reuse empty arrays

h2/src/main/org/h2/compress/LZFInputStream.java

@@ -9,7 +9,7 @@ package org.h2.compress;
 import java.io.IOException;
 import java.io.InputStream;
 
-import org.h2.util.ByteUtils;
+import org.h2.util.MemoryUtils;
 
 /**
  * An input stream to read from an LZF stream.
@@ -32,7 +32,7 @@ public class LZFInputStream extends InputStream {
     }
 
     private byte[] ensureSize(byte[] buff, int len) {
-        return buff == null || buff.length < len ? ByteUtils.newBytes(len) : buff;
+        return buff == null || buff.length < len ? MemoryUtils.newBytes(len) : buff;
     }
 
     private void fillBuffer() throws IOException {

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

@@ -41,7 +41,6 @@ import org.h2.table.TableFilter;
 import org.h2.tools.CompressTool;
 import org.h2.tools.Csv;
 import org.h2.util.AutoCloseInputStream;
-import org.h2.util.ByteUtils;
 import org.h2.util.DateTimeIso8601Utils;
 import org.h2.util.DateTimeUtils;
 import org.h2.util.FileUtils;
@@ -1172,7 +1171,7 @@ public class Function extends Expression implements FunctionCall {
 
     private byte[] getPaddedArrayCopy(byte[] data, int blockSize) {
         int size = MathUtils.roundUp(data.length, blockSize);
-        byte[] newData = ByteUtils.newBytes(size);
+        byte[] newData = MemoryUtils.newBytes(size);
         System.arraycopy(data, 0, newData, 0, data.length);
         return newData;
     }

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

@@ -18,6 +18,7 @@ import org.h2.store.DataPage;
 import org.h2.store.DiskFile;
 import org.h2.table.Column;
 import org.h2.util.IntArray;
+import org.h2.util.MemoryUtils;
 import org.h2.util.ObjectArray;
 import org.h2.value.Value;
 
@@ -37,7 +38,7 @@ public class BtreeNode extends BtreePage {
     BtreeNode(BtreeIndex index, DataPage s) throws SQLException {
         super(index);
         int len = s.readInt();
-        int[] array = new int[len];
+        int[] array = MemoryUtils.newInts(len);
         for (int i = 0; i < array.length; i++) {
             array[i] = s.readInt();
         }

h2/src/main/org/h2/jdbc/JdbcConnection.java

@@ -33,6 +33,7 @@ import org.h2.message.Message;
 import org.h2.message.Trace;
 import org.h2.message.TraceObject;
 import org.h2.result.ResultInterface;
+import org.h2.util.MemoryUtils;
 import org.h2.util.ObjectUtils;
 import org.h2.value.Value;
 import org.h2.value.ValueInt;
@@ -1403,7 +1404,7 @@ public class JdbcConnection extends TraceObject implements Connection {
             int id = getNextId(TraceObject.CLOB);
             debugCodeAssign("Clob", TraceObject.CLOB, id, "createClob()");
             checkClosedForWrite();
-            ValueLob v = ValueLob.createSmallLob(Value.CLOB, new byte[0]);
+            ValueLob v = ValueLob.createSmallLob(Value.CLOB, MemoryUtils.EMPTY_BYTES);
             return new JdbcClob(this, v, id);
         } catch (Exception e) {
             throw logAndConvert(e);
@@ -1420,7 +1421,7 @@ public class JdbcConnection extends TraceObject implements Connection {
             int id = getNextId(TraceObject.BLOB);
             debugCodeAssign("Blob", TraceObject.BLOB, id, "createClob()");
             checkClosedForWrite();
-            ValueLob v = ValueLob.createSmallLob(Value.BLOB, new byte[0]);
+            ValueLob v = ValueLob.createSmallLob(Value.BLOB, MemoryUtils.EMPTY_BYTES);
             return new JdbcBlob(this, v, id);
         } catch (Exception e) {
             throw logAndConvert(e);
@@ -1438,7 +1439,7 @@ public class JdbcConnection extends TraceObject implements Connection {
             int id = getNextId(TraceObject.CLOB);
             debugCodeAssign("NClob", TraceObject.CLOB, id, "createNClob()");
             checkClosedForWrite();
-            ValueLob v = ValueLob.createSmallLob(Value.CLOB, new byte[0]);
+            ValueLob v = ValueLob.createSmallLob(Value.CLOB, ByteUtils.EMPTY);
             return new JdbcClob(this, v, id);
         } catch (Exception e) {
             throw logAndConvert(e);

h2/src/main/org/h2/log/LogFile.java

@@ -21,9 +21,9 @@ import org.h2.store.DiskFile;
 import org.h2.store.FileStore;
 import org.h2.store.Record;
 import org.h2.store.Storage;
-import org.h2.util.ByteUtils;
 import org.h2.util.FileUtils;
 import org.h2.util.MathUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.util.ObjectArray;
 
