initial commit

.gitattributes

@@ -0,0 +1,6 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# These are explicitly windows files and should use crlf
+*.bat           text eol=crlf
+

.gitignore

@@ -0,0 +1,5 @@
+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build

build.gradle

@@ -0,0 +1,66 @@
+plugins {
+    id 'org.jetbrains.kotlin.jvm'
+    id 'application'
+    id 'maven-publish'
+}
+
+group = 'net.woggioni'
+
+version = '0.1'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation group: 'org.slf4j', name: 'slf4j-api', version: getProperty('slf4j.version')
+    implementation group: 'com.h2database', name: 'h2', version: getProperty('h2.version')
+    implementation group: 'io.netty', name: 'netty-codec-http', version: getProperty('netty.version')
+
+    runtimeOnly group: 'org.slf4j', name: 'slf4j-simple', version: getProperty('slf4j.version')
+
+    testImplementation group: 'org.junit.jupiter', name: 'junit-jupiter-api', version: getProperty('junit.jupiter.version')
+    testImplementation group: 'org.junit.jupiter', name: 'junit-jupiter-params', version: getProperty('junit.jupiter.version')
+    testRuntimeOnly group: 'org.junit.jupiter', name: 'junit-jupiter-engine', version: getProperty('junit.jupiter.version')
+}
+
+java {
+    withJavadocJar()
+    withSourcesJar()
+}
+
+if(JavaVersion.current() > JavaVersion.VERSION_1_8) {
+    tasks.named(JavaPlugin.COMPILE_JAVA_TASK_NAME) {
+        options.release = 8
+    }
+}
+
+//lombok {
+//    version = getProperty('lombok.version')
+//}
+
+run {
+    systemProperty 'org.slf4j.simpleLogger.defaultLogLevel', 'trace'
+}
+
+application {
+    mainClassName = 'net.woggioni.gcs.GradleBuildCacheServer'
+}
+
+wrapper {
+    distributionType = Wrapper.DistributionType.BIN
+    gradleVersion = getProperty('gradle.version')
+}
+
+publishing {
+    repositories {
+        maven {
+            url = 'https://mvn.woggioni.net/'
+        }
+    }
+    publications {
+        maven(MavenPublication) {
+            from(components["java"])
+        }
+    }
+}

gradle.properties

@@ -0,0 +1,10 @@
+gradle.lombok.plugin.version = 0.1
+
+gradle.version = 7.4
+kotlin.version = 1.6.10
+
+junit.jupiter.version = 5.8.2
+netty.version = 4.1.74.Final
+h2.version = 2.1.210
+slf4j.version = 1.7.36
+lombok.version = 1.18.22

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle

@@ -0,0 +1,15 @@
+pluginManagement {
+    repositories {
+        maven {
+            url = 'https://woggioni.net/mvn/'
+        }
+        gradlePluginPortal()
+    }
+
+    plugins {
+        id "net.woggioni.gradle.lombok" version "0.1"
+        id 'org.jetbrains.kotlin.jvm' version getProperty('kotlin.version')
+    }
+}
+
+rootProject.name = 'gbcs'

