temporary commit

gbcs-api/build.gradle

@@ -5,6 +5,7 @@ plugins {
 }
 
 dependencies {
+    api catalog.netty.buffer
 }
 
 publishing {

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

@@ -1,6 +1,8 @@
 module net.woggioni.gbcs.api {
     requires static lombok;
     requires java.xml;
+    requires io.netty.buffer;
     exports net.woggioni.gbcs.api;
     exports net.woggioni.gbcs.api.exception;
+    exports net.woggioni.gbcs.api.event;
 }

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

@@ -3,10 +3,10 @@ package net.woggioni.gbcs.api;
 import net.woggioni.gbcs.api.exception.ContentTooLargeException;
 
 import java.nio.channels.ReadableByteChannel;
+import java.util.concurrent.CompletableFuture;
 
 
 public interface Cache extends AutoCloseable {
-    ReadableByteChannel get(String key);
-
-    void put(String key, byte[] content) throws ContentTooLargeException;
+    CompletableFuture<CallHandle<Void>> get(String key, ResponseEventListener responseEventListener);
+    CompletableFuture<CallHandle<Void>> put(String key) throws ContentTooLargeException;
 }

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

@@ -0,0 +1,10 @@
+package net.woggioni.gbcs.api;
+
+import net.woggioni.gbcs.api.event.RequestEvent;
+
+import java.util.concurrent.CompletableFuture;
+
+public interface CallHandle<T> {
+    void postEvent(RequestEvent evt);
+    CompletableFuture<T> call();
+}

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

@@ -0,0 +1,7 @@
+package net.woggioni.gbcs.api;
+
+import net.woggioni.gbcs.api.event.ResponseEvent;
+
+public interface ResponseEventListener {
+    void listen(ResponseEvent evt);
+}

gbcs-api/src/main/java/net/woggioni/gbcs/api/event/RequestEvent.java

@@ -0,0 +1,20 @@
+package net.woggioni.gbcs.api.event;
+
+import io.netty.buffer.ByteBuf;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import net.woggioni.gbcs.api.CallHandle;
+
+sealed public abstract class RequestEvent {
+    @Getter
+    @RequiredArgsConstructor
+    public static final class ChunkSent extends RequestEvent {
+        private final ByteBuf chunk;
+    }
+
+    @Getter
+    @RequiredArgsConstructor
+    public static final class LastChunkSent extends RequestEvent {
+        private final ByteBuf chunk;
+    }
+}

gbcs-api/src/main/java/net/woggioni/gbcs/api/event/ResponseEvent.java

@@ -0,0 +1,28 @@
+package net.woggioni.gbcs.api.event;
+
+import io.netty.buffer.ByteBuf;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+sealed public abstract class ResponseEvent {
+    @Getter
+    @RequiredArgsConstructor
+    public final static class ChunkReceived extends ResponseEvent {
+        private final ByteBuf chunk;
+    }
+
+    public final static class NoContent extends ResponseEvent {
+    }
+
+    @Getter
+    @RequiredArgsConstructor
+    public final static class LastChunkReceived extends ResponseEvent {
+        private final ByteBuf chunk;
+    }
+
+    @Getter
+    @RequiredArgsConstructor
+    public final static class ExceptionCaught extends ResponseEvent {
+        private final Throwable cause;
+    }
+}

gbcs-server-memcached/build.gradle

@@ -26,13 +26,24 @@ configurations {
         canBeResolved = true
         visible = true
     }
+
+    testImplementation {
+        extendsFrom compileOnly
+    }
 }
 
 dependencies {
     compileOnly project(':gbcs-common')
     compileOnly project(':gbcs-api')
     compileOnly catalog.jwo
+    compileOnly catalog.slf4j.api
     implementation catalog.xmemcached
+    implementation catalog.netty.codec.memcache
+    implementation catalog.netty.common
+    implementation group: 'io.netty', name: 'netty-handler', version: catalog.versions.netty.get()
+
+    testRuntimeOnly catalog.logback.classic
+
 }
 
 Provider<Tar> bundleTask = tasks.register("bundle", Tar) {
@@ -41,6 +52,11 @@ Provider<Tar> bundleTask = tasks.register("bundle", Tar) {
     group = BasePlugin.BUILD_GROUP
 }
 
+tasks.named(JavaPlugin.TEST_TASK_NAME, Test) {
+    systemProperty("io.netty.leakDetectionLevel", "PARANOID")
+}
+
+
 tasks.named(BasePlugin.ASSEMBLE_TASK_NAME) {
     dependsOn(bundleTask)
 }

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

@@ -7,6 +7,13 @@ module net.woggioni.gbcs.server.memcached {
     requires net.woggioni.jwo;
     requires java.xml;
     requires kotlin.stdlib;
+    requires io.netty.common;
+    requires io.netty.handler;
+    requires io.netty.codec.memcache;
+    requires io.netty.transport;
+    requires org.slf4j;
+    requires io.netty.buffer;
+    requires io.netty.codec;
 
     provides CacheProvider with net.woggioni.gbcs.server.memcached.MemcachedCacheProvider;
 

