Parallel processing of files

src/main/java/org/codehaus/mojo/license/AbstractFileHeaderMojo.java

@@ -24,16 +24,17 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 import java.util.Collections;
 import java.util.EnumMap;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
+import java.util.concurrent.ConcurrentHashMap;
 
 import freemarker.template.Template;
 import org.apache.commons.lang3.StringUtils;
@@ -360,7 +361,7 @@ public abstract class AbstractFileHeaderMojo extends AbstractLicenseNameMojo {
     /**
      * Dictionary of treated files indexed by their state.
      */
-    EnumMap<FileState, Set<File>> result;
+    Map<FileState, Set<File>> result;
 
     /**
      * Dictionary of files to treat indexed by their CommentStyle.
@@ -533,7 +534,7 @@ public void doAction() throws Exception {
 
         long t0 = System.nanoTime();
 
-        processedFiles = new HashSet<>();
+        processedFiles = ConcurrentHashMap.newKeySet();
         result = new EnumMap<>(FileState.class);
 
         try {
@@ -586,7 +587,7 @@ public void doAction() throws Exception {
      * @param result processed files by their status
      * @throws MojoFailureException if check is not ok (some file with no header or to update)
      */
-    private void checkResults(EnumMap<FileState, Set<File>> result) throws MojoFailureException {
+    private void checkResults(Map<FileState, Set<File>> result) throws MojoFailureException {
         Set<FileState> states = result.keySet();
 
         StringBuilder builder = new StringBuilder();
@@ -633,10 +634,18 @@ private void processCommentStyle(String commentStyle, List<File> filesToTreat) t
 
         // use header transformer according to comment style given in header
         FileHeaderTransformer transformer = getTransformer(transformers, commentStyle);
-        FileHeaderProcessor processor = getFileHeaderProcessor(license, transformer);
 
-        for (File file : filesToTreat) {
-            processFile(processor, file);
+        try {
+            filesToTreat.parallelStream().forEach(file -> {
+                try {
+                    FileHeaderProcessor processor = getFileHeaderProcessor(license, transformer);
+                    processFile(processor, file);
+                } catch (IOException e) {
+                    throw new UncheckedIOException(e);
+                }
+            });
+        } catch (UncheckedIOException e) {
+            throw e.getCause();
         }
         filesToTreat.clear();
     }

src/main/java/org/codehaus/mojo/license/AbstractLicenseNameMojo.java

@@ -27,7 +27,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -388,7 +387,7 @@ FileHeaderTransformer getTransformer(Map<String, FileHeaderTransformer> transfor
      * @param state  state of file to report
      * @param buffer where to report
      */
-    void reportType(EnumMap<FileState, Set<File>> result, FileState state, StringBuilder buffer) {
+    void reportType(Map<FileState, Set<File>> result, FileState state, StringBuilder buffer) {
         String operation = state.name();
 
         Set<File> set = getFiles(result, state);
@@ -499,7 +498,7 @@ Map<String, List<File>> obtainFilesToProcessByCommentStyle(
      * @param state state of files to get
      * @return all files of the given state
      */
-    private Set<File> getFiles(EnumMap<FileState, Set<File>> result, FileState state) {
+    private Set<File> getFiles(Map<FileState, Set<File>> result, FileState state) {
         return result.get(state);
     }
 

src/main/java/org/codehaus/mojo/license/FileState.java

@@ -23,9 +23,9 @@
  */
 
 import java.io.File;
-import java.util.EnumMap;
-import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Defines state of a file after process.
@@ -70,12 +70,7 @@ public enum FileState {
      * @param file    file to add
      * @param results dictionary to update
      */
-    public void addFile(File file, EnumMap<FileState, Set<File>> results) {
-        Set<File> fileSet = results.get(this);
-        if (fileSet == null) {
-            fileSet = new HashSet<>();
-            results.put(this, fileSet);
-        }
-        fileSet.add(file);
+    public void addFile(File file, Map<FileState, Set<File>> results) {
+        results.computeIfAbsent(this, k -> ConcurrentHashMap.newKeySet()).add(file);
     }
 }