/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-  */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef _MDB_
#  include "mdb.h"
#endif

#ifndef _MORK_
#  include "mork.h"
#endif

#ifndef _MORKNODE_
#  include "morkNode.h"
#endif

#ifndef _MORKSTORE_
#  include "morkStore.h"
#endif

#ifndef _MORKPOOL_
#  include "morkPool.h"
#endif

#ifndef _MORKENV_
#  include "morkEnv.h"
#endif

#ifndef _MORKCELL_
#  include "morkCell.h"
#endif

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void morkCell::SetYarn(morkEnv* ev, const mdbYarn* inYarn, morkStore* ioStore) {
  morkAtom* atom = ioStore->YarnToAtom(ev, inYarn, true /* create */);
  if (atom) this->SetAtom(ev, atom, ioStore->StorePool());  // refcounts atom
}

void morkCell::GetYarn(morkEnv* ev, mdbYarn* outYarn) const {
  MORK_USED_1(ev);
  morkAtom::GetYarn(mCell_Atom, outYarn);
}

void morkCell::AliasYarn(morkEnv* ev, mdbYarn* outYarn) const {
  MORK_USED_1(ev);
  morkAtom::AliasYarn(mCell_Atom, outYarn);
}

void morkCell::SetCellClean() {
  mork_column col = this->GetColumn();
  this->SetColumnAndChange(col, morkChange_kNil);
}

void morkCell::SetCellDirty() {
  mork_column col = this->GetColumn();
  this->SetColumnAndChange(col, morkChange_kAdd);
}

void morkCell::SetAtom(morkEnv* ev, morkAtom* ioAtom, morkPool* ioPool)
// SetAtom() "acquires" the new ioAtom if non-nil, by calling AddCellUse()
// to increase the refcount, and puts ioAtom into mCell_Atom.  If the old
// atom in mCell_Atom is non-nil, then it is "released" first by a call to
// CutCellUse(), and if the use count then becomes zero, then the old atom
// is deallocated by returning it to the pool ioPool.  (And this is
// why ioPool is a parameter to this method.)  Note that ioAtom can be nil
// to cause the cell to refer to nothing, and the old atom in mCell_Atom
// can also be nil, and all the atom refcounting is handled correctly.
//
// Note that if ioAtom was just created, it typically has a zero use count
// before calling SetAtom().  But use count is one higher after SetAtom().
{
  morkAtom* oldAtom = mCell_Atom;
  if (oldAtom != ioAtom)  // ioAtom is not already installed in this cell?
  {
    if (oldAtom) {
      mCell_Atom = 0;
      if (oldAtom->CutCellUse(ev) == 0) {
        // this was zapping atoms still in use - comment out until davidmc
        // can figure out a better fix.
        //        if ( ioPool )
        //        {
        //          if ( oldAtom->IsBook() )
        //            ((morkBookAtom*) oldAtom)->CutBookAtomFromSpace(ev);

        //          ioPool->ZapAtom(ev, oldAtom);
        //        }
        //        else
        //          ev->NilPointerError();
      }
    }
    if (ioAtom) ioAtom->AddCellUse(ev);

    mCell_Atom = ioAtom;
  }
}

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