content: /*
   * Copyright 2014-2025 Real Logic Limited.
   *
   * 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
   *
   * https://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.
   */
  package io.aeron.logbuffer;
  
  import org.agrona.concurrent.UnsafeBuffer;
  
  import static io.aeron.logbuffer.FrameDescriptor.*;
  import static io.aeron.logbuffer.LogBufferDescriptor.applyDefaultHeader;
  import static io.aeron.protocol.HeaderFlyweight.HDR_TYPE_PAD;
  
  /**
   * Fills a gap in a term with a padding record.
   */
  public class TermGapFiller
  {
      /**
       * Try to gap fill the current term at a given offset if the gap contains no data.
       * <p>
       * Note: the gap offset plus gap length must end on a {@link FrameDescriptor#FRAME_ALIGNMENT} boundary.
       *
       * @param logMetaDataBuffer containing the default headers
       * @param termBuffer        to gap fill
       * @param termId            for the current term.
       * @param gapOffset         to fill from
       * @param gapLength         to length of the gap.
       * @return true if the gap has been filled with a padding record or false if data found.
       */
      public static boolean tryFillGap(
          final UnsafeBuffer logMetaDataBuffer,
          final UnsafeBuffer termBuffer,
          final int termId,
          final int gapOffset,
          final int gapLength)
      {
          int offset = (gapOffset + gapLength) - FRAME_ALIGNMENT;
  
          while (offset >= gapOffset)
          {
              if (0 != termBuffer.getInt(offset))
              {
                  return false;
              }
  
              offset -= FRAME_ALIGNMENT;
          }
  
          applyDefaultHeader(logMetaDataBuffer, termBuffer, gapOffset);
          frameType(termBuffer, gapOffset, HDR_TYPE_PAD);
          frameTermOffset(termBuffer, gapOffset);
          frameTermId(termBuffer, gapOffset, termId);
          frameLengthOrdered(termBuffer, gapOffset, gapLength);
  
          return true;
      }
  }
  