Merge pull request #968 from katzyn/misc

Assorted changes

h2/src/java9/src/org/h2/util/Bits.java

@@ -8,6 +8,7 @@ package org.h2.util;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import java.nio.ByteOrder;
+import java.util.Arrays;
 import java.util.UUID;
 
 /**
@@ -28,6 +29,46 @@ public final class Bits {
      */
     private static final VarHandle LONG_VH = MethodHandles.byteArrayViewVarHandle(long[].class, ByteOrder.BIG_ENDIAN);
 
+    /**
+     * Compare the contents of two byte arrays. If the content or length of the
+     * first array is smaller than the second array, -1 is returned. If the content
+     * or length of the second array is smaller than the first array, 1 is returned.
+     * If the contents and lengths are the same, 0 is returned.
+     *
+     * <p>
+     * This method interprets bytes as signed.
+     * </p>
+     *
+     * @param data1
+     *            the first byte array (must not be null)
+     * @param data2
+     *            the second byte array (must not be null)
+     * @return the result of the comparison (-1, 1 or 0)
+     */
+    public static int compareNotNullSigned(byte[] data1, byte[] data2) {
+        return Integer.signum(Arrays.compare(data1, data2));
+    }
+
+    /**
+     * Compare the contents of two byte arrays. If the content or length of the
+     * first array is smaller than the second array, -1 is returned. If the content
+     * or length of the second array is smaller than the first array, 1 is returned.
+     * If the contents and lengths are the same, 0 is returned.
+     *
+     * <p>
+     * This method interprets bytes as unsigned.
+     * </p>
+     *
+     * @param data1
+     *            the first byte array (must not be null)
+     * @param data2
+     *            the second byte array (must not be null)
+     * @return the result of the comparison (-1, 1 or 0)
+     */
+    public static int compareNotNullUnsigned(byte[] data1, byte[] data2) {
+        return Integer.signum(Arrays.compareUnsigned(data1, data2));
+    }
+
     /**
      * Reads a int value from the byte array at the given position in big-endian
      * order.

h2/src/main/org/h2/command/Command.java

@@ -311,7 +311,7 @@ public abstract class Command implements CommandInterface {
                 errorCode != ErrorCode.ROW_NOT_FOUND_WHEN_DELETING_1) {
             throw e;
         }
-        long now = System.nanoTime() / 1000000;
+        long now = System.nanoTime() / 1_000_000;
         if (start != 0 && now - start > session.getLockTimeout()) {
             throw DbException.get(ErrorCode.LOCK_TIMEOUT_1, e.getCause(), "");
         }
@@ -327,7 +327,7 @@ public abstract class Command implements CommandInterface {
             } catch (InterruptedException e1) {
                 // ignore
             }
-            long slept = System.nanoTime() / 1000000 - now;
+            long slept = System.nanoTime() / 1_000_000 - now;
             if (slept >= sleep) {
                 break;
             }

h2/src/main/org/h2/command/dml/Query.java

@@ -149,7 +149,7 @@ public abstract class Query extends Prepared {
     public int getCostAsExpression() {
         // ensure the cost is not larger than 1 million,
         // so that adding other values can't overflow
-        return (int) Math.min(1000000.0, 10.0 + 10.0 * getCost());
+        return (int) Math.min(1_000_000d, 10d + 10d * getCost());
     }
 
     /**

h2/src/main/org/h2/engine/ConnectionInfo.java

@@ -445,9 +445,7 @@ public class ConnectionInfo implements Cloneable {
      * @return the property keys
      */
     String[] getKeys() {
-        String[] keys = new String[prop.size()];
-        prop.keySet().toArray(keys);
-        return keys;
+        return prop.keySet().toArray(new String[prop.size()]);
     }
 
     /**

h2/src/main/org/h2/engine/Constants.java

@@ -246,12 +246,12 @@ public class Constants {
     /**
      * The default value for the MAX_MEMORY_UNDO setting.
      */
-    public static final int DEFAULT_MAX_MEMORY_UNDO = 50000;
+    public static final int DEFAULT_MAX_MEMORY_UNDO = 50_000;
 
     /**
      * The default for the setting MAX_OPERATION_MEMORY.
      */
-    public static final int DEFAULT_MAX_OPERATION_MEMORY = 100000;
+    public static final int DEFAULT_MAX_OPERATION_MEMORY = 100_000;
 
     /**
      * The default page size to use for new databases.
@@ -312,7 +312,7 @@ public class Constants {
     /**
      * The highest possible parameter index.
      */
-    public static final int MAX_PARAMETER_INDEX = 100000;
+    public static final int MAX_PARAMETER_INDEX = 100_000;
 
     /**
      * The memory needed by a object of class Data
@@ -404,7 +404,7 @@ public class Constants {
     /**
      * The number of distinct values to keep in memory when running ANALYZE.
      */
-    public static final int SELECTIVITY_DISTINCT_COUNT = 10000;
+    public static final int SELECTIVITY_DISTINCT_COUNT = 10_000;
 
