Final State Machine

This commit is contained in:
Vyacheslav N. Boyko 2017-12-28 15:30:26 +03:00
parent 9a0e88bd40
commit 9fa1b6b6a5
18 changed files with 764 additions and 0 deletions

14
build.gradle Normal file
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group 'ru.bvn13'
version '1.0'
apply plugin: 'java'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}
dependencies {
testCompile group: 'junit', name: 'junit', version: '4.12'
}

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gradlew vendored Normal file
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#!/usr/bin/env sh
##############################################################################
##
## Gradle start up script for UN*X
##
##############################################################################
# Attempt to set APP_HOME
# Resolve links: $0 may be a link
PRG="$0"
# Need this for relative symlinks.
while [ -h "$PRG" ] ; do
ls=`ls -ld "$PRG"`
link=`expr "$ls" : '.*-> \(.*\)$'`
if expr "$link" : '/.*' > /dev/null; then
PRG="$link"
else
PRG=`dirname "$PRG"`"/$link"
fi
done
SAVED="`pwd`"
cd "`dirname \"$PRG\"`/" >/dev/null
APP_HOME="`pwd -P`"
cd "$SAVED" >/dev/null
APP_NAME="Gradle"
APP_BASE_NAME=`basename "$0"`
# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
DEFAULT_JVM_OPTS=""
# Use the maximum available, or set MAX_FD != -1 to use that value.
MAX_FD="maximum"
warn () {
echo "$*"
}
die () {
echo
echo "$*"
echo
exit 1
}
# OS specific support (must be 'true' or 'false').
cygwin=false
msys=false
darwin=false
nonstop=false
case "`uname`" in
CYGWIN* )
cygwin=true
;;
Darwin* )
darwin=true
;;
MINGW* )
msys=true
;;
NONSTOP* )
nonstop=true
;;
esac
CLASSPATH=$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" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
MAX_FD_LIMIT=`ulimit -H -n`
if [ $? -eq 0 ] ; then
if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
MAX_FD="$MAX_FD_LIMIT"
fi
ulimit -n $MAX_FD
if [ $? -ne 0 ] ; then
warn "Could not set maximum file descriptor limit: $MAX_FD"
fi
else
warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
fi
fi
# For Darwin, add options to specify how the application appears in the dock
if $darwin; then
GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
fi
# For Cygwin, switch paths to Windows format before running java
if $cygwin ; then
APP_HOME=`cygpath --path --mixed "$APP_HOME"`
CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
JAVACMD=`cygpath --unix "$JAVACMD"`
# We build the pattern for arguments to be converted via cygpath
ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
SEP=""
for dir in $ROOTDIRSRAW ; do
ROOTDIRS="$ROOTDIRS$SEP$dir"
SEP="|"
done
OURCYGPATTERN="(^($ROOTDIRS))"
# Add a user-defined pattern to the cygpath arguments
if [ "$GRADLE_CYGPATTERN" != "" ] ; then
OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
fi
# Now convert the arguments - kludge to limit ourselves to /bin/sh
i=0
for arg in "$@" ; do
CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
else
eval `echo args$i`="\"$arg\""
fi
i=$((i+1))
done
case $i in
(0) set -- ;;
(1) set -- "$args0" ;;
(2) set -- "$args0" "$args1" ;;
(3) set -- "$args0" "$args1" "$args2" ;;
(4) set -- "$args0" "$args1" "$args2" "$args3" ;;
(5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
(6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
(7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
(8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
(9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
esac
fi
# Escape application args
save () {
for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
echo " "
}
APP_ARGS=$(save "$@")
# Collect all arguments for the java command, following the shell quoting and substitution rules
eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
cd "$(dirname "$0")"
fi
exec "$JAVACMD" "$@"

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gradlew.bat vendored Normal file
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@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 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=
@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 init
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 init
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
:init
@rem Get command-line arguments, handling Windows variants
if not "%OS%" == "Windows_NT" goto win9xME_args
:win9xME_args
@rem Slurp the command line arguments.
set CMD_LINE_ARGS=
set _SKIP=2
:win9xME_args_slurp
if "x%~1" == "x" goto execute
set CMD_LINE_ARGS=%*
: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 %CMD_LINE_ARGS%
: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

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settings.gradle Normal file
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rootProject.name = 'FinalStateMachine'

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package ru.bvn13.fsm;
/**
* Created by bvn13 on 28.12.2017.
*/
public class Condition implements ConditionBehaviour {
private FSM fsm;
protected void setFSM(FSM fsm) {
this.fsm = fsm;
}
@Override
public boolean check() {
return false;
}
}

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package ru.bvn13.fsm;
/**
* Created by bvn13 on 28.12.2017.
*/
public interface ConditionBehaviour {
boolean check();
}

