JsonArray optimizations

src/main/java/io/vertx/core/json/JsonArray.java

@@ -19,6 +19,7 @@
 import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 import static io.vertx.core.json.impl.JsonUtil.*;
 import static java.time.format.DateTimeFormatter.ISO_INSTANT;
@@ -52,7 +53,7 @@ public JsonArray(String json) {
     if (json == null) {
       throw new NullPointerException();
     }
-    fromJson(json);
+    list = Json.CODEC.fromString(json, List.class);
     if (list == null) {
       throw new DecodeException("Invalid JSON array: " + json);
     }
@@ -62,7 +63,14 @@ public JsonArray(String json) {
    * Create an empty instance
    */
   public JsonArray() {
-    list = new ArrayList<>();
+    list = new ArrayList<>();// empty, see ArrayList.DEFAULTCAPACITY_EMPTY_ELEMENTDATA
+  }
+
+  /**
+   * Create an empty instance with initialCapacity
+   */
+  public JsonArray(int initialCapacity) {
+    list = new ArrayList<>(initialCapacity);
   }
 
   /**
@@ -77,6 +85,21 @@ public JsonArray(List list) {
     this.list = list;
   }
 
+  /**
+   * Create an instance from a collections. If the collection is a list, it is not copied.
+   *
+   * @param collection collection to copy or use as the underlying backing list
+   */
+  public JsonArray(Collection collection) {
+    if (collection instanceof List) {
+      list = (List) collection;
+    } else if (collection == null) {
+      throw new NullPointerException();
+    } else {
+      list = new ArrayList(collection);
+    }
+  }
+
   /**
    * Create an instance from a Buffer of JSON.
    *
@@ -86,7 +109,7 @@ public JsonArray(Buffer buf) {
     if (buf == null) {
       throw new NullPointerException();
     }
-    fromBuffer(buf);
+    list = Json.CODEC.fromBuffer(buf, List.class);
     if (list == null) {
       throw new DecodeException("Invalid JSON array: " + buf);
     }
@@ -100,12 +123,13 @@ public JsonArray(Buffer buf) {
    */
   public static JsonArray of(Object... values) {
     // implicit nullcheck of values
-    if (values.length == 0) {
+    int len = values.length;
+    if (len == 0) {
       return new JsonArray();
     }
 
-    JsonArray arr = new JsonArray(new ArrayList<>(values.length));
-    for(int i = 0; i< values.length; ++i) {
+    JsonArray arr = new JsonArray(new ArrayList<>(len));
+    for (int i = 0; i < len; ++i) {
       arr.add(values[i]);
     }
 
@@ -616,7 +640,13 @@ public JsonArray copy(Function<Object, ?> cloner) {
    * @return a Stream
    */
   public Stream<Object> stream() {
-    return asStream(iterator());
+    // JsonUtil.asStream(iterator()) is too generic
+    return StreamSupport.stream(spliterator(), false);
+  }
+
+  @Override
+  public Spliterator<Object> spliterator() {
+    return Spliterators.spliterator(iterator(), list.size(), Spliterator.ORDERED);
   }
 
   @Override
@@ -704,17 +734,10 @@ public int readFromBuffer(int pos, Buffer buffer) {
     int length = buffer.getInt(pos);
     int start = pos + 4;
     Buffer buf = buffer.getBuffer(start, start + length);
-    fromBuffer(buf);
+    list = Json.CODEC.fromBuffer(buf, List.class);
     return pos + length + 4;
   }
 
-  private void fromJson(String json) {
-    list = Json.CODEC.fromString(json, List.class);
-  }
-
-  private void fromBuffer(Buffer buf) {
-    list = Json.CODEC.fromBuffer(buf, List.class);
-  }
 
   private static class Iter implements Iterator<Object> {
 

src/test/java/io/vertx/core/json/JsonArrayTest.java

@@ -1449,4 +1449,38 @@ public void testJsonArrayOfArgs() {
   public void testJsonArrayOfEmpty() {
     assertEquals(new JsonArray(), JsonArray.of());
   }
+
+  @Test
+  public void testPR() {
+    JsonArray ja = new JsonArray(JsonArray.of(null, null).stream()
+      .collect(Collectors.toSet()));
+    assertEquals("[null]", ja.toString());
+    assertEquals("[null]", ja.toBuffer().toString());
+
+    ja.remove(null);
+    assertEquals(0, ja.size());
+
+    ja = new JsonArray(new ArrayList<>(Arrays.asList("a", null, Instant.MIN, Arrays.asList(1,2))));
+    assertEquals("[\"a\",null,\"-1000000000-01-01T00:00:00Z\",[1,2]]", ja.toString());
+
+    Buffer buf = Buffer.buffer();
+    buf.appendLong(Long.MIN_VALUE);
+    ja.writeToBuffer(buf);
+    JsonArray ja2 = new JsonArray();
+    ja2.readFromBuffer(8, buf);
+    assertEquals(ja, ja2);
+
+    // test remove
+    assertEquals(4, ja.size());
+
+    ja.remove(null);
+    assertEquals(3, ja.size());
+
+    ja.remove(Instant.MIN);
+    assertEquals(2, ja.size());
+
+    ja.remove(Arrays.asList(1,2));
+    assertEquals(1, ja.size());
+    assertEquals("[\"a\"]", ja.toString());
+  }
 }