├── .gitattributes
├── .gitignore
├── DEVIEW2020_RequestScoping.pdf
├── README.md
├── build.gradle
├── gradle
└── wrapper
│ ├── gradle-wrapper.jar
│ └── gradle-wrapper.properties
├── gradlew
├── gradlew.bat
├── settings.gradle
└── src
└── main
└── java
└── deview2020
└── requestscoping
├── AsyncServer.java
└── BlockingClient.java
/.gitattributes:
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1 | * text=auto eol=lf
2 |
3 | *.bat text eol=crlf
4 | *.cmd text eol=crlf
5 |
6 | *.ai binary
7 | *.binarypb binary
8 | *.br binary
9 | *.class binary
10 | *.crt binary
11 | *.eot binary
12 | *.exe binary
13 | *.gif binary
14 | *.gz binary
15 | *.ico binary
16 | *.jar binary
17 | *.jks binary
18 | *.jpg binary
19 | *.jpeg binary
20 | *.m4a binary
21 | *.m4v binary
22 | *.mp4 binary
23 | *.otf binary
24 | *.p12 binary
25 | *.pdf binary
26 | *.pem binary
27 | *.pkcs12 binary
28 | *.png binary
29 | *.ttc binary
30 | *.ttf binary
31 | *.webm binary
32 | *.webp binary
33 | *.woff binary
34 | *.woff2 binary
35 | *.xz binary
36 | *.zip binary
37 |
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/.gitignore:
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1 | # Build output
2 | /build
3 | /*/build
4 | /*/*/build
5 | /*/*/*/build
6 | /out
7 | /*/out
8 | /*/*/out
9 | /*/*/*/out
10 | **/gen-java
11 | **/gen-src
12 | /reports
13 | /site/public
14 | /site/.cache
15 |
16 | # Package Files #
17 | *.jar
18 | !**/src/**/WEB-INF/lib/*.jar
19 | !/gradle/wrapper/gradle-wrapper.jar
20 | !/settings/intellij_idea/settings.jar
21 | *.war
22 | *.ear
23 |
24 | # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
25 | hs_err_pid*
26 |
27 | # Gradle
28 | .gradle
29 |
30 | # IntelliJ
31 | .idea
32 | *.iml
33 | *.iws
34 | *.ipr
35 | *.ids
36 | *.orig
37 | /classes
38 | /out
39 |
40 | # VSCode
41 | /.vscode
42 |
43 | # Eclipse
44 | *.pydevproject
45 | .project
46 | .metadata
47 | /bin
48 | /*/bin
49 | /tmp
50 | /*/tmp
51 | *.tmp
52 | *.bak
53 | *.swp
54 | *~.nib
55 | .classpath
56 | .settings
57 | .loadpath
58 |
59 | # External tool builders
60 | .externalToolBuilders/**
61 |
62 | # Locally stored "Eclipse launch configurations"
63 | *.launch
64 |
65 | # CDT-specific
66 | .cproject
67 |
68 | # PDT-specific
69 | .buildpath
70 |
71 | ### Node template
72 | # Logs
73 | logs
74 | *.log
75 | npm-debug.log*
76 | yarn-debug.log*
77 | yarn-error.log*
78 |
79 | # Runtime data
80 | pids
81 | *.pid
82 | *.seed
83 | *.pid.lock
84 |
85 | # Directory for instrumented libs generated by jscoverage/JSCover
86 | lib-cov
87 |
88 | # Coverage directory used by tools like istanbul
89 | coverage
90 |
91 | # nyc test coverage
92 | .nyc_output
93 |
94 | # Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
95 | .grunt
96 |
97 | # Bower dependency directory (https://bower.io/)
98 | bower_components
99 |
100 | # node-waf configuration
101 | .lock-wscript
102 |
103 | # Compiled binary addons (https://nodejs.org/api/addons.html)
104 | build/Release
105 |
106 | # Dependency directories
107 | node_modules/
108 | jspm_packages/
109 |
110 | # TypeScript v1 declaration files
111 | typings/
112 |
113 | # Optional npm cache directory
114 | .npm
115 |
116 | # Optional eslint cache
117 | .eslintcache
118 |
119 | # Optional REPL history
120 | .node_repl_history
121 |
122 | # Output of 'npm pack'
123 | *.tgz
124 |
125 | # Yarn Integrity file
126 | .yarn-integrity
127 |
128 | # dotenv environment variables file
129 | .env
130 |
131 | # next.js build output
132 | .next
133 |
134 | # ASDF
135 | .tool-versions
136 |
137 | # SDKMAN rc file
138 | .sdkmanrc
139 |
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/DEVIEW2020_RequestScoping.pdf:
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https://raw.githubusercontent.com/minwoox/deview2020-requestscoping/740c1392505c08b7b35b4d5e76b969baa734a723/DEVIEW2020_RequestScoping.pdf
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/README.md:
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1 | # You are done with the asynchronous server if you know what request scoping is.
