added epoll native transport for server

gbcs-api/src/main/java/net/woggioni/gbcs/api/Configuration.java

@@ -27,6 +27,7 @@ public class Configuration {
     Cache cache;
     Authentication authentication;
     Tls tls;
+    boolean useNativeTransport;
 
     @Value
     public static class EventExecutor {
@@ -151,7 +152,8 @@ public class Configuration {
             Map<String, Group> groups,
             Cache cache,
             Authentication authentication,
-            Tls tls
+            Tls tls,
+            boolean useNativeTransport
     ) {
         return new Configuration(
                 host,
@@ -164,7 +166,8 @@ public class Configuration {
                 groups,
                 cache,
                 authentication,
-                tls
+                tls,
+                useNativeTransport
         );
     }
 }

gbcs-cli/build.gradle

@@ -32,6 +32,13 @@ configurations {
         canBeResolved = true
         visible = true
     }
+
+    nativeLibraries {
+        transitive = false
+        canBeConsumed = false
+        canBeResolved = true
+        visible = false
+    }
 }
 
 envelopeJar {
@@ -53,6 +60,8 @@ dependencies {
 //    runtimeOnly catalog.slf4j.jdk14
     runtimeOnly catalog.logback.classic
 //    runtimeOnly catalog.slf4j.simple
+
+    nativeLibraries group: 'io.netty', name: 'netty-transport-native-epoll', version: catalog.versions.netty.get(), classifier: 'linux-x86_64'
 }
 
 Provider<EnvelopeJarTask> envelopeJarTaskProvider = tasks.named('envelopeJar', EnvelopeJarTask.class) {
@@ -67,6 +76,9 @@ Provider<EnvelopeJarTask> envelopeJarTaskProvider = tasks.named('envelopeJar', E
 //    systemProperties['org.slf4j.simpleLogger.log.com.google.code.yanf4j'] = 'warn'
 //    systemProperties['org.slf4j.simpleLogger.log.net.rubyeye.xmemcached'] = 'warn'
 //    systemProperties['org.slf4j.simpleLogger.dateTimeFormat'] = 'yyyy-MM-dd\'T\'HH:mm:ss.SSSZ'
+    from {
+        configurations.nativeLibraries.collect { it.isDirectory() ? it : zipTree(it) }
+    }
 }
 
 tasks.named(NativeImagePlugin.CONFIGURE_NATIVE_IMAGE_TASK_NAME, NativeImageConfigurationTask) {

gbcs-cli/src/main/kotlin/net/woggioni/gbcs/cli/GradleBuildCacheServerCli.kt

@@ -5,6 +5,7 @@ import net.woggioni.gbcs.cli.impl.GbcsCommand
 import net.woggioni.gbcs.cli.impl.commands.BenchmarkCommand
 import net.woggioni.gbcs.cli.impl.commands.ClientCommand
 import net.woggioni.gbcs.cli.impl.commands.GetCommand
+import net.woggioni.gbcs.cli.impl.commands.HealthCheckCommand
 import net.woggioni.gbcs.cli.impl.commands.PasswordHashCommand
 import net.woggioni.gbcs.cli.impl.commands.PutCommand
 import net.woggioni.gbcs.cli.impl.commands.ServerCommand
@@ -24,8 +25,12 @@ class GradleBuildCacheServerCli : GbcsCommand() {
     companion object {
         @JvmStatic
         fun main(vararg args: String) {
-            Thread.currentThread().contextClassLoader = GradleBuildCacheServerCli::class.java.classLoader
+            val currentClassLoader = GradleBuildCacheServerCli::class.java.classLoader
+            Thread.currentThread().contextClassLoader = currentClassLoader
+            if(currentClassLoader.javaClass.name == "net.woggioni.envelope.loader.ModuleClassLoader") {
+                //We're running in an envelope jar and custom URL protocols won't work
                 GbcsUrlStreamHandlerFactory.install()
+            }
             val log = contextLogger()
             val app = Application.builder("gbcs")
                 .configurationDirectoryEnvVar("GBCS_CONFIGURATION_DIR")
@@ -44,6 +49,7 @@ class GradleBuildCacheServerCli : GbcsCommand() {
                     addSubcommand(BenchmarkCommand())
                     addSubcommand(PutCommand())
                     addSubcommand(GetCommand())
+                    addSubcommand(HealthCheckCommand())
                 })
             System.exit(commandLine.execute(*args))
         }

