1 files changed, 76 insertions, 0 deletions
diff --git a/jimfs/src/main/java/com/google/common/jimfs/WatchServiceConfiguration.java b/jimfs/src/main/java/com/google/common/jimfs/WatchServiceConfiguration.java
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+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.common.jimfs;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static java.util.concurrent.TimeUnit.SECONDS;
+
+import java.nio.file.WatchService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Configuration for the {@link WatchService} implementation used by a file system.
+ *
+ * @author Colin Decker
+ * @since 1.1
+ */
+public abstract class WatchServiceConfiguration {
+
+  /** The default configuration that's used if the user doesn't provide anything more specific. */
+  static final WatchServiceConfiguration DEFAULT = polling(5, SECONDS);
+
+  /**
+   * Returns a configuration for a {@link WatchService} that polls watched directories for changes
+   * every {@code interval} of the given {@code timeUnit} (e.g. every 5 {@link TimeUnit#SECONDS
+   * seconds}).
+   */
+  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
+  public static WatchServiceConfiguration polling(long interval, TimeUnit timeUnit) {
+    return new PollingConfig(interval, timeUnit);
+  }
+
+  WatchServiceConfiguration() {}
+
+  /** Creates a new {@link AbstractWatchService} implementation. */
+  // return type and parameters of this method subject to change if needed for any future
+  // implementations
+  abstract AbstractWatchService newWatchService(FileSystemView view, PathService pathService);
+
+  /** Implementation for {@link #polling}. */
+  private static final class PollingConfig extends WatchServiceConfiguration {
+
+    private final long interval;
+    private final TimeUnit timeUnit;
+
+    private PollingConfig(long interval, TimeUnit timeUnit) {
+      checkArgument(interval > 0, "interval (%s) must be positive", interval);
+      this.interval = interval;
+      this.timeUnit = checkNotNull(timeUnit);
+    }
+
+    @Override
+    AbstractWatchService newWatchService(FileSystemView view, PathService pathService) {
+      return new PollingWatchService(view, pathService, view.state(), interval, timeUnit);
+    }
+
+    @Override
+    public String toString() {
+      return "WatchServiceConfiguration.polling(" + interval + ", " + timeUnit + ")";
+    }
+  }
+}