2 | - [Session](https://deview.kr/2020/sessions)
3 | - [Slide](https://github.com/minwoox/deview2020-requestscoping/blob/master/DEVIEW2020_RequestScoping.pdf)
4 | - [Asynchronous server example](https://github.com/minwoox/deview2020-requestscoping/blob/master/src/main/java/deview2020/requestscoping/AsyncServer.java)
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/build.gradle:
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1 | /*
2 | * This file was generated by the Gradle 'init' task.
3 | *
4 | * This generated file contains a sample Java project to get you started.
5 | * For more details take a look at the Java Quickstart chapter in the Gradle
6 | * User Manual available at https://docs.gradle.org/6.5/userguide/tutorial_java_projects.html
7 | */
8 |
9 | plugins {
10 | // Apply the java plugin to add support for Java
11 | id 'java'
12 |
13 | // Apply the application plugin to add support for building a CLI application.
14 | id 'application'
15 | }
16 |
17 | repositories {
18 | // Use jcenter for resolving dependencies.
19 | // You can declare any Maven/Ivy/file repository here.
20 | jcenter()
21 | }
22 |
23 | dependencies {
24 | // This dependency is used by the application.
25 | implementation 'com.google.guava:guava:29.0-jre'
26 |
27 | // Use JUnit Jupiter API for testing.
28 | testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.2'
29 |
30 | // Use JUnit Jupiter Engine for testing.
31 | testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.6.2'
32 | }
33 |
34 | test {
35 | // Use junit platform for unit tests
36 | useJUnitPlatform()
37 | }
38 |
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/gradle/wrapper/gradle-wrapper.jar:
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https://raw.githubusercontent.com/minwoox/deview2020-requestscoping/740c1392505c08b7b35b4d5e76b969baa734a723/gradle/wrapper/gradle-wrapper.jar
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/gradle/wrapper/gradle-wrapper.properties:
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1 | distributionBase=GRADLE_USER_HOME
2 | distributionPath=wrapper/dists
3 | distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-bin.zip
4 | zipStoreBase=GRADLE_USER_HOME
5 | zipStorePath=wrapper/dists
6 |
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/gradlew:
--------------------------------------------------------------------------------
1 | #!/usr/bin/env sh
2 |
3 | #
4 | # Copyright 2015 the original author or authors.
5 | #
6 | # Licensed under the Apache License, Version 2.0 (the "License");
7 | # you may not use this file except in compliance with the License.
8 | # You may obtain a copy of the License at
9 | #
10 | # https://www.apache.org/licenses/LICENSE-2.0
11 | #
12 | # Unless required by applicable law or agreed to in writing, software
13 | # distributed under the License is distributed on an "AS IS" BASIS,
14 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 | # See the License for the specific language governing permissions and
16 | # limitations under the License.
17 | #
18 |
19 | ##############################################################################
20 | ##
21 | ## Gradle start up script for UN*X
22 | ##
23 | ##############################################################################
24 |
25 | # Attempt to set APP_HOME
26 | # Resolve links: $0 may be a link
27 | PRG="$0"
28 | # Need this for relative symlinks.