gbcs-cli/src/main/kotlin/net/woggioni/gbcs/cli/impl/commands/BenchmarkCommand.kt

@@ -46,7 +46,7 @@ class BenchmarkCommand : GbcsCommand() {
             clientCommand.configuration.profiles[profileName]
                 ?: throw IllegalArgumentException("Profile $profileName does not exist in configuration")
         }
-        val client = GradleBuildCacheClient(profile)
+        GradleBuildCacheClient(profile).use { client ->
 
             val entryGenerator = sequence {
                 val random = Random(SecureRandom.getInstance("NativePRNGNonBlocking").nextLong())
@@ -67,8 +67,8 @@ class BenchmarkCommand : GbcsCommand() {
                 val start = Instant.now()
                 val semaphore = Semaphore(profile.maxConnections * 3)
                 val iterator = entryGenerator.take(numberOfEntries).iterator()
-            while(completionCounter.get() < numberOfEntries) {
+                while (completionCounter.get() < numberOfEntries) {
-                if(iterator.hasNext()) {
+                    if (iterator.hasNext()) {
                         val entry = iterator.next()
                         semaphore.acquire()
                         val future = client.put(entry.first, entry.second).thenApply { entry }
@@ -81,6 +81,8 @@ class BenchmarkCommand : GbcsCommand() {
                             semaphore.release()
                             completionCounter.incrementAndGet()
                         }
+                    } else {
+                        Thread.sleep(0)
                     }
                 }
 
@@ -103,9 +105,10 @@ class BenchmarkCommand : GbcsCommand() {
                 val completionCounter = AtomicLong(0)
                 val semaphore = Semaphore(profile.maxConnections * 3)
                 val start = Instant.now()
-            entries.forEach { entry ->
+                val it = entries.iterator()
-                semaphore.acquire()
+                while (completionCounter.get() < entries.size) {
-
+                    if (it.hasNext()) {
+                        val entry = it.next()
                         val future = client.get(entry.first).thenApply {
                             if (it == null) {
                                 log.error {
@@ -121,6 +124,9 @@ class BenchmarkCommand : GbcsCommand() {
                             completionCounter.incrementAndGet()
                             semaphore.release()
                         }
+                    } else {
+                        Thread.sleep(0)
+                    }
                 }
                 val end = Instant.now()
                 log.info {
@@ -132,4 +138,5 @@ class BenchmarkCommand : GbcsCommand() {
                 log.error("Skipping retrieval benchmark as it was not possible to insert any entry in the cache")
             }
         }
+    }
 }

gbcs-cli/src/main/kotlin/net/woggioni/gbcs/cli/impl/commands/HealthCheckCommand.kt

@@ -0,0 +1,45 @@
+package net.woggioni.gbcs.cli.impl.commands
+
+import net.woggioni.gbcs.cli.impl.GbcsCommand
+import net.woggioni.gbcs.client.GradleBuildCacheClient
+import net.woggioni.gbcs.common.contextLogger
+import picocli.CommandLine
+import java.security.SecureRandom
+import kotlin.random.Random
+
+@CommandLine.Command(
+    name = "health",
+    description = ["Check server health"],
+    showDefaultValues = true
+)
+class HealthCheckCommand : GbcsCommand() {
+    private val log = contextLogger()
+
+    @CommandLine.Spec
+    private lateinit var spec: CommandLine.Model.CommandSpec
+
+    override fun run() {
+        val clientCommand = spec.parent().userObject() as ClientCommand
+        val profile = clientCommand.profileName.let { profileName ->
+            clientCommand.configuration.profiles[profileName]
+                ?: throw IllegalArgumentException("Profile $profileName does not exist in configuration")
+        }
+        GradleBuildCacheClient(profile).use { client ->
+            val random = Random(SecureRandom.getInstance("NativePRNGNonBlocking").nextLong())
+            val nonce = ByteArray(0xa0)
+            random.nextBytes(nonce)
+            client.healthCheck(nonce).thenApply { value ->
+                if(value == null) {
+                    throw IllegalStateException("Empty response from server")
+                }
+                for(i in 0 until nonce.size) {
+                    for(j in value.size - nonce.size until nonce.size) {
+                        if(nonce[i] != value[j]) {
+                            throw IllegalStateException("Server nonce does not match")
+                        }
+                    }
+                }
+            }.get()
+        }
+    }
+}

gbcs-cli/src/main/kotlin/net/woggioni/gbcs/cli/impl/commands/ServerCommand.kt

@@ -2,6 +2,7 @@ package net.woggioni.gbcs.cli.impl.commands
 
 import net.woggioni.gbcs.api.Configuration
 import net.woggioni.gbcs.cli.impl.GbcsCommand
+import net.woggioni.gbcs.cli.impl.converters.DurationConverter
 import net.woggioni.gbcs.common.contextLogger
 import net.woggioni.gbcs.common.debug
 import net.woggioni.gbcs.common.info
@@ -13,6 +14,7 @@ import picocli.CommandLine
 import java.io.ByteArrayOutputStream
 import java.nio.file.Files
 import java.nio.file.Path
+import java.time.Duration
 
