# HG changeset patch
# User Jaroslav Tulach <jtulach@netbeans.org>
# Date 1213430028 -7200
# Node ID 618b79994cd457aaa50d9b0b469e649e502d2305
# Parent  adf4440db8886de15c929d72543240878d7b0655
How to eliminate cyclic dependencies

diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/build.xml
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/build.xml	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,67 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project name="preventcyclicdependencies" default="run" basedir=".">
+    <target name="clean">
+        <delete dir="build"/>
+    </target>
+    
+    <target name="build">
+        <antcall target="-build-one">
+            <param name="version" value="cyclic"/>
+        </antcall>
+        <antcall target="-build-one">
+            <param name="version" value="test"/>
+            <param name="cp" location="build/cyclic/classes"/>
+        </antcall>
+        <antcall target="-build-one">
+            <param name="version" value="acyclic1"/>
+        </antcall>
+        <antcall target="-build-one">
+            <param name="version" value="acyclic2"/>
+            <param name="cp" location="build/acyclic1/classes"/>
+        </antcall>
+    </target>
+    
+    <target name="run" depends="build">
+        <echo level="info" message="Running old API with cycles between packages:"/>
+        <antcall target="-run-one">
+            <param name="version1" value="cyclic"/>
+        </antcall>
+        <echo level="info" message="Running new API without cycles:"/>
+        <antcall target="-run-one">
+            <param name="version1" value="acyclic1"/>
+            <param name="version2" value="acyclic2"/>
+        </antcall>
+    </target>
+
+    
+    <!-- support methods -->
+    
+    <target name="-run-one">
+        <java 
+            classpath="build/${version1}/classes:build/${version2}/classes:build/test/classes:../libs/dist/org-openide-util.jar" 
+            classname="org.apidesign.cycles.array.test.Main"
+            failonerror="true" 
+        >
+            <jvmarg value="-ea"/>
+        </java>
+    </target>
+    
+    <target name="-build-one">
+        <fail message="You need to specify version number" unless="version"/>
+        
+        <mkdir dir="build/${version}/classes"/>
+        <property name="cp" value=""/>
+        <javac 
+            srcdir="src-${version}" 
+            destdir="build/${version}/classes" 
+            source="1.5" target="1.5"
+            debug="true"
+            classpath="${cp}"
+        />
+        <copy todir="build/${version}/classes">
+            <fileset dir="src-${version}">
+                <exclude name="**/*.java"/>
+            </fileset>
+        </copy>
+    </target>
+</project>
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/nbproject/project.xml
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/nbproject/project.xml	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,116 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://www.netbeans.org/ns/project/1" xmlns:ns4="null">
+    <type>org.netbeans.modules.ant.freeform</type>
+    <configuration>
+        <general-data xmlns="http://www.netbeans.org/ns/freeform-project/1">
+            <name>preventcyclicdependencies</name>
+        </general-data>
+        <general-data xmlns="http://www.netbeans.org/ns/freeform-project/2">
+            <!-- Do not use Project Properties customizer when editing this file manually. -->
+            <name>preventcyclicdependencies</name>
+            <properties/>
+            <folders>
+                <source-folder>
+                    <label>preventcyclicdependencies</label>
+                    <location>.</location>
+                    <encoding>UTF-8</encoding>
+                </source-folder>
+                <source-folder>
+                    <label>src-cyclic</label>
+                    <type>java</type>
+                    <location>src-cyclic</location>
+                    <encoding>UTF-8</encoding>
+                </source-folder>
+                <source-folder>
+                    <label>src-test</label>
+                    <type>java</type>
+                    <location>src-test</location>
+                    <encoding>UTF-8</encoding>
+                </source-folder>
+                <source-folder>
+                    <label>src-acyclic1</label>
+                    <type>java</type>
+                    <location>src-acyclic1</location>
+                    <encoding>UTF-8</encoding>