29 | while [ -h "$PRG" ] ; do
30 | ls=`ls -ld "$PRG"`
31 | link=`expr "$ls" : '.*-> \(.*\)$'`
32 | if expr "$link" : '/.*' > /dev/null; then
33 | PRG="$link"
34 | else
35 | PRG=`dirname "$PRG"`"/$link"
36 | fi
37 | done
38 | SAVED="`pwd`"
39 | cd "`dirname \"$PRG\"`/" >/dev/null
40 | APP_HOME="`pwd -P`"
41 | cd "$SAVED" >/dev/null
42 |
43 | APP_NAME="Gradle"
44 | APP_BASE_NAME=`basename "$0"`
45 |
46 | # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
47 | DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
48 |
49 | # Use the maximum available, or set MAX_FD != -1 to use that value.
50 | MAX_FD="maximum"
51 |
52 | warn () {
53 | echo "$*"
54 | }
55 |
56 | die () {
57 | echo
58 | echo "$*"
59 | echo
60 | exit 1
61 | }
62 |
63 | # OS specific support (must be 'true' or 'false').
64 | cygwin=false
65 | msys=false
66 | darwin=false
67 | nonstop=false
68 | case "`uname`" in
69 | CYGWIN* )
70 | cygwin=true
71 | ;;
72 | Darwin* )
73 | darwin=true
74 | ;;
75 | MINGW* )
76 | msys=true
77 | ;;
78 | NONSTOP* )
79 | nonstop=true
80 | ;;
81 | esac
82 |
83 | CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
84 |
85 |
86 | # Determine the Java command to use to start the JVM.
87 | if [ -n "$JAVA_HOME" ] ; then
88 | if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
89 | # IBM's JDK on AIX uses strange locations for the executables
90 | JAVACMD="$JAVA_HOME/jre/sh/java"
91 | else
92 | JAVACMD="$JAVA_HOME/bin/java"
93 | fi
94 | if [ ! -x "$JAVACMD" ] ; then
95 | die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
96 |
97 | Please set the JAVA_HOME variable in your environment to match the
98 | location of your Java installation."
99 | fi
100 | else
101 | JAVACMD="java"
102 | which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
103 |
104 | Please set the JAVA_HOME variable in your environment to match the
105 | location of your Java installation."
106 | fi
107 |
108 | # Increase the maximum file descriptors if we can.
109 | if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
110 | MAX_FD_LIMIT=`ulimit -H -n`
111 | if [ $? -eq 0 ] ; then
112 | if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
113 | MAX_FD="$MAX_FD_LIMIT"
114 | fi
115 | ulimit -n $MAX_FD
116 | if [ $? -ne 0 ] ; then
117 | warn "Could not set maximum file descriptor limit: $MAX_FD"
118 | fi
119 | else
120 | warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
121 | fi
122 | fi
123 |
124 | # For Darwin, add options to specify how the application appears in the dock
125 | if $darwin; then
126 | GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
127 | fi
128 |
129 | # For Cygwin or MSYS, switch paths to Windows format before running java
130 | if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
131 | APP_HOME=`cygpath --path --mixed "$APP_HOME"`
132 | CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
133 |
134 | JAVACMD=`cygpath --unix "$JAVACMD"`
135 |
136 | # We build the pattern for arguments to be converted via cygpath
137 | ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
138 | SEP=""
139 | for dir in $ROOTDIRSRAW ; do
140 | ROOTDIRS="$ROOTDIRS$SEP$dir"
141 | SEP="|"
142 | done
143 | OURCYGPATTERN="(^($ROOTDIRS))"
144 | # Add a user-defined pattern to the cygpath arguments
145 | if [ "$GRADLE_CYGPATTERN" != "" ] ; then
146 | OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
147 | fi
148 | # Now convert the arguments - kludge to limit ourselves to /bin/sh
149 | i=0
150 | for arg in "$@" ; do
151 | CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
152 | CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
153 |
154 | if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
155 | eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
156 | else
157 | eval `echo args$i`="\"$arg\""
158 | fi
159 | i=`expr $i + 1`
160 | done
161 | case $i in
162 | 0) set -- ;;
163 | 1) set -- "$args0" ;;
164 | 2) set -- "$args0" "$args1" ;;
165 | 3) set -- "$args0" "$args1" "$args2" ;;
166 | 4) set -- "$args0" "$args1" "$args2" "$args3" ;;
167 | 5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
168 | 6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
169 | 7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
170 | 8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
171 | 9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
172 | esac
173 | fi
174 |
175 | # Escape application args
176 | save () {
177 | for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
178 | echo " "
179 | }
180 | APP_ARGS=`save "$@"`
181 |
182 | # Collect all arguments for the java command, following the shell quoting and substitution rules
183 | eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
184 |
185 | exec "$JAVACMD" "$@"
186 |
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/gradlew.bat:
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1 | @rem
2 | @rem Copyright 2015 the original author or authors.