 @CommandLine.Command(
     name = "server",
@@ -35,6 +37,14 @@ class ServerCommand(app : Application) : GbcsCommand() {
         }
     }
 
+    @CommandLine.Option(
+        names = ["-t", "--timeout"],
+        description = ["Exit after the specified time"],
+        paramLabel = "TIMEOUT",
+        converter = [DurationConverter::class]
+    )
+    private var timeout: Duration? = null
+
     @CommandLine.Option(
         names = ["-c", "--config-file"],
         description = ["Read the application configuration from this file"],
@@ -42,10 +52,6 @@ class ServerCommand(app : Application) : GbcsCommand() {
     )
     private var configurationFile: Path = findConfigurationFile(app, "gbcs-server.xml")
 
-    val configuration : Configuration by lazy {
-        GradleBuildCacheServer.loadConfiguration(configurationFile)
-    }
-
     override fun run() {
         if (!Files.exists(configurationFile)) {
             Files.createDirectories(configurationFile.parent)
@@ -61,7 +67,11 @@ class ServerCommand(app : Application) : GbcsCommand() {
             }
         }
         val server = GradleBuildCacheServer(configuration)
-        server.run().use {
+        server.run().use { server ->
+            timeout?.let {
+                Thread.sleep(it)
+                server.shutdown()
+            }
         }
     }
 }

gbcs-cli/src/main/kotlin/net/woggioni/gbcs/cli/impl/converters/DurationConverter.kt

@@ -0,0 +1,11 @@
+package net.woggioni.gbcs.cli.impl.converters
+
+import picocli.CommandLine
+import java.time.Duration
+
+
+class DurationConverter : CommandLine.ITypeConverter<Duration> {
+    override fun convert(value: String): Duration {
+        return Duration.parse(value)
+    }
+}

gbcs-cli/src/main/resources/net/woggioni/gbcs/cli/logback.xml

@@ -15,6 +15,4 @@
     <root level="info">
         <appender-ref ref="console"/>
     </root>
-    <logger name="com.google.code.yanf4j" level="warn"/>
-    <logger name="net.rubyeye.xmemcached" level="warn"/>
 </configuration>

gbcs-client/src/main/kotlin/net/woggioni/gbcs/client/Client.kt

@@ -213,6 +213,25 @@ class GradleBuildCacheClient(private val profile: Configuration.Profile) : AutoC
         }
     }
 
+    fun healthCheck(nonce: ByteArray): CompletableFuture<ByteArray?> {
+        return executeWithRetry {
+            sendRequest(profile.serverURI, HttpMethod.TRACE, nonce)
+        }.thenApply {
+            val status = it.status()
+            if (it.status() != HttpResponseStatus.OK) {
+                throw HttpException(status)
+            } else {
+                it.content()
+            }
+        }.thenApply { maybeByteBuf ->
+            maybeByteBuf?.let {
+                val result = ByteArray(it.readableBytes())
+                it.getBytes(0, result)
+                result
+            }
+        }
+    }
+
     fun get(key: String): CompletableFuture<ByteArray?> {
         return executeWithRetry {
             sendRequest(profile.serverURI.resolve(key), HttpMethod.GET, null)

gbcs-common/src/main/kotlin/net/woggioni/gbcs/common/ByteBufOutputStream.kt

@@ -0,0 +1,19 @@
+package net.woggioni.gbcs.common
+
+import io.netty.buffer.ByteBuf
+import java.io.InputStream
+import java.io.OutputStream
+
+class ByteBufOutputStream(private val buf : ByteBuf) : OutputStream() {
+    override fun write(b: Int) {
+        buf.writeByte(b)
+    }
+
+    override fun write(b: ByteArray, off: Int, len: Int) {
+        buf.writeBytes(b, off, len)
+    }
+
+    override fun close() {
+        buf.release()
+    }
+}

gbcs-common/src/main/kotlin/net/woggioni/gbcs/common/Exception.kt

@@ -0,0 +1,7 @@
+package net.woggioni.gbcs.common
+
+class ResourceNotFoundException(msg : String? = null, cause: Throwable? = null) : RuntimeException(msg, cause) {
+}
+
+class ModuleNotFoundException(msg : String? = null, cause: Throwable? = null) : RuntimeException(msg, cause) {
+}

gbcs-common/src/main/kotlin/net/woggioni/gbcs/common/GbcsUrlStreamHandlerFactory.kt

