/*

 * Copyright (c) 1997, 2012, 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

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 */

#include "precompiled.hpp"

#include "libadt/vectset.hpp"

#include "memory/allocation.inline.hpp"

// Vector Sets - An Abstract Data Type

// BitsInByte is a lookup table which tells the number of bits that

// are in the looked-up number.  It is very useful in VectorSet_Size.

uint8_t bitsInByte[BITS_IN_BYTE_ARRAY_SIZE] = {

  0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,

  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,

  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,

  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,

  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,

  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,

  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,

  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,

  1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,

  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,

  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,

  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,

  2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,

  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,

  3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,

  4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8

};

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

// Create a new, empty Set.

VectorSet::VectorSet(Arena *arena) : Set(arena) {

  size = 2;                     // Small initial size

  data = (uint32_t *)_set_arena->Amalloc(size*sizeof(uint32_t));

  data[0] = 0;                  // No elements

  data[1] = 0;

}

//------------------------------Construct--------------------------------------

Set &VectorSet_Construct(Arena *arena)

{

  return *(new VectorSet(arena));

}

//------------------------------operator=--------------------------------------

Set &VectorSet::operator = (const Set &set)

{

  if( &set == this ) return *this;

  FREE_FAST(data);

  // The cast is a virtual function that checks that "set" is a VectorSet.

  slamin(*(set.asVectorSet()));

  return *this;

}

//------------------------------slamin-----------------------------------------

// Initialize one set with another.  No regard is made to the existing Set.

void VectorSet::slamin(const VectorSet& s)

{

  size = s.size;                // Use new size

  data = (uint32_t*)s._set_arena->Amalloc(size*sizeof(uint32_t)); // Make array of required size

  memcpy( data, s.data, size*sizeof(uint32_t) ); // Fill the array

}

//------------------------------grow-------------------------------------------

// Expand the existing set to a bigger size

void VectorSet::grow( uint newsize )

{

  newsize = (newsize+31) >> 5;  // Convert to longwords

  uint x = size;

  while( x < newsize ) x <<= 1;

  data = (uint32_t *)_set_arena->Arealloc(data, size*sizeof(uint32_t), x*sizeof(uint32_t));

  memset((char *)(data + size), 0, (x - size)*sizeof(uint32_t));

  size = x;

}

//------------------------------operator<<=------------------------------------

// Insert a member into an existing Set.

Set &VectorSet::operator <<= (uint elem)

{

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

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

  if( word >= size )            // Need to grow set?

    grow(elem+1);               // Then grow it

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

  return *this;

}

//------------------------------operator>>=------------------------------------

// Delete a member from an existing Set.

Set &VectorSet::operator >>= (uint elem)

{

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

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

    return *this;                 // Then it's clear & return clear

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

  data[word] &= ~mask;            // Clear bit

  return *this;

}

//------------------------------operator&=-------------------------------------

// Intersect one set into another.

VectorSet &VectorSet::operator &= (const VectorSet &s)

{

  // NOTE: The intersection is never any larger than the smallest set.

  if( s.size < size ) size = s.size; // Get smaller size

  register uint32_t *u1 = data;   // Pointer to the destination data

  register uint32_t *u2 = s.data; // Pointer to the source data

  for( uint i=0; i<size; i++)   // For data in set

    *u1++ &= *u2++;             // Copy and AND longwords

  return *this;                 // Return set

}

//------------------------------operator&=-------------------------------------

Set &VectorSet::operator &= (const Set &set)

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  return (*this) &= *(set.asVectorSet());

}

//------------------------------operator|=-------------------------------------

// Union one set into another.

VectorSet &VectorSet::operator |= (const VectorSet &s)

{

  // This many words must be unioned

  register uint cnt = ((size<s.size)?size:s.size);

  register uint32_t *u1 = data;   // Pointer to the destination data

  register uint32_t *u2 = s.data; // Pointer to the source data

  for( uint i=0; i<cnt; i++)    // Copy and OR the two sets

    *u1++ |= *u2++;

  if( size < s.size ) {         // Is set 2 larger than set 1?

    // Extend result by larger set

    grow(s.size*sizeof(uint32_t)*8);

    memcpy(&data[cnt], u2, (s.size - cnt)*sizeof(uint32_t));

  }

  return *this;                 // Return result set

}

//------------------------------operator|=-------------------------------------

Set &VectorSet::operator |= (const Set &set)

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  return (*this) |= *(set.asVectorSet());

}

//------------------------------operator-=-------------------------------------

// Difference one set from another.

VectorSet &VectorSet::operator -= (const VectorSet &s)

{

  // This many words must be unioned

  register uint cnt = ((size<s.size)?size:s.size);

  register uint32_t *u1 = data;   // Pointer to the destination data

  register uint32_t *u2 = s.data; // Pointer to the source data

  for( uint i=0; i<cnt; i++ )   // For data in set

    *u1++ &= ~(*u2++);          // A <-- A & ~B  with longwords

  return *this;                 // Return new set

}

//------------------------------operator-=-------------------------------------

Set &VectorSet::operator -= (const Set &set)

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  return (*this) -= *(set.asVectorSet());

}

//------------------------------compare----------------------------------------

// Compute 2 booleans: bits in A not B, bits in B not A.