3 | @rem
4 | @rem Licensed under the Apache License, Version 2.0 (the "License");
5 | @rem you may not use this file except in compliance with the License.
6 | @rem You may obtain a copy of the License at
7 | @rem
8 | @rem https://www.apache.org/licenses/LICENSE-2.0
9 | @rem
10 | @rem Unless required by applicable law or agreed to in writing, software
11 | @rem distributed under the License is distributed on an "AS IS" BASIS,
12 | @rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 | @rem See the License for the specific language governing permissions and
14 | @rem limitations under the License.
15 | @rem
16 |
17 | @if "%DEBUG%" == "" @echo off
18 | @rem ##########################################################################
19 | @rem
20 | @rem Gradle startup script for Windows
21 | @rem
22 | @rem ##########################################################################
23 |
24 | @rem Set local scope for the variables with windows NT shell
25 | if "%OS%"=="Windows_NT" setlocal
26 |
27 | set DIRNAME=%~dp0
28 | if "%DIRNAME%" == "" set DIRNAME=.
29 | set APP_BASE_NAME=%~n0
30 | set APP_HOME=%DIRNAME%
31 |
32 | @rem Resolve any "." and ".." in APP_HOME to make it shorter.
33 | for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
34 |
35 | @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
36 | set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
37 |
38 | @rem Find java.exe
39 | if defined JAVA_HOME goto findJavaFromJavaHome
40 |
41 | set JAVA_EXE=java.exe
42 | %JAVA_EXE% -version >NUL 2>&1
43 | if "%ERRORLEVEL%" == "0" goto init
44 |
45 | echo.
46 | echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
47 | echo.
48 | echo Please set the JAVA_HOME variable in your environment to match the
49 | echo location of your Java installation.
50 |
51 | goto fail
52 |
53 | :findJavaFromJavaHome
54 | set JAVA_HOME=%JAVA_HOME:"=%
55 | set JAVA_EXE=%JAVA_HOME%/bin/java.exe
56 |
57 | if exist "%JAVA_EXE%" goto init
58 |
59 | echo.
60 | echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
61 | echo.
62 | echo Please set the JAVA_HOME variable in your environment to match the
63 | echo location of your Java installation.
64 |
65 | goto fail
66 |
67 | :init
68 | @rem Get command-line arguments, handling Windows variants
69 |
70 | if not "%OS%" == "Windows_NT" goto win9xME_args
71 |
72 | :win9xME_args
73 | @rem Slurp the command line arguments.
74 | set CMD_LINE_ARGS=
75 | set _SKIP=2
76 |
77 | :win9xME_args_slurp
78 | if "x%~1" == "x" goto execute
79 |
80 | set CMD_LINE_ARGS=%*
81 |
82 | :execute
83 | @rem Setup the command line
84 |
85 | set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
86 |
87 |
88 | @rem Execute Gradle
89 | "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
90 |
91 | :end
92 | @rem End local scope for the variables with windows NT shell
93 | if "%ERRORLEVEL%"=="0" goto mainEnd
94 |
95 | :fail
96 | rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
97 | rem the _cmd.exe /c_ return code!
98 | if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
99 | exit /b 1
100 |
101 | :mainEnd
102 | if "%OS%"=="Windows_NT" endlocal
103 |
104 | :omega
105 |
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/settings.gradle:
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1 | /*
2 | * This file was generated by the Gradle 'init' task.
3 | *
4 | * The settings file is used to specify which projects to include in your build.