@@ -36,13 +36,17 @@ class GbcsUrlStreamHandlerFactory : URLStreamHandlerProvider() {
     private class JpmsHandler : URLStreamHandler() {
 
         override fun openConnection(u: URL): URLConnection {
-            val thisModule = javaClass.module
-            val sourceModule = Optional.ofNullable(thisModule)
-                .map { obj: Module -> obj.layer }
-                .flatMap { layer: ModuleLayer ->
             val moduleName = u.host
-                    layer.findModule(moduleName)
+            val thisModule = javaClass.module
-                }.orElse(thisModule)
+            val sourceModule =
+                thisModule
+                ?.let(Module::getLayer)
+                ?.let { layer: ModuleLayer ->
+                    layer.findModule(moduleName).orElse(null)
+                } ?: if(thisModule.layer == null) {
+                    thisModule
+                } else throw ModuleNotFoundException("Module '$moduleName' not found")
+
             return JpmsResourceURLConnection(u, sourceModule)
         }
     }
@@ -53,7 +57,9 @@ class GbcsUrlStreamHandlerFactory : URLStreamHandlerProvider() {
 
         @Throws(IOException::class)
         override fun getInputStream(): InputStream {
-            return module.getResourceAsStream(getURL().path)
+            val resource = getURL().path
+            return module.getResourceAsStream(resource)
+                ?: throw ResourceNotFoundException("Resource '$resource' not found in module '${module.name}'")
         }
     }
 

gbcs-server-memcache/src/main/kotlin/net/woggioni/gbcs/server/memcache/client/MemcacheClient.kt

@@ -24,6 +24,7 @@ import io.netty.handler.codec.memcache.binary.FullBinaryMemcacheRequest
 import io.netty.handler.codec.memcache.binary.FullBinaryMemcacheResponse
 import io.netty.util.concurrent.GenericFutureListener
 import net.woggioni.gbcs.common.ByteBufInputStream
+import net.woggioni.gbcs.common.ByteBufOutputStream
 import net.woggioni.gbcs.common.GBCS.digest
 import net.woggioni.gbcs.common.HostAndPort
 import net.woggioni.gbcs.common.contextLogger
@@ -114,13 +115,14 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
                     val channel = channelFuture.now
                     val pipeline = channel.pipeline()
                     channel.pipeline()
-                        .addLast("handler", object : SimpleChannelInboundHandler<FullBinaryMemcacheResponse>() {
+                        .addLast("client-handler", object : SimpleChannelInboundHandler<FullBinaryMemcacheResponse>() {
                             override fun channelRead0(
                                 ctx: ChannelHandlerContext,
                                 msg: FullBinaryMemcacheResponse
                             ) {
                                 pipeline.removeLast()
                                 pool.release(channel)
+                                msg.touch("The method's caller must remember to release this")
                                 response.complete(msg.retain())
                             }
 
@@ -135,6 +137,7 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
                                 response.completeExceptionally(ex)
                             }
                         })
+                    request.touch()
                     channel.writeAndFlush(request)
                 } else {
                     response.completeExceptionally(channelFuture.cause())
@@ -161,10 +164,12 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
             }
         }
         return sendRequest(request).thenApply { response ->
+            try {
                 when (val status = response.status()) {
                     BinaryMemcacheResponseStatus.SUCCESS -> {
                         val compressionMode = cfg.compressionMode
-                    val content = response.content()
+                        val content = response.content().retain()
+                        content.touch()
                         if (compressionMode != null) {
                             when (compressionMode) {
                                 MemcacheCacheConfiguration.CompressionMode.GZIP -> {
@@ -179,11 +184,16 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
                             ByteBufInputStream(content)
                         }.let(Channels::newChannel)
                     }
+
                     BinaryMemcacheResponseStatus.KEY_ENOENT -> {
                         null
                     }
+
                     else -> throw MemcacheException(status)
                 }
+            } finally {
+                response.release()
+            }
         }
     }
 
@@ -197,16 +207,18 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
             extras.writeInt(0)
             extras.writeInt(encodeExpiry(expiry))
             val compressionMode = cfg.compressionMode
+            content.retain()
             val payload = if (compressionMode != null) {
-                val inputStream = ByteBufInputStream(Unpooled.wrappedBuffer(content))
+                val inputStream = ByteBufInputStream(content)
-                val baos = ByteArrayOutputStream()
+                val buf = content.alloc().buffer()
+                buf.retain()
                 val outputStream = when (compressionMode) {
                     MemcacheCacheConfiguration.CompressionMode.GZIP -> {
-                        GZIPOutputStream(baos)
+                        GZIPOutputStream(ByteBufOutputStream(buf))
                     }
 
