Avoid .java regeneration when source model file is not modified

graphwalker-dsl/src/main/java/org/graphwalker/dsl/antlr/generator/GeneratorFactoryScanner.java

@@ -29,7 +29,7 @@
 import org.apache.commons.io.FilenameUtils;
 import org.graphwalker.core.generator.PathGeneratorBase;
 import org.reflections.Reflections;
-import org.reflections.scanners.SubTypesScanner;
+import org.reflections.scanners.Scanners;
 import org.reflections.util.ClasspathHelper;
 import org.reflections.util.ConfigurationBuilder;
 import org.slf4j.Logger;
@@ -47,10 +47,6 @@ private GeneratorFactoryScanner() {
 
   private static final Logger logger = LoggerFactory.getLogger(GeneratorFactoryScanner.class);
 
-  static {
-    Reflections.log = null;
-  }
-
   private static boolean valid(URL url) {
     String extension = FilenameUtils.getExtension(url.getPath());
     return "".equals(extension) || "jar".equals(extension);
@@ -71,7 +67,7 @@ private static Collection<URL> getUrls() {
   }
 
   public static Class get(String generator) {
-    return get(new Reflections(new ConfigurationBuilder().addUrls(getUrls()).addScanners(new SubTypesScanner())), generator);
+    return get(new Reflections(new ConfigurationBuilder().addUrls(getUrls()).setScanners(Scanners.SubTypes)), generator);
   }
 
   public static Class get(Reflections reflections, String generatorString) {

graphwalker-io/src/main/java/org/graphwalker/io/factory/ContextFactoryScanner.java

@@ -33,9 +33,16 @@
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ExecutionException;
+
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
 import org.apache.commons.io.FilenameUtils;
 import org.reflections.Reflections;
-import org.reflections.scanners.SubTypesScanner;
+import org.reflections.scanners.Scanners;
 import org.reflections.util.ClasspathHelper;
 import org.reflections.util.ConfigurationBuilder;
 import org.slf4j.Logger;
@@ -56,10 +63,6 @@ private ContextFactoryScanner() {
 
   private static final Logger logger = LoggerFactory.getLogger(ContextFactoryScanner.class);
 
-  static {
-    Reflections.log = null;
-  }
-
   private static Map<Class<? extends ContextFactory>, ContextFactory> factories = new HashMap<>();
 
   private static boolean valid(URL url) {
@@ -80,13 +83,28 @@ private static Collection<URL> getUrls() {
     return filteredUrls;
   }
 
-  public static ContextFactory get(Path path) {
-    return get(new Reflections(new ConfigurationBuilder().addUrls(getUrls()).addScanners(new SubTypesScanner())), path);
+  private static Reflections getReflections(Collection<URL> urls) {
+    return new Reflections(new ConfigurationBuilder().addUrls(urls).setScanners(Scanners.SubTypes));
+  }
+
+  public static ContextFactory get(Path path){
+    Supplier<Collection<URL>> memoizedUrls;
+    memoizedUrls = Suppliers.memoize(ContextFactoryScanner::getUrls);
+
+    return get(getReflections(memoizedUrls.get()), path);
   }
 
   public static ContextFactory get(Reflections reflections, Path path) {
+    LoadingCache<Class<? extends ContextFactory>, ContextFactory> memo = CacheBuilder.newBuilder()
+      .build(CacheLoader.from(ContextFactoryScanner::create));
+
     for (Class<? extends ContextFactory> factoryClass : reflections.getSubTypesOf(ContextFactory.class)) {
-      ContextFactory factory = create(factoryClass);
+      ContextFactory factory = null;
+      try {
+        factory = memo.get(factoryClass);
+      } catch (ExecutionException e) {
+        factory = create(factoryClass);
+      }
       if (null != factory && factory.accept(path)) {
         return factory;
       }

graphwalker-java/pom.xml

@@ -81,6 +81,10 @@
       <artifactId>classgraph</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+    </dependency>
   </dependencies>
 
