Add readBytesIfExists to UnixPath

2 files changed, 22 insertions, 0 deletions

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 de3555b24a5..20a02e91bce 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
@@ -72,6 +72,17 @@ public class UnixPath {
         return uncheck(() -> Files.readAllBytes(path));
     }
 
+    /** Reads and returns all bytes contained in this path, if any such path exists. */
+    public Optional<byte[]> readBytesIfExists() {
+        try {
+            return Optional.of(Files.readAllBytes(path));
+        } catch (NoSuchFileException ignored) {
+            return Optional.empty();
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
     public UnixPath writeUtf8File(String content, OpenOption... options) {
         return writeBytes(content.getBytes(StandardCharsets.UTF_8), options);
     }
diff --git a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPathTest.java b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPathTest.java
index 6dfbc258474..802ca43ef56 100644
--- a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPathTest.java
+++ b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/file/UnixPathTest.java
@@ -9,6 +9,7 @@ import java.nio.file.FileSystem;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -17,6 +18,7 @@ import static org.junit.Assert.assertTrue;
  * @author hakonhall
  */
 public class UnixPathTest {
+
     private final FileSystem fs = TestFileSystem.create();
 
     @Test
@@ -87,4 +89,13 @@ public class UnixPathTest {
         UnixPath link = path.createSymbolicLink(fs.getPath("link-to-example.txt"));
         assertEquals(original, link.readUtf8File());
     }
+
+    @Test
+    public void readBytesIfExists() {
+        UnixPath path = new UnixPath(fs.getPath("example.txt"));
+        assertFalse(path.readBytesIfExists().isPresent());
+        path.writeBytes(new byte[]{42});
+        assertArrayEquals(new byte[]{42}, path.readBytesIfExists().get());
+    }
+
 }