                     MemcacheCacheConfiguration.CompressionMode.DEFLATE -> {
-                        DeflaterOutputStream(baos, Deflater(Deflater.DEFAULT_COMPRESSION, false))
+                        DeflaterOutputStream(ByteBufOutputStream(buf), Deflater(Deflater.DEFAULT_COMPRESSION, false))
                     }
                 }
                 inputStream.use { i ->
@@ -214,7 +226,7 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
                         JWO.copy(i, o)
                     }
                 }
-                Unpooled.wrappedBuffer(baos.toByteArray())
+                buf
             } else {
                 content
             }
@@ -224,10 +236,14 @@ class MemcacheClient(private val cfg: MemcacheCacheConfiguration) : AutoCloseabl
             }
         }
         return sendRequest(request).thenApply { response ->
-            when(val status = response.status()) {
+            try {
+                when (val status = response.status()) {
                     BinaryMemcacheResponseStatus.SUCCESS -> null
                     else -> throw MemcacheException(status)
                 }
+            } finally {
+                response.release()
+            }
         }
     }
 

gbcs-server/src/main/java/module-info.java

@@ -18,6 +18,7 @@ module net.woggioni.gbcs.server {
     requires net.woggioni.jwo;
     requires net.woggioni.gbcs.common;
     requires net.woggioni.gbcs.api;
+    requires io.netty.transport.classes.epoll;
 
     exports net.woggioni.gbcs.server;
 

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/GradleBuildCacheServer.kt

@@ -10,6 +10,9 @@ import io.netty.channel.ChannelInboundHandlerAdapter
 import io.netty.channel.ChannelInitializer
 import io.netty.channel.ChannelOption
 import io.netty.channel.ChannelPromise
+import io.netty.channel.MultithreadEventLoopGroup
+import io.netty.channel.epoll.EpollEventLoopGroup
+import io.netty.channel.epoll.EpollServerSocketChannel
 import io.netty.channel.nio.NioEventLoopGroup
 import io.netty.channel.socket.nio.NioServerSocketChannel
 import io.netty.handler.codec.compression.CompressionOptions
@@ -49,6 +52,7 @@ import net.woggioni.gbcs.server.exception.ExceptionHandler
 import net.woggioni.gbcs.server.handler.ServerHandler
 import net.woggioni.gbcs.server.throttling.ThrottlingHandler
 import net.woggioni.jwo.JWO
+import net.woggioni.jwo.OS
 import net.woggioni.jwo.Tuple2
 import java.io.OutputStream
 import java.net.InetSocketAddress
@@ -399,10 +403,23 @@ class GradleBuildCacheServer(private val cfg: Configuration) {
     }
 
     fun run(): ServerHandle {
-        // Create the multithreaded event loops for the server
+        val bossGroup : MultithreadEventLoopGroup
-        val bossGroup = NioEventLoopGroup(1)
+        val workerGroup : MultithreadEventLoopGroup
-        val serverSocketChannel = NioServerSocketChannel::class.java
+        val serverSocketChannel : Class<*>
-        val workerGroup = NioEventLoopGroup(0)
+        if(cfg.isUseNativeTransport) {
+            if(OS.isLinux) {
+                bossGroup = EpollEventLoopGroup(1)
+                serverSocketChannel = EpollServerSocketChannel::class.java
+                workerGroup = EpollEventLoopGroup(0)
+            } else {
+                throw java.lang.IllegalArgumentException("Native transport is not supported on ${OS.current.name}")
+            }
+        } else {
+            bossGroup = NioEventLoopGroup(1)
+            serverSocketChannel = NioServerSocketChannel::class.java
+            workerGroup = NioEventLoopGroup(0)
+        }
+
         val eventExecutorGroup = run {
             val threadFactory = if (cfg.eventExecutor.isUseVirtualThreads) {
                 Thread.ofVirtual().factory()

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/cache/InMemoryCache.kt

@@ -1,12 +1,12 @@
 package net.woggioni.gbcs.server.cache
 
 import io.netty.buffer.ByteBuf
-import io.netty.buffer.Unpooled
 import net.woggioni.gbcs.api.Cache
 import net.woggioni.gbcs.common.ByteBufInputStream
+import net.woggioni.gbcs.common.ByteBufOutputStream
 import net.woggioni.gbcs.common.GBCS.digestString
+import net.woggioni.gbcs.common.contextLogger
 import net.woggioni.jwo.JWO
-import java.io.ByteArrayOutputStream
 import java.nio.channels.Channels
 import java.security.MessageDigest
 import java.time.Duration
@@ -14,6 +14,7 @@ import java.time.Instant
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.PriorityBlockingQueue
+import java.util.concurrent.atomic.AtomicLong
 import java.util.zip.Deflater
 import java.util.zip.DeflaterOutputStream
 import java.util.zip.Inflater
@@ -21,11 +22,18 @@ import java.util.zip.InflaterInputStream
 
 class InMemoryCache(
     val maxAge: Duration,
+    val maxSize: Long,
     val digestAlgorithm: String?,
     val compressionEnabled: Boolean,
     val compressionLevel: Int
 ) : Cache {
 