src/main/java/net/woggioni/gcs/GradleBuildCacheServer23.java

@@ -0,0 +1,264 @@
+package net.woggioni.gcs;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.handler.codec.compression.StandardCompressionOptions;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContentCompressor;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaderValues;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpObjectAggregator;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.HttpServerCodec;
+import io.netty.handler.codec.http.HttpUtil;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.util.ReferenceCountUtil;
+import io.netty.util.concurrent.DefaultEventExecutorGroup;
+import io.netty.util.concurrent.EventExecutorGroup;
+import org.h2.mvstore.MVStore;
+
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.AbstractMap;
+import java.util.Base64;
+import java.util.Map;
+import java.util.Objects;
+
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+public class GradleBuildCacheServer23 {
+
+//    private static final class NettyHttpBasicAuthenticator extends ChannelInboundHandlerAdapter {
+//
+//        private static final FullHttpResponse AUTHENTICATION_FAILED = new DefaultFullHttpResponse(
+//                HTTP_1_1, HttpResponseStatus.UNAUTHORIZED, Unpooled.EMPTY_BUFFER);
+//
+//        private final String basicAuthHeader;
+//
+//        public NettyHttpBasicAuthenticator(String username, String password) {
+//            this.basicAuthHeader =
+//                    "Basic " + Base64.getEncoder()
+//                            .encodeToString((username + ":" + password)
+//                                    .getBytes(StandardCharsets.ISO_8859_1));
+//        }
+//
+//        @Override
+//        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+//            if (msg instanceof HttpRequest) {
+//                HttpRequest req = (HttpRequest) msg;
+//                String authorizationHeader = req.headers().get(HttpHeaderNames.AUTHORIZATION);
+//                log.warn();
+//
+//                int cursor = authorizationHeader.indexOf(' ');
+//                if(cursor < 0) {
+//                    if(log.isDebugEnabled()) {
+//                        log.debug("Invalid Authorization header: '{}'", authorizationHeader);
+//                    }
+//                    authenticationFailure(ctx, msg);
+//                }
+//                String authenticationType = authorizationHeader.substring(0, cursor);
+//                if(!Objects.equals("Basic", authenticationType)) {
+//                    if(log.isDebugEnabled()) {
+//                        ((InetSocketAddress) ctx.channel().remoteAddress()).getAddress().getHostAddress();
+//                        log.debug("Invalid authentication type header: '{}'", authenticationType);
+//                    }
+//                    authenticationFailure(ctx, msg);
+//                }
+//
+//                if (HttpUtil.is100ContinueExpected(req)) {
+//                    HttpResponse accept = acceptMessage(req);
+//
+//                    if (accept == null) {
+//                        // the expectation failed so we refuse the request.
+//                        HttpResponse rejection = rejectResponse(req);
+//                        ReferenceCountUtil.release(msg);
+//                        ctx.writeAndFlush(rejection).addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
+//                        return;
+//                    }
+//
+//                    ctx.writeAndFlush(accept).addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
+//                    req.headers().remove(HttpHeaderNames.EXPECT);
+//                }
+//            }
+//            super.channelRead(ctx, msg);
+//        }
+//
+//        public void authenticationFailure(ChannelHandlerContext ctx, Object msg) {
+//            ReferenceCountUtil.release(msg);
+//            ctx.writeAndFlush(AUTHENTICATION_FAILED.retainedDuplicate()).addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
+//        }
+//    }
+//
+//    @RequiredArgsConstructor
+//    private static class ServerInitializer extends ChannelInitializer<Channel> {
+//
+//        private final MVStore mvStore;
+//        static final EventExecutorGroup group =
+//            new DefaultEventExecutorGroup(Runtime.getRuntime().availableProcessors());
+//
+//        @Override
+//        protected void initChannel(Channel ch) {
+//            ChannelPipeline pipeline = ch.pipeline();
+//            pipeline.addLast(new HttpServerCodec());
+//            pipeline.addLast(new HttpObjectAggregator(Integer.MAX_VALUE));
+//            pipeline.addLast(group, new ServerHandler(mvStore, "/cache"));
+//            pipeline.addLast(
+//                new HttpContentCompressor(1024,
+//                    StandardCompressionOptions.deflate(),
+//                    StandardCompressionOptions.brotli(),
+//                    StandardCompressionOptions.gzip(),
+//                    StandardCompressionOptions.zstd()));
+//        }
+//    }
+//
+//    private static  class AuthenticationHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
+//        @Override
+//        protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
+//
+//        }
+//    }
+//
+//    @Slf4j
+//    private static class ServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
+//
+//        private final String serverPrefix;
+//        private final Map<String, byte[]> cache;
+//
+//        public ServerHandler(MVStore mvStore, String serverPrefix) {
+//            this.serverPrefix = serverPrefix;
+//            cache = mvStore.openMap("buildCache");
+//        }
+//
