/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file bufferContextChain.cxx
 * @author drose
 * @date 2006-03-16
 */

#include "bufferContextChain.h"
#include "bufferContext.h"
#include "indent.h"

/**
 * Returns the first BufferContext object stored in the tracker.  You can walk
 * through the entire list of objects stored on the tracker by calling
 * get_next() on each returned object, until the return value is NULL.
 */
BufferContext *BufferContextChain::
get_first() {
  // This method is declared non-inline so we can include bufferContext.h,
  // which is necessary for proper downcasting of the _next pointer.
  if (_next == this) {
    return nullptr;
  }
  return (BufferContext *)_next;
}

/**
 * Moves all of the BufferContexts from the other tracker onto this one.
 */
void BufferContextChain::
take_from(BufferContextChain &other) {
  _total_size += other._total_size;
  _count += other._count;
  other._total_size = 0;
  other._count = 0;

  LinkedListNode *llnode = other._next;
  while (llnode != &other) {
    nassertv(((BufferContext *)llnode)->_owning_chain == &other);
    ((BufferContext *)llnode)->_owning_chain = this;
    llnode = ((BufferContext *)llnode)->_next;
  }

  take_list_from(&other);
}

/**
 *
 */
void BufferContextChain::
write(std::ostream &out, int indent_level) const {
  indent(out, indent_level)
    << _count << " objects, consuming " << _total_size << " bytes:\n";

  LinkedListNode *llnode = _next;
  while (llnode != this) {
    ((BufferContext *)llnode)->write(out, indent_level + 2);
    llnode = ((BufferContext *)llnode)->_next;
  }
}