+    companion object {
+        @JvmStatic
+        private val log = contextLogger()
+    }
+
+    private val size = AtomicLong()
     private val map = ConcurrentHashMap<String, ByteBuf>()
     
     private class RemovalQueueElement(val key: String, val value : ByteBuf, val expiry : Instant) : Comparable<RemovalQueueElement> {
@@ -38,9 +46,17 @@ class InMemoryCache(
     private val garbageCollector = Thread {
         while(true) {
             val el = removalQueue.take()
+            val buf = el.value
             val now = Instant.now()
             if(now > el.expiry) {
-                map.remove(el.key, el.value)
+                val removed = map.remove(el.key, buf)
+                if(removed) {
+                    updateSizeAfterRemoval(buf)
+                    //Decrease the reference count for map
+                    buf.release()
+                }
+                //Decrease the reference count for removalQueue
+                buf.release()
             } else {
                 removalQueue.put(el)
                 Thread.sleep(minOf(Duration.between(now, el.expiry), Duration.ofSeconds(1)))
@@ -50,6 +66,28 @@ class InMemoryCache(
         start()
     }
 
+    private fun removeEldest() : Long {
+        while(true) {
+            val el = removalQueue.take()
+            val buf = el.value
+            val removed = map.remove(el.key, buf)
+            //Decrease the reference count for removalQueue
+            buf.release()
+            if(removed) {
+                val newSize = updateSizeAfterRemoval(buf)
+                //Decrease the reference count for map
+                buf.release()
+                return newSize
+            }
+        }
+    }
+
+    private fun updateSizeAfterRemoval(removed: ByteBuf) : Long {
+        return size.updateAndGet { currentSize : Long ->
+            currentSize - removed.readableBytes()
+        }
+    }
+
     override fun close() {
         running = false
         garbageCollector.join()
@@ -64,11 +102,13 @@ class InMemoryCache(
                 ).let { digest ->
                 map[digest]
                     ?.let { value ->
+                    val copy = value.retainedDuplicate()
+                    copy.touch("This has to be released by the caller of the cache")
                     if (compressionEnabled) {
                         val inflater = Inflater()
-                        Channels.newChannel(InflaterInputStream(ByteBufInputStream(value), inflater))
+                        Channels.newChannel(InflaterInputStream(ByteBufInputStream(copy), inflater))
                     } else {
-                        Channels.newChannel(ByteBufInputStream(value))
+                        Channels.newChannel(ByteBufInputStream(copy))
                     }
                 }
             }.let {
@@ -81,18 +121,29 @@ class InMemoryCache(
             ?.let { md ->
                 digestString(key.toByteArray(), md)
             } ?: key).let { digest ->
+            content.retain()
             val value = if (compressionEnabled) {
                 val deflater = Deflater(compressionLevel)
-                val baos = ByteArrayOutputStream()
+                val buf = content.alloc().buffer()
-                DeflaterOutputStream(baos, deflater).use { stream ->
+                buf.retain()
-                    JWO.copy(ByteBufInputStream(content), stream)
+                DeflaterOutputStream(ByteBufOutputStream(buf), deflater).use { outputStream ->
+                    ByteBufInputStream(content).use { inputStream ->
+                        JWO.copy(inputStream, outputStream)
                     }
-                Unpooled.wrappedBuffer(baos.toByteArray())
+                }
+                buf
             } else {
                 content
             }
-            map[digest] = value
+            val old = map.put(digest, value)
-            removalQueue.put(RemovalQueueElement(digest, value, Instant.now().plus(maxAge)))
+            val delta = value.readableBytes() - (old?.readableBytes() ?: 0)
+            var newSize = size.updateAndGet { currentSize : Long ->
+                currentSize + delta
+            }
+            removalQueue.put(RemovalQueueElement(digest, value.retain(), Instant.now().plus(maxAge)))
+            while(newSize > maxSize) {
+                newSize = removeEldest()
+            }
         }.let {
             CompletableFuture.completedFuture<Void>(null)
         }

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/cache/InMemoryCacheConfiguration.kt