+//        private static Map.Entry<String, String> splitPath(HttpRequest req) {
+//            String uri = req.uri();
+//            int i = uri.lastIndexOf('/');
+//            if(i < 0) throw new RuntimeException(String.format("Malformed request URI: '%s'", uri));
+//            return new AbstractMap.SimpleEntry<>(uri.substring(0, i), uri.substring(i + 1));
+//        }
+//
+//        private void authenticate(HttpRequest req) {
+//            String authorizationHeader = req.headers().get(HttpHeaderNames.AUTHORIZATION);
+//            if(authorizationHeader != null) {
+//                int cursor = authorizationHeader.indexOf(' ');
+//                if(cursor < 0) {
+//                    throw new IllegalArgumentException(
+//                            String.format("Illegal format for 'Authorization' HTTP header: '%s'", authorizationHeader));
+//                }
+//                String authorizationType = authorizationHeader.substring(0, cursor);
+//                if(!Objects.equals("Basic", authorizationType) {
+//
+//                }
+//            }
+//
+//        }
+//
+//        @Override
+//        protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest msg) {
+//            HttpMethod method = msg.method();
+//            FullHttpResponse response;
+//            if(method == HttpMethod.GET) {
+//                Map.Entry<String, String> prefixAndKey = splitPath(msg);
+//                String prefix = prefixAndKey.getKey();
+//                String key = prefixAndKey.getValue();
+//                if(Objects.equals(serverPrefix, prefix)) {
+//                    byte[] value = cache.get(key);
+//                    if(value != null) {
+//                        if(log.isDebugEnabled()) {
+//                            log.debug("Successfully retrieved value for key '{}' from build cache", key);
+//                        }
+//                        ByteBuf content = Unpooled.copiedBuffer(value);
+//                        response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);
+//                        response.headers().set(HttpHeaderNames.CONTENT_TYPE, HttpHeaderValues.APPLICATION_OCTET_STREAM);
+//                        response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
+//                    } else {
+//                        if(log.isDebugEnabled()) {
+//                            log.debug("Cache miss for key '{}'", key);
+//                        }
+//                        response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.NOT_FOUND);
+//                    }
+//                } else {
+//                    if(log.isWarnEnabled()) {
+//                        log.warn("Got request for unhandled path '{}'", msg.uri());
+//                    }
+//                    response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST);
+//                }
+//            } else if(method == HttpMethod.PUT) {
+//                Map.Entry<String, String> prefixAndKey = splitPath(msg);
+//                String prefix = prefixAndKey.getKey();
+//                String key = prefixAndKey.getValue();
+//                if(Objects.equals(serverPrefix, prefix)) {
+//                    if(log.isDebugEnabled()) {
+//                        log.debug("Added value for key '{}' to build cache", key);
+//                    }
+//                    cache.put(key, msg.content().array());
+//                    ByteBuf content = Unpooled.copiedBuffer(key, StandardCharsets.UTF_8);
+//                    response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CREATED, content);
+//                } else {
+//                    if(log.isWarnEnabled()) {
+//                        log.warn("Got request for unhandled path '{}'", msg.uri());
+//                    }
+//                    response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST);
+//                }
+//            } else {
+//                if(log.isWarnEnabled()) {
+//                    log.warn("Got request with unhandled method '{}'", msg.method().name());
+//                }
+//                response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST);
+//            }
+//            ctx.write(response);
+//            ctx.flush();
+//        }
+//    }
+//
+//    private static final int HTTP_PORT = 8080;
+//
+//    public void run() throws Exception {
+//
+//        // Create the multithreaded event loops for the server
+//        EventLoopGroup bossGroup = new NioEventLoopGroup();
+//        EventLoopGroup workerGroup = new NioEventLoopGroup();
+//        try(MVStore mvStore = MVStore.open("/tmp/buildCache")) {
+//            // A helper class that simplifies server configuration
+//            ServerBootstrap httpBootstrap = new ServerBootstrap();
+//
+//            // Configure the server
+//            httpBootstrap.group(bossGroup, workerGroup)
+//                .channel(NioServerSocketChannel.class)
+//                .childHandler(new ServerInitializer(mvStore)) // <-- Our handler created here
+//                .option(ChannelOption.SO_BACKLOG, 128)
+//                .childOption(ChannelOption.SO_KEEPALIVE, true);
+//
+//            // Bind and start to accept incoming connections.
+//            ChannelFuture httpChannel = httpBootstrap.bind(HTTP_PORT).sync();
+//
+//            // Wait until server socket is closed
+//            httpChannel.channel().closeFuture().sync();
+//        }
+//        finally {
+//            workerGroup.shutdownGracefully();
+//            bossGroup.shutdownGracefully();
+//        }
+//    }
+//
+//    public static void main(String[] args) throws Exception {
+//        new GradleBuildCacheServer().run();
+//    }
+}

