Add method to convert Slime array to Stream

2 files changed, 34 insertions, 0 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java b/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java
index 2ed7331a60c..5084e6554cb 100644
--- a/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java
+++ b/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java
@@ -4,7 +4,12 @@ package com.yahoo.slime;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.util.Iterator;
 import java.util.Optional;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 /**
  * Extra utilities/operations on slime trees.
@@ -118,4 +123,20 @@ public class SlimeUtils {
     public static Optional<String> optionalString(Inspector inspector) {
         return Optional.of(inspector.asString()).filter(s -> !s.isEmpty());
     }
+
+    public static Iterator<Inspector> entriesIterator(Inspector inspector) {
+        return new Iterator<>() {
+            private int current = 0;
+            @Override public boolean hasNext() { return current < inspector.entries(); }
+            @Override public Inspector next() { return inspector.entry(current++); }
+        };
+    }
+
+    /** Returns stream of entries for given inspector. If the inspector is not an array, empty stream is returned */
+    public static Stream<Inspector> entriesStream(Inspector inspector) {
+        int characteristics = Spliterator.NONNULL | Spliterator.SIZED | Spliterator.ORDERED;
+        return StreamSupport.stream(
+                Spliterators.spliteratorUnknownSize(entriesIterator(inspector), characteristics),
+                false);
+    }
 }
diff --git a/vespajlib/src/test/java/com/yahoo/slime/SlimeUtilsTest.java b/vespajlib/src/test/java/com/yahoo/slime/SlimeUtilsTest.java
index 237b1575bfb..5757202aaf1 100644
--- a/vespajlib/src/test/java/com/yahoo/slime/SlimeUtilsTest.java
+++ b/vespajlib/src/test/java/com/yahoo/slime/SlimeUtilsTest.java
@@ -5,6 +5,8 @@ import com.yahoo.text.Utf8;
 import org.junit.Test;
 
 import java.io.IOException;
+import java.util.List;
+import java.util.stream.Collectors;
 
 import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertEquals;
@@ -97,4 +99,15 @@ public class SlimeUtilsTest {
         }
     }
 
+    @Test
+    public void test_stream() {
+        String json = "{\"constant\":0,\"list\":[1,2,4,3,0],\"object\":{\"a\":1,\"c\":3,\"b\":2}}";
+        Inspector inspector = SlimeUtils.jsonToSlimeOrThrow(json).get();
+        assertEquals(0, SlimeUtils.entriesStream(inspector.field("constant")).count());
+        assertEquals(0, SlimeUtils.entriesStream(inspector.field("object")).count());
+
+        assertEquals(List.of(1L, 2L, 4L, 3L, 0L),
+                SlimeUtils.entriesStream(inspector.field("list")).map(Inspector::asLong).collect(Collectors.toList()));
+    }
+
 }