@@ -6,12 +6,14 @@ import java.time.Duration
 
 data class InMemoryCacheConfiguration(
     val maxAge: Duration,
+    val maxSize: Long,
     val digestAlgorithm : String?,
     val compressionEnabled: Boolean,
     val compressionLevel: Int,
 ) : Configuration.Cache {
     override fun materialize() = InMemoryCache(
         maxAge,
+        maxSize,
         digestAlgorithm,
         compressionEnabled,
         compressionLevel

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/cache/InMemoryCacheProvider.kt

@@ -21,6 +21,9 @@ class InMemoryCacheProvider : CacheProvider<InMemoryCacheConfiguration> {
         val maxAge = el.renderAttribute("max-age")
             ?.let(Duration::parse)
             ?: Duration.ofDays(1)
+        val maxSize = el.renderAttribute("max-size")
+            ?.let(java.lang.Long::decode)
+            ?: 0x1000000
         val enableCompression = el.renderAttribute("enable-compression")
             ?.let(String::toBoolean)
             ?: true
@@ -31,6 +34,7 @@ class InMemoryCacheProvider : CacheProvider<InMemoryCacheConfiguration> {
 
         return InMemoryCacheConfiguration(
             maxAge,
+            maxSize,
             digestAlgorithm,
             enableCompression,
             compressionLevel
@@ -43,6 +47,7 @@ class InMemoryCacheProvider : CacheProvider<InMemoryCacheConfiguration> {
             val prefix = doc.lookupPrefix(GBCS.GBCS_NAMESPACE_URI)
             attr("xs:type", "${prefix}:inMemoryCacheType", GBCS.XML_SCHEMA_NAMESPACE_URI)
             attr("max-age", maxAge.toString())
+            attr("max-size", maxSize.toString())
             digestAlgorithm?.let { digestAlgorithm ->
                 attr("digest", digestAlgorithm)
             }

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/configuration/Parser.kt

@@ -44,6 +44,7 @@ object Parser {
         val serverPath = root.renderAttribute("path")
         var incomingConnectionsBacklogSize = 1024
         var authentication: Authentication? = null
+        var useNativeTransport = false
         for (child in root.asIterable()) {
             val tagName = child.localName
             when (tagName) {
@@ -136,7 +137,7 @@ object Parser {
                 }
 
                 "event-executor" -> {
-                    val useVirtualThread = root.renderAttribute("use-virtual-threads")
+                    val useVirtualThread = child.renderAttribute("use-virtual-threads")
                         ?.let(String::toBoolean) ?: true
                     eventExecutor = Configuration.EventExecutor(useVirtualThread)
                 }
@@ -180,6 +181,10 @@ object Parser {
                     }
                     tls = Tls(keyStore, trustStore)
                 }
+                "transport" -> {
+                    useNativeTransport = child.renderAttribute("use-native-transport")
+                        ?.let(String::toBoolean) ?: false
+                }
             }
         }
         return Configuration.of(
@@ -194,6 +199,7 @@ object Parser {
             cache!!,
             authentication,
             tls,
+            useNativeTransport
         )
     }
 

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/configuration/Serializer.kt

@@ -44,8 +44,12 @@ object Serializer {
                     attr("max-request-size", connection.maxRequestSize.toString())
                 }
             }
+            node("transport") {
+                attr("use-native-transport", conf.isUseNativeTransport.toString())
+            }
             node("event-executor") {
                 attr("use-virtual-threads", conf.eventExecutor.isUseVirtualThreads.toString())
+                attr("use-virtual-threads", conf.eventExecutor.isUseVirtualThreads.toString())
             }
             val cache = conf.cache
             val serializer : CacheProvider<Configuration.Cache> =

gbcs-server/src/main/kotlin/net/woggioni/gbcs/server/handler/ServerHandler.kt

@@ -57,10 +57,9 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                             response.headers().set(HttpHeaderNames.TRANSFER_ENCODING, HttpHeaderValues.CHUNKED)
                         }
                         ctx.write(response)
-                        val content : Any = when (channel) {
+                        when (channel) {
-                            is FileChannel -> DefaultFileRegion(channel, 0, channel.size())
+                            is FileChannel -> {
-                            else -> ChunkedNioStream(channel)
+                                val content = DefaultFileRegion(channel, 0, channel.size())
-                        }
                                 if (keepAlive) {
                                     ctx.write(content)
                                     ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT.retainedDuplicate())
@@ -68,6 +67,20 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                                     ctx.writeAndFlush(content)
                                         .addListener(ChannelFutureListener.CLOSE)
                                 }
+                            }
+                            else -> {
+                                val content = ChunkedNioStream(channel)
+                                if (keepAlive) {
+                                    ctx.write(content).addListener {
+                                        content.close()
+                                    }
+                                    ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT.retainedDuplicate())
+                                } else {
+                                    ctx.writeAndFlush(content)
+                                        .addListener(ChannelFutureListener.CLOSE)
+                                }
+                            }
+                        }
                     } else {
                         log.debug(ctx) {
                             "Cache miss for key '$key'"
@@ -94,7 +107,7 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                 log.debug(ctx) {
                     "Added value for key '$key' to build cache"
                 }
-                cache.put(key, msg.content().retain()).thenRun {
+                cache.put(key, msg.content()).thenRun {
                     val response = DefaultFullHttpResponse(
                         msg.protocolVersion(), HttpResponseStatus.CREATED,
                         Unpooled.copiedBuffer(key.toByteArray())