src/main/kotlin/net/woggioni/gcs/Authenticator.kt

@@ -0,0 +1,53 @@
+package net.woggioni.gcs
+
+import io.netty.buffer.Unpooled
+import io.netty.channel.ChannelFutureListener
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelInboundHandlerAdapter
+import io.netty.handler.codec.http.DefaultFullHttpResponse
+import io.netty.handler.codec.http.FullHttpResponse
+import io.netty.handler.codec.http.HttpHeaderNames
+import io.netty.handler.codec.http.HttpRequest
+import io.netty.handler.codec.http.HttpResponseStatus
+import io.netty.handler.codec.http.HttpVersion
+import io.netty.util.ReferenceCountUtil
+
+abstract class AbstractNettyHttpAuthenticator(private val authorizer : Authorizer)
+        : ChannelInboundHandlerAdapter() {
+
+    private companion object {
+        private val AUTHENTICATION_FAILED: FullHttpResponse = DefaultFullHttpResponse(
+                HttpVersion.HTTP_1_1, HttpResponseStatus.UNAUTHORIZED, Unpooled.EMPTY_BUFFER).apply {
+            headers()[HttpHeaderNames.CONTENT_LENGTH] = "0"
+        }
+
+        private val NOT_AUTHORIZED: FullHttpResponse = DefaultFullHttpResponse(
+                HttpVersion.HTTP_1_1, HttpResponseStatus.FORBIDDEN, Unpooled.EMPTY_BUFFER).apply {
+            headers()[HttpHeaderNames.CONTENT_LENGTH] = "0"
+        }
+    }
+    abstract fun authenticate(ctx : ChannelHandlerContext, req : HttpRequest) : String?
+
+    override fun channelRead(ctx: ChannelHandlerContext, msg: Any) {
+        if(msg is HttpRequest) {
+            val user = authenticate(ctx, msg) ?: return authenticationFailure(ctx, msg)
+            val authorized = authorizer.authorize(user, msg)
+            if(authorized) {
+                super.channelRead(ctx, msg)
+            } else {
+                authorizationFailure(ctx, msg)
+            }
+        }
+    }
+
+    private fun authenticationFailure(ctx: ChannelHandlerContext, msg: Any) {
+        ReferenceCountUtil.release(msg)
+        ctx.writeAndFlush(AUTHENTICATION_FAILED.retainedDuplicate()).addListener(ChannelFutureListener.CLOSE_ON_FAILURE)
+    }
+
+    private fun authorizationFailure(ctx: ChannelHandlerContext, msg: Any) {
+        ReferenceCountUtil.release(msg)
+        ctx.writeAndFlush(NOT_AUTHORIZED.retainedDuplicate()).addListener(ChannelFutureListener.CLOSE_ON_FAILURE)
+    }
+
+}

src/main/kotlin/net/woggioni/gcs/Authorizer.kt

@@ -0,0 +1,7 @@
+package net.woggioni.gcs
+
+import io.netty.handler.codec.http.HttpRequest
+
+fun interface Authorizer {
+    fun authorize(user : String, request: HttpRequest) : Boolean
+}