     /**
      * The default directory name of the server properties file for the H2
@@ -512,7 +512,7 @@ public class Constants {
      * The maximum time in milliseconds to keep the cost of a view.
      * 10000 means 10 seconds.
      */
-    public static final int VIEW_COST_CACHE_MAX_AGE = 10000;
+    public static final int VIEW_COST_CACHE_MAX_AGE = 10_000;
 
     /**
      * The name of the index cache that is used for temporary view (subqueries

h2/src/main/org/h2/engine/Database.java

@@ -1234,8 +1234,7 @@ public class Database implements DataHandler {
     }
 
     private synchronized void closeAllSessionsException(Session except) {
-        Session[] all = new Session[userSessions.size()];
-        userSessions.toArray(all);
+        Session[] all = userSessions.toArray(new Session[userSessions.size()]);
         for (Session s : all) {
             if (s != except) {
                 try {

h2/src/main/org/h2/engine/DbSettings.java

@@ -54,7 +54,7 @@ public class DbSettings extends SettingsBase {
      * Database setting <code>ANALYZE_SAMPLE</code> (default: 10000).<br />
      * The default sample size when analyzing a table.
      */
-    public final int analyzeSample = get("ANALYZE_SAMPLE", 10000);
+    public final int analyzeSample = get("ANALYZE_SAMPLE", 10_000);
 
     /**
      * Database setting <code>DATABASE_TO_UPPER</code> (default: true).<br />
@@ -144,7 +144,7 @@ public class DbSettings extends SettingsBase {
      * times out. After the timeout, the LOB is no longer accessible using this
      * reference.
      */
-    public final int lobTimeout = get("LOB_TIMEOUT", 300000);
+    public final int lobTimeout = get("LOB_TIMEOUT", 300_000);
 
     /**
      * Database setting <code>MAX_COMPACT_COUNT</code>

h2/src/main/org/h2/engine/Session.java

@@ -352,9 +352,7 @@ public class Session extends SessionWithState {
         if (variables == null) {
             return new String[0];
         }
-        String[] list = new String[variables.size()];
-        variables.keySet().toArray(list);
-        return list;
+        return variables.keySet().toArray(new String[variables.size()]);
     }
 
     /**
@@ -835,8 +833,7 @@ public class Session extends SessionWithState {
             }
         }
         if (savepoints != null) {
-            String[] names = new String[savepoints.size()];
-            savepoints.keySet().toArray(names);
+            String[] names = savepoints.keySet().toArray(new String[savepoints.size()]);
             for (String name : names) {
                 Savepoint sp = savepoints.get(name);
                 int savepointIndex = sp.logIndex;

h2/src/main/org/h2/engine/SysProperties.java

@@ -129,7 +129,7 @@ public class SysProperties {
      * been set for the database.
      */
     public static final int COLLATOR_CACHE_SIZE =
-            Utils.getProperty("h2.collatorCacheSize", 32000);
+            Utils.getProperty("h2.collatorCacheSize", 32_000);
 
     /**
      * System property <code>h2.consoleTableIndexes</code>
@@ -260,7 +260,7 @@ public class SysProperties {
      * The default maximum number of rows to be kept in memory in a result set.
      */
     public static final int MAX_MEMORY_ROWS =
-            getAutoScaledForMemoryProperty("h2.maxMemoryRows", 40000);
+            getAutoScaledForMemoryProperty("h2.maxMemoryRows", 40_000);
 
     /**
      * System property <code>h2.maxTraceDataLength</code>

h2/src/main/org/h2/expression/AggregateDataMedian.java

@@ -259,7 +259,7 @@ class AggregateDataMedian extends AggregateData {
                 nanos += DateTimeUtils.NANOS_PER_DAY / 2;
             }
             if ((offset & 1) != 0) {
-                nanos += 30L * 1000000000;
+                nanos += 30_000_000_000L;
             }
             if (nanos >= DateTimeUtils.NANOS_PER_DAY) {
                 nanos -= DateTimeUtils.NANOS_PER_DAY;

h2/src/main/org/h2/expression/Function.java

@@ -2234,10 +2234,10 @@ public class Function extends Expression implements FunctionCall {
     }
 
     private static double roundMagic(double d) {
-        if ((d < 0.0000000000001) && (d > -0.0000000000001)) {
+        if ((d < 0.000_000_000_000_1) && (d > -0.000_000_000_000_1)) {
             return 0.0;
         }
-        if ((d > 1000000000000.) || (d < -1000000000000.)) {
+        if ((d > 1_000_000_000_000d) || (d < -1_000_000_000_000d)) {
             return d;
         }
         StringBuilder s = new StringBuilder();