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package ru.bvn13.fsm.Exceptions;
import java.util.List;
/**
* Created by bvn13 on 28.12.2017.
*/
public class AmbiguousTransitionException extends FSMException {
public AmbiguousTransitionException(String message) {
super(message);
}
public AmbiguousTransitionException(String from, List<String> next) {
super("");
String msg = "";
for (String to : next) {
msg += (msg.length() > 0 ? ", " : "") + to;
}
this.message = String.format("Ambiguous transition from state %s. Candidates are: %s", from, msg);
}
}

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package ru.bvn13.fsm.Exceptions;
/**
* Created by bvn13 on 28.12.2017.
*/
public class BrokenTransitionException extends FSMException {
public BrokenTransitionException(String from) {
super("Broken transition from: "+from);
}
}

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package ru.bvn13.fsm.Exceptions;
/**
* Created by bvn13 on 28.12.2017.
*/
public class ConditionExistsException extends FSMException {
public ConditionExistsException(String from, String to) {
super(String.format("Condition exists: %s -> %s", from, to));
}
}

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package ru.bvn13.fsm.Exceptions;
import java.io.PrintWriter;
import java.io.StringWriter;
/**
* Created by bvn13 on 28.12.2017.
*/
public class FSMException extends Exception {
protected String message;
public FSMException(String message) {
this.message = message;
}
protected String getStackTraceString() {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
this.printStackTrace(pw);
return sw.toString();
}
public void printStackTrace() {
System.out.println(String.format("FSMException: %s / %s", message, getStackTraceString()));
}
}

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package ru.bvn13.fsm.Exceptions;
/**
* Created by bvn13 on 28.12.2017.
*/
public class NotInitedException extends FSMException {
public NotInitedException(String message) {
super(message);
}
public NotInitedException() {
super("FSM is not inited");
}
}

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package ru.bvn13.fsm.Exceptions;
/**
* Created by bvn13 on 28.12.2017.
*/
public class StateExistsException extends FSMException {
public StateExistsException(String stateName) {
super(String.format("State exist: %s", stateName));
}
}

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package ru.bvn13.fsm.Exceptions;
/**
* Created by bvn13 on 28.12.2017.
*/
public class TransitionMissedException extends FSMException {
public TransitionMissedException(String from) {
super(String.format("Missed conditions from: %s", from));
}
}

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package ru.bvn13.fsm;
import ru.bvn13.fsm.Exceptions.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Created by bvn13 on 28.12.2017.
*/
public class FSM {
private boolean done = false;
private State initialState;
private State currentState;
private Map<String, State> states;
private Map<String, Map<String, ConditionBehaviour>> transitions;
public FSM() {
this.states = new HashMap<>();
this.transitions = new HashMap<>();
}
private void checkStateExist(String name) throws StateExistsException {
if (this.states.containsKey(name)) {
throw new StateExistsException(name);
}
}
public void init() throws NotInitedException {
currentState = initialState;
if (currentState == null) {
throw new NotInitedException();
}
done = false;
currentState.beforeEvent();
currentState.process();
}
public State getCurrentState() {
return currentState;
}
public void next() throws FSMException {
if (done) {
return;
}
currentState.afterEvent();
if (currentState.isFinish()) {
done = true;
return;
}
if (!transitions.containsKey(currentState.getName())) {
throw new TransitionMissedException(currentState.getName());
}
Map<String, ConditionBehaviour> conditions = transitions.get(currentState.getName());
List<String> nextStates = new ArrayList<>();
for (String key : conditions.keySet()) {
if (conditions.get(key) == null) {
nextStates.add(key);
} else if(conditions.get(key).check()) {
nextStates.add(key);
}
}
if (nextStates.size() > 1) {
throw new AmbiguousTransitionException(currentState.getName(), nextStates);
}
if (nextStates.size() == 0) {
throw new BrokenTransitionException(currentState.getName());
}
State nextState = states.get(nextStates.get(0));
nextState(nextState);
}
private void nextState(State state) {
state.beforeEvent();
currentState = state;
currentState.process();
}
public void initState(State state) throws FSMException {
state.setFSM(this);
addState(state);
initialState = state;
}
public void addState(State state) throws FSMException {
checkStateExist(state.getName());
this.states.put(state.getName(), state);
}
public void addTransition(String fromState, String toState) throws FSMException {
storeTransition(fromState, toState, null);
}
public void addTransition(String fromState, String toState, Condition condition) throws FSMException {
condition.setFSM(this);
storeTransition(fromState, toState, condition);
}
public void addTransition(String fromState, State toState) throws FSMException {
addState(toState);
addTransition(fromState, toState.getName());
}
public void addTransition(String fromState, State toState, Condition condition) throws FSMException {
addState(toState);
addTransition(fromState, toState.getName(), condition);
}
private void storeTransition(String fromState, String toState, Condition condition) throws FSMException {
if (!transitions.containsKey(fromState)) {
transitions.put(fromState, new HashMap<>());
}
if (transitions.get(fromState).containsKey(toState)) {
throw new ConditionExistsException(fromState, toState);
}
transitions.get(fromState).put(toState, condition);
}
}

