Esempio n. 1
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  /** Returns a temporary buffer of at least the given size */
  public static ByteBuffer getTemporaryDirectBuffer(int size) {
    // If a buffer of this size is too large for the cache, there
    // should not be a buffer in the cache that is at least as
    // large. So we'll just create a new one. Also, we don't have
    // to remove the buffer from the cache (as this method does
    // below) given that we won't put the new buffer in the cache.
    if (isBufferTooLarge(size)) {
      return ByteBuffer.allocateDirect(size);
    }

    BufferCache cache = bufferCache.get();
    ByteBuffer buf = cache.get(size);
    if (buf != null) {
      return buf;
    } else {
      // No suitable buffer in the cache so we need to allocate a new
      // one. To avoid the cache growing then we remove the first
      // buffer from the cache and free it.
      if (!cache.isEmpty()) {
        buf = cache.removeFirst();
        free(buf);
      }
      return ByteBuffer.allocateDirect(size);
    }
  }
Esempio n. 2
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  /**
   * Releases a temporary buffer by returning to the cache or freeing it. If returning to the cache
   * then insert it at the end. This makes it suitable for scatter/gather operations where the
   * buffers are returned to cache in same order that they were obtained.
   */
  static void offerLastTemporaryDirectBuffer(ByteBuffer buf) {
    // If the buffer is too large for the cache we don't have to
    // check the cache. We'll just free it.
    if (isBufferTooLarge(buf)) {
      free(buf);
      return;
    }

    assert buf != null;
    BufferCache cache = bufferCache.get();
    if (!cache.offerLast(buf)) {
      // cache is full
      free(buf);
    }
  }