improve method names and add comments to ValueTimestamp and related classes

h2/src/main/org/h2/mvstore/db/ValueDataType.java

@@ -261,7 +261,7 @@ public class ValueDataType implements DataType {
         case Value.TIMESTAMP: {
             ValueTimestamp ts = (ValueTimestamp) v;
             long dateValue = ts.getDateValue();
-            long nanos = ts.getNanos();
+            long nanos = ts.getTimeNanos();
             long millis = nanos / 1000000;
             nanos -= millis * 1000000;
             buff.put((byte) type).

h2/src/main/org/h2/store/Data.java

@@ -519,7 +519,7 @@ public class Data {
                 ValueTimestamp ts = (ValueTimestamp) v;
                 long dateValue = ts.getDateValue();
                 writeVarLong(dateValue);
-                long nanos = ts.getNanos();
+                long nanos = ts.getTimeNanos();
                 long millis = nanos / 1000000;
                 nanos -= millis * 1000000;
                 writeVarLong(millis);
@@ -1006,7 +1006,7 @@ public class Data {
             if (SysProperties.STORE_LOCAL_TIME) {
                 ValueTimestamp ts = (ValueTimestamp) v;
                 long dateValue = ts.getDateValue();
-                long nanos = ts.getNanos();
+                long nanos = ts.getTimeNanos();
                 long millis = nanos / 1000000;
                 nanos -= millis * 1000000;
                 return 1 + getVarLongLen(dateValue) + getVarLongLen(millis) +

h2/src/main/org/h2/util/DateTimeUtils.java

@@ -149,7 +149,7 @@ public class DateTimeUtils {
         cal.clear();
         cal.setLenient(true);
         long dateValue = ts.getDateValue();
-        long nanos = ts.getNanos();
+        long nanos = ts.getTimeNanos();
         long millis = nanos / 1000000;
         nanos -= millis * 1000000;
         long s = millis / 1000;
@@ -651,13 +651,13 @@ public class DateTimeUtils {
      * timezone.
      *
      * @param dateValue the date value
-     * @param nanos the nanoseconds since midnight
+     * @param timeNanos the nanoseconds since midnight
      * @return the timestamp
      */
     public static Timestamp convertDateValueToTimestamp(long dateValue,
-            long nanos) {
-        long millis = nanos / 1000000;
-        nanos -= millis * 1000000;
+            long timeNanos) {
+        long millis = timeNanos / 1000000;
+        timeNanos -= millis * 1000000;
         long s = millis / 1000;
         millis -= s * 1000;
         long m = s / 60;
@@ -670,7 +670,7 @@ public class DateTimeUtils {
                 dayFromDateValue(dateValue),
                 (int) h, (int) m, (int) s, 0);
         Timestamp ts = new Timestamp(ms);
-        ts.setNanos((int) (nanos + millis * 1000000));
+        ts.setNanos((int) (timeNanos + millis * 1000000));
         return ts;
     }
 

h2/src/main/org/h2/value/Transfer.java

@@ -379,7 +379,7 @@ public class Transfer {
             if (version >= Constants.TCP_PROTOCOL_VERSION_9) {
                 ValueTimestamp ts = (ValueTimestamp) v;
                 writeLong(ts.getDateValue());
-                writeLong(ts.getNanos());
+                writeLong(ts.getTimeNanos());
             } else if (version >= Constants.TCP_PROTOCOL_VERSION_7) {
                 Timestamp ts = v.getTimestamp();
                 writeLong(DateTimeUtils.getTimeLocalWithoutDst(ts));

h2/src/main/org/h2/value/Value.java

@@ -732,7 +732,7 @@ public abstract class Value {
                     return ValueTime.fromNanos(0);
                 case TIMESTAMP:
                     return ValueTime.fromNanos(
-                            ((ValueTimestamp) this).getNanos());
+                            ((ValueTimestamp) this).getTimeNanos());
                 }
                 break;
             }

h2/src/main/org/h2/value/ValueTimestamp.java

@@ -40,23 +40,29 @@ public class ValueTimestamp extends Value {
      */
     static final int DEFAULT_SCALE = 10;
 
+    /**
+     * A bit field with bits for the year, month, and day (see DateTimeUtils for encoding)
+     */
     private final long dateValue;
-    private final long nanos;
+    /**
+     * The nanoseconds since midnight.
+     */
+    private final long timeNanos;
 
-    private ValueTimestamp(long dateValue, long nanos) {
+    private ValueTimestamp(long dateValue, long timeNanos) {
         this.dateValue = dateValue;
-        this.nanos = nanos;
+        this.timeNanos = timeNanos;
     }
 
     /**
      * Get or create a date value for the given date.
      *
-     * @param dateValue the date value
-     * @param nanos the nanoseconds
+     * @param dateValue the date value, a bit field with bits for the year, month, and day
+     * @param timeNanos the nanoseconds since midnight
      * @return the value
      */
-    public static ValueTimestamp fromDateValueAndNanos(long dateValue, long nanos) {
-        return (ValueTimestamp) Value.cache(new ValueTimestamp(dateValue, nanos));
+    public static ValueTimestamp fromDateValueAndNanos(long dateValue, long timeNanos) {
+        return (ValueTimestamp) Value.cache(new ValueTimestamp(dateValue, timeNanos));
     }
 
