Supports configurable compression level

docs/modules/ROOT/pages/http-server.adoc

@@ -162,6 +162,16 @@ You can configure the `HTTP` server to send a compressed response, depending on
 * `compress(int)`: The compression is performed once the response size exceeds the given value (in bytes).
 * `compress(BiPredicate<HttpServerRequest, HttpServerResponse>)`: The compression is performed if
 the predicate returns `true`.
+* `compressOptions(HttpCompressionOption... compressionOptions)`: Specifies the compression level for GZIP, DEFLATE, and ZSTD.
++
+[NOTE]
+====
+Supported Compression Levels
+
+* gzip : only the range 0 to 9 is allowed. (default: 6)
+* deflate : only the range 0 to 9 is allowed. (default: 6)
+* zstd : only the range -131072 to 22 is allowed. (default: 3)
+====
 
 The following example uses the `compress` method (set to `true`) to enable compression:
 

reactor-netty-http/src/main/java/reactor/netty/http/server/Http2StreamBridgeServerHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2024 VMware, Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2018-2025 VMware, Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,6 +47,7 @@
 import reactor.netty.ReactorNetty;
 import reactor.netty.http.logging.HttpMessageArgProviderFactory;
 import reactor.netty.http.logging.HttpMessageLogFactory;
+import reactor.netty.http.server.compression.HttpCompressionOptionsSpec;
 import reactor.util.annotation.Nullable;
 
 import static io.netty.handler.codec.http.LastHttpContent.EMPTY_LAST_CONTENT;
@@ -62,6 +63,7 @@
 final class Http2StreamBridgeServerHandler extends ChannelDuplexHandler {
 
 	final BiPredicate<HttpServerRequest, HttpServerResponse>      compress;
+	final HttpCompressionOptionsSpec compressionOptions;
 	final ServerCookieDecoder                                     cookieDecoder;
 	final ServerCookieEncoder                                     cookieEncoder;
 	final HttpServerFormDecoderProvider                           formDecoderProvider;
@@ -84,6 +86,7 @@ final class Http2StreamBridgeServerHandler extends ChannelDuplexHandler {
 
 	Http2StreamBridgeServerHandler(
 			@Nullable BiPredicate<HttpServerRequest, HttpServerResponse> compress,
+			HttpCompressionOptionsSpec compressionOptions,
 			ServerCookieDecoder decoder,
 			ServerCookieEncoder encoder,
 			HttpServerFormDecoderProvider formDecoderProvider,
@@ -94,6 +97,7 @@ final class Http2StreamBridgeServerHandler extends ChannelDuplexHandler {
 			@Nullable Duration readTimeout,
 			@Nullable Duration requestTimeout) {
 		this.compress = compress;
+		this.compressionOptions = compressionOptions;
 		this.cookieDecoder = decoder;
 		this.cookieEncoder = encoder;
 		this.formDecoderProvider = formDecoderProvider;
@@ -140,6 +144,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) {
 						listener,
 						request,
 						compress,
+						compressionOptions,
 						connectionInfo,
 						cookieDecoder,
 						cookieEncoder,

reactor-netty-http/src/main/java/reactor/netty/http/server/Http3Codec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024 VMware, Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2024-2025 VMware, Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@
 import reactor.netty.channel.ChannelMetricsRecorder;
 import reactor.netty.channel.ChannelOperations;
 import reactor.netty.http.logging.HttpMessageLogFactory;
+import reactor.netty.http.server.compression.HttpCompressionOptionsSpec;
 import reactor.netty.http.server.logging.AccessLog;
 import reactor.netty.http.server.logging.AccessLogArgProvider;
 import reactor.netty.http.server.logging.AccessLogHandlerFactory;
@@ -63,6 +64,7 @@ final class Http3Codec extends ChannelInitializer<QuicStreamChannel> {
 	final Function<String, String>                                methodTagValue;
 	final ChannelMetricsRecorder                                  metricsRecorder;
 	final int                                                     minCompressionSize;
+	final HttpCompressionOptionsSpec compressionOptions;
 	final ChannelOperations.OnSetup                               opsFactory;
 	final Duration                                                readTimeout;
 	final Duration                                                requestTimeout;
@@ -83,6 +85,7 @@ final class Http3Codec extends ChannelInitializer<QuicStreamChannel> {
 			@Nullable Function<String, String> methodTagValue,
 			@Nullable ChannelMetricsRecorder metricsRecorder,
 			int minCompressionSize,
+			HttpCompressionOptionsSpec compressionOptions,
 			ChannelOperations.OnSetup opsFactory,
 			@Nullable Duration readTimeout,
 			@Nullable Duration requestTimeout,
@@ -101,6 +104,7 @@ final class Http3Codec extends ChannelInitializer<QuicStreamChannel> {
 		this.methodTagValue = methodTagValue;
 		this.metricsRecorder = metricsRecorder;
 		this.minCompressionSize = minCompressionSize;
+		this.compressionOptions = compressionOptions;
 		this.opsFactory = opsFactory;
 		this.readTimeout = readTimeout;
 		this.requestTimeout = requestTimeout;
@@ -118,13 +122,13 @@ protected void initChannel(QuicStreamChannel channel) {
 