// Return X0 --  A is not a subset of B

//        X1 --  A is a subset of B

//        0X --  B is not a subset of A

//        1X --  B is a subset of A

int VectorSet::compare (const VectorSet &s) const

{

  register uint32_t *u1 = data;   // Pointer to the destination data

  register uint32_t *u2 = s.data; // Pointer to the source data

  register uint32_t AnotB = 0, BnotA = 0;

  // This many words must be unioned

  register uint cnt = ((size<s.size)?size:s.size);

  // Get bits for both sets

  uint i;                       // Exit value of loop

  for( i=0; i<cnt; i++ ) {      // For data in BOTH sets

    register uint32_t A = *u1++;  // Data from one guy

    register uint32_t B = *u2++;  // Data from other guy

    AnotB |= (A & ~B);          // Compute bits in A not B

    BnotA |= (B & ~A);          // Compute bits in B not A

  }

  // Get bits from bigger set

  if( size < s.size ) {

    for( ; i<s.size; i++ )      // For data in larger set

      BnotA |= *u2++;           // These bits are in B not A

  } else {

    for( ; i<size; i++ )        // For data in larger set

      AnotB |= *u1++;           // These bits are in A not B

  }

  // Set & return boolean flags

  return ((!BnotA)<<1) + (!AnotB);

}

//------------------------------operator==-------------------------------------

// Test for set equality

int VectorSet::operator == (const VectorSet &s) const

{

  return compare(s) == 3;       // TRUE if A and B are mutual subsets

}

//------------------------------operator==-------------------------------------

int VectorSet::operator == (const Set &set) const

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  return (*this) == *(set.asVectorSet());

}

//------------------------------disjoint---------------------------------------

// Check for sets being disjoint.

int VectorSet::disjoint(const Set &set) const

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  const VectorSet &s = *(set.asVectorSet());

  // NOTE: The intersection is never any larger than the smallest set.

  register uint small_size = ((size<s.size)?size:s.size);

  register uint32_t *u1 = data;        // Pointer to the destination data

  register uint32_t *u2 = s.data;      // Pointer to the source data

  for( uint i=0; i<small_size; i++)  // For data in set

    if( *u1++ & *u2++ )              // If any elements in common

      return 0;                      // Then not disjoint

  return 1;                          // Else disjoint

}

//------------------------------operator<--------------------------------------

// Test for strict subset

int VectorSet::operator < (const VectorSet &s) const

{

  return compare(s) == 1;       // A subset B, B not subset A

}

//------------------------------operator<--------------------------------------

int VectorSet::operator < (const Set &set) const

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  return (*this) < *(set.asVectorSet());

}

//------------------------------operator<=-------------------------------------

// Test for subset

int VectorSet::operator <= (const VectorSet &s) const

{

  return compare(s) & 1;        // A subset B

}

//------------------------------operator<=-------------------------------------

int VectorSet::operator <= (const Set &set) const

{

  // The cast is a virtual function that checks that "set" is a VectorSet.

  return (*this) <= *(set.asVectorSet());

}

//------------------------------operator[]-------------------------------------

// Test for membership.  A Zero/Non-Zero value is returned!

int VectorSet::operator[](uint elem) const

{

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

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

    return 0;                     // Then it's clear

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

  return ((data[word] & mask))!=0;           // Return the sense of the bit

}

//------------------------------getelem----------------------------------------

// Get any element from the set.

uint VectorSet::getelem(void) const

{

  uint i;                       // Exit value of loop

  for( i=0; i<size; i++ )

    if( data[i] )

      break;

  uint32_t word = data[i];

  int j;                        // Exit value of loop

  for( j= -1; word; j++, word>>=1 );

  return (i<<5)+j;

}

//------------------------------Clear------------------------------------------

// Clear a set

void VectorSet::Clear(void)

{

  if( size > 100 ) {            // Reclaim storage only if huge

    FREE_RESOURCE_ARRAY(uint32_t,data,size);

    size = 2;                   // Small initial size

    data = NEW_RESOURCE_ARRAY(uint32_t,size);

  }

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

}

//------------------------------Size-------------------------------------------

// Return number of elements in a Set

uint VectorSet::Size(void) const

{

  uint sum = 0;                 // Cumulative size so far.

  uint8_t* currByte = (uint8_t*) data;

  for( uint32_t i = 0; i < (size<<2); i++) // While have bytes to process

    sum += bitsInByte[*currByte++];      // Add bits in current byte to size.

  return sum;

}

//------------------------------Sort-------------------------------------------

// Sort the elements for the next forall statement

void VectorSet::Sort(void)

{

}

//------------------------------hash-------------------------------------------

int VectorSet::hash() const

{

  uint32_t _xor = 0;

  uint lim = ((size<4)?size:4);

  for( uint i = 0; i < lim; i++ )

    _xor ^= data[i];

  return (int)_xor;

}

//------------------------------iterate----------------------------------------

// Used by Set::print().

class VSetI_ : public SetI_ {

  VectorSetI vsi;

public:

  VSetI_( const VectorSet *vset, uint &elem ) : vsi(vset) { elem = vsi.elem; }

  uint next(void) { ++vsi; return vsi.elem; }

  int  test(void) { return vsi.test(); }

};

SetI_ *VectorSet::iterate(uint &elem) const {

  return new(ResourceObj::C_HEAP, mtInternal) VSetI_(this, elem);

}

//=============================================================================

//------------------------------next-------------------------------------------

// Find and return the next element of a vector set, or return garbage and

// make "VectorSetI::test()" fail.

uint VectorSetI::next(void)

{

  j++;                          // Next element in word

  mask = (mask & max_jint) << 1;// Next bit in word

  do {                          // Do While still have words

    while( mask ) {             // While have bits in word

      if( s->data[i] & mask ) { // If found a bit

        return (i<<5)+j;        // Return the bit address

      }

      j++;                      // Skip to next bit

      mask = (mask & max_jint) << 1;

    }

    j = 0;                      // No more bits in word; setup for next word

    mask = 1;

    for( i++; (i<s->size) && (!s->data[i]); i++ ); // Skip to non-zero word

  } while( i<s->size );

  return max_juint;             // No element, iterated them all

}