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/CustomChunkedInput.kt

@@ -0,0 +1,33 @@
+package net.woggioni.gbcs.server.memcached
+
+import io.netty.buffer.ByteBuf
+import io.netty.buffer.ByteBufAllocator
+import io.netty.channel.ChannelHandlerContext
+import io.netty.handler.stream.ChunkedInput
+import java.nio.channels.ReadableByteChannel
+
+class CustomChunkedInput(private val readableByteChannel: ReadableByteChannel) : ChunkedInput<ByteBuf> {
+    override fun isEndOfInput(): Boolean {
+        TODO("Not yet implemented")
+    }
+
+    override fun close() {
+        TODO("Not yet implemented")
+    }
+
+    override fun readChunk(ctx: ChannelHandlerContext): ByteBuf {
+        TODO("Not yet implemented")
+    }
+
+    override fun readChunk(allocator: ByteBufAllocator): ByteBuf {
+        TODO("Not yet implemented")
+    }
+
+    override fun length(): Long {
+        TODO("Not yet implemented")
+    }
+
+    override fun progress(): Long {
+        TODO("Not yet implemented")
+    }
+}

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/Exception.kt

@@ -0,0 +1,4 @@
+package net.woggioni.gbcs.server.memcached
+
+class MemcachedException(status : Short, msg : String? = null, cause : Throwable? = null)
+    : RuntimeException(msg ?: "Memcached status $status", cause)

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/MemcachedCache.kt

@@ -1,59 +1,85 @@
 package net.woggioni.gbcs.server.memcached
 
-import net.rubyeye.xmemcached.XMemcachedClientBuilder
-import net.rubyeye.xmemcached.command.BinaryCommandFactory
-import net.rubyeye.xmemcached.transcoders.CompressionMode
-import net.rubyeye.xmemcached.transcoders.SerializingTranscoder
+import io.netty.buffer.Unpooled
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheResponseStatus
 import net.woggioni.gbcs.api.Cache
-import net.woggioni.gbcs.api.exception.ContentTooLargeException
-import net.woggioni.gbcs.common.HostAndPort
-import net.woggioni.jwo.JWO
-import java.io.ByteArrayInputStream
-import java.net.InetSocketAddress
-import java.nio.channels.Channels
-import java.nio.channels.ReadableByteChannel
-import java.nio.charset.StandardCharsets
-import java.security.MessageDigest
-import java.time.Duration
+import net.woggioni.gbcs.api.CallHandle
+import net.woggioni.gbcs.api.ResponseEventListener
+import net.woggioni.gbcs.api.event.RequestEvent
+import net.woggioni.gbcs.api.event.ResponseEvent
+import net.woggioni.gbcs.server.memcached.client.MemcachedClient
+import net.woggioni.gbcs.server.memcached.client.ResponseEvent.ExceptionCaught
+import net.woggioni.gbcs.server.memcached.client.ResponseEvent.LastResponseContentChunkReceived
+import net.woggioni.gbcs.server.memcached.client.ResponseEvent.ResponseContentChunkReceived
+import net.woggioni.gbcs.server.memcached.client.ResponseEvent.ResponseReceived
+import net.woggioni.gbcs.server.memcached.client.ResponseListener
+import java.util.concurrent.CompletableFuture
 
 class MemcachedCache(
-    servers: List<HostAndPort>,
-    private val maxAge: Duration,
-    maxSize : Int,
-    digestAlgorithm: String?,
-    compressionMode: CompressionMode,
+    private val cfg : MemcachedCacheConfiguration
 ) : Cache {
-    private val memcachedClient = XMemcachedClientBuilder(
-        servers.stream().map { addr: HostAndPort -> InetSocketAddress(addr.host, addr.port) }.toList()
-    ).apply {
-        commandFactory = BinaryCommandFactory()
-        digestAlgorithm?.let { dAlg ->
-            setKeyProvider { key ->
-                val md = MessageDigest.getInstance(dAlg)
-                md.update(key.toByteArray(StandardCharsets.UTF_8))
-                JWO.bytesToHex(md.digest())
-            }
-        }
-        transcoder = SerializingTranscoder(maxSize).apply {
-            setCompressionMode(compressionMode)
-        }
-    }.build()
-
-    override fun get(key: String): ReadableByteChannel? {
-        return memcachedClient.get<ByteArray>(key)
-            ?.let(::ByteArrayInputStream)
-            ?.let(Channels::newChannel)
-    }
-
-    override fun put(key: String, content: ByteArray) {
-        try {
-            memcachedClient[key, maxAge.toSeconds().toInt()] = content
-        } catch (e: IllegalArgumentException) {
-            throw ContentTooLargeException(e.message, e)
-        }
-    }
+    private val client = MemcachedClient(cfg)
 
