Add ListFlag

5 files changed, 76 insertions, 0 deletions

diff --git a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
index 0f521649a6c..bfccbd1e46c 100644
--- a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
+++ b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
@@ -118,6 +118,12 @@ public class Flags {
                 flagId, defaultValue, description, modificationEffect, dimensions);
     }
 
+    /** WARNING: public for testing: All flags should be defined in {@link Flags}. */
+    public static <T> UnboundListFlag<T> defineListFlag(String flagId, List<T> defaultValue, String description,
+                                                        String modificationEffect, FetchVector.Dimension... dimensions) {
+        return define(UnboundListFlag::new, flagId, defaultValue, description, modificationEffect, dimensions);
+    }
+
     @FunctionalInterface
     private interface TypedUnboundFlagFactory<T, U extends UnboundFlag<?, ?, ?>> {
         U create(FlagId id, T defaultVale, FetchVector defaultFetchVector);
diff --git a/flags/src/main/java/com/yahoo/vespa/flags/JacksonArraySerializer.java b/flags/src/main/java/com/yahoo/vespa/flags/JacksonArraySerializer.java
new file mode 100644
index 00000000000..619c0c51c17
--- /dev/null
+++ b/flags/src/main/java/com/yahoo/vespa/flags/JacksonArraySerializer.java
@@ -0,0 +1,21 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.flags;
+
+import java.util.List;
+
+/**
+ * @author freva
+ */
+public class JacksonArraySerializer<T> implements FlagSerializer<List<T>> {
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public List<T> deserialize(RawFlag rawFlag) {
+        return (List<T>) JsonNodeRawFlag.fromJsonNode(rawFlag.asJsonNode()).toJacksonClass(List.class);
+    }
+
+    @Override
+    public RawFlag serialize(List<T> value) {
+        return null;
+    }
+}
diff --git a/flags/src/main/java/com/yahoo/vespa/flags/ListFlag.java b/flags/src/main/java/com/yahoo/vespa/flags/ListFlag.java
new file mode 100644
index 00000000000..6fefc5e22e3
--- /dev/null
+++ b/flags/src/main/java/com/yahoo/vespa/flags/ListFlag.java
@@ -0,0 +1,19 @@
+// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.flags;
+
+import javax.annotation.concurrent.Immutable;
+import java.util.List;
+
+/**
+ * @author freva
+ */
+@Immutable
+public class ListFlag<T> extends FlagImpl<List<T>, ListFlag<T>> {
+    public ListFlag(FlagId id, List<T> defaultValue, FetchVector vector, FlagSerializer<List<T>> serializer, FlagSource source) {
+        super(id, defaultValue, vector, serializer, source, ListFlag::new);
+    }
+
+    public List<T> value() {
+        return boxedValue();
+    }
+}
diff --git a/flags/src/main/java/com/yahoo/vespa/flags/UnboundListFlag.java b/flags/src/main/java/com/yahoo/vespa/flags/UnboundListFlag.java
new file mode 100644
index 00000000000..f5150604231
--- /dev/null
+++ b/flags/src/main/java/com/yahoo/vespa/flags/UnboundListFlag.java
@@ -0,0 +1,22 @@
+// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.flags;
+
+import javax.annotation.concurrent.Immutable;
+import java.util.List;
+
+/**
+ * @author freva
+ */
+@Immutable
+public class UnboundListFlag<T> extends UnboundFlagImpl<List<T>, ListFlag<T>, UnboundListFlag<T>> {
+    public UnboundListFlag(FlagId id, List<T> defaultValue) {
+        this(id, defaultValue, new FetchVector());
+    }
+
+    public UnboundListFlag(FlagId id, List<T> defaultValue, FetchVector defaultFetchVector) {
+        super(id, defaultValue, defaultFetchVector,
+                new JacksonArraySerializer<T>(),
+                UnboundListFlag::new,
+                ListFlag::new);
+    }
+}
diff --git a/flags/src/test/java/com/yahoo/vespa/flags/FlagsTest.java b/flags/src/test/java/com/yahoo/vespa/flags/FlagsTest.java
index 570058ae1d2..aa41cbbd94d 100644
--- a/flags/src/test/java/com/yahoo/vespa/flags/FlagsTest.java
+++ b/flags/src/test/java/com/yahoo/vespa/flags/FlagsTest.java
@@ -7,6 +7,8 @@ import com.fasterxml.jackson.databind.node.BooleanNode;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
 
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.Objects;
 import java.util.Optional;
 
@@ -87,6 +89,12 @@ public class FlagsTest {
     }
 
     @Test
+    public void testList() {
+        testGeneric(Flags.defineListFlag("list-id", Collections.singletonList("a"), "desc", "mod"),
+                Collections.singletonList("a"), Arrays.asList("a", "b", "c"));
+    }
+
+    @Test
     public void testJacksonClass() {
         ExampleJacksonClass defaultInstance = new ExampleJacksonClass();
         ExampleJacksonClass instance = new ExampleJacksonClass();