content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.client.file.cache.cuckoofilter;
  
  /**
   * The cuckoo table that supports to store and access data positioned by a specific bucket and slot.
   */
  public interface CuckooTable {
    /**
     * Reads the value of tag in specified position.
     *
     * @param bucketIndex the bucket index
     * @param slotIndex the slot in bucket
     * @return the tag value to read
     */
    int readTag(int bucketIndex, int slotIndex);
  
    /**
     * Set the value of tag in specified position.
     *
     * @param bucketIndex the bucket index
     * @param slotIndex the slot in bucket
     * @param tag the tag value to write
     */
    void writeTag(int bucketIndex, int slotIndex, int tag);
  
    /**
     * Find a tag in specified bucket and return its position.
     *
     * @param bucketIndex the bucket index
     * @param tag the tag value to find
     * @return the valid position of this tag if it is found; otherwise an invalid position indicates
     *         that tag is not found
     */
    TagPosition findTag(int bucketIndex, int tag);
  
    /**
     * Find a tag in specified two buckets and return its position.
     *
     * @param bucketIndex1 the first bucket index
     * @param bucketIndex2 the second bucket index
     * @param tag the tag value to find
     * @return the valid position of this tag if it is found; otherwise an invalid position indicates
     *         that tag is not found
     */
    TagPosition findTag(int bucketIndex1, int bucketIndex2, int tag);
  
    /**
     * Delete a tag in specified bucket and return its position.
     *
     * @param bucketIndex the bucket to delete from
     * @param tag the tag value to find
     * @return the valid position of this tag if it is found and deleted; otherwise an invalid
     *         position indicates that tag is not found
     */
    TagPosition deleteTag(int bucketIndex, int tag);
  
    /**
     * Insert a tag into specified bucket. If no empty slot found, it will kickout one randomly and
     * return the victim's tag value.
     *
     * @param bucketIndex the bucket index
     * @param tag the tag value to find
     * @return the tag value kicked out
     */
    int insertOrKickTag(int bucketIndex, int tag);
  
    /**
     * @return the number of tags per bucket
     */
    int getNumTagsPerBuckets();
  
    /**
     * @return the number of buckets
     */
    int getNumBuckets();
  
    /**
     * @return the number of bits per tag
     */
    int getBitsPerTag();
  
    /**
     * @return the number of bytes
     */
    int getSizeInBytes();
  
    /**
     * @return the number of tags
     */
    int getSizeInTags();
  }
  