     override fun close() {
-        memcachedClient.shutdown()
+        client.close()
+    }
+
+    override fun get(key: String, responseEventListener: ResponseEventListener): CompletableFuture<CallHandle<Void>> {
+        val listener = ResponseListener { evt ->
+            when(evt) {
+                is ResponseContentChunkReceived -> {
+                    responseEventListener.listen(ResponseEvent.ChunkReceived(Unpooled.wrappedBuffer(evt.chunk)))
+                }
+                is LastResponseContentChunkReceived -> {
+                    responseEventListener.listen(ResponseEvent.LastChunkReceived(Unpooled.wrappedBuffer(evt.chunk)))
+                }
+                is ExceptionCaught -> {
+                    responseEventListener.listen(ResponseEvent.ExceptionCaught(evt.cause))
+                }
+                is ResponseReceived -> {
+                    when(val status = evt.response.status) {
+                        BinaryMemcacheResponseStatus.SUCCESS -> {
+                        }
+                        BinaryMemcacheResponseStatus.KEY_ENOENT -> {
+                            responseEventListener.listen(ResponseEvent.NoContent())
+                        }
+                        else -> {
+                            responseEventListener.listen(ResponseEvent.ExceptionCaught(MemcachedException(status)))
+                        }
+                    }
+                }
+            }
+        }
+        return client.get(key, listener).thenApply { clientCallHandle ->
+            object : CallHandle<Void> {
+                override fun postEvent(evt: RequestEvent) {
+                    when(evt) {
+                        is RequestEvent.ChunkSent -> clientCallHandle.sendChunk(evt.chunk.nioBuffer())
+                        is RequestEvent.LastChunkSent -> clientCallHandle.sendChunk(evt.chunk.nioBuffer())
+                    }
+                }
+
+                override fun call(): CompletableFuture<Void> {
+                    return clientCallHandle.waitForResponse().thenApply { null }
+                }
+            }
+        }
+    }
+
+    override fun put(key: String): CompletableFuture<CallHandle<Void>> {
+        return client.put(key, cfg.maxAge).thenApply { clientCallHandle ->
+            object : CallHandle<Void> {
+                override fun postEvent(evt: RequestEvent) {
+                    when(evt) {
+                        is RequestEvent.ChunkSent -> clientCallHandle.sendChunk(evt.chunk.nioBuffer())
+                        is RequestEvent.LastChunkSent -> clientCallHandle.sendChunk(evt.chunk.nioBuffer())
+                    }
+                }
+
+                override fun call(): CompletableFuture<Void> {
+                    return clientCallHandle.waitForResponse().thenApply { null }
+                }
+            }
+        }
     }
 }

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/MemcachedCacheConfiguration.kt

@@ -1,25 +1,45 @@
 package net.woggioni.gbcs.server.memcached
 
-import net.rubyeye.xmemcached.transcoders.CompressionMode
 import net.woggioni.gbcs.api.Configuration
 import net.woggioni.gbcs.common.HostAndPort
 import java.time.Duration
 
 data class MemcachedCacheConfiguration(
-    var servers: List<HostAndPort>,
-    var maxAge: Duration = Duration.ofDays(1),
-    var maxSize: Int = 0x100000,
-    var digestAlgorithm: String? = null,
-    var compressionMode: CompressionMode = CompressionMode.ZIP,
+    val servers: List<Server>,
+    val maxAge: Duration = Duration.ofDays(1),
+    val maxSize: Int = 0x100000,
+    val digestAlgorithm: String? = null,
+    val compressionMode: CompressionMode? = CompressionMode.DEFLATE,
 ) : Configuration.Cache {
-    override fun materialize() = MemcachedCache(
-        servers,
-        maxAge,
-        maxSize,
-        digestAlgorithm,
-        compressionMode
+
+    enum class CompressionMode {
+        /**
+         * Gzip mode
+         */
+        GZIP,
+
+        /**
+         * Deflate mode
+         */
+        DEFLATE
+    }
+
+    class RetryPolicy(
+        val maxAttempts: Int,
+        val initialDelayMillis: Long,
+        val exp: Double
     )
 
+    data class Server(
+        val endpoint : HostAndPort,
+        val connectionTimeoutMillis : Int?,
+        val retryPolicy : RetryPolicy?,
+        val maxConnections : Int
+    )
+
+
+    override fun materialize() = MemcachedCache(this)
+
     override fun getNamespaceURI() = "urn:net.woggioni.gbcs.server.memcached"
 
     override fun getTypeName() = "memcachedCacheType"

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/MemcachedCacheProvider.kt

@@ -51,7 +51,7 @@ class MemcachedCacheProvider : CacheProvider<MemcachedCacheConfiguration> {
         }
 
         return MemcachedCacheConfiguration(
-            servers,
+            servers.map { MemcachedCacheConfiguration.Server(it, null, null, 1) },
             maxAge,
             maxSize,
             digestAlgorithm,
@@ -67,8 +67,8 @@ class MemcachedCacheProvider : CacheProvider<MemcachedCacheConfiguration> {
             attr("xs:type", "${xmlNamespacePrefix}:$xmlType", GBCS.XML_SCHEMA_NAMESPACE_URI)
             for (server in servers) {
                 node("server") {
-                    attr("host", server.host)
-                    attr("port", server.port.toString())
+                    attr("host", server.endpoint.host)
+                    attr("port", server.endpoint.port.toString())
                 }
             }
             attr("max-age", maxAge.toString())

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/client/CallHandle.kt

@@ -0,0 +1,9 @@
+package net.woggioni.gbcs.server.memcached.client
+
+import java.nio.ByteBuffer
+import java.util.concurrent.CompletableFuture
+
+interface CallHandle {
+    fun sendChunk(requestBodyChunk : ByteBuffer)
+    fun waitForResponse() : CompletableFuture<Short>
+}

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/client/MemcacheResponse.kt

@@ -0,0 +1,24 @@
+package net.woggioni.gbcs.server.memcached.client
+
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheResponse
+import java.nio.ByteBuffer
+
+data class MemcacheResponse(
+    val status: Short,
+    val opcode: Byte,
+    val cas: Long?,
+    val opaque: Int?,
+    val key: ByteBuffer?,
+    val extra: ByteBuffer?
+) {
+    companion object {
+        fun of(response : BinaryMemcacheResponse) = MemcacheResponse(
+            response.status(),
+            response.opcode(),
+            response.cas(),
+            response.opaque(),
+            response.key()?.nioBuffer(),
+            response.extras()?.nioBuffer()
+        )
+    }
+}