src/main/kotlin/net/woggioni/gcs/GradleBuildCacheServer.kt

@@ -0,0 +1,222 @@
+package net.woggioni.gcs
+
+import io.netty.bootstrap.ServerBootstrap
+import io.netty.buffer.Unpooled
+import io.netty.channel.Channel
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelInitializer
+import io.netty.channel.ChannelOption
+import io.netty.channel.EventLoopGroup
+import io.netty.channel.SimpleChannelInboundHandler
+import io.netty.channel.nio.NioEventLoopGroup
+import io.netty.channel.socket.nio.NioServerSocketChannel
+import io.netty.handler.codec.compression.Brotli
+import io.netty.handler.codec.compression.CompressionOptions
+import io.netty.handler.codec.compression.StandardCompressionOptions
+import io.netty.handler.codec.compression.Zstd
+import io.netty.handler.codec.http.DefaultFullHttpResponse
+import io.netty.handler.codec.http.FullHttpRequest
+import io.netty.handler.codec.http.FullHttpResponse
+import io.netty.handler.codec.http.HttpContentCompressor
+import io.netty.handler.codec.http.HttpHeaderNames
+import io.netty.handler.codec.http.HttpHeaderValues
+import io.netty.handler.codec.http.HttpMethod
+import io.netty.handler.codec.http.HttpObjectAggregator
+import io.netty.handler.codec.http.HttpRequest
+import io.netty.handler.codec.http.HttpRequestDecoder
+import io.netty.handler.codec.http.HttpResponseStatus
+import io.netty.handler.codec.http.HttpServerCodec
+import io.netty.handler.codec.http.HttpVersion
+import io.netty.util.concurrent.DefaultEventExecutorGroup
+import io.netty.util.concurrent.EventExecutorGroup
+import org.h2.mvstore.FileStore
+import org.h2.mvstore.MVStore
+import java.util.AbstractMap.SimpleEntry
+import java.util.Base64
+
+
+class GradleBuildCacheServer {
+    private class NettyHttpBasicAuthenticator(
+            private val credentials: Map<String, String>, authorizer: Authorizer) : AbstractNettyHttpAuthenticator(authorizer) {
+
+        companion object {
+            private val log = contextLogger()
+        }
+
+        override fun authenticate(ctx: ChannelHandlerContext, req: HttpRequest): String? {
+            val authorizationHeader = req.headers()[HttpHeaderNames.AUTHORIZATION] ?: let {
+                log.debug(ctx) {
+                    "Missing Authorization header"
+                }
+                return null
+            }
+            val cursor = authorizationHeader.indexOf(' ')
+            if (cursor < 0) {
+                log.debug(ctx) {
+                    "Invalid Authorization header: '$authorizationHeader'"
+                }
+                return null
+            }
+            val authenticationType = authorizationHeader.substring(0, cursor)
+            if ("Basic" != authenticationType) {
+                log.debug(ctx) {
+                    "Invalid authentication type header: '$authenticationType'"
+                }
+                return null
+            }
+            val (user, password) = Base64.getDecoder().decode(authorizationHeader.substring(cursor + 1))
+                    .let(::String)
+                    .let {
+                        val colon = it.indexOf(':')
+                        if(colon < 0) {
+                            log.debug(ctx) {
+                                "Missing colon from authentication"
+                            }
+                            return null
+                        }
+                        it.substring(0, colon) to it.substring(colon + 1)
+                    }
+            return user.takeIf {
+                credentials[user] == password
+            }
+        }
+    }
+
+    private class ServerInitializer(private val mvStore: MVStore) : ChannelInitializer<Channel>() {
+
+        override fun initChannel(ch: Channel) {
+            val pipeline = ch.pipeline()
+            pipeline.addLast(HttpServerCodec())
+            pipeline.addLast(HttpObjectAggregator(Int.MAX_VALUE))
+            pipeline.addLast(HttpContentCompressor(1024, *emptyArray<CompressionOptions>()))
+            pipeline.addLast(NettyHttpBasicAuthenticator(mapOf("user" to "password")) { user, _ -> user == "user" })
+            pipeline.addLast(group, ServerHandler(mvStore, "/cache"))
+        }
+
+        companion object {
+            val group: EventExecutorGroup = DefaultEventExecutorGroup(Runtime.getRuntime().availableProcessors())
+        }
+    }
+
+    private class ServerHandler(private val mvStore: MVStore, private val serverPrefix: String) : SimpleChannelInboundHandler<FullHttpRequest>() {
+
+        companion object {
+            private val log = contextLogger()
+
+            private fun splitPath(req: HttpRequest): Map.Entry<String, String> {
+                val uri = req.uri()
+                val i = uri.lastIndexOf('/')
+                if (i < 0) throw RuntimeException(String.format("Malformed request URI: '%s'", uri))
+                return SimpleEntry(uri.substring(0, i), uri.substring(i + 1))