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package ru.bvn13.fsm;
/**
* Created by bvn13 on 28.12.2017.
*/
public class State implements StateBehaviour {
private String name;
private boolean finish;
private FSM fsm;
public void setFSM(FSM fsm) {
this.fsm = fsm;
}
public State(String name) {
this.name = name;
}
public State(String name, boolean finish) {
this.name = name;
this.finish = finish;
}
public String getName() {
return this.name;
}
public boolean isFinish() {
return finish;
}
}

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package ru.bvn13.fsm;
/**
* Created by bvn13 on 28.12.2017.
*/
public interface StateBehaviour {
default void beforeEvent() {
}
default void afterEvent() {
}
default void process() {
}
}

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package ru.bvn13.fsm.examples;
import ru.bvn13.fsm.Condition;
import ru.bvn13.fsm.Exceptions.FSMException;
import ru.bvn13.fsm.Exceptions.NotInitedException;
import ru.bvn13.fsm.FSM;
import ru.bvn13.fsm.State;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/**
* Created by bvn13 on 28.12.2017.
*/
public class Application {
public static class DialogFSM extends FSM {
public String command;
private BufferedReader br = null;
public void readCommand() {
System.out.print("Command: ");
br = new BufferedReader(new InputStreamReader(System.in));
try {
command = br.readLine();
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
}
}
public static void main(String argc[]) {
DialogFSM fsm = new DialogFSM();
try {
fsm.initState(new State("greeting") {
@Override
public void beforeEvent() {
System.out.println("Welcome!");
}
@Override
public void process() {
fsm.readCommand();
try {
fsm.next();
} catch (FSMException e) {
e.printStackTrace();
System.exit(-1);
}
}
@Override
public void afterEvent() {
System.out.println("Your command: "+fsm.command);
}
});
} catch (FSMException e) {
e.printStackTrace();
}
try {
fsm.addTransition("greeting", new State("hello", true) {
@Override
public void beforeEvent() {
System.out.println("Hello!");
}
@Override
public void process() {
}
@Override
public void afterEvent() {
System.out.println("DONE");
}
}, new Condition() {
@Override
public boolean check() {
return fsm.command.equalsIgnoreCase("hello");
}
});
} catch (FSMException e) {
e.printStackTrace();
}
try {
fsm.addTransition("greeting", "greeting", new Condition() {
@Override
public boolean check() {
return !fsm.command.equalsIgnoreCase("hello");
}
});
} catch (FSMException e) {
e.printStackTrace();
}
try {
fsm.init();
} catch (NotInitedException e) {
e.printStackTrace();
}
}
}

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package ru.bvn13.fsm.tests;
import org.junit.Assert;
import org.junit.Test;
import ru.bvn13.fsm.Exceptions.FSMException;
import ru.bvn13.fsm.Exceptions.NotInitedException;
import ru.bvn13.fsm.FSM;
import ru.bvn13.fsm.State;
/**
* Created by bvn13 on 28.12.2017.
*/
public class Tests {
public static class NamedFSM extends FSM {
public NamedFSM() {
super();
}
private String name;
public NamedFSM setName(String name) {
this.name = name;
return this;
}
public String toString() {
return this.name;
}
}
@Test
public void creatingFSM() {
NamedFSM fsm = (new NamedFSM()).setName("TEST FSM");
Assert.assertNotNull(fsm);
try {
fsm.initState(new State("init") {
@Override
public void process() {
System.out.println("" + fsm + " -> " + getName() + ": processed init");
try {
fsm.next();
} catch (FSMException e) {
e.printStackTrace();
Assert.fail();
}
}
});
} catch (FSMException e) {
e.printStackTrace();
Assert.fail();
}
try {
fsm.addTransition("init", new State("first", true) {
@Override
public void process() {
System.out.println("" + fsm + " -> " + getName() + ": processed first");
try {
fsm.next();
} catch (FSMException e) {
e.printStackTrace();
Assert.fail();
}
}
});
} catch (FSMException e) {
e.printStackTrace();
Assert.fail();
}
try {
fsm.init();
} catch (NotInitedException e) {
e.printStackTrace();
Assert.fail();
}
Assert.assertTrue(fsm.getCurrentState().getName().equals("first"));
}
}