   <build>

graphwalker-java/src/main/java/org/graphwalker/java/source/CodeGenerator.java

@@ -49,8 +49,10 @@
 import java.io.IOException;
 import java.lang.reflect.Modifier;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.*;
 import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.FileTime;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -91,7 +93,7 @@ public FileVisitResult visitFile(Path file, BasicFileAttributes attributes) thro
         }
 
         private boolean isModified(Path file) throws IOException {
-          return !Files.getLastModifiedTime(file).equals(cache.get(file).getLastModifiedTime());
+          return Files.getLastModifiedTime(file).toMillis() != cache.get(file).getLastModifiedTime().toMillis();
         }
 
         @Override
@@ -111,7 +113,7 @@ private static void write(Context context, SourceFile file) throws IOException {
       RuntimeModel model = context.getModel();
       String source = generator.generate(file, model);
       Files.createDirectories(file.getOutputPath().getParent());
-      Files.write(file.getOutputPath(), source.getBytes(Charset.forName("UTF-8"))
+      Files.write(file.getOutputPath(), source.getBytes(StandardCharsets.UTF_8)
         , StandardOpenOption.CREATE
         , StandardOpenOption.TRUNCATE_EXISTING);
     } catch (Throwable t) {

graphwalker-java/src/main/java/org/graphwalker/java/source/cache/SimpleCache.java

@@ -32,6 +32,7 @@
 import java.io.IOException;
 import java.lang.reflect.Type;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -60,7 +61,7 @@ public SimpleCache(Path path) {
   private void read() {
     if (Files.exists(path)) {
       try {
-        String json = new String(Files.readAllBytes(path), Charset.forName("UTF-8"));
+        String json = new String(Files.readAllBytes(path), StandardCharsets.UTF_8);
         Map<String, CacheEntry> data = gson.fromJson(json, type);
         storage.putAll(data);
       } catch (IOException e) {
@@ -74,7 +75,7 @@ private void save() {
     try {
       String json = gson.toJson(storage);
       Files.createDirectories(path.getParent());
-      Files.write(path, json.getBytes(Charset.forName("UTF-8")));
+      Files.write(path, json.getBytes(StandardCharsets.UTF_8));
     } catch (IOException e) {
       logger.error(e.getMessage());
       throw new CacheException(e);

graphwalker-java/src/main/java/org/graphwalker/java/test/TestExecutor.java

@@ -40,8 +40,7 @@
 import org.graphwalker.java.factory.PathGeneratorFactory;
 import org.graphwalker.java.report.XMLReportGenerator;
 import org.reflections.Reflections;
-import org.reflections.scanners.SubTypesScanner;
-import org.reflections.scanners.TypeAnnotationsScanner;
+import org.reflections.scanners.Scanners;
 import org.reflections.util.ClasspathHelper;
 import org.reflections.util.ConfigurationBuilder;
 import org.slf4j.Logger;
@@ -70,10 +69,9 @@ public final class TestExecutor implements Executor, Observer {
 
   private static final Reflections reflections = new Reflections(new ConfigurationBuilder()
     .addUrls(filter(ClasspathHelper.forJavaClassPath(), ClasspathHelper.forClassLoader()))
-    .addScanners(new SubTypesScanner(), new TypeAnnotationsScanner()));
+    .setScanners(Scanners.SubTypes, Scanners.TypesAnnotated));
 
   private static Collection<URL> filter(Collection<URL> classPath, Collection<URL> classLoader) {
-    Reflections.log = null;
     List<URL> urls = new ArrayList<>(), filteredUrls = new ArrayList<>();
     urls.addAll(classPath);
     urls.addAll(classLoader);

graphwalker-java/src/test/java/org/graphwalker/java/source/CodeGeneratorTest.java