 		p.addLast(NettyPipeline.H3ToHttp11Codec, new Http3FrameToHttpObjectCodec(true, validate))
 		 .addLast(NettyPipeline.HttpTrafficHandler,
-		         new Http3StreamBridgeServerHandler(compressPredicate, cookieDecoder, cookieEncoder, formDecoderProvider,
+		         new Http3StreamBridgeServerHandler(compressPredicate, compressionOptions, cookieDecoder, cookieEncoder, formDecoderProvider,
 		                 forwardedHeaderHandler, httpMessageLogFactory, listener, mapHandle, readTimeout, requestTimeout));
 
 		boolean alwaysCompress = compressPredicate == null && minCompressionSize == 0;
 
 		if (alwaysCompress) {
-			p.addLast(NettyPipeline.CompressionHandler, new SimpleCompressionHandler());
+			p.addLast(NettyPipeline.CompressionHandler, SimpleCompressionHandler.create(compressionOptions));
 		}
 
 		ChannelOperations.addReactiveBridge(channel, opsFactory, listener);
@@ -166,14 +170,15 @@ static ChannelHandler newHttp3ServerConnectionHandler(
 			@Nullable Function<String, String> methodTagValue,
 			@Nullable ChannelMetricsRecorder metricsRecorder,
 			int minCompressionSize,
+			HttpCompressionOptionsSpec compressionOptions,
 			ChannelOperations.OnSetup opsFactory,
 			@Nullable Duration readTimeout,
 			@Nullable Duration requestTimeout,
 			@Nullable Function<String, String> uriTagValue,
 			boolean validate) {
 		return new Http3ServerConnectionHandler(
 				new Http3Codec(accessLogEnabled, accessLog, compressPredicate, decoder, encoder, formDecoderProvider, forwardedHeaderHandler,
-						httpMessageLogFactory, listener, mapHandle, methodTagValue, metricsRecorder, minCompressionSize,
+						httpMessageLogFactory, listener, mapHandle, methodTagValue, metricsRecorder, minCompressionSize, compressionOptions,
 						opsFactory, readTimeout, requestTimeout, uriTagValue, validate));
 	}
 }

reactor-netty-http/src/main/java/reactor/netty/http/server/Http3ServerOperations.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024 VMware, Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2024-2025 VMware, Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@
 import reactor.netty.Connection;
 import reactor.netty.ConnectionObserver;
 import reactor.netty.http.logging.HttpMessageLogFactory;
+import reactor.netty.http.server.compression.HttpCompressionOptionsSpec;
 import reactor.util.annotation.Nullable;
 
 import java.net.SocketAddress;
@@ -43,6 +44,7 @@ final class Http3ServerOperations extends HttpServerOperations {
 			ConnectionObserver listener,
 			HttpRequest nettyRequest,
 			@Nullable BiPredicate<HttpServerRequest, HttpServerResponse> compressionPredicate,
+			HttpCompressionOptionsSpec compressionOptions,
 			ConnectionInfo connectionInfo,
 			ServerCookieDecoder decoder,
 			ServerCookieEncoder encoder,
@@ -54,7 +56,7 @@ final class Http3ServerOperations extends HttpServerOperations {
 			@Nullable Duration requestTimeout,
 			boolean secured,
 			ZonedDateTime timestamp) {
-		super(c, listener, nettyRequest, compressionPredicate, connectionInfo, decoder, encoder, formDecoderProvider,
+		super(c, listener, nettyRequest, compressionPredicate, compressionOptions, connectionInfo, decoder, encoder, formDecoderProvider,
 				httpMessageLogFactory, isHttp2, mapHandle, readTimeout, requestTimeout, secured, timestamp, true);
 	}
 

