Class DeflatingZstdEntityProducer

java.lang.Object
org.apache.hc.client5.http.async.methods.DeflatingZstdEntityProducer
All Implemented Interfaces:
org.apache.hc.core5.http.EntityDetails, org.apache.hc.core5.http.nio.AsyncDataProducer, org.apache.hc.core5.http.nio.AsyncEntityProducer, org.apache.hc.core5.http.nio.ResourceHolder
public final class DeflatingZstdEntityProducer extends Object implements org.apache.hc.core5.http.nio.AsyncEntityProducer
AsyncEntityProducer that compresses the bytes produced by a delegate entity into a single Zstandard (zstd) frame on the fly.

This producer wraps a AsyncEntityProducer and performs streaming, ByteBuffer-to-ByteBuffer compression as the delegate writes to the provided DataStreamChannel. No InputStream is used in the client pipeline.

Metadata reported by this producer:

Behavior

  • Streaming & back-pressure: compressed output is staged in direct ByteBuffers and written only when the channel accepts bytes. When DataStreamChannel.write(...) returns 0, the producer pauses and requests another output turn.
  • Finalization: after the delegate signals endStream(), this producer emits the zstd frame epilogue and then calls DataStreamChannel.endStream().
  • Repeatability: repeatable only if the delegate is repeatable.
  • Headers: callers are responsible for sending Content-Encoding: zstd on the request if required by the server. Content length is not known in advance.
  • Resources: invoke releaseResources() to free native compressor resources.

Constructors

  • DeflatingZstdEntityProducer(delegate) – uses a default compression level.
  • DeflatingZstdEntityProducer(delegate, level) – explicitly sets the zstd level.

Thread-safety

Not thread-safe; one instance per message exchange.

Runtime dependency

Requires com.github.luben:zstd-jni on the classpath.

Since:
5.6
See Also:

  • Field Details

    • IN_BUF

      private static final int IN_BUF
      See Also:

    • OUT_BUF_DEFAULT

      private static final int OUT_BUF_DEFAULT
      See Also:

    • delegate

      private final org.apache.hc.core5.http.nio.AsyncEntityProducer delegate

    • inDirect

      private final ByteBuffer inDirect
      Direct staging for heap inputs.

    • pending

      private final Deque<ByteBuffer> pending
      Pending compressed output buffers, ready to write (pos=0..limit).

    • outBuf

      private ByteBuffer outBuf
      Current output buffer owned by zstd; replaced when it overflows or flushes.

    • zstream

      private com.github.luben.zstd.ZstdDirectBufferCompressingStream zstream
      Zstd compressor stream.

    • upstreamEnded

      private volatile boolean upstreamEnded

    • finished

      private volatile boolean finished

    • released

      private final AtomicBoolean released

    • level

      private final int level

    • outCap

      private final int outCap

  • Constructor Details

    • DeflatingZstdEntityProducer

      public DeflatingZstdEntityProducer(org.apache.hc.core5.http.nio.AsyncEntityProducer delegate)

    • DeflatingZstdEntityProducer

      public DeflatingZstdEntityProducer(org.apache.hc.core5.http.nio.AsyncEntityProducer delegate, int level)

  • Method Details

    • isRepeatable

      public boolean isRepeatable()
      Specified by:
      isRepeatable in interface org.apache.hc.core5.http.nio.AsyncEntityProducer

    • getContentLength

      public long getContentLength()
      Specified by:
      getContentLength in interface org.apache.hc.core5.http.EntityDetails

    • getContentType

      public String getContentType()
      Specified by:
      getContentType in interface org.apache.hc.core5.http.EntityDetails

    • getContentEncoding

      public String getContentEncoding()
      Specified by:
      getContentEncoding in interface org.apache.hc.core5.http.EntityDetails

    • isChunked

      public boolean isChunked()
      Specified by:
      isChunked in interface org.apache.hc.core5.http.EntityDetails

    • getTrailerNames

      public Set<String> getTrailerNames()
      Specified by:
      getTrailerNames in interface org.apache.hc.core5.http.EntityDetails

    • available

      public int available()
      Specified by:
      available in interface org.apache.hc.core5.http.nio.AsyncDataProducer

    • produce

      public void produce(org.apache.hc.core5.http.nio.DataStreamChannel chan) throws IOException
      Specified by:
      produce in interface org.apache.hc.core5.http.nio.AsyncDataProducer
      Throws:
      IOException

    • ensureStreamInitialized

      private void ensureStreamInitialized() throws IOException
      Throws:
      IOException

    • flushPending

      private boolean flushPending(org.apache.hc.core5.http.nio.DataStreamChannel chan) throws IOException
      Try to write as much of the pending compressed data as the channel accepts.
      Throws:
      IOException

    • compressFrom

      private int compressFrom(ByteBuffer src) throws IOException
      Compress the bytes in src (may be heap or direct).
      Throws:
      IOException

    • failed

      public void failed(Exception cause)
      Specified by:
      failed in interface org.apache.hc.core5.http.nio.AsyncEntityProducer

    • releaseResources

      public void releaseResources()
      Specified by:
      releaseResources in interface org.apache.hc.core5.http.nio.ResourceHolder