Java 类org.apache.hadoop.hbase.io.hfile.BlockCacheUtil 实例源码

/**
 * Cache the block to ramCache
 * @param cacheKey block's cache key
 * @param cachedItem block buffer
 * @param inMemory if block is in-memory
 * @param wait if true, blocking wait when queue is full
 */
public void cacheBlockWithWait(BlockCacheKey cacheKey, Cacheable cachedItem, boolean inMemory,
    boolean wait) {
  if (LOG.isTraceEnabled()) LOG.trace("Caching key=" + cacheKey + ", item=" + cachedItem);
  if (!cacheEnabled) {
    return;
  }

  if (backingMap.containsKey(cacheKey)) {
    Cacheable existingBlock = getBlock(cacheKey, false, false, false);
    try {
      if (BlockCacheUtil.compareCacheBlock(cachedItem, existingBlock) != 0) {
        throw new RuntimeException("Cached block contents differ, which should not have happened."
            + "cacheKey:" + cacheKey);
      }
      String msg = "Caching an already cached block: " + cacheKey;
      msg += ". This is harmless and can happen in rare cases (see HBASE-8547)";
      LOG.warn(msg);
    } finally {
      // return the block since we need to decrement the count
      returnBlock(cacheKey, existingBlock);
    }
    return;
  }

  /*
   * Stuff the entry into the RAM cache so it can get drained to the persistent store
   */
  RAMQueueEntry re =
      new RAMQueueEntry(cacheKey, cachedItem, accessCount.incrementAndGet(), inMemory);
  if (ramCache.putIfAbsent(cacheKey, re) != null) {
    return;
  }
  int queueNum = (cacheKey.hashCode() & 0x7FFFFFFF) % writerQueues.size();
  BlockingQueue<RAMQueueEntry> bq = writerQueues.get(queueNum);
  boolean successfulAddition = false;
  if (wait) {
    try {
      successfulAddition = bq.offer(re, DEFAULT_CACHE_WAIT_TIME, TimeUnit.MILLISECONDS);
    } catch (InterruptedException e) {
      Thread.currentThread().interrupt();
    }
  } else {
    successfulAddition = bq.offer(re);
  }
  if (!successfulAddition) {
    ramCache.remove(cacheKey);
    cacheStats.failInsert();
  } else {
    this.blockNumber.increment();
    this.heapSize.add(cachedItem.heapSize());
    blocksByHFile.add(cacheKey);
  }
}