/*

 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_VM_LIBADT_VECTSET_HPP

#define SHARE_VM_LIBADT_VECTSET_HPP

#include "libadt/set.hpp"

#define BITS_IN_BYTE_ARRAY_SIZE 256

// Vector Sets - An Abstract Data Type

//INTERFACE

// These sets can grow or shrink, based on the initial size and the largest

// element currently in them.  Slow and bulky for sparse sets, these sets

// are super for dense sets.  They are fast and compact when dense.

// TIME:

// O(1) - Insert, Delete, Member, Sort

// O(max_element) - Create, Clear, Size, Copy, Union, Intersect, Difference,

//                  Equal, ChooseMember, Forall

// SPACE: (max_element)/(8*sizeof(int))

//------------------------------VectorSet--------------------------------------

class VectorSet : public Set {

friend class VectorSetI;        // Friendly iterator class

protected:

  uint size;                    // Size of data IN LONGWORDS (32bits)

  uint32_t* data;               // The data, bit packed

  void slamin( const VectorSet& s );     // Initialize one set with another

  int compare(const VectorSet &s) const; // Compare set contents

  void grow(uint newsize);               // Grow vector to required bitsize

public:

  VectorSet(Arena *arena);                      // Creates a new, empty set.

  VectorSet(const VectorSet &s) : Set(s._set_arena) {slamin(s);} // Set clone; deep-copy guts

  Set &operator =(const Set &s);                // Set clone; deep-copy guts

  VectorSet &operator =(const VectorSet &s)     // Set clone; deep-copy guts

  { if( &s != this ) { slamin(s); } return *this; }

  ~VectorSet() {}

  Set &clone(void) const { return *(new VectorSet(*this)); }

  Set &operator <<=(uint elem);          // Add member to set

  VectorSet operator << (uint elem)      // Add member to new set

  { VectorSet foo(*this); foo <<= elem; return foo; }

  Set &operator >>=(uint elem);          // Delete member from set

  VectorSet operator >> (uint elem)      // Delete member from new set

  { VectorSet foo(*this); foo >>= elem; return foo; }

  VectorSet &operator &=(const VectorSet &s); // Intersect sets into first set

  Set       &operator &=(const Set       &s); // Intersect sets into first set

  VectorSet operator & (const VectorSet &s) const

  { VectorSet foo(*this); foo &= s; return foo; }

  VectorSet &operator |=(const VectorSet &s); // Intersect sets into first set

  Set       &operator |=(const Set       &s); // Intersect sets into first set

  VectorSet operator | (const VectorSet &s) const

  { VectorSet foo(*this); foo |= s; return foo; }

  VectorSet &operator -=(const VectorSet &s); // Intersect sets into first set

  Set       &operator -=(const Set       &s); // Intersect sets into first set

  VectorSet operator - (const VectorSet &s) const

  { VectorSet foo(*this); foo -= s; return foo; }

  int operator ==(const VectorSet &s) const;  // True if sets are equal

  int operator ==(const Set       &s) const;  // True if sets are equal

  int operator < (const VectorSet &s) const;  // True if strict subset

  int operator < (const Set       &s) const;  // True if strict subset

  int operator <=(const VectorSet &s) const;  // True if subset relation holds.

  int operator <=(const Set       &s) const;  // True if subset relation holds.

  int disjoint   (const Set       &s) const;  // True if sets are disjoint

  int operator [](uint elem) const; // Test for membership

  uint getelem(void) const;         // Return a random element

  void Clear(void);                 // Clear a set

  uint Size(void) const;            // Number of elements in the Set.

  void Sort(void);                  // Sort before iterating

  int hash() const;                 // Hash function

  void Reset(void) {                // Reset a set

    memset( data, 0, size*sizeof(uint32_t) );

  }

  /* Removed for MCC BUG

     operator const VectorSet* (void) const { return this; } */

  const VectorSet *asVectorSet() const { return this; }

  // Expose internals for speed-critical fast iterators

  uint word_size() const { return size; }

  uint32_t* EXPOSE() const { return data; }

  // Fast inlined "test and set".  Replaces the idiom:

  //     if( visited[idx] ) return;

  //     visited <<= idx;

  // With:

  //     if( visited.test_set(idx) ) return;

  //

  int test_set( uint elem ) {

    uint word = elem >> 5;           // Get the longword offset

    if( word >= size )               // Beyond the last?

      return test_set_grow(elem);    // Then grow; set; return 0;

    uint32_t mask = 1L << (elem & 31); // Get bit mask

    uint32_t datum = data[word] & mask;// Get bit

    data[word] |= mask;              // Set bit

    return datum;                    // Return bit

  }

  int test_set_grow( uint elem ) {    // Insert & return 0;

    (*this) <<= elem;                 // Insert into set

    return 0;                         // Return 0!

  }

  // Fast inlined test

  int test( uint elem ) const {

    uint word = elem >> 5;      // Get the longword offset

    if( word >= size ) return 0; // Beyond the last?

    uint32_t mask = 1L << (elem & 31); // Get bit mask

    return data[word] & mask;   // Get bit

  }

  // Fast inlined set

  void set( uint elem ) {

    uint word = elem >> 5;      // Get the longword offset

    if( word >= size ) {        // Beyond the last?

      test_set_grow(elem);      // Then grow and set

    } else {

      uint32_t mask = 1L << (elem & 31); // Get bit mask

      data[word] |= mask;       // Set bit

    }

  }

private:

  SetI_ *iterate(uint&) const;

};

//------------------------------Iteration--------------------------------------

// Loop thru all elements of the set, setting "elem" to the element numbers

// in random order.  Inserted or deleted elements during this operation may

// or may not be iterated over; untouched elements will be affected once.

// Usage:  for( VectorSetI i(s); i.test(); i++ ) { body = i.elem; }

class VectorSetI : public StackObj {

  friend class VectorSet;

  const VectorSet *s;

  uint i, j;

  uint32_t mask;

  uint next(void);

public:

  uint elem;                    // The publically accessible element

  VectorSetI( const VectorSet *vset ) :

    s(vset),

    i((uint)-1L),

    j((uint)-1L),

    mask((unsigned)(1L<<31)) {

    elem = next();

  }

  void operator ++(void) { elem = next(); }

  int test(void) { return i < s->size; }

};

#endif // SHARE_VM_LIBADT_VECTSET_HPP