h2/src/main/org/h2/index/IndexCondition.java

@@ -155,8 +155,7 @@ public class IndexCondition {
             v = column.convert(v);
             valueSet.add(v);
         }
-        Value[] array = new Value[valueSet.size()];
-        valueSet.toArray(array);
+        Value[] array = valueSet.toArray(new Value[valueSet.size()]);
         final CompareMode mode = session.getDatabase().getCompareMode();
         Arrays.sort(array, new Comparator<Value>() {
             @Override

h2/src/main/org/h2/index/PageDataIndex.java

@@ -143,7 +143,7 @@ public class PageDataIndex extends PageIndex {
                 if (add == 0) {
                     // in the first re-try add a small random number,
                     // to avoid collisions after a re-start
-                    row.setKey((long) (row.getKey() + Math.random() * 10000));
+                    row.setKey((long) (row.getKey() + Math.random() * 10_000));
                 } else {
                     row.setKey(row.getKey() + add);
                 }

h2/src/main/org/h2/mvstore/FileStore.java

@@ -314,7 +314,7 @@ public class FileStore {
      * @return the retention time
      */
     public int getDefaultRetentionTime() {
-        return 45000;
+        return 45_000;
     }
 
     /**

h2/src/main/org/h2/mvstore/MVStore.java

@@ -141,7 +141,7 @@ public final class MVStore {
      * Used to mark a chunk as free, when it was detected that live bookkeeping
      * is incorrect.
      */
-    private static final int MARKED_FREE = 10000000;
+    private static final int MARKED_FREE = 10_000_000;
 
     /**
      * The background thread, if any.

h2/src/main/org/h2/mvstore/type/ObjectDataType.java

@@ -1479,7 +1479,7 @@ public class ObjectDataType implements DataType {
      */
     static class SerializedObjectType extends AutoDetectDataType {
 
-        private int averageSize = 10000;
+        private int averageSize = 10_000;
 
         SerializedObjectType(ObjectDataType base) {
             super(base, TYPE_SERIALIZED_OBJECT);

h2/src/main/org/h2/server/web/WebApp.java

@@ -1775,7 +1775,7 @@ public class WebApp {
         String d = rs.getString(columnIndex);
         if (d == null) {
             return "<i>null</i>";
-        } else if (d.length() > 100000) {
+        } else if (d.length() > 100_000) {
             String s;
             if (isBinary(rs.getMetaData().getColumnType(columnIndex))) {
                 s = PageParser.escapeHtml(d.substring(0, 6)) +

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

@@ -491,8 +491,8 @@ public class Data {
                 writeByte((byte) LOCAL_TIME);
                 ValueTime t = (ValueTime) v;
                 long nanos = t.getNanos();
-                long millis = nanos / 1000000;
-                nanos -= millis * 1000000;
+                long millis = nanos / 1_000_000;
+                nanos -= millis * 1_000_000;
                 writeVarLong(millis);
                 writeVarLong(nanos);
             } else {
@@ -519,15 +519,15 @@ public class Data {
                 long dateValue = ts.getDateValue();
                 writeVarLong(dateValue);
                 long nanos = ts.getTimeNanos();
-                long millis = nanos / 1000000;
-                nanos -= millis * 1000000;
+                long millis = nanos / 1_000_000;
+                nanos -= millis * 1_000_000;
                 writeVarLong(millis);
                 writeVarLong(nanos);
             } else {
                 Timestamp ts = v.getTimestamp();
                 writeByte((byte) type);
                 writeVarLong(DateTimeUtils.getTimeLocalWithoutDst(ts));
-                writeVarInt(ts.getNanos() % 1000000);
+                writeVarInt(ts.getNanos() % 1_000_000);
             }
             break;
         }
@@ -758,7 +758,7 @@ public class Data {
             return ValueDate.fromMillis(DateTimeUtils.getTimeUTCWithoutDst(x));
         }
         case LOCAL_TIME: {
-            long nanos = readVarLong() * 1000000 + readVarLong();
+            long nanos = readVarLong() * 1_000_000 + readVarLong();
             return ValueTime.fromNanos(nanos);
         }
         case Value.TIME:
@@ -767,7 +767,7 @@ public class Data {
                     DateTimeUtils.getTimeUTCWithoutDst(readVarLong()));
         case LOCAL_TIMESTAMP: {
             long dateValue = readVarLong();
-            long nanos = readVarLong() * 1000000 + readVarLong();
+            long nanos = readVarLong() * 1_000_000 + readVarLong();
             return ValueTimestamp.fromDateValueAndNanos(dateValue, nanos);
         }
         case Value.TIMESTAMP: {
@@ -1003,8 +1003,8 @@ public class Data {
         case Value.TIME:
             if (STORE_LOCAL_TIME) {
                 long nanos = ((ValueTime) v).getNanos();
-                long millis = nanos / 1000000;
-                nanos -= millis * 1000000;
+                long millis = nanos / 1_000_000;
+                nanos -= millis * 1_000_000;
                 return 1 + getVarLongLen(millis) + getVarLongLen(nanos);
             }
             return 1 + getVarLongLen(DateTimeUtils.getTimeLocalWithoutDst(v.getTime()));
@@ -1021,14 +1021,14 @@ public class Data {
                 ValueTimestamp ts = (ValueTimestamp) v;
                 long dateValue = ts.getDateValue();
                 long nanos = ts.getTimeNanos();
-                long millis = nanos / 1000000;
-                nanos -= millis * 1000000;
+                long millis = nanos / 1_000_000;
+                nanos -= millis * 1_000_000;
                 return 1 + getVarLongLen(dateValue) + getVarLongLen(millis) +
                         getVarLongLen(nanos);
             }
             Timestamp ts = v.getTimestamp();
             return 1 + getVarLongLen(DateTimeUtils.getTimeLocalWithoutDst(ts)) +
-                    getVarIntLen(ts.getNanos() % 1000000);
+                    getVarIntLen(ts.getNanos() % 1_000_000);
         }
         case Value.TIMESTAMP_TZ: {
             ValueTimestampTimeZone ts = (ValueTimestampTimeZone) v;

