X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=common%2Futil%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Futil%2FOptionalBoolean.java;fp=common%2Futil%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Futil%2FOptionalBoolean.java;h=824dbe6e47a7b133fd661712be971c2e2af4218b;hb=e856047ff9cd6b5cfca9b59d4ef7c289df8f0782;hp=0000000000000000000000000000000000000000;hpb=efddb856bf959eb04e18d0bb92c21d519e8b4f04;p=yangtools.git diff --git a/common/util/src/main/java/org/opendaylight/yangtools/util/OptionalBoolean.java b/common/util/src/main/java/org/opendaylight/yangtools/util/OptionalBoolean.java new file mode 100644 index 0000000000..824dbe6e47 --- /dev/null +++ b/common/util/src/main/java/org/opendaylight/yangtools/util/OptionalBoolean.java @@ -0,0 +1,156 @@ +/* + * Copyright (c) 2017 Pantheon Technologies, s.r.o. and others. All rights reserved. + * + * This program and the accompanying materials are made available under the + * terms of the Eclipse Public License v1.0 which accompanies this distribution, + * and is available at http://www.eclipse.org/legal/epl-v10.html + */ +package org.opendaylight.yangtools.util; + +import com.google.common.annotations.Beta; +import java.util.Optional; +import javax.annotation.Nullable; + +/** + * Utility class for storing an optional boolean in a single byte value. This cuts down the memory requirement quite + * at very small computational cost. + * + *
+ * Note: fields do not have to be explicitly initialized, as default initialization value for 'byte', 0, is used to
+ * represent 'absent' condition.
+ *
+ * @author Robert Varga
+ */
+@Beta
+public final class OptionalBoolean {
+ private static final byte ABSENT = 0;
+ private static final byte FALSE = 1;
+ private static final byte TRUE = 2;
+
+ private OptionalBoolean() {
+ throw new UnsupportedOperationException();
+ }
+
+ /**
+ * Check if a field value has been set, just like {@link Optional#isPresent()}.
+ *
+ * @param value field value
+ * @return True if the value is set.
+ * @throws IllegalArgumentException if value is invalid
+ */
+ public static boolean isPresent(final byte value) {
+ switch (value) {
+ case ABSENT:
+ return false;
+ case FALSE:
+ case TRUE:
+ return true;
+ default:
+ throw invalidValue(value);
+ }
+ }
+
+ /**
+ * Decode boolean from a field value, just like {@link Optional#get()}.
+ *
+ * @param value Field value
+ * @return Decoded boolean.
+ * @throws IllegalArgumentException if value is invalid
+ * @throws IllegalStateException if value has not been set
+ */
+ public static boolean get(final byte value) {
+ switch (value) {
+ case ABSENT:
+ throw new IllegalStateException("Field has not been initialized");
+ case FALSE:
+ return false;
+ case TRUE:
+ return true;
+ default:
+ throw invalidValue(value);
+ }
+ }
+
+ /**
+ * Encode a boolean to a field value, just like {@link Optional#of(Object)}.
+ *
+ * @param bool Boolean value.
+ * @return Field value.
+ */
+ public static byte of(final boolean bool) {
+ return bool ? TRUE : FALSE;
+ }
+
+ /**
+ * Convert a nullable {@link Boolean} into a field value, just like {@link Optional#ofNullable(Object)}.
+ *
+ * @param bool Boolean value.
+ * @return Field value.
+ */
+ public static byte ofNullable(final @Nullable Boolean bool) {
+ return bool == null ? ABSENT : of(bool.booleanValue());
+ }
+
+ /**
+ * Convert a field value to a nullable {@link Boolean}. Similar to {@code Optional.orElse(null)}.
+ *
+ * @param value Fied value.
+ * @return Nullable Boolean.
+ */
+ public static @Nullable Boolean toNullable(final byte value) {
+ switch (value) {
+ case ABSENT:
+ return null;
+ case FALSE:
+ return Boolean.FALSE;
+ case TRUE:
+ return Boolean.TRUE;
+ default:
+ throw invalidValue(value);
+ }
+ }
+
+ /**
+ * Convert a field value into an {@link Optional} {@link Boolean}.
+ *
+ * @param value Field value.
+ * @return Optional {@link Boolean}.
+ * @throws IllegalArgumentException if value is invalid.
+ */
+ public static Optional