5 | *
6 | * Detailed information about configuring a multi-project build in Gradle can be found
7 | * in the user manual at https://docs.gradle.org/6.5/userguide/multi_project_builds.html
8 | */
9 |
10 | rootProject.name = 'deview2020-requestscoping'
11 |
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/src/main/java/deview2020/requestscoping/AsyncServer.java:
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1 | package deview2020.requestscoping;
2 |
3 | import java.io.IOException;
4 | import java.net.InetSocketAddress;
5 | import java.nio.ByteBuffer;
6 | import java.nio.channels.SelectionKey;
7 | import java.nio.channels.Selector;
8 | import java.nio.channels.ServerSocketChannel;
9 | import java.nio.channels.SocketChannel;
10 | import java.nio.charset.StandardCharsets;
11 | import java.util.Queue;
12 | import java.util.Set;
13 | import java.util.concurrent.CompletableFuture;
14 | import java.util.concurrent.ConcurrentLinkedQueue;
15 | import java.util.concurrent.Executor;
16 | import java.util.concurrent.ExecutorService;
17 | import java.util.concurrent.Executors;
18 |
19 | import javax.annotation.Nullable;
20 |
21 | /**
22 | * NB: This server is greatly simplified to show the concept of asynchronous server, so you shouldn't use this
23 | * in production. You might want to use Netty or Armeria if you are using HTTP protocol.
24 | *
25 | * The server which works asynchronously. The protocol is:
26 | * {@code
27 | * -----------------------------------------
28 | * | length(4bytes) | body(variable) |
29 | * -----------------------------------------
30 | * }
31 | * the length has a 32bit integer value which indicates the size of the whole packet.
32 | */
33 | public final class AsyncServer {
34 |
35 | public static void main(String[] args) throws IOException {
36 | final ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
37 | serverSocketChannel.bind(new InetSocketAddress(8080));
38 |
39 | final Selector selector = Selector.open();
40 | new EventLoop(selector).start();
41 | for (;;) {
42 | final SocketChannel socketChannel = serverSocketChannel.accept();
43 | socketChannel.configureBlocking(false);
44 | socketChannel.register(selector, SelectionKey.OP_READ | SelectionKey.OP_WRITE);
45 | }
46 | }
47 |
48 | private static class EventLoop extends Thread implements Executor {
49 |
50 | private final Selector selector;
51 | private final HelloService service;
52 | private final Queue jobs = new ConcurrentLinkedQueue<>();
53 |
54 | EventLoop(Selector selector) {
55 | this.selector = selector;
56 | service = new HelloService();
57 | }
58 |
59 | @Override
60 | public void run() {
61 | for (;;) {
62 | try {
63 | final int keys = selector.select(500);
64 | if (keys > 0) {
65 | final Set selectionKeys = selector.selectedKeys();
66 | for (SelectionKey selectionKey : selectionKeys) {
67 | if (selectionKey.isReadable()) {
68 | final SocketChannel channel = (SocketChannel) selectionKey.channel();
69 | final ByteBuffer request = readRequest(channel);
70 | if (request == null) {
71 | channel.close();
72 | continue;
73 | }
74 | final CompletableFuture future = service.serve(request, this);
75 | future.thenAcceptAsync(response -> writeResponse(channel, response), this);
76 | }
77 | }
78 | }
79 | runJobs();
80 | } catch (IOException e) {
81 | System.err.println("Unexpected exception while selecting. " + e);
82 | }
83 | }
84 | }
85 |
86 | private void runJobs() {
87 | for (;;) {
88 | final Runnable work = jobs.poll();
89 | if (work == null) {
90 | return;
91 | }
92 | work.run();
93 | }
94 | }
95 |
96 | @Nullable
97 | private static ByteBuffer readRequest(SocketChannel channel) throws IOException {
98 | final ByteBuffer sizeBuffer = readBytes(channel, 4);
99 | if (sizeBuffer == null) {
100 | return null;
101 | }
102 | return readBytes(channel, sizeBuffer.getInt());
103 | }
104 |
105 | @Nullable
106 | private static ByteBuffer readBytes(SocketChannel channel, int size) throws IOException {
107 | final ByteBuffer bodyBuffer = ByteBuffer.allocate(size);
108 | int totalRead = 0;
109 | while (totalRead < size) {
110 | final int read = channel.read(bodyBuffer);
111 | if (read < 0) {
112 | // The sender violated the protocol so we just return null for simplicity.