+            }
+        }
+
+        private val cache: MutableMap<String, ByteArray>
+
+        init {
+            cache = mvStore.openMap("buildCache")
+        }
+
+        override fun channelRead0(ctx: ChannelHandlerContext, msg: FullHttpRequest) {
+            val method = msg.method()
+            val response: FullHttpResponse
+            if (method === HttpMethod.GET) {
+                val (prefix, key) = splitPath(msg)
+                if (serverPrefix == prefix) {
+                    val value = cache[key]
+                    if (value != null) {
+                        log.debug(ctx) {
+                            "Cache hit for key '$key'"
+                        }
+                        val content = Unpooled.copiedBuffer(value)
+                        response = DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content)
+                        response.headers()[HttpHeaderNames.CONTENT_TYPE] = HttpHeaderValues.APPLICATION_OCTET_STREAM
+                        response.headers()[HttpHeaderNames.CONTENT_LENGTH] = content.readableBytes()
+                    } else {
+                        log.debug(ctx) {
+                            "Cache miss for key '$key'"
+                        }
+                        response = DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.NOT_FOUND)
+                        response.headers()[HttpHeaderNames.CONTENT_LENGTH] = 0
+                    }
+                } else {
+                    log.warn(ctx) {
+                        "Got request for unhandled path '${msg.uri()}'"
+                    }
+                    response = DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST)
+                    response.headers()[HttpHeaderNames.CONTENT_LENGTH] = 0
+                }
+            } else if (method === HttpMethod.PUT) {
+                val (prefix, key) = splitPath(msg)
+                if (serverPrefix == prefix) {
+                    log.debug(ctx) {
+                        "Added value for key '$key' to build cache"
+                    }
+                    val content = msg.content()
+                    val value = ByteArray(content.capacity())
+                    content.readBytes(value)
+                    cache[key] = value
+                    mvStore.commit()
+                    response = DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CREATED,
+                            Unpooled.copiedBuffer(key.toByteArray()))
+                    response.headers()[HttpHeaderNames.CONTENT_LENGTH] = response.content().readableBytes()
+                } else {
+                    log.warn(ctx) {
+                        "Got request for unhandled path '${msg.uri()}'"
+                    }
+                    response = DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST)
+                    response.headers()[HttpHeaderNames.CONTENT_LENGTH] = "0"
+                }
+            } else {
+                log.warn(ctx) {
+                    "Got request with unhandled method '${msg.method().name()}'"
+                }
+                response = DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST)
+                response.headers()[HttpHeaderNames.CONTENT_LENGTH] = "0"
+            }
+            response.retain()
+            ctx.write(response)
+            ctx.flush()
+        }
+    }
+
+    fun run() {
+        // Create the multithreaded event loops for the server
+        val bossGroup: EventLoopGroup = NioEventLoopGroup()
+        val workerGroup: EventLoopGroup = NioEventLoopGroup()
+        val mvStore = MVStore.Builder()
+                .compress()
+                .fileName("/tmp/buildCache.mv")
+                .open()
+        val initialState = mvStore.commit()
+        try {
+            // A helper class that simplifies server configuration
+            val httpBootstrap = ServerBootstrap()
+
+            // Configure the server
+            httpBootstrap.group(bossGroup, workerGroup)
+                    .channel(NioServerSocketChannel::class.java)
+                    .childHandler(ServerInitializer(mvStore)) // <-- Our handler created here
+                    .option(ChannelOption.SO_BACKLOG, 128)
+                    .childOption(ChannelOption.SO_KEEPALIVE, true)
+
+            // Bind and start to accept incoming connections.
+            val httpChannel = httpBootstrap.bind(HTTP_PORT).sync()
+
+            // Wait until server socket is closed
+            httpChannel.channel().closeFuture().sync()
+        } finally {
+            mvStore.close()
+            workerGroup.shutdownGracefully()
+            bossGroup.shutdownGracefully()
+        }
+    }
+
+    companion object {
+        private const val HTTP_PORT = 8080
+        @JvmStatic
+        fun main(args: Array<String>) {
+            GradleBuildCacheServer().run()
+        }
+    }
+}

