X-Git-Url: https://git.argeo.org/?a=blobdiff_plain;f=org.argeo.api.uuid%2Fsrc%2Forg%2Fargeo%2Fapi%2Fuuid%2FTimeUuid.java;fp=org.argeo.api.uuid%2Fsrc%2Forg%2Fargeo%2Fapi%2Fuuid%2FTimeUuid.java;h=2f3a73fffc7c4cfd4af511557ef29cdfe0a18bb1;hb=e8e2c65f356b30b35e4d8a1de66691a789c183bb;hp=0000000000000000000000000000000000000000;hpb=5b33b0f7a92debf285b31d308add6470a31894a9;p=lgpl%2Fargeo-commons.git

diff --git a/org.argeo.api.uuid/src/org/argeo/api/uuid/TimeUuid.java b/org.argeo.api.uuid/src/org/argeo/api/uuid/TimeUuid.java
new file mode 100644
index 000000000..2f3a73fff
--- /dev/null
+++ b/org.argeo.api.uuid/src/org/argeo/api/uuid/TimeUuid.java
@@ -0,0 +1,78 @@
+package org.argeo.api.uuid;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.util.UUID;
+
+/**
+ * A time based UUID, whose content can therefore be usefully interpreted as
+ * time and node identifier information.
+ */
+public class TimeUuid extends TypedUuid {
+	private static final long serialVersionUID = APM.SERIAL;
+	/**
+	 * Start of the Gregorian time on October 15th 1582, equivalent to
+	 * <code>{@link UUID#timestamp()} == 0</code>.
+	 */
+	public final static Instant TIMESTAMP_ZERO = ZonedDateTime.of(1582, 10, 15, 0, 0, 0, 0, ZoneOffset.UTC).toInstant();
+
+	public TimeUuid(UUID uuid) {
+		super(uuid);
+		if (uuid.version() != 1 && uuid.variant() != 2)
+			throw new IllegalArgumentException("The provided UUID is not a time based UUID.");
+	}
+
+	/** {@link UUID#timestamp()} as an {@link Instant}. */
+	public final Instant getInstant() {
+		long timestamp = uuid.timestamp();
+		return TIMESTAMP_ZERO.plus(timestampDifferenceToDuration(timestamp));
+	}
+
+	/** {@link UUID#node()} as an hex string. */
+	public final String getNodeId() {
+		return Long.toHexString(uuid.node());
+	}
+
+	/** {@link UUID#clockSequence()} as an hex string. */
+	public final String getClockSequence() {
+		return Long.toHexString(uuid.clockSequence());
+	}
+
+	/**
+	 * Always returns <code>false</code> since time UUIDs are by definition not
+	 * opaque.
+	 */
+	@Override
+	public final boolean isOpaque() {
+		return false;
+	}
+
+	/*
+	 * STATIC UTILITIES
+	 */
+	/** Converts from duration in the time UUID timestamp format. */
+	public static Duration timestampDifferenceToDuration(long timestampDifference) {
+		long seconds = timestampDifference / 10000000;
+		long nano = (timestampDifference % 10000000) * 100;
+		return Duration.ofSeconds(seconds, nano);
+	}
+
+	/**
+	 * A duration expressed in the time UUID timestamp format based on units of 100
+	 * ns.
+	 */
+	public static long durationToTimestamp(Duration duration) {
+		return (duration.getSeconds() * 10000000 + duration.getNano() / 100);
+	}
+
+	/**
+	 * An instant expressed in the time UUID timestamp format based on units of 100
+	 * ns since {@link #TIMESTAMP_ZERO}.
+	 */
+	public static long instantToTimestamp(Instant instant) {
+		Duration duration = Duration.between(TimeUuid.TIMESTAMP_ZERO, instant);
+		return durationToTimestamp(duration);
+	}
+}