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/client/MemcachedClient.kt

@@ -0,0 +1,241 @@
+package net.woggioni.gbcs.server.memcached.client
+
+import io.netty.bootstrap.Bootstrap
+import io.netty.buffer.ByteBuf
+import io.netty.buffer.Unpooled
+import io.netty.channel.Channel
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelOption
+import io.netty.channel.ChannelPipeline
+import io.netty.channel.SimpleChannelInboundHandler
+import io.netty.channel.nio.NioEventLoopGroup
+import io.netty.channel.pool.AbstractChannelPoolHandler
+import io.netty.channel.pool.ChannelPool
+import io.netty.channel.pool.FixedChannelPool
+import io.netty.channel.socket.nio.NioSocketChannel
+import io.netty.handler.codec.DecoderException
+import io.netty.handler.codec.memcache.DefaultLastMemcacheContent
+import io.netty.handler.codec.memcache.DefaultMemcacheContent
+import io.netty.handler.codec.memcache.LastMemcacheContent
+import io.netty.handler.codec.memcache.MemcacheContent
+import io.netty.handler.codec.memcache.MemcacheObject
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheClientCodec
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheOpcodes
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheRequest
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheResponse
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheResponseStatus
+import io.netty.handler.codec.memcache.binary.DefaultBinaryMemcacheRequest
+import io.netty.util.concurrent.GenericFutureListener
+import net.woggioni.gbcs.common.GBCS.digest
+import net.woggioni.gbcs.common.HostAndPort
+import net.woggioni.gbcs.common.contextLogger
+import net.woggioni.gbcs.server.memcached.MemcachedCacheConfiguration
+import net.woggioni.gbcs.server.memcached.MemcachedException
+import java.net.InetSocketAddress
+import java.nio.ByteBuffer
+import java.security.MessageDigest
+import java.time.Duration
+import java.time.Instant
+import java.util.concurrent.CompletableFuture
+import java.util.concurrent.ConcurrentHashMap
+import io.netty.util.concurrent.Future as NettyFuture
+
+
+class MemcachedClient(private val cfg: MemcachedCacheConfiguration) : AutoCloseable {
+
+    private val log = contextLogger()
+    private val group: NioEventLoopGroup
+    private val connectionPool: MutableMap<HostAndPort, ChannelPool> = ConcurrentHashMap()
+
+    init {
+        group = NioEventLoopGroup()
+    }
+
+    private fun newConnectionPool(server : MemcachedCacheConfiguration.Server) : FixedChannelPool {
+        val bootstrap = Bootstrap().apply {
+            group(group)
+            channel(NioSocketChannel::class.java)
+            option(ChannelOption.SO_KEEPALIVE, true)
+            remoteAddress(InetSocketAddress(server.endpoint.host, server.endpoint.port))
+            server.connectionTimeoutMillis?.let {
+                option(ChannelOption.CONNECT_TIMEOUT_MILLIS, it)
+            }
+        }
+        val channelPoolHandler = object : AbstractChannelPoolHandler() {
+
+            override fun channelCreated(ch: Channel) {
+                val pipeline: ChannelPipeline = ch.pipeline()
+                pipeline.addLast(BinaryMemcacheClientCodec())
+            }
+        }
+        return FixedChannelPool(bootstrap, channelPoolHandler, server.maxConnections)
+    }
+
+
+    private fun sendRequest(request: BinaryMemcacheRequest,
+                            responseListener: ResponseListener?
+    ): CompletableFuture<CallHandle> {
+
+        val server = cfg.servers.let { servers ->
+            if(servers.size > 1) {
+                val key = request.key().duplicate()
+                var checksum = 0
+                while(key.readableBytes() > 4) {
+                    val byte = key.readInt()
+                    checksum = checksum xor byte
+                }
+                while(key.readableBytes() > 0) {
+                    val byte = key.readByte()
+                    checksum = checksum xor byte.toInt()
+                }
+                servers[checksum % servers.size]
+            } else {
+                servers.first()
+            }
+        }
+
+        val callHandleFuture = CompletableFuture<CallHandle>()
+        val result = CompletableFuture<Short>()
+        // Custom handler for processing responses
+        val pool = connectionPool.computeIfAbsent(server.endpoint) {
+            newConnectionPool(server)
+        }
+        pool.acquire().addListener(object : GenericFutureListener<NettyFuture<Channel>> {
+            override fun operationComplete(channelFuture: NettyFuture<Channel>) {
+                if (channelFuture.isSuccess) {
+                    val channel = channelFuture.now
+                    val pipeline = channel.pipeline()
+                    channel.pipeline().addLast("handler", object : SimpleChannelInboundHandler<MemcacheObject>() {
+                        val response : MemcacheResponse? = null
+                        override fun channelRead0(
+                            ctx: ChannelHandlerContext,
+                            msg: MemcacheObject
+                        ) {
+                            if(msg is BinaryMemcacheResponse) {
+                                val resp = MemcacheResponse.of(msg)
+                                responseListener?.listen(ResponseEvent.ResponseReceived(resp))
+                                if(msg.totalBodyLength() == msg.keyLength() + msg.extrasLength()) {