reactor-netty-http/src/main/java/reactor/netty/http/server/Http3StreamBridgeServerHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024 VMware, Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2024-2025 VMware, Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -41,6 +41,7 @@
 import reactor.netty.ReactorNetty;
 import reactor.netty.http.logging.HttpMessageArgProviderFactory;
 import reactor.netty.http.logging.HttpMessageLogFactory;
+import reactor.netty.http.server.compression.HttpCompressionOptionsSpec;
 import reactor.util.annotation.Nullable;
 
 import java.net.SocketAddress;
@@ -54,6 +55,7 @@
 
 final class Http3StreamBridgeServerHandler extends ChannelDuplexHandler {
 	final BiPredicate<HttpServerRequest, HttpServerResponse>      compress;
+	final HttpCompressionOptionsSpec compressionOptions;
 	final ServerCookieDecoder                                     cookieDecoder;
 	final ServerCookieEncoder                                     cookieEncoder;
 	final HttpServerFormDecoderProvider                           formDecoderProvider;
@@ -74,6 +76,7 @@ final class Http3StreamBridgeServerHandler extends ChannelDuplexHandler {
 
 	Http3StreamBridgeServerHandler(
 			@Nullable BiPredicate<HttpServerRequest, HttpServerResponse> compress,
+			HttpCompressionOptionsSpec compressionOptions,
 			ServerCookieDecoder decoder,
 			ServerCookieEncoder encoder,
 			HttpServerFormDecoderProvider formDecoderProvider,
@@ -84,6 +87,7 @@ final class Http3StreamBridgeServerHandler extends ChannelDuplexHandler {
 			@Nullable Duration readTimeout,
 			@Nullable Duration requestTimeout) {
 		this.compress = compress;
+		this.compressionOptions = compressionOptions;
 		this.cookieDecoder = decoder;
 		this.cookieEncoder = encoder;
 		this.formDecoderProvider = formDecoderProvider;
@@ -131,6 +135,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) {
 						listener,
 						request,
 						compress,
+						compressionOptions,
 						connectionInfo,
 						cookieDecoder,
 						cookieEncoder,

reactor-netty-http/src/main/java/reactor/netty/http/server/HttpServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2024 VMware, Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2011-2025 VMware, Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,6 +45,8 @@
 import reactor.netty.http.HttpProtocol;
 import reactor.netty.http.logging.HttpMessageLogFactory;
 import reactor.netty.http.logging.ReactorNettyHttpMessageLogFactory;
+import reactor.netty.http.server.compression.HttpCompressionOption;
+import reactor.netty.http.server.compression.HttpCompressionOptionsSpec;
 import reactor.netty.http.server.logging.AccessLog;
 import reactor.netty.http.server.logging.AccessLogArgProvider;
 import reactor.netty.http.server.logging.AccessLogFactory;
@@ -301,6 +303,7 @@ public final HttpServer compress(BiPredicate<HttpServerRequest, HttpServerRespon
 	/**
 	 * Specifies whether GZip response compression is enabled if the client request
 	 * presents accept encoding.
+	 *  default compression level is 6.
 	 *
 	 * @param compressionEnabled if true GZip response compression
 	 * is enabled if the client request presents accept encoding, otherwise disabled.
@@ -336,6 +339,30 @@ public final HttpServer compress(int minResponseSize) {
 		return dup;
 	}
 
+	/**
+	 * Specifies GZIP, DEFLATE, ZSTD Compression Level.
+	 *
+	 * @param compressionOptions configures {@link HttpCompressionOption} after enable compress.
+	 *  <pre>
+	 *  {@code
+	 *      HttpServer.create()
+	 *                       .compress(true)
+	 *  					.compressOptions(
+	 *                         StandardHttpCompressionOptions.gzip(6, 15, 8)
+	 *  					 )
+	 *  					.bindNow();
+	 *  }
+	 *  </pre>
+	 * @return a new {@link HttpServer}
+	 */
+	public final HttpServer compressOptions(HttpCompressionOption... compressionOptions) {
+		Objects.requireNonNull(compressionOptions, "compressionOptions");
+
+		HttpServer dup = duplicate();
+		dup.configuration().compressionOptions = new HttpCompressionOptionsSpec(compressionOptions);
+		return dup;
+	}
+
 	/**
 	 * Configure the
 	 * {@link ServerCookieEncoder}; {@link ServerCookieDecoder} will be