src/main/kotlin/net/woggioni/gcs/Logging.kt

@@ -0,0 +1,107 @@
+package net.woggioni.gcs
+
+import io.netty.channel.ChannelHandlerContext
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+import java.net.InetSocketAddress
+
+inline fun <reified T> T.contextLogger() = LoggerFactory.getLogger(T::class.java)
+
+inline fun Logger.traceParam(messageBuilder : () -> Pair<String, Array<Any>>) {
+    if(isTraceEnabled) {
+        val (format, params) = messageBuilder()
+        trace(format, params)
+    }
+}
+
+inline fun Logger.debugParam(messageBuilder : () -> Pair<String, Array<Any>>) {
+    if(isDebugEnabled) {
+        val (format, params) = messageBuilder()
+        info(format, params)
+    }
+}
+
+inline fun Logger.infoParam(messageBuilder : () -> Pair<String, Array<Any>>) {
+    if(isInfoEnabled) {
+        val (format, params) = messageBuilder()
+        info(format, params)
+    }
+}
+
+inline fun Logger.warnParam(messageBuilder : () -> Pair<String, Array<Any>>) {
+    if(isWarnEnabled) {
+        val (format, params) = messageBuilder()
+        warn(format, params)
+    }
+}
+
+inline fun Logger.errorParam(messageBuilder : () -> Pair<String, Array<Any>>) {
+    if(isErrorEnabled) {
+        val (format, params) = messageBuilder()
+        error(format, params)
+    }
+}
+
+
+inline fun log(log : Logger,
+               filter : Logger.() -> Boolean,
+               loggerMethod : Logger.(String) -> Unit, messageBuilder : () -> String) {
+    if(log.filter()) {
+        log.loggerMethod(messageBuilder())
+    }
+}
+
+inline fun Logger.trace(messageBuilder : () -> String) {
+    if(isTraceEnabled) {
+        trace(messageBuilder())
+    }
+}
+
+inline fun Logger.debug(messageBuilder : () -> String) {
+    if(isDebugEnabled) {
+        debug(messageBuilder())
+    }
+}
+
+inline fun Logger.info(messageBuilder : () -> String) {
+    if(isInfoEnabled) {
+        info(messageBuilder())
+    }
+}
+
+inline fun Logger.warn(messageBuilder : () -> String) {
+    if(isWarnEnabled) {
+        warn(messageBuilder())
+    }
+}
+
+inline fun Logger.error(messageBuilder : () -> String) {
+    if(isErrorEnabled) {
+        error(messageBuilder())
+    }
+}
+
+inline fun Logger.trace(ctx : ChannelHandlerContext, messageBuilder : () -> String) {
+    log(this, ctx, { isTraceEnabled }, { trace(it) } , messageBuilder)
+}
+inline fun Logger.debug(ctx : ChannelHandlerContext, messageBuilder : () -> String) {
+    log(this, ctx, { isDebugEnabled }, { debug(it) } , messageBuilder)
+}
+inline fun Logger.info(ctx : ChannelHandlerContext, messageBuilder : () -> String) {
+    log(this, ctx, { isInfoEnabled }, { info(it) } , messageBuilder)
+}
+inline fun Logger.warn(ctx : ChannelHandlerContext, messageBuilder : () -> String) {
+    log(this, ctx, { isWarnEnabled }, { warn(it) } , messageBuilder)
+}
+inline fun Logger.error(ctx : ChannelHandlerContext, messageBuilder : () -> String) {
+    log(this, ctx, { isErrorEnabled }, { error(it) } , messageBuilder)
+}
+
+inline fun log(log : Logger, ctx : ChannelHandlerContext,
+                        filter : Logger.() -> Boolean,
+                        loggerMethod : Logger.(String) -> Unit, messageBuilder : () -> String) {
+    if(log.filter()) {
+        val clientAddress = (ctx.channel().remoteAddress() as InetSocketAddress).address.hostAddress
+        log.loggerMethod(clientAddress + " - " + messageBuilder())
+    }
+}