+                                    result.complete(resp.status)
+                                }
+                            }
+                            if(responseListener != null) {
+                                when (msg) {
+                                    is LastMemcacheContent -> {
+                                        responseListener.listen(ResponseEvent.LastResponseContentChunkReceived(msg.content().nioBuffer()))
+                                        result.complete(response?.status)
+                                        pipeline.removeLast()
+                                        pool.release(channel)
+                                    }
+                                    is MemcacheContent ->  {
+                                        responseListener.listen(ResponseEvent.ResponseContentChunkReceived(msg.content().nioBuffer()))
+                                    }
+                                }
+                            }
+                        }
+
+                        override fun exceptionCaught(ctx: ChannelHandlerContext, cause: Throwable) {
+                            val ex = when (cause) {
+                                is DecoderException -> cause.cause!!
+                                else -> cause
+                            }
+                            responseListener?.listen(ResponseEvent.ExceptionCaught(ex))
+                            result.completeExceptionally(ex)
+                            ctx.close()
+                            pipeline.removeLast()
+                            pool.release(channel)
+                        }
+                    })
+
+                    val chunks = mutableListOf <ByteBuffer>()
+                    fun sendRequest() {
+                        val valueLen = chunks.fold(0) { acc : Int, c2 : ByteBuffer ->
+                            acc + c2.remaining()
+                        }
+                        request.setTotalBodyLength(request.keyLength() + request.extrasLength() + valueLen)
+                        channel.write(request)
+                        for((i, chunk) in chunks.withIndex()) {
+                            if(i + 1 < chunks.size) {
+                                channel.write(DefaultMemcacheContent(Unpooled.wrappedBuffer(chunk)))
+                            } else {
+                                channel.write(DefaultLastMemcacheContent(Unpooled.wrappedBuffer(chunk)))
+                            }
+                        }
+                        channel.flush()
+                    }
+
+                    callHandleFuture.complete(object : CallHandle {
+                        override fun sendChunk(requestBodyChunk: ByteBuffer) {
+                                chunks.addLast(requestBodyChunk)
+                        }
+
+                        override fun waitForResponse(): CompletableFuture<Short> {
+                            sendRequest()
+                            return result
+                        }
+                    })
+                } else {
+                    callHandleFuture.completeExceptionally(channelFuture.cause())
+                }
+            }
+        })
+        return callHandleFuture
+    }
+
+    private fun encodeExpiry(expiry: Duration) : Int {
+        val expirySeconds = expiry.toSeconds()
+        return expirySeconds.toInt().takeIf { it.toLong() == expirySeconds }
+            ?: Instant.ofEpochSecond(expirySeconds).epochSecond.toInt()
+    }
+
+    fun get(key: String, responseListener: ResponseListener) : CompletableFuture<CallHandle> {
+        val request = (cfg.digestAlgorithm
+            ?.let(MessageDigest::getInstance)
+            ?.let { md ->
+                digest(key.toByteArray(), md)
+            } ?: key.toByteArray(Charsets.UTF_8)).let { digest ->
+            DefaultBinaryMemcacheRequest().apply {
+                setKey(Unpooled.wrappedBuffer(digest))
+                setOpcode(BinaryMemcacheOpcodes.GET)
+            }
+        }
+        return sendRequest(request, responseListener)
+    }
+
+    fun put(key: String, expiry : Duration, cas : Long? = null): CompletableFuture<CallHandle> {
+        val request = (cfg.digestAlgorithm
+            ?.let(MessageDigest::getInstance)
+            ?.let { md ->
+                digest(key.toByteArray(), md)
+            } ?: key.toByteArray(Charsets.UTF_8)).let { digest ->
+            val extras = Unpooled.buffer(8, 8)
+            extras.writeInt(0)
+            extras.writeInt(encodeExpiry(expiry))
+            DefaultBinaryMemcacheRequest().apply {
+                setExtras(extras)
+                setKey(Unpooled.wrappedBuffer(digest))
+                setOpcode(BinaryMemcacheOpcodes.SET)
+                cas?.let(this::setCas)
+            }
+        }
+        return sendRequest(request) { evt ->
+            when (evt) {
+                is ResponseEvent.ResponseReceived -> {
+                    if (evt.response.status != BinaryMemcacheResponseStatus.SUCCESS) {
+                        throw MemcachedException(evt.response.status)
+                    }
+                }
+                else -> {}
+            }
+        }
+    }
+
+
+
+    fun shutDown(): NettyFuture<*> {
+        return group.shutdownGracefully()
+    }
+
+    override fun close() {
+        shutDown().sync()
+    }
+}