+                </source-folder>
+                <source-folder>
+                    <label>src-acyclic2</label>
+                    <type>java</type>
+                    <location>src-acyclic2</location>
+                    <encoding>UTF-8</encoding>
+                </source-folder>
+            </folders>
+            <ide-actions>
+                <action name="build">
+                    <target>build</target>
+                </action>
+                <action name="clean">
+                    <target>clean</target>
+                </action>
+                <action name="run">
+                    <target>run</target>
+                </action>
+                <action name="rebuild">
+                    <target>clean</target>
+                    <target>build</target>
+                </action>
+            </ide-actions>
+            <view>
+                <items>
+                    <source-folder style="packages">
+                        <label>src-cyclic</label>
+                        <location>src-cyclic</location>
+                    </source-folder>
+                    <source-folder style="packages">
+                        <label>src-test</label>
+                        <location>src-test</location>
+                    </source-folder>
+                    <source-folder style="packages">
+                        <label>src-acyclic1</label>
+                        <location>src-acyclic1</location>
+                    </source-folder>
+                    <source-folder style="packages">
+                        <label>src-acyclic2</label>
+                        <location>src-acyclic2</location>
+                    </source-folder>
+                    <source-file>
+                        <location>build.xml</location>
+                    </source-file>
+                </items>
+                <context-menu>
+                    <ide-action name="build"/>
+                    <ide-action name="rebuild"/>
+                    <ide-action name="clean"/>
+                    <ide-action name="run"/>
+                    <ide-action name="debug"/>
+                </context-menu>
+            </view>
+            <subprojects/>
+        </general-data>
+        <java-data xmlns="http://www.netbeans.org/ns/freeform-project-java/1">
+            <compilation-unit>
+                <package-root>src-cyclic</package-root>
+                <built-to>build/cyclic/classes</built-to>
+                <source-level>1.5</source-level>
+            </compilation-unit>
+            <compilation-unit>
+                <package-root>src-test</package-root>
+                <classpath mode="compile">src-cyclic</classpath>
+                <built-to>build/test/classes</built-to>
+                <source-level>1.5</source-level>
+            </compilation-unit>
+            <compilation-unit>
+                <package-root>src-acyclic1</package-root>
+                <classpath mode="compile">../libs/dist/org-openide-util.jar</classpath>
+                <built-to>build/acyclic1/classes</built-to>
+                <source-level>1.5</source-level>
+            </compilation-unit>
+            <compilation-unit>
+                <package-root>src-acyclic2</package-root>
+                <classpath mode="compile">src-acyclic1</classpath>
+                <built-to>build/acyclic2/classes</built-to>
+                <source-level>1.5</source-level>
+            </compilation-unit>
+        </java-data>
+    </configuration>
+</project>
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-acyclic1/org/apidesign/cycles/array/MutableArray.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-acyclic1/org/apidesign/cycles/array/MutableArray.java	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,38 @@
+package org.apidesign.cycles.array;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import org.openide.util.Lookup;
+// BEGIN: nocycles.ma2
+public class MutableArray {
+    private byte[] arr;
+
+    public MutableArray(byte[] arr) {
+        this.arr = arr;
+    }
+
+    public void xor(byte b) {
+        for (int i = 0; i < arr.length; i++) { arr[i] ^= b; }
+    }
+
+    public void and(byte b) {
+        for (int i = 0; i < arr.length; i++) { arr[i] &= b; }
+    }
+
+    public void or(byte b) {
+        for (int i = 0; i < arr.length; i++) { arr[i] |= b; }
+    }
+
+    public void encrypt(OutputStream os) throws IOException {
+        DoEncode en = Lookup.getDefault().lookup(DoEncode.class);
