text: /*
   * Copyright (C) 2013, The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "dictionary/structure/pt_common/dynamic_pt_reading_utils.h"
  
  #include "defines.h"
  #include "dictionary/utils/byte_array_utils.h"
  
  namespace turbokeyboard {
  
  const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::MASK_MOVED = 0xC0;
  const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_IS_NOT_MOVED = 0xC0;
  const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_IS_MOVED = 0x40;
  const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_IS_DELETED = 0x80;
  const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_WILL_BECOME_NON_TERMINAL = 0x00;
  
  // TODO: Make DICT_OFFSET_ZERO_OFFSET = 0.
  // Currently, DICT_OFFSET_INVALID is 0 in Java side but offset can be 0 during GC. So, the maximum
  // value of offsets, which is 0x7FFFFF is used to represent 0 offset.
  const int DynamicPtReadingUtils::DICT_OFFSET_INVALID = 0;
  const int DynamicPtReadingUtils::DICT_OFFSET_ZERO_OFFSET = 0x7FFFFF;
  
  /* static */ int DynamicPtReadingUtils::getForwardLinkPosition(const uint8_t *const buffer,
          const int pos) {
      int linkAddressPos = pos;
      return ByteArrayUtils::readSint24AndAdvancePosition(buffer, &linkAddressPos);
  }
  
  /* static */ int DynamicPtReadingUtils::getParentPtNodePosOffsetAndAdvancePosition(
          const uint8_t *const buffer, int *const pos) {
      return ByteArrayUtils::readSint24AndAdvancePosition(buffer, pos);
  }
  
  /* static */ int DynamicPtReadingUtils::getParentPtNodePos(const int parentOffset,
          const int ptNodePos) {
      if (parentOffset == DICT_OFFSET_INVALID) {
          return NOT_A_DICT_POS;
      } else if (parentOffset == DICT_OFFSET_ZERO_OFFSET) {
          return ptNodePos;
      } else {
          return parentOffset + ptNodePos;
      }
  }
  
  /* static */ int DynamicPtReadingUtils::readChildrenPositionAndAdvancePosition(
          const uint8_t *const buffer, int *const pos) {
      const int base = *pos;
      const int offset = ByteArrayUtils::readSint24AndAdvancePosition(buffer, pos);
      if (offset == DICT_OFFSET_INVALID) {
          // The PtNode does not have children.
          return NOT_A_DICT_POS;
      } else if (offset == DICT_OFFSET_ZERO_OFFSET) {
          return base;
      } else {
          return base + offset;
      }
  }
  
  } // namespace turbokeyboard
  