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/client/ResponseEvent.kt

@@ -0,0 +1,10 @@
+package net.woggioni.gbcs.server.memcached.client
+
+import java.nio.ByteBuffer
+
+sealed interface ResponseEvent {
+    class ResponseReceived(val response : MemcacheResponse) : ResponseEvent
+    class ResponseContentChunkReceived(val chunk: ByteBuffer) : ResponseEvent
+    class LastResponseContentChunkReceived(val chunk: ByteBuffer) : ResponseEvent
+    class ExceptionCaught(val cause : Throwable) : ResponseEvent
+}

gbcs-server-memcached/src/main/kotlin/net/woggioni/gbcs/server/memcached/client/ResponseListener.kt

@@ -0,0 +1,5 @@
+package net.woggioni.gbcs.server.memcached.client
+
+fun interface ResponseListener {
+    fun listen(evt : ResponseEvent)
+}

gbcs-server-memcached/src/test/kotlin/net/woggioni/gbcs/server/memcached/test/MemcachedClientTest.kt

@@ -0,0 +1,80 @@
+package net.woggioni.gbcs.server.memcached.test
+
+import io.netty.buffer.ByteBuf
+import io.netty.buffer.Unpooled
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheResponse
+import io.netty.handler.codec.memcache.binary.BinaryMemcacheResponseStatus
+import net.woggioni.gbcs.api.event.ChunkReceived
+import net.woggioni.gbcs.common.HostAndPort
+
+import net.woggioni.gbcs.server.memcached.MemcachedCacheConfiguration
+import net.woggioni.gbcs.server.memcached.client.MemcacheResponse
+import net.woggioni.gbcs.server.memcached.client.MemcachedClient
+import net.woggioni.gbcs.server.memcached.client.ResponseEvent
+import net.woggioni.gbcs.server.memcached.client.ResponseListener
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+import java.nio.ByteBuffer
+import java.security.SecureRandom
+import java.time.Duration
+import java.util.Objects
+import java.util.concurrent.TimeUnit
+import kotlin.random.Random
+
+class MemcachedClientTest {
+
+    @Test
+    fun test() {
+        val client = MemcachedClient(MemcachedCacheConfiguration(
+            servers = listOf(
+                MemcachedCacheConfiguration.Server(
+                    endpoint = HostAndPort("127.0.0.1", 11211),
+                    connectionTimeoutMillis = null,
+                    retryPolicy = null,
+                    maxConnections = 1
+                )
+            )
+        ))
+
+        val random = Random(SecureRandom.getInstance("NativePRNGNonBlocking").nextLong())
+        val key = "101325"
+        val value = random.nextBytes(0x1000)
+        val requestListener = client.put(key, Duration.ofDays(2), null)
+
+        val response = Unpooled.buffer(value.size)
+        requestListener.thenCompose { listener ->
+            listener.sendChunk(ByteBuffer.wrap(value))
+            listener.waitForResponse()
+        }.get(10, TimeUnit.SECONDS)
+
+        client.get(key, object: ResponseListener {
+            override fun listen(evt: ResponseEvent) {
+                when(evt) {
+                    is ResponseEvent.ResponseReceived -> {
+                        if(evt.response.status != BinaryMemcacheResponseStatus.SUCCESS) {
+                            Assertions.fail<String> {
+                                "Memcache status ${evt.response.status}"
+                            }
+                        }
+                    }
+                    is ResponseEvent.ResponseContentChunkReceived -> response.writeBytes(evt.chunk)
+                    else -> {}
+                }
+            }
+        }).thenCompose { it.waitForResponse() }.get(1, TimeUnit.SECONDS)
+        val retrievedResponse = response.array()
+        Assertions.assertArrayEquals(value, retrievedResponse)
+
+    }
+
+    @Test
+    fun test2() {
+        val a1 = ByteArray(10) {
+            it.toByte()
+        }
+        val a2 = ByteArray(10) {
+            it.toByte()
+        }
+        Assertions.assertTrue(Objects.equals(a1, a1))
+    }
+}

gbcs-server-memcached/src/test/resources/logback.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE configuration>
+
+<configuration>
+    <import class="ch.qos.logback.classic.encoder.PatternLayoutEncoder"/>
+    <import class="ch.qos.logback.core.ConsoleAppender"/>
+
+    <appender name="console" class="ConsoleAppender">
+        <target>System.err</target>
+        <encoder class="PatternLayoutEncoder">
+            <pattern>%d [%highlight(%-5level)] \(%thread\) %logger{36} -%kvp- %msg %n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="info">
+        <appender-ref ref="console"/>
+    </root>
+    <logger name="io.netty" level="debug"/>
+    <logger name="com.google.code.yanf4j" level="warn"/>
+    <logger name="net.rubyeye.xmemcached" level="warn"/>
+</configuration>

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

@@ -1,36 +1,83 @@
 package net.woggioni.gbcs.server.handler
 
 import io.netty.buffer.Unpooled
-import io.netty.channel.ChannelFutureListener
-import io.netty.channel.ChannelHandler
 import io.netty.channel.ChannelHandlerContext
-import io.netty.channel.DefaultFileRegion
 import io.netty.channel.SimpleChannelInboundHandler
 import io.netty.handler.codec.http.DefaultFullHttpResponse
+import io.netty.handler.codec.http.DefaultHttpContent
 import io.netty.handler.codec.http.DefaultHttpResponse
-import io.netty.handler.codec.http.FullHttpRequest
+import io.netty.handler.codec.http.DefaultLastHttpContent
+import io.netty.handler.codec.http.HttpContent
 import io.netty.handler.codec.http.HttpHeaderNames
 import io.netty.handler.codec.http.HttpHeaderValues
+import io.netty.handler.codec.http.HttpMessage
 import io.netty.handler.codec.http.HttpMethod
+import io.netty.handler.codec.http.HttpRequest
 import io.netty.handler.codec.http.HttpResponseStatus
 import io.netty.handler.codec.http.HttpUtil
 import io.netty.handler.codec.http.LastHttpContent
-import io.netty.handler.stream.ChunkedNioStream
 import net.woggioni.gbcs.api.Cache
-import net.woggioni.gbcs.api.exception.CacheException
+import net.woggioni.gbcs.api.CallHandle
+import net.woggioni.gbcs.api.ResponseEventListener
+import net.woggioni.gbcs.api.event.RequestEvent
+import net.woggioni.gbcs.api.event.ResponseEvent
 import net.woggioni.gbcs.common.contextLogger
 import net.woggioni.gbcs.server.debug
 import net.woggioni.gbcs.server.warn
-import java.nio.channels.FileChannel
 import java.nio.file.Path
+import java.util.concurrent.CompletableFuture
 
