add overridden methods to support exclusive file entitlement

Author: jdconrad

server/src/main/java/org/elasticsearch/common/file/AbstractFileWatchingService.java

@@ -63,6 +63,7 @@ public abstract class AbstractFileWatchingService extends AbstractLifecycleCompo
     private WatchKey settingsDirWatchKey;
     private WatchKey configDirWatchKey;
 
+    @SuppressWarnings("this-escape")
     public AbstractFileWatchingService(Path settingsDir) {
         if (filesExists(settingsDir) && filesIsDirectory(settingsDir) == false) {
             throw new IllegalArgumentException("settingsDir should be a directory");

server/src/main/java/org/elasticsearch/reservedstate/service/FileSettingsService.java

@@ -350,26 +350,32 @@ public synchronized HealthIndicatorResult calculate(boolean verbose, int maxAffe
     // the following methods are a workaround to ensure exclusive access for files
     // required by child watchers; this is required because we only check the caller's module
     // not the entire stack
+    @Override
     protected boolean filesExists(Path path) {
         return Files.exists(path);
     }
 
+    @Override
     protected boolean filesIsDirectory(Path path) {
         return Files.isDirectory(path);
     }
 
+    @Override
     protected <A extends BasicFileAttributes> A filesReadAttributes(Path path, Class<A> clazz) throws IOException {
         return Files.readAttributes(path, clazz);
     }
 
+    @Override
     protected Stream<Path> filesList(Path dir) throws IOException {
         return Files.list(dir);
     }
 
+    @Override
     protected Path filesSetLastModifiedTime(Path path, FileTime time) throws IOException {
         return Files.setLastModifiedTime(path, time);
     }
 
+    @Override
     protected InputStream filesNewInputStream(Path path) throws IOException {
         return Files.newInputStream(path);
     }

server/src/test/java/org/elasticsearch/common/file/AbstractFileWatchingServiceTests.java

@@ -24,11 +24,13 @@
 import org.junit.Before;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardWatchEventKinds;
 import java.nio.file.WatchKey;
+import java.nio.file.attribute.BasicFileAttributes;
 import java.nio.file.attribute.FileTime;
 import java.time.Instant;
 import java.time.LocalDateTime;
@@ -40,6 +42,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
+import java.util.stream.Stream;
 
 import static org.elasticsearch.node.Node.NODE_NAME_SETTING;
 import static org.elasticsearch.test.hamcrest.OptionalMatchers.isEmpty;
@@ -81,6 +84,39 @@ protected void processInitialFilesMissing() {
                 called.accept(null);
             }
         }
+
+        // the following methods are a workaround to ensure exclusive access for files
+        // required by child watchers; this is required because we only check the caller's module
+        // not the entire stack
+        @Override
+        protected boolean filesExists(Path path) {
+            return Files.exists(path);
+        }
+
+        @Override
+        protected boolean filesIsDirectory(Path path) {
+            return Files.isDirectory(path);
+        }
+
+        @Override
+        protected <A extends BasicFileAttributes> A filesReadAttributes(Path path, Class<A> clazz) throws IOException {
+            return Files.readAttributes(path, clazz);
+        }
+
+        @Override
+        protected Stream<Path> filesList(Path dir) throws IOException {
+            return Files.list(dir);
+        }
+
+        @Override
+        protected Path filesSetLastModifiedTime(Path path, FileTime time) throws IOException {
+            return Files.setLastModifiedTime(path, time);
+        }
+
+        @Override
+        protected InputStream filesNewInputStream(Path path) throws IOException {
+            return Files.newInputStream(path);
+        }
     }
 
     private Path watchedFile;

server/src/test/java/org/elasticsearch/common/file/MasterNodeFileWatchingServiceTests.java

@@ -26,9 +26,14 @@
 import org.junit.Before;
 
 import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.FileTime;
 import java.util.concurrent.ExecutionException;
 import java.util.function.Consumer;
+import java.util.stream.Stream;
 
 import static org.hamcrest.Matchers.is;
 import static org.mockito.Mockito.mock;
@@ -62,6 +67,39 @@ protected void processFileChanges(Path file) throws InterruptedException, Execut
             protected void processInitialFilesMissing() throws InterruptedException, ExecutionException, IOException {
                 // file always exists, but we don't care about the missing case for master node behavior
             }
+
+            // the following methods are a workaround to ensure exclusive access for files
+            // required by child watchers; this is required because we only check the caller's module
+            // not the entire stack
+            @Override
+            protected boolean filesExists(Path path) {
+                return Files.exists(path);
+            }
+
+            @Override
+            protected boolean filesIsDirectory(Path path) {
+                return Files.isDirectory(path);
+            }
+
+            @Override
+            protected <A extends BasicFileAttributes> A filesReadAttributes(Path path, Class<A> clazz) throws IOException {
+                return Files.readAttributes(path, clazz);
+            }
+
+            @Override
+            protected Stream<Path> filesList(Path dir) throws IOException {
+                return Files.list(dir);
+            }
+
+            @Override
+            protected Path filesSetLastModifiedTime(Path path, FileTime time) throws IOException {
+                return Files.setLastModifiedTime(path, time);
+            }
+
+            @Override
+            protected InputStream filesNewInputStream(Path path) throws IOException {
+                return Files.newInputStream(path);
+            }
         };
         testService.start();
     }