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

@@ -78,7 +78,7 @@ public class LobStorageBackend implements LobStorageInterface {
     /**
      * The size of the chunks we use when storing LOBs inside the database file.
      */
-    private static final int BLOCK_LENGTH = 20000;
+    private static final int BLOCK_LENGTH = 20_000;
 
     /**
      * The size of cache for lob block hashes. Each entry needs 2 longs (16

h2/src/main/org/h2/store/fs/FilePathNioMapped.java

@@ -44,7 +44,7 @@ public class FilePathNioMapped extends FilePathNio {
  */
 class FileNioMapped extends FileBase {
 
-    private static final long GC_TIMEOUT_MS = 10000;
+    private static final long GC_TIMEOUT_MS = 10_000;
     private final String name;
     private final MapMode mode;
     private RandomAccessFile file;

h2/src/main/org/h2/table/TableLink.java

@@ -47,7 +47,7 @@ public class TableLink extends Table {
 
     private static final int MAX_RETRY = 2;
 
-    private static final long ROW_COUNT_APPROXIMATION = 100000;
+    private static final long ROW_COUNT_APPROXIMATION = 100_000;
 
     private final String originalSchema;
     private String driver, url, user, password, originalTable, qualifiedTableName;

h2/src/main/org/h2/tools/CompressTool.java

@@ -181,13 +181,13 @@ public class CompressTool {
             buff[pos++] = (byte) (0x80 | (x >> 8));
             buff[pos] = (byte) x;
             return 2;
-        } else if (x < 0x200000) {
+        } else if (x < 0x20_0000) {
             buff[pos++] = (byte) (0xc0 | (x >> 16));
             buff[pos++] = (byte) (x >> 8);
             buff[pos] = (byte) x;
             return 3;
-        } else if (x < 0x10000000) {
-            Bits.writeInt(buff, pos, x | 0xe0000000);
+        } else if (x < 0x1000_0000) {
+            Bits.writeInt(buff, pos, x | 0xe000_0000);
             return 4;
         } else {
             buff[pos++] = (byte) 0xf0;
@@ -210,9 +210,9 @@ public class CompressTool {
             return 1;
         } else if (x < 0x4000) {
             return 2;
-        } else if (x < 0x200000) {
+        } else if (x < 0x20_0000) {
             return 3;
-        } else if (x < 0x10000000) {
+        } else if (x < 0x1000_0000) {
             return 4;
         } else {
             return 5;

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

@@ -20,6 +20,68 @@ public final class Bits {
      * h2/src/java9/precompiled/org/h2/util/Bits.class.
      */
 
