/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program 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 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */

#include "ArenaPool.hpp"
#include <ndbd_exit_codes.h>
#include <NdbOut.hpp>

static
Uint32
computeBlockSize(Uint32 blockSz, Uint32 wpp)
{
  Uint32 minspill = wpp % blockSz;
  Uint32 minspill_bs = blockSz;

  for (Uint32 i = 16; i<blockSz/4; i += 16)
  {
    Uint32 spillsz = wpp % (blockSz - i);
    if (spillsz == 0)
    {
      return blockSz - i;
    }
    else if (spillsz < minspill)
    {
      minspill = spillsz;
      minspill_bs = blockSz -i;
    }
  }
  ndbout_c("blockSz: %u, wpp: %u -> %u (%u)",
           blockSz, wpp, minspill_bs, minspill);
  return minspill_bs;
}

void
ArenaAllocator::init(Uint32 sz, Uint32 type_id, const Pool_context& pc)
{
  Uint32 blocksz = ArenaBlock::computeBlockSizeInWords(sz);
  Uint32 wpp = m_pool.WORDS_PER_PAGE;

  Uint32 bs = computeBlockSize(blocksz, wpp);
  Record_info ri;
  ri.m_size = 4 * bs;
  {
    ArenaBlock tmp;
    const char * off_base = (char*)&tmp;
    const char * off_next = (char*)&tmp.nextPool;
    const char * off_magic = (char*)&tmp.m_magic;

    ri.m_offset_next_pool = Uint32(off_next - off_base);
    ri.m_offset_magic = Uint32(off_magic - off_base);
  }
  ri.m_type_id = type_id;
  m_pool.init(ri, pc);
  m_block_size = bs - ArenaBlock::HeaderSize;
}

bool
ArenaAllocator::seize(ArenaHead& ah)
{
  Ptr<void> tmp;
  if (m_pool.seize(tmp))
  {
    ah.m_first_block = tmp.i;
    ah.m_current_block = tmp.i;
    ah.m_block_size = m_block_size;
    ah.m_current_block_ptr = static_cast<ArenaBlock*>(tmp.p);
    ah.m_current_block_ptr->m_next_block = RNIL;
    return true;
  }
  return false;
}

void
ArenaAllocator::release(ArenaHead& ah)
{
  Ptr<void> curr;
  curr.i = ah.m_first_block;
  while (curr.i != RNIL)
  {
    curr.p = m_pool.getPtr(curr.i);
    Uint32 next = static_cast<ArenaBlock*>(curr.p)->m_next_block;
    m_pool.release(curr);
    curr.i = next;
  }

  new (&ah) ArenaHead();
}

void
ArenaPool::init(ArenaAllocator * alloc,
                const Record_info& ri, const Pool_context&)
{
  m_record_info = ri;
#if SIZEOF_CHARP == 4
  m_record_info.m_size = ((ri.m_size + 3) >> 2); // Align to word boundary
#else
  m_record_info.m_size = ((ri.m_size + 7) >> 3) << 1; // align 8-byte
#endif
  m_record_info.m_offset_magic = ((ri.m_offset_magic + 3) >> 2);
  m_record_info.m_offset_next_pool = ((ri.m_offset_next_pool + 3) >> 2);
  m_allocator = alloc;
}

bool
ArenaPool::seize(ArenaHead & ah, Ptr<void>& ptr)
{
  Uint32 pos = ah.m_first_free;
  Uint32 bs = ah.m_block_size;
  Uint32 ptrI = ah.m_current_block;
  ArenaBlock * block = ah.m_current_block_ptr;

  Uint32 sz = m_record_info.m_size;
  Uint32 off = m_record_info.m_offset_magic;

  if (0)
    ndbout_c("pos: %u sz: %u (sum: %u) bs: %u",
             pos, sz, (pos + sz), bs);

  if (pos + sz <= bs)
  {
    /**
     * Alloc in this block
     */
    ptr.i =
      ((ptrI >> POOL_RECORD_BITS) << POOL_RECORD_BITS) +
      (ptrI & POOL_RECORD_MASK) + pos + ArenaBlock::HeaderSize;
    ptr.p = block->m_data + pos;
    block->m_data[pos+off] = ~(Uint32)m_record_info.m_type_id;

    ah.m_first_free = pos + sz;
    return true;
  }
  else
  {
    Ptr<void> tmp;
    if (m_allocator->m_pool.seize(tmp))
    {
      ah.m_first_free = 0;
      ah.m_current_block = tmp.i;
      ah.m_current_block_ptr->m_next_block = tmp.i;
      ah.m_current_block_ptr = static_cast<ArenaBlock*>(tmp.p);
      ah.m_current_block_ptr->m_next_block = RNIL;
      bool ret = seize(ah, ptr);
      (void)ret;
      assert(ret == true);
      return true;
    }
  }
  return false;
}

void
ArenaPool::handle_invalid_release(Ptr<void> ptr)
{
  char buf[255];

  //Uint32 pos = ptr.i & POOL_RECORD_MASK;
  //Uint32 pageI = ptr.i >> POOL_RECORD_BITS;
  Uint32 * record_ptr_p = (Uint32*)ptr.p;

  Uint32 magic = * (record_ptr_p + m_record_info.m_offset_magic);
  BaseString::snprintf(buf, sizeof(buf),
                       "Invalid memory release: ptr (%x %p) magic: (%.8x %.8x)",
                       ptr.i, ptr.p, magic, m_record_info.m_type_id);

  m_allocator->m_pool.m_ctx.handleAbort(NDBD_EXIT_PRGERR, buf);
}