-@ChannelHandler.Sharable
 class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
-    SimpleChannelInboundHandler<FullHttpRequest>() {
+    SimpleChannelInboundHandler<HttpMessage>() {
 
-    private val log = contextLogger()
+    companion object {
+        @JvmStatic
+        private val log = contextLogger()
+    }
 
-    override fun channelRead0(ctx: ChannelHandlerContext, msg: FullHttpRequest) {
+    private data class TransientContext(
+        var key: String?,
+        var callHandle: CompletableFuture<CallHandle<Void>>
+    )
+
+    private var transientContext: TransientContext? = null
+
+    override fun channelRead0(ctx: ChannelHandlerContext, msg: HttpMessage) {
+        when (msg) {
+            is HttpRequest -> {
+                handleRequest(ctx, msg)
+            }
+
+            is LastHttpContent -> {
+                transientContext?.run {
+                    callHandle.thenCompose { callHandle ->
+                        callHandle.postEvent(RequestEvent.LastChunkSent(msg.content()))
+                        callHandle.call()
+                    }.thenApply {
+                        val response = DefaultFullHttpResponse(
+                            msg.protocolVersion(), HttpResponseStatus.CREATED,
+                            key?.let(String::toByteArray)
+                                ?.let(Unpooled::copiedBuffer)
+                        )
+//                response.headers()[HttpHeaderNames.CONTENT_LENGTH] = response.content().readableBytes()
+                        ctx.writeAndFlush(response)
+                    }
+                }
+            }
+
+            is HttpContent -> {
+                transientContext?.run {
+                    callHandle = callHandle.thenApply { it ->
+                        it.postEvent(RequestEvent.ChunkSent(msg.content()))
+                        it
+                    }
+                }
+            }
+        }
+
+    }
+
+    private fun handleRequest(ctx: ChannelHandlerContext, msg: HttpRequest) {
         val keepAlive: Boolean = HttpUtil.isKeepAlive(msg)
         val method = msg.method()
         if (method === HttpMethod.GET) {
@@ -43,49 +90,61 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                 return
             }
             if (serverPrefix == prefix) {
-                try {
-                    cache.get(key)
-                } catch(ex : Throwable) {
-                    throw CacheException("Error accessing the cache backend", ex)
-                }?.let { channel ->
-                    log.debug(ctx) {
-                        "Cache hit for key '$key'"
-                    }
-                    val response = DefaultHttpResponse(msg.protocolVersion(), HttpResponseStatus.OK)
-                    response.headers()[HttpHeaderNames.CONTENT_TYPE] = HttpHeaderValues.APPLICATION_OCTET_STREAM
-                    if (!keepAlive) {
-                        response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE)
-                        response.headers().set(HttpHeaderNames.TRANSFER_ENCODING, HttpHeaderValues.IDENTITY)
-                    } else {
-                        response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE)
-                        response.headers().set(HttpHeaderNames.TRANSFER_ENCODING, HttpHeaderValues.CHUNKED)
-                    }
-                    ctx.write(response)
-                    when (channel) {
-                        is FileChannel -> {
-                            if (keepAlive) {
-                                ctx.write(DefaultFileRegion(channel, 0, channel.size()))
-                                ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT.retainedDuplicate())
-                            } else {
-                                ctx.writeAndFlush(DefaultFileRegion(channel, 0, channel.size()))
-                                    .addListener(ChannelFutureListener.CLOSE)
+                cache.get(key, object : ResponseEventListener {
+                    var first = false
+                    override fun listen(evt: ResponseEvent) {
+                        when (evt) {
+                            is ResponseEvent.NoContent -> {
+                                log.debug(ctx) {
+                                    "Cache miss for key '$key'"
+                                }
+                                val response =
+                                    DefaultFullHttpResponse(msg.protocolVersion(), HttpResponseStatus.NOT_FOUND)
+                                response.headers()[HttpHeaderNames.CONTENT_LENGTH] = 0
+                                ctx.writeAndFlush(response)
+                            }
+
+                            is ResponseEvent.ChunkReceived, is ResponseEvent.LastChunkReceived -> {
+                                if (first) {
+                                    first = false
+                                    log.debug(ctx) {
+                                        "Cache hit for key '$key'"
+                                    }
+                                    val response = DefaultHttpResponse(msg.protocolVersion(), HttpResponseStatus.OK)
+                                    response.headers()[HttpHeaderNames.CONTENT_TYPE] =
+                                        HttpHeaderValues.APPLICATION_OCTET_STREAM
+                                    if (!keepAlive) {
+                                        response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE)
+                                        response.headers()
+                                            .set(HttpHeaderNames.TRANSFER_ENCODING, HttpHeaderValues.IDENTITY)
+                                    } else {
+                                        response.headers()
+                                            .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE)
+                                        response.headers()
+                                            .set(HttpHeaderNames.TRANSFER_ENCODING, HttpHeaderValues.CHUNKED)
+                                    }
+                                    ctx.write(response)
+                                }
+                                if (evt is ResponseEvent.LastChunkReceived)
+                                    ctx.write(DefaultLastHttpContent(evt.chunk))
+                                else if (evt is ResponseEvent.ChunkReceived)
+                                    ctx.write(DefaultHttpContent(evt.chunk))