+    /**
+     * Compare the contents of two byte arrays. If the content or length of the
+     * first array is smaller than the second array, -1 is returned. If the content
+     * or length of the second array is smaller than the first array, 1 is returned.
+     * If the contents and lengths are the same, 0 is returned.
+     *
+     * <p>
+     * This method interprets bytes as signed.
+     * </p>
+     *
+     * @param data1
+     *            the first byte array (must not be null)
+     * @param data2
+     *            the second byte array (must not be null)
+     * @return the result of the comparison (-1, 1 or 0)
+     */
+    public static int compareNotNullSigned(byte[] data1, byte[] data2) {
+        if (data1 == data2) {
+            return 0;
+        }
+        int len = Math.min(data1.length, data2.length);
+        for (int i = 0; i < len; i++) {
+            byte b = data1[i];
+            byte b2 = data2[i];
+            if (b != b2) {
+                return b > b2 ? 1 : -1;
+            }
+        }
+        return Integer.signum(data1.length - data2.length);
+    }
+
+    /**
+     * Compare the contents of two byte arrays. If the content or length of the
+     * first array is smaller than the second array, -1 is returned. If the content
+     * or length of the second array is smaller than the first array, 1 is returned.
+     * If the contents and lengths are the same, 0 is returned.
+     *
+     * <p>
+     * This method interprets bytes as unsigned.
+     * </p>
+     *
+     * @param data1
+     *            the first byte array (must not be null)
+     * @param data2
+     *            the second byte array (must not be null)
+     * @return the result of the comparison (-1, 1 or 0)
+     */
+    public static int compareNotNullUnsigned(byte[] data1, byte[] data2) {
+        if (data1 == data2) {
+            return 0;
+        }
+        int len = Math.min(data1.length, data2.length);
+        for (int i = 0; i < len; i++) {
+            int b = data1[i] & 0xff;
+            int b2 = data2[i] & 0xff;
+            if (b != b2) {
+                return b > b2 ? 1 : -1;
+            }
+        }
+        return Integer.signum(data1.length - data2.length);
+    }
+
     /**
      * Reads a int value from the byte array at the given position in big-endian
      * order.

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

@@ -50,7 +50,7 @@ public class DateTimeUtils {
     /**
      * The number of nanoseconds per day.
      */
-    public static final long NANOS_PER_DAY = MILLIS_PER_DAY * 1000000;
+    public static final long NANOS_PER_DAY = MILLIS_PER_DAY * 1_000_000;
 
     private static final int SHIFT_YEAR = 9;
     private static final int SHIFT_MONTH = 5;
@@ -229,10 +229,10 @@ public class DateTimeUtils {
         cal.clear();
         cal.setLenient(true);
         long nanos = t.getNanos();
-        long millis = nanos / 1000000;
-        nanos -= millis * 1000000;
-        long s = millis / 1000;
-        millis -= s * 1000;
+        long millis = nanos / 1_000_000;
+        nanos -= millis * 1_000_000;
+        long s = millis / 1_000;
+        millis -= s * 1_000;
         long m = s / 60;
         s -= m * 60;
         long h = m / 60;
@@ -257,10 +257,10 @@ public class DateTimeUtils {
         cal.setLenient(true);
         long dateValue = ts.getDateValue();
         long nanos = ts.getTimeNanos();
-        long millis = nanos / 1000000;
-        nanos -= millis * 1000000;
-        long s = millis / 1000;
-        millis -= s * 1000;
+        long millis = nanos / 1_000_000;
+        nanos -= millis * 1_000_000;
+        long s = millis / 1_000;
+        millis -= s * 1_000;
         long m = s / 60;
         s -= m * 60;
         long h = m / 60;
@@ -269,7 +269,7 @@ public class DateTimeUtils {
                 monthFromDateValue(dateValue), dayFromDateValue(dateValue),
                 (int) h, (int) m, (int) s, (int) millis);
         Timestamp x = new Timestamp(ms);
-        x.setNanos((int) (nanos + millis * 1000000));
+        x.setNanos((int) (nanos + millis * 1_000_000));
         return x;
     }
 
@@ -323,7 +323,7 @@ public class DateTimeUtils {
         cal.setTimeInMillis(x.getTime());
         long dateValue = dateValueFromCalendar(cal);
         long nanos = nanosFromCalendar(cal);
-        nanos += x.getNanos() % 1000000;
+        nanos += x.getNanos() % 1_000_000;
         return ValueTimestamp.fromDateValueAndNanos(dateValue, nanos);
     }
 
@@ -408,14 +408,14 @@ public class DateTimeUtils {
             String n = (s.substring(s3 + 1, end) + "000000000").substring(0, 9);
             nanos = Integer.parseInt(n);
         }
-        if (hour >= 2000000 || minute < 0 || minute >= 60 || second < 0
+        if (hour >= 2_000_000 || minute < 0 || minute >= 60 || second < 0
                 || second >= 60) {
             throw new IllegalArgumentException(s);
         }
         if (timeOfDay && hour >= 24) {
             throw new IllegalArgumentException(s);
         }
-        nanos += ((((hour * 60L) + minute) * 60) + second) * 1000000000;
+        nanos += ((((hour * 60L) + minute) * 60) + second) * 1_000_000_000;
         return negative ? -nanos : nanos;
     }
 