@@ -0,0 +1,70 @@
+package org.graphwalker.java.source;
+
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.*;
+import java.nio.file.attribute.FileTime;
+import java.util.Arrays;
+
+import static org.junit.Assert.*;
+
+public class CodeGeneratorTest {
+
+@Test
+public void testOnlyRegenerateWhenSourceIsModified() throws IOException, URISyntaxException {
+    String tmpdir = System.getProperty("java.io.tmpdir");
+    Path inputDir = Files.createTempDirectory(Paths.get(tmpdir), "input").toAbsolutePath();
+    Path outputDir = Files.createTempDirectory(Paths.get(tmpdir), "output").toAbsolutePath();
+
+    // sample file
+    URL resource = getClass().getClassLoader().getResource("org/graphwalker/java/path with space/MyModel.graphml");
+    File testFile = new File(resource.toURI());
+
+    Files.copy(testFile.toPath(), inputDir.resolve(testFile.getName()), StandardCopyOption.REPLACE_EXISTING);
+    FileTime sourceLastModified = Files.getLastModifiedTime(inputDir.resolve(testFile.getName()));
+
+    File[] inputFiles = Arrays.stream(inputDir.toFile().listFiles())
+      .toArray(File[]::new);
+
+    assertEquals(1, inputFiles.length);
+
+    // run codegenerator  for each input files in inputDir
+    CodeGenerator.generate(inputDir, outputDir);
+
+    // source modified time should not be altered
+    FileTime sourceLastModifiedDelta = Files.getLastModifiedTime(inputDir.resolve(testFile.getName()));
+    assertEquals(sourceLastModified.toMillis(), sourceLastModifiedDelta.toMillis());
+
+    // glob the output files, find the one with the same name as the input file
+    File[] outputFiles = Arrays.stream(outputDir.toFile().listFiles())
+      .filter(f -> f.getName().equals(testFile.getName().replace(".graphml", ".java")))
+      .toArray(File[]::new);
+
+    assertEquals(1, outputFiles.length);
+    assertEquals("MyModel.java", outputFiles[0].getName());
+
+    // note lst modified time is in milliseconds
+    long lastModified = outputFiles[0].lastModified();
+
+    // sleep 5 seconds to make sure the last modified time is different
+    try {
+      Thread.sleep(5000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+
+    // regenerate the file
+    CodeGenerator.generate(inputDir, outputDir);
+
+    // check that the file was not regenerated
+    outputFiles = Arrays.stream(outputDir.toFile().listFiles())
+      .filter(f -> f.getName().equals(testFile.getName().replace(".graphml", ".java")))
+      .toArray(File[]::new);
+    assertEquals(1, outputFiles.length);
+    assertEquals(lastModified, outputFiles[0].lastModified());
+  }
+}

graphwalker-java/src/test/java/org/graphwalker/java/source/cache/SimpleCacheTest.java

@@ -0,0 +1,30 @@
+package org.graphwalker.java.source.cache;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import static org.junit.Assert.*;
+
+public class SimpleCacheTest {
+
+  @Test
+  public void get() throws IOException {
+    SimpleCache cache = new SimpleCache(Paths.get("./"));
+    // create temporary file
+    File foo = File.createTempFile("prefix", "suffix");
+    foo.deleteOnExit();
+    Path key = foo.toPath();
+    long lastModified = foo.lastModified();
+    cache.add(key, new CacheEntry(lastModified, true));
+    CacheEntry cached = cache.get(key);
+    assertEquals(lastModified, cached.getLastModifiedTime().toMillis());
+    assertEquals(true, cached.isGenerated());
+
+    assertTrue(cache.contains(key));
+  }
+}

pom.xml

@@ -206,7 +206,7 @@
       <dependency>
         <groupId>org.reflections</groupId>
         <artifactId>reflections</artifactId>
-        <version>0.9.12</version>
+        <version>0.10.2</version>
       </dependency>
       <dependency>
         <groupId>com.google.code.javaparser</groupId>