gbcs-server/src/main/resources/net/woggioni/gbcs/server/schema/gbcs.xsd

@@ -9,6 +9,7 @@
         <xs:sequence minOccurs="0">
             <xs:element name="bind" type="gbcs:bindType" maxOccurs="1"/>
             <xs:element name="connection" type="gbcs:connectionType" minOccurs="0" maxOccurs="1"/>
+            <xs:element name="transport" type="gbcs:transportType" minOccurs="0" maxOccurs="1"/>
             <xs:element name="event-executor" type="gbcs:eventExecutorType" minOccurs="0" maxOccurs="1"/>
             <xs:element name="cache" type="gbcs:cacheType" maxOccurs="1"/>
             <xs:element name="authorization" type="gbcs:authorizationType" minOccurs="0">
@@ -42,6 +43,10 @@
         <xs:attribute name="max-request-size" type="xs:unsignedInt" use="optional" default="67108864"/>
     </xs:complexType>
 
+    <xs:complexType name="transportType">
+        <xs:attribute name="use-native-transport" type="xs:boolean" use="optional" default="false"/>
+    </xs:complexType>
+
     <xs:complexType name="eventExecutorType">
         <xs:attribute name="use-virtual-threads" type="xs:boolean" use="optional" default="true"/>
     </xs:complexType>
@@ -52,6 +57,7 @@
         <xs:complexContent>
             <xs:extension base="gbcs:cacheType">
                 <xs:attribute name="max-age" type="xs:duration" default="P1D"/>
+                <xs:attribute name="max-size" type="xs:token" default="0x1000000"/>
                 <xs:attribute name="digest" type="xs:token" default="MD5"/>
                 <xs:attribute name="enable-compression" type="xs:boolean" default="true"/>
                 <xs:attribute name="compression-level" type="xs:byte" default="-1"/>

gbcs-server/src/test/kotlin/net/woggioni/gbcs/server/test/AbstractBasicAuthServerTest.kt

@@ -55,6 +55,7 @@ abstract class AbstractBasicAuthServerTest : AbstractServerTest() {
             ),
             Configuration.BasicAuthentication(),
             null,
+            false,
         )
         Xml.write(Serializer.serialize(cfg), System.out)
     }

gbcs-server/src/test/kotlin/net/woggioni/gbcs/server/test/AbstractTlsServerTest.kt

@@ -171,7 +171,8 @@ abstract class AbstractTlsServerTest : AbstractServerTest() {
             Configuration.Tls(
                 Configuration.KeyStore(this.serverKeyStoreFile, null, SERVER_CERTIFICATE_ENTRY, PASSWORD),
                 Configuration.TrustStore(this.trustStoreFile, null, false, false),
-            )
+            ),
+            false
         )
         Xml.write(Serializer.serialize(cfg), System.out)
     }

gbcs-server/src/test/kotlin/net/woggioni/gbcs/server/test/NoAuthServerTest.kt

@@ -51,10 +51,12 @@ class NoAuthServerTest : AbstractServerTest() {
                 maxAge = Duration.ofSeconds(3600 * 24),
                 compressionEnabled = true,
                 digestAlgorithm = "MD5",
-                compressionLevel = Deflater.DEFAULT_COMPRESSION
+                compressionLevel = Deflater.DEFAULT_COMPRESSION,
+                maxSize = 0x1000000
             ),
             null,
             null,
+            false,
         )
         Xml.write(Serializer.serialize(cfg), System.out)
     }

gbcs-server/src/test/resources/net/woggioni/gbcs/server/test/valid/gbcs-default.xml

@@ -10,6 +10,7 @@
             write-idle-timeout="PT11M"
             idle-timeout="PT30M"
             max-request-size="101325"/>
+    <transport use-native-transport="true"/>
     <event-executor use-virtual-threads="false"/>
     <cache xs:type="gbcs:fileSystemCacheType" path="/tmp/gbcs" max-age="P7D"/>
     <authentication>