+                                ctx.flush()
+                            }
+
+                            is ResponseEvent.ExceptionCaught -> {
+                                log.error(evt.cause.message, evt.cause)
+                                val errorResponse = DefaultFullHttpResponse(
+                                    msg.protocolVersion(), HttpResponseStatus.INTERNAL_SERVER_ERROR,
+                                    evt.cause.message
+                                        ?.let(String::toByteArray)
+                                        ?.let(Unpooled::copiedBuffer)
+                                )
+                                ctx.write(errorResponse)
                             }
                         }
-                        else -> {
-                            ctx.write(ChunkedNioStream(channel)).addListener { evt ->
-                                channel.close()
-                            }
-                            ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT.retainedDuplicate())
-                        }
                     }
-                } ?: let {
-                    log.debug(ctx) {
-                        "Cache miss for key '$key'"
-                    }
-                    val response = DefaultFullHttpResponse(msg.protocolVersion(), HttpResponseStatus.NOT_FOUND)
-                    response.headers()[HttpHeaderNames.CONTENT_LENGTH] = 0
-                    ctx.writeAndFlush(response)
-                }
+                }).thenCompose(CallHandle<Void>::call)
             } else {
                 log.warn(ctx) {
                     "Got request for unhandled path '${msg.uri()}'"
@@ -93,35 +152,22 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                 val response = DefaultFullHttpResponse(msg.protocolVersion(), HttpResponseStatus.BAD_REQUEST)
                 response.headers()[HttpHeaderNames.CONTENT_LENGTH] = 0
                 ctx.writeAndFlush(response)
+                ctx.channel().read()
             }
         } else if (method === HttpMethod.PUT) {
             val path = Path.of(msg.uri())
             val prefix = path.parent
             val key = path.fileName.toString()
-
             if (serverPrefix == prefix) {
                 log.debug(ctx) {
                     "Added value for key '$key' to build cache"
                 }
-                val bodyBytes = msg.content().run {
-                    if (isDirect) {
-                        ByteArray(readableBytes()).also {
-                            readBytes(it)
-                        }
-                    } else {
-                        array()
-                    }
-                }
-                try {
-                    cache.put(key, bodyBytes)
-                } catch(ex : Throwable) {
-                    throw CacheException("Error accessing the cache backend", ex)
-                }
+                transientContext = TransientContext(key, cache.put(key))
                 val response = DefaultFullHttpResponse(
                     msg.protocolVersion(), HttpResponseStatus.CREATED,
                     Unpooled.copiedBuffer(key.toByteArray())
                 )
-                response.headers()[HttpHeaderNames.CONTENT_LENGTH] = response.content().readableBytes()
+//                response.headers()[HttpHeaderNames.CONTENT_LENGTH] = response.content().readableBytes()
                 ctx.writeAndFlush(response)
             } else {
                 log.warn(ctx) {
@@ -131,9 +177,12 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                 response.headers()[HttpHeaderNames.CONTENT_LENGTH] = "0"
                 ctx.writeAndFlush(response)
             }
-        } else if(method == HttpMethod.TRACE) {
+        } else if (method == HttpMethod.TRACE) {
             val replayedRequestHead = ctx.alloc().buffer()
-            replayedRequestHead.writeCharSequence("TRACE ${Path.of(msg.uri())} ${msg.protocolVersion().text()}\r\n", Charsets.US_ASCII)
+            replayedRequestHead.writeCharSequence(
+                "TRACE ${Path.of(msg.uri())} ${msg.protocolVersion().text()}\r\n",
+                Charsets.US_ASCII
+            )
             msg.headers().forEach { (key, value) ->
                 replayedRequestHead.apply {
                     writeCharSequence(key, Charsets.US_ASCII)
@@ -143,18 +192,30 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
                 }
             }
             replayedRequestHead.writeCharSequence("\r\n", Charsets.US_ASCII)
-            val requestBody = msg.content()
-            requestBody.retain()
-            val responseBody = ctx.alloc().compositeBuffer(2).apply {
-                addComponents(true, replayedRequestHead)
-                addComponents(true, requestBody)
-            }
-            val response = DefaultFullHttpResponse(msg.protocolVersion(), HttpResponseStatus.OK, responseBody)
+            val response = DefaultHttpResponse(msg.protocolVersion(), HttpResponseStatus.OK)
             response.headers().apply {
                 set(HttpHeaderNames.CONTENT_TYPE, "message/http")
-                set(HttpHeaderNames.CONTENT_LENGTH, responseBody.readableBytes())
             }
-            ctx.writeAndFlush(response)
+            ctx.write(response)
+            ctx.writeAndFlush(DefaultHttpContent(replayedRequestHead))
+            val callHandle = object : CallHandle<Void> {
+                override fun postEvent(evt: RequestEvent) {
+                    when (evt) {
+                        is RequestEvent.ChunkSent -> {
+                            ctx.writeAndFlush(DefaultHttpContent(evt.chunk))
+                        }
+
+                        is RequestEvent.LastChunkSent -> {
+                            ctx.writeAndFlush(DefaultLastHttpContent(evt.chunk))
+                        }
+                    }
+                }
+
+                override fun call(): CompletableFuture<Void> {
+                    return CompletableFuture.completedFuture(null)
+                }
+            }
+            transientContext = TransientContext(null, CompletableFuture.completedFuture(callHandle))
         } else {
             log.warn(ctx) {
                 "Got request with unhandled method '${msg.method().name()}'"
@@ -163,5 +224,6 @@ class ServerHandler(private val cache: Cache, private val serverPrefix: Path) :
             response.headers()[HttpHeaderNames.CONTENT_LENGTH] = "0"
             ctx.writeAndFlush(response)
         }
+
     }
 }