Introduce StoredBoolean

2 files changed, 61 insertions, 0 deletions

diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/StoredBoolean.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/StoredBoolean.java
new file mode 100644
index 00000000000..8edf5f7dcbd
--- /dev/null
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/StoredBoolean.java
@@ -0,0 +1,45 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.node.admin.task.util.file;
+
+import com.yahoo.vespa.hosted.node.admin.component.TaskContext;
+
+import java.nio.file.Path;
+import java.util.logging.Logger;
+
+/**
+ * Class wrapping a boolean stored on disk.
+ *
+ * <p>The implementation is compatible with {@link StoredInteger} when absence or 0 means false.
+ *
+ * @author hakonhall
+ */
+public class StoredBoolean {
+    private static Logger logger = Logger.getLogger(StoredBoolean.class.getName());
+
+    private final UnixPath path;
+
+    /** The parent directory must exist. Value is false by default. */
+    public StoredBoolean(Path path) {
+        this.path = new UnixPath(path);
+    }
+
+    public boolean value() {
+        return path.readUtf8FileIfExists().map(String::trim).map(s -> !"0".equals(s)).orElse(false);
+    }
+
+    /** Sets value to true. */
+    public void set(TaskContext context) {
+        if (!value()) {
+            context.log(logger, "Writes " + path);
+            path.writeUtf8File("1");
+        }
+    }
+
+    /** Sets value to false. */
+    public void clear(TaskContext context) {
+        if (value()) {
+            context.log(logger, "Deletes " + path);
+            path.deleteIfExists();
+        }
+    }
+}
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPath.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPath.java
index 1d0299ae272..cd008c5bdfc 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPath.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPath.java
@@ -1,6 +1,8 @@
 // Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.node.admin.task.util.file;
 
+import org.eclipse.jetty.io.RuntimeIOException;
+
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.nio.charset.StandardCharsets;
@@ -50,10 +52,24 @@ public class UnixPath {
         return path;
     }
 
+    public boolean exists() {
+        return Files.exists(path);
+    }
+
     public String readUtf8File() {
         return new String(readBytes(), StandardCharsets.UTF_8);
     }
 
+    public Optional<String> readUtf8FileIfExists() {
+        try {
+            return Optional.of(new String(Files.readAllBytes(path), StandardCharsets.UTF_8));
+        } catch (NoSuchFileException ignored) {
+            return Optional.empty();
+        } catch (IOException e) {
+            throw new RuntimeIOException(e);
+        }
+    }
+
     public byte[] readBytes() {
         return uncheck(() -> Files.readAllBytes(path));
     }