@@ -507,13 +507,13 @@ public class DateTimeUtils {
             if (tz != null) {
                 if (withTimeZone) {
                     if (tz != UTC) {
-                        long millis = convertDateTimeValueToMillis(tz, dateValue, nanos / 1000000);
+                        long millis = convertDateTimeValueToMillis(tz, dateValue, nanos / 1_000_000);
                         tzMinutes = (short) (tz.getOffset(millis) / 1000 / 60);
                     }
                 } else {
-                    long millis = convertDateTimeValueToMillis(tz, dateValue, nanos / 1000000);
+                    long millis = convertDateTimeValueToMillis(tz, dateValue, nanos / 1_000_000);
                     dateValue = dateValueFromDate(millis);
-                    nanos = nanos % 1000000 + nanosFromDate(millis);
+                    nanos = nanos % 1_000_000 + nanosFromDate(millis);
                 }
             }
         }
@@ -1031,9 +1031,9 @@ public class DateTimeUtils {
      * @return the time
      */
     public static Time convertNanoToTime(long nanosSinceMidnight) {
-        long millis = nanosSinceMidnight / 1000000;
-        long s = millis / 1000;
-        millis -= s * 1000;
+        long millis = nanosSinceMidnight / 1_000_000;
+        long s = millis / 1_000;
+        millis -= s * 1_000;
         long m = s / 60;
         s -= m * 60;
         long h = m / 60;
@@ -1246,7 +1246,7 @@ public class DateTimeUtils {
             y--;
             m += 12;
         }
-        long a = ((y * 2922L) >> 3) + DAYS_OFFSET[m - 3] + d - 719484;
+        long a = ((y * 2922L) >> 3) + DAYS_OFFSET[m - 3] + d - 719_484;
         if (y <= 1582 && ((y < 1582) || (m * 100 + d < 1015))) {
             // Julian calendar (cutover at 1582-10-04 / 1582-10-15)
             a += 13;
@@ -1272,7 +1272,7 @@ public class DateTimeUtils {
             y--;
             m += 12;
         }
-        long a = ((y * 2922L) >> 3) + DAYS_OFFSET[m - 3] + d - 719484;
+        long a = ((y * 2922L) >> 3) + DAYS_OFFSET[m - 3] + d - 719_484;
         if (y < 1901 || y > 2099) {
             // Slow mode
             a += (y / 400) - (y / 100) + 15;
@@ -1287,19 +1287,19 @@ public class DateTimeUtils {
      * @return the date value
      */
     public static long dateValueFromAbsoluteDay(long absoluteDay) {
-        long d = absoluteDay + 719468;
+        long d = absoluteDay + 719_468;
         long y100 = 0, offset;
-        if (d > 578040) {
+        if (d > 578_040) {
             // Gregorian calendar
-            long y400 = d / 146097;
-            d -= y400 * 146097;
-            y100 = d / 36524;
-            d -= y100 * 36524;
+            long y400 = d / 146_097;
+            d -= y400 * 146_097;
+            y100 = d / 36_524;
+            d -= y100 * 36_524;
             offset = y400 * 400 + y100 * 100;
         } else {
             // Julian calendar
-            d += 292200000002L;
-            offset = -800000000;
+            d += 292_200_000_002L;
+            offset = -800_000_000;
         }
         long y4 = d / 1461;
         d -= y4 * 1461;
@@ -1330,7 +1330,7 @@ public class DateTimeUtils {
         int y = yearFromDateValue(dateValue);
         int m = monthFromDateValue(dateValue);
         int d = dayFromDateValue(dateValue);
-        if (y > 0 && y < 10000) {
+        if (y > 0 && y < 10_000) {
             StringUtils.appendZeroPadded(buff, 4, y);
         } else {
             buff.append(y);
@@ -1358,10 +1358,10 @@ public class DateTimeUtils {
          * get correct result. The simplest way to do this with such constraints is to
          * divide -nanos by -1000000.
          */
-        long ms = -nanos / -1000000;
-        nanos -= ms * 1000000;
-        long s = ms / 1000;
-        ms -= s * 1000;
+        long ms = -nanos / -1_000_000;
+        nanos -= ms * 1_000_000;
+        long s = ms / 1_000;
+        ms -= s * 1_000;
         long m = s / 60;
         s -= m * 60;
         long h = m / 60;

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

@@ -224,7 +224,7 @@ public class MathUtils {
     public static int nextPowerOf2(int x) throws IllegalArgumentException {
         if (x == 0) {
             return 1;
-        } else if (x < 0 || x > 0x40000000 ) {
+        } else if (x < 0 || x > 0x4000_0000 ) {
             throw new IllegalArgumentException("Argument out of range"
                     + " [0x0-0x40000000]. Argument was: " + x);
         }

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

@@ -44,7 +44,7 @@ public class ThreadDeadlockDetector {
             public void run() {
                 checkForDeadlocks();
             }
-        }, 10, 10000);
+        }, 10, 10_000);
     }
 
     /**

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

@@ -126,8 +126,8 @@ public class ToDateParser {
             if (timeZone == null) {
                 timeZone = TimeZone.getDefault();
             }
-            long millis = DateTimeUtils.convertDateTimeValueToMillis(timeZone, dateValue, nanos / 1000000);
-            offset = (short) (timeZone.getOffset(millis) / 1000 / 60);
+            long millis = DateTimeUtils.convertDateTimeValueToMillis(timeZone, dateValue, nanos / 1_000_000);
+            offset = (short) (timeZone.getOffset(millis) / 60_000);
         }
         return ValueTimestampTimeZone.fromDateValueAndNanos(dateValue, ts.getTimeNanos(), offset);
     }