+        assert en != null : "We need org.netbeans.example.crypt to be enabled!";
+        byte[] clone = (byte[]) arr.clone();
+        en.encode(clone);
+        os.write(clone);
+    }
+    
+    public interface DoEncode {
+        public void encode(byte[] arr);
+    }
+}
+// END: nocycles.ma2
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-acyclic2/META-INF/services/org.apidesign.cycles.array.MutableArray$DoEncode
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-acyclic2/META-INF/services/org.apidesign.cycles.array.MutableArray$DoEncode	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,1 @@
+org.apidesign.cycles.crypt.DoEncodeImpl
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-acyclic2/org/apidesign/cycles/crypt/DoEncodeImpl.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-acyclic2/org/apidesign/cycles/crypt/DoEncodeImpl.java	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,12 @@
+// BEGIN: nocycles.encrypt2
+package org.apidesign.cycles.crypt;
+
+import org.apidesign.cycles.array.MutableArray;
+
+public class DoEncodeImpl implements MutableArray.DoEncode {
+    public void encode(byte[] arr) {
+        Encryptor en = new Encryptor();
+        en.encode(arr);
+    }
+}
+// END: nocycles.encrypt2
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-acyclic2/org/apidesign/cycles/crypt/Encryptor.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-acyclic2/org/apidesign/cycles/crypt/Encryptor.java	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,10 @@
+package org.apidesign.cycles.crypt;
+
+import org.apidesign.cycles.array.MutableArray;
+
+public final class Encryptor {
+    public void encode(byte[] arr) {
+        MutableArray m = new MutableArray(arr);
+        m.xor((byte)0x3d);
+    }
+}
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-cyclic/org/apidesign/cycles/array/MutableArray.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-cyclic/org/apidesign/cycles/array/MutableArray.java	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,35 @@
+// BEGIN: cycles.ma1
+package org.apidesign.cycles.array;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import org.apidesign.cycles.crypt.Encryptor;
+
+public class MutableArray {
+    private byte[] arr;
+
+    public MutableArray(byte[] arr) {
+        this.arr = arr;
+    }
+
+    public void xor(byte b) {
+        for (int i = 0; i < arr.length; i++) { arr[i] ^= b; }
+    }
+
+    public void and(byte b) {
+        for (int i = 0; i < arr.length; i++) { arr[i] &= b; }
+    }
+
+    public void or(byte b) {
+        for (int i = 0; i < arr.length; i++) { arr[i] |= b; }
+    }
+
+    public void encrypt(OutputStream os) throws IOException {
+        Encryptor en = new Encryptor();
+        byte[] clone = (byte[]) arr.clone();
+        en.encode(clone);
+        os.write(clone);
+    }
+}
+// END: cycles.ma1
+
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-cyclic/org/apidesign/cycles/crypt/Encryptor.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-cyclic/org/apidesign/cycles/crypt/Encryptor.java	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,12 @@
+// BEGIN: cycles.encryptor1
+package org.apidesign.cycles.crypt;
+
+import org.apidesign.cycles.array.MutableArray;
+
+public final class Encryptor {
+    public void encode(byte[] arr) {
+        MutableArray m = new MutableArray(arr);
+        m.xor((byte)0x3d);
+    }
+}
+// END: cycles.encryptor1
diff -r adf4440db888 -r 618b79994cd4 samples/preventcyclicdependencies/src-test/org/apidesign/cycles/array/test/Main.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/preventcyclicdependencies/src-test/org/apidesign/cycles/array/test/Main.java	Sat Jun 14 09:53:48 2008 +0200
@@ -0,0 +1,29 @@
+package org.apidesign.cycles.array.test;
+
+import org.apidesign.cycles.array.*;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import org.apidesign.cycles.crypt.Encryptor;
+
+public class Main {
+    public static void main(String[] args) throws Exception {
+        byte[] five = { 1, 2, 3, 4, 5 };
+        MutableArray arr = new MutableArray(five);
+        
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        arr.encrypt(os);
+        
+        byte[] out = os.toByteArray();
+        assert out.length == 5;
+        
+        for (int i = 0; i < 5; i++) {
+            int exp = five[i] ^ 0x3d;
+            if (exp != out[i]) {
+                assert false : "Index: " + i + " exp: " + exp + " was: " + out[i];
+            }
+        }
+        System.err.println("OK");
+    }
+}
+