113 | return null;
114 | }
115 | totalRead += read;
116 | }
117 | bodyBuffer.flip();
118 | return bodyBuffer;
119 | }
120 |
121 | private static void writeResponse(SocketChannel channel, ByteBuffer response) {
122 | final int total = 4 + response.remaining();
123 | final ByteBuffer responseBuffer = ByteBuffer.allocate(total);
124 | responseBuffer.putInt(response.remaining());
125 | responseBuffer.put(response);
126 | responseBuffer.flip();
127 | try {
128 | int written = channel.write(responseBuffer);
129 | while (written < total) {
130 | written += channel.write(responseBuffer);
131 | }
132 | } catch (IOException e) {
133 | System.err.println("Unexpected exception while writing. " + e);
134 | }
135 | }
136 |
137 | @Override
138 | public void execute(Runnable command) {
139 | jobs.add(command);
140 | }
141 | }
142 |
143 | private static final class HelloService {
144 |
145 | private final ExecutorService blockingExecutor = Executors.newFixedThreadPool(10);
146 |
147 | CompletableFuture serve(ByteBuffer request, EventLoop eventLoop) {
148 | final String requestBody = StandardCharsets.UTF_8.decode(request).toString();
149 | final CompletableFuture future = new CompletableFuture<>();
150 | eventLoop.execute(() -> {
151 | // Let's suppose that response is complete later by another event.
152 | // (e.g. an HTTP call to another backend)
153 | final ByteBuffer response = StandardCharsets.UTF_8.encode("Hello " + requestBody);
154 | future.complete(response);
155 | });
156 |
157 | /* If it's a blocking call, we should use other executor to do the job.
158 | blockingExecutor.submit(() -> {
159 | System.err.println("request body: " + requestBody);
160 | try {
161 | // Simulate a blocking call (e.g. send a query to RDB)
162 | Thread.sleep(3000);
163 | } catch (InterruptedException e) {
164 | // ignored
165 | }
166 | final ByteBuffer response = StandardCharsets.UTF_8.encode("Hello " + requestBody);
167 | future.complete(response);
168 | });
169 | */
170 | return future;
171 | }
172 | }
173 | }
174 |
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/src/main/java/deview2020/requestscoping/BlockingClient.java:
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1 | package deview2020.requestscoping;
2 |
3 | import java.io.IOException;
4 | import java.io.InputStream;
5 | import java.io.OutputStream;
6 | import java.net.Socket;
7 | import java.nio.ByteBuffer;
8 | import java.nio.charset.StandardCharsets;
9 |
10 | public final class BlockingClient {
11 |
12 | public static void main(String[] args) throws IOException {
13 | final Socket socket = new Socket("127.0.0.1", 8080);
14 | System.err.println("Connected");
15 | try {
16 | final OutputStream outputStream = socket.getOutputStream();
17 | final String name = "Armeria";
18 | final byte[] request = name.getBytes(StandardCharsets.UTF_8);
19 |
20 | final byte[] size = ByteBuffer.allocate(4).putInt(request.length).array();
21 | outputStream.write(size);
22 | outputStream.write(request);
23 | outputStream.flush();
24 |
25 | final InputStream inputStream = socket.getInputStream();
26 | final ByteBuffer responseSizeBuffer = ByteBuffer.allocate(4);
27 | inputStream.read(responseSizeBuffer.array());
28 | final int responseSize = responseSizeBuffer.getInt();
29 | final ByteBuffer response = ByteBuffer.allocate(responseSize);
30 | inputStream.read(response.array());
31 | System.err.println("Received response: " + StandardCharsets.UTF_8.decode(response));
32 | socket.close();
33 | } catch (IOException e) {
34 | System.err.println("Unexpected exception while sending and receiving. " + e);
35 | }
36 | }
37 | }
38 |
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