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

@@ -138,60 +138,6 @@ public class Utils {
         return bits == 0;
     }
 
-    /**
-     * Compare the contents of two byte arrays. If the content or length of the
-     * first array is smaller than the second array, -1 is returned. If the
-     * content or length of the second array is smaller than the first array, 1
-     * is returned. If the contents and lengths are the same, 0 is returned.
-     * <p>
-     * This method interprets bytes as signed.
-     *
-     * @param data1 the first byte array (must not be null)
-     * @param data2 the second byte array (must not be null)
-     * @return the result of the comparison (-1, 1 or 0)
-     */
-    public static int compareNotNullSigned(byte[] data1, byte[] data2) {
-        if (data1 == data2) {
-            return 0;
-        }
-        int len = Math.min(data1.length, data2.length);
-        for (int i = 0; i < len; i++) {
-            byte b = data1[i];
-            byte b2 = data2[i];
-            if (b != b2) {
-                return b > b2 ? 1 : -1;
-            }
-        }
-        return Integer.signum(data1.length - data2.length);
-    }
-
-    /**
-     * Compare the contents of two byte arrays. If the content or length of the
-     * first array is smaller than the second array, -1 is returned. If the
-     * content or length of the second array is smaller than the first array, 1
-     * is returned. If the contents and lengths are the same, 0 is returned.
-     * <p>
-     * This method interprets bytes as unsigned.
-     *
-     * @param data1 the first byte array (must not be null)
-     * @param data2 the second byte array (must not be null)
-     * @return the result of the comparison (-1, 1 or 0)
-     */
-    public static int compareNotNullUnsigned(byte[] data1, byte[] data2) {
-        if (data1 == data2) {
-            return 0;
-        }
-        int len = Math.min(data1.length, data2.length);
-        for (int i = 0; i < len; i++) {
-            int b = data1[i] & 0xff;
-            int b2 = data2[i] & 0xff;
-            if (b != b2) {
-                return b > b2 ? 1 : -1;
-            }
-        }
-        return Integer.signum(data1.length - data2.length);
-    }
-
     /**
      * Copy the contents of the source array to the target array. If the size if
      * the target array is too small, a larger array is created.

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

@@ -372,11 +372,11 @@ public class Transfer {
             } else if (version >= Constants.TCP_PROTOCOL_VERSION_7) {
                 Timestamp ts = v.getTimestamp();
                 writeLong(DateTimeUtils.getTimeLocalWithoutDst(ts));
-                writeInt(ts.getNanos() % 1000000);
+                writeInt(ts.getNanos() % 1_000_000);
             } else {
                 Timestamp ts = v.getTimestamp();
                 writeLong(ts.getTime());
-                writeInt(ts.getNanos() % 1000000);
+                writeInt(ts.getNanos() % 1_000_000);
             }
             break;
         }
@@ -573,10 +573,10 @@ public class Transfer {
             } else if (version >= Constants.TCP_PROTOCOL_VERSION_7) {
                 return ValueTimestamp.fromMillisNanos(
                         DateTimeUtils.getTimeUTCWithoutDst(readLong()),
-                        readInt() % 1000000);
+                        readInt() % 1_000_000);
             }
             return ValueTimestamp.fromMillisNanos(readLong(),
-                    readInt() % 1000000);
+                    readInt() % 1_000_000);
         }
         case Value.TIMESTAMP_TZ: {
             return ValueTimestampTimeZone.fromDateValueAndNanos(readLong(),

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

@@ -10,6 +10,7 @@ import java.sql.SQLException;
 import java.util.Arrays;
 
 import org.h2.engine.SysProperties;
+import org.h2.util.Bits;
 import org.h2.util.MathUtils;
 import org.h2.util.StringUtils;
 import org.h2.util.Utils;
@@ -93,9 +94,9 @@ public class ValueBytes extends Value {
     protected int compareSecure(Value v, CompareMode mode) {
         byte[] v2 = ((ValueBytes) v).value;
         if (mode.isBinaryUnsigned()) {
-            return Utils.compareNotNullUnsigned(value, v2);
+            return Bits.compareNotNullUnsigned(value, v2);
         }
-        return Utils.compareNotNullSigned(value, v2);
+        return Bits.compareNotNullSigned(value, v2);
     }
 
     @Override

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

@@ -48,7 +48,7 @@ public class ValueDecimal extends Value {
     /**
      * The maximum scale of a BigDecimal value.
      */
-    private static final int BIG_DECIMAL_SCALE_MAX = 100000;
+    private static final int BIG_DECIMAL_SCALE_MAX = 100_000;
 
     private final BigDecimal value;
     private String valueString;