     /**
@@ -165,17 +171,23 @@ public class ValueTimestamp extends Value {
         return ValueTimestamp.fromDateValueAndNanos(dateValue, nanos);
     }
 
+    /**
+     * A bit field with bits for the year, month, and day (see DateTimeUtils for encoding)
+     */
     public long getDateValue() {
         return dateValue;
     }
 
-    public long getNanos() {
-        return nanos;
+    /**
+     * The nanoseconds since midnight.
+     */
+    public long getTimeNanos() {
+        return timeNanos;
     }
 
     @Override
     public Timestamp getTimestamp() {
-        return DateTimeUtils.convertDateValueToTimestamp(dateValue, nanos);
+        return DateTimeUtils.convertDateValueToTimestamp(dateValue, timeNanos);
     }
 
     @Override
@@ -188,7 +200,7 @@ public class ValueTimestamp extends Value {
         StringBuilder buff = new StringBuilder(DISPLAY_SIZE);
         ValueDate.appendDate(buff, dateValue);
         buff.append(' ');
-        ValueTime.appendTime(buff, nanos, true);
+        ValueTime.appendTime(buff, timeNanos, true);
         return buff.toString();
     }
 
@@ -220,7 +232,7 @@ public class ValueTimestamp extends Value {
         if (targetScale < 0) {
             throw DbException.getInvalidValueException("scale", targetScale);
         }
-        long n = nanos;
+        long n = timeNanos;
         BigDecimal bd = BigDecimal.valueOf(n);
         bd = bd.movePointLeft(9);
         bd = ValueDecimal.setScale(bd, targetScale);
@@ -239,7 +251,7 @@ public class ValueTimestamp extends Value {
         if (c != 0) {
             return c;
         }
-        return MathUtils.compareLong(nanos, t.nanos);
+        return MathUtils.compareLong(timeNanos, t.timeNanos);
     }
 
     @Override
@@ -250,12 +262,12 @@ public class ValueTimestamp extends Value {
             return false;
         }
         ValueTimestamp x = (ValueTimestamp) other;
-        return dateValue == x.dateValue && nanos == x.nanos;
+        return dateValue == x.dateValue && timeNanos == x.timeNanos;
     }
 
     @Override
     public int hashCode() {
-        return (int) (dateValue ^ (dateValue >>> 32) ^ nanos ^ (nanos >>> 32));
+        return (int) (dateValue ^ (dateValue >>> 32) ^ timeNanos ^ (timeNanos >>> 32));
     }
 
     @Override
@@ -274,7 +286,7 @@ public class ValueTimestamp extends Value {
         ValueTimestamp t = (ValueTimestamp) v.convertTo(Value.TIMESTAMP);
         long d1 = DateTimeUtils.absoluteDayFromDateValue(dateValue);
         long d2 = DateTimeUtils.absoluteDayFromDateValue(t.dateValue);
-        return DateTimeUtils.normalizeTimestamp(d1 + d2, nanos + t.nanos);
+        return DateTimeUtils.normalizeTimestamp(d1 + d2, timeNanos + t.timeNanos);
     }
 
     @Override
@@ -282,7 +294,7 @@ public class ValueTimestamp extends Value {
         ValueTimestamp t = (ValueTimestamp) v.convertTo(Value.TIMESTAMP);
         long d1 = DateTimeUtils.absoluteDayFromDateValue(dateValue);
         long d2 = DateTimeUtils.absoluteDayFromDateValue(t.dateValue);
-        return DateTimeUtils.normalizeTimestamp(d1 - d2, nanos - t.nanos);
+        return DateTimeUtils.normalizeTimestamp(d1 - d2, timeNanos - t.timeNanos);
     }
 
 }

h2/src/test/org/h2/test/unit/TestDate.java

@@ -234,7 +234,7 @@ public class TestDate extends TestBase {
         assertEquals("TIMESTAMP '2001-01-01 01:01:01.111'", t1.toString());
         assertEquals(Value.TIMESTAMP, t1.getType());
         long dateValue = t1.getDateValue();
-        long nanos = t1.getNanos();
+        long nanos = t1.getTimeNanos();
         assertEquals((int) ((dateValue >>> 32) ^ dateValue ^
                 (nanos >>> 32) ^ nanos),
                 t1.hashCode());
@@ -311,7 +311,7 @@ public class TestDate extends TestBase {
         assertEquals(0, DateTimeUtils.absoluteDayFromDateValue(
                 ValueTimestamp.parse("1970-01-01").getDateValue()));
         assertEquals(0, ValueTimestamp.parse(
-                "1970-01-01").getNanos());
+                "1970-01-01").getTimeNanos());
         assertEquals(0, ValueTimestamp.parse(
                 "1970-01-01 00:00:00.000 UTC").getTimestamp().getTime());
         assertEquals(0, ValueTimestamp.parse(