+      return;
+   }
+   BidirectionalIterator first_cut = first;
+   BidirectionalIterator second_cut = middle;
+   size_type len11 = 0;
+   size_type len22 = 0;
+   if (len1 > len2)  //(len1 < len2)
+   {
+      len11 = len1 / 2;
+      first_cut += len11;
+      second_cut = boost::movelib::lower_bound(middle, last, *first_cut, comp);
+      len22 = second_cut - middle;
+   }
+   else
+   {
+      len22 = len2 / 2;
+      second_cut += len22;
+      first_cut = boost::movelib::upper_bound(first, middle, *second_cut, comp);
+      len11 = first_cut - first;
+   }
+
+   BidirectionalIterator new_middle
+      = rotate_adaptive(first_cut, middle, second_cut,
+         size_type(len1 - len11), len22, buffer,
+         buffer_size);
+   merge_adaptive_ONlogN_recursive(first, first_cut, new_middle, len11,
+      len22, buffer, buffer_size, comp);
+   merge_adaptive_ONlogN_recursive(new_middle, second_cut, last,
+      len1 - len11, len2 - len22, buffer, buffer_size, comp);
+}
+
+
+template<typename BidirectionalIterator, typename Compare, typename RandRawIt>
+void merge_adaptive_ONlogN(BidirectionalIterator first,
+		                     BidirectionalIterator middle,
+		                     BidirectionalIterator last,
+		                     Compare comp,
+                           RandRawIt uninitialized,
+                           typename iterator_traits<BidirectionalIterator>::size_type uninitialized_len)
+{
+   typedef typename iterator_traits<BidirectionalIterator>::value_type  value_type;
+   typedef typename iterator_traits<BidirectionalIterator>::size_type   size_type;
+
+   if (first == middle || middle == last)
+      return;
+
+   if(uninitialized_len)
+   {
+      const size_type len1 = size_type(middle - first);
+      const size_type len2 = size_type(last - middle);
+
+      ::boost::movelib::adaptive_xbuf<value_type, RandRawIt> xbuf(uninitialized, uninitialized_len);
+      xbuf.initialize_until(uninitialized_len, *first);
+	   merge_adaptive_ONlogN_recursive(first, middle, last, len1, len2, xbuf.begin(), uninitialized_len, comp);
+   }
+   else
+   {
+      merge_bufferless(first, middle, last, comp);
+   }
+}
+
 
 }  //namespace movelib {
 }  //namespace boost {
 
 #endif   //#define BOOST_MOVE_MERGE_HPP