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

@@ -11,6 +11,7 @@ import java.sql.Types;
 
 import org.h2.engine.SysProperties;
 import org.h2.store.DataHandler;
+import org.h2.util.Bits;
 import org.h2.util.JdbcUtils;
 import org.h2.util.Utils;
 
@@ -131,8 +132,7 @@ public class ValueJavaObject extends ValueBytes {
                 if (o1.equals(o2)) {
                     return 0;
                 }
-
-                return Utils.compareNotNullSigned(getBytesNoCopy(), v.getBytesNoCopy());
+                return Bits.compareNotNullSigned(getBytesNoCopy(), v.getBytesNoCopy());
             }
 
             return h1 > h2 ? 1 : -1;

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

@@ -26,6 +26,7 @@ import org.h2.store.FileStoreOutputStream;
 import org.h2.store.RangeInputStream;
 import org.h2.store.RangeReader;
 import org.h2.store.fs.FileUtils;
+import org.h2.util.Bits;
 import org.h2.util.IOUtils;
 import org.h2.util.MathUtils;
 import org.h2.util.SmallLRUCache;
@@ -674,7 +675,7 @@ public class ValueLob extends Value {
             return Integer.signum(getString().compareTo(v.getString()));
         }
         byte[] v2 = v.getBytesNoCopy();
-        return Utils.compareNotNullSigned(getBytes(), v2);
+        return Bits.compareNotNullSigned(getBytesNoCopy(), v2);
     }
 
     @Override

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

@@ -27,6 +27,7 @@ import org.h2.store.LobStorageFrontend;
 import org.h2.store.LobStorageInterface;
 import org.h2.store.RangeReader;
 import org.h2.store.fs.FileUtils;
+import org.h2.util.Bits;
 import org.h2.util.IOUtils;
 import org.h2.util.MathUtils;
 import org.h2.util.StringUtils;
@@ -363,7 +364,7 @@ public class ValueLobDb extends Value implements Value.ValueClob,
             return Integer.signum(getString().compareTo(v.getString()));
         }
         byte[] v2 = v.getBytesNoCopy();
-        return Utils.compareNotNullSigned(getBytes(), v2);
+        return Bits.compareNotNullSigned(getBytesNoCopy(), v2);
     }
 
     @Override

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

@@ -70,7 +70,7 @@ public class ValueTime extends Value {
      */
     public static ValueTime fromNanos(long nanos) {
         if (!SysProperties.UNLIMITED_TIME_RANGE) {
-            if (nanos < 0L || nanos >= 86400000000000L) {
+            if (nanos < 0L || nanos >= DateTimeUtils.NANOS_PER_DAY) {
                 StringBuilder builder = new StringBuilder();
                 DateTimeUtils.appendTime(builder, nanos);
                 throw DbException.get(ErrorCode.INVALID_DATETIME_CONSTANT_2,

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

@@ -88,7 +88,7 @@ public class ValueTimestamp extends Value {
      */
     public static ValueTimestamp get(Timestamp timestamp) {
         long ms = timestamp.getTime();
-        long nanos = timestamp.getNanos() % 1000000;
+        long nanos = timestamp.getNanos() % 1_000_000;
         long dateValue = DateTimeUtils.dateValueFromDate(ms);
         nanos += DateTimeUtils.nanosFromDate(ms);
         return fromDateValueAndNanos(dateValue, nanos);

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

@@ -54,7 +54,7 @@ public class ValueUuid extends Value {
         // version 4 (random)
         high = (high & (~0xf000L)) | 0x4000L;
         // variant (Leach-Salz)
-        low = (low & 0x3fffffffffffffffL) | 0x8000000000000000L;
+        low = (low & 0x3fff_ffff_ffff_ffffL) | 0x8000_0000_0000_0000L;
         return new ValueUuid(high, low);
     }
 

h2/src/test/org/h2/samples/DirectInsert.java

@@ -30,7 +30,7 @@ public class DirectInsert {
         Class.forName("org.h2.Driver");
         DeleteDbFiles.execute("~", "test", true);
         String url = "jdbc:h2:~/test";
-        initialInsert(url, 200000);
+        initialInsert(url, 200_000);
         for (int i = 0; i < 3; i++) {
             createAsSelect(url, true);
             createAsSelect(url, false);

h2/src/tools/org/h2/build/doc/SpellChecker.java

@@ -81,8 +81,7 @@ public class SpellChecker {
         // System.out.println(unused);
         if (printDictionary) {
             System.out.println("USED WORDS");
-            String[] list = new String[used.size()];
-            used.toArray(list);
+            String[] list = used.toArray(new String[used.size()]);
             Arrays.sort(list);
             StringBuilder buff = new StringBuilder();
             for (String s : list) {