 /**
@@ -220,7 +220,7 @@ public class LogFile {
             // Math.abs(Integer.MIN_VALUE) == Integer.MIN_VALUE
             s.reset();
         } else {
-            byte[] b2 = ByteUtils.newBytes(blocks * BLOCK_SIZE);
+            byte[] b2 = MemoryUtils.newBytes(blocks * BLOCK_SIZE);
             System.arraycopy(buff, 0, b2, 0, BLOCK_SIZE);
             buff = b2;
             file.readFully(buff, BLOCK_SIZE, blocks * BLOCK_SIZE - BLOCK_SIZE);
@@ -308,7 +308,7 @@ public class LogFile {
                 break;
             }
             int sumLength = in.readInt();
-            byte[] summary = ByteUtils.newBytes(sumLength);
+            byte[] summary = MemoryUtils.newBytes(sumLength);
             if (sumLength > 0) {
                 in.read(summary, 0, sumLength);
             }

h2/src/main/org/h2/server/pg/PgServerThread.java

@@ -34,9 +34,9 @@ import org.h2.constant.SysProperties;
 import org.h2.engine.ConnectionInfo;
 import org.h2.jdbc.JdbcConnection;
 import org.h2.message.Message;
-import org.h2.util.ByteUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.JdbcUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.util.New;
 import org.h2.util.Resources;
 import org.h2.util.ScriptReader;
@@ -133,7 +133,7 @@ public class PgServerThread implements Runnable {
         }
         int len = dataInRaw.readInt();
         len -= 4;
-        byte[] data = ByteUtils.newBytes(len);
+        byte[] data = MemoryUtils.newBytes(len);
         dataInRaw.readFully(data, 0, len);
         dataIn = new DataInputStream(new ByteArrayInputStream(data, 0, len));
         switch (x) {
@@ -245,7 +245,7 @@ public class PgServerThread implements Runnable {
             int paramCount = readShort();
             for (int i = 0; i < paramCount; i++) {
                 int paramLen = readInt();
-                byte[] d2 = ByteUtils.newBytes(paramLen);
+                byte[] d2 = MemoryUtils.newBytes(paramLen);
                 readFully(d2);
                 try {
                     setParameter(portal.prep, i, d2, formatCodes);

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

@@ -62,7 +62,6 @@ import org.h2.tools.Restore;
 import org.h2.tools.RunScript;
 import org.h2.tools.Script;
 import org.h2.tools.SimpleResultSet;
-import org.h2.util.ByteUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.JdbcUtils;
 import org.h2.util.MathUtils;
@@ -408,7 +407,7 @@ class WebThread extends Thread implements DatabaseEventListener {
             }
         }
         if (session != null && len > 0) {
-            byte[] bytes = ByteUtils.newBytes(len);
+            byte[] bytes = MemoryUtils.newBytes(len);
             for (int pos = 0; pos < len;) {
                 pos += input.read(bytes, pos, len - pos);
             }

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

@@ -253,23 +253,4 @@ public class ByteUtils {
         return copy;
     }
 
-    /**
-     * Create an array of bytes with the given size. If this is not possible
-     * because not enough memory is available, an OutOfMemoryError with the
-     * requested size in the message is thrown.
-     *
-     * @param len the number of bytes requested
-     * @return the byte array
-     * @throws OutOfMemoryError
-     */
-    public static byte[] newBytes(int len) {
-        try {
-            return new byte[len];
-        } catch (OutOfMemoryError e) {
-            Error e2 = new OutOfMemoryError("Requested memory: " + len);
-            e2.initCause(e);
-            throw e2;
-        }
-    }
-
 }

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

@@ -13,6 +13,16 @@ import org.h2.constant.SysProperties;
  */
 public class MemoryUtils {
 
+    /**
+     * An 0-size byte array.
+     */
+    public static final byte[] EMPTY_BYTES = new byte[0];
+
+    /**
+     * An 0-size int array.
+     */
+    public static final int[] EMPTY_INTS = new int[0];
+
     private static long lastGC;
     private static final int GC_DELAY = 50;
     private static final int MAX_GC = 8;
@@ -80,4 +90,39 @@ public class MemoryUtils {
         reserveMemory = null;
     }
 
+    /**
+     * Create an array of bytes with the given size. If this is not possible
+     * because not enough memory is available, an OutOfMemoryError with the
+     * requested size in the message is thrown.
+     *
+     * @param len the number of bytes requested
+     * @return the byte array
+     * @throws OutOfMemoryError
+     */
+    public static byte[] newBytes(int len) {
+        try {
+            if (len == 0) {
+                return EMPTY_BYTES;
+            }
+            return new byte[len];
+        } catch (OutOfMemoryError e) {
+            Error e2 = new OutOfMemoryError("Requested memory: " + len);
+            e2.initCause(e);
+            throw e2;
+        }
+    }
+
+    /**
+     * Create an array of ints with the given size.
+     *
+     * @param len the number of bytes requested
+     * @return the int array
+     */
+    public static int[] newInts(int len) {
+        if (len == 0) {
+            return EMPTY_INTS;
+        }
+        return new int[len];
+    }
+
 }

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

@@ -76,7 +76,7 @@ public class Resources {
         } else {
             data = FILES.get(name);
         }
-        return data == null ? new byte[0] : data;
+        return data == null ? MemoryUtils.EMPTY_BYTES : data;
     }
 
 }

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

@@ -33,9 +33,9 @@ import org.h2.engine.SessionInterface;
 import org.h2.message.Message;
 import org.h2.message.TraceSystem;
 import org.h2.tools.SimpleResultSet;
-import org.h2.util.ByteUtils;
 import org.h2.util.ExactUTF8InputStreamReader;
 import org.h2.util.IOUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.util.NetUtils;
 import org.h2.util.StringCache;
 
@@ -274,7 +274,7 @@ public class Transfer {
         if (len == -1) {
             return null;
         }
-        byte[] b = ByteUtils.newBytes(len);
+        byte[] b = MemoryUtils.newBytes(len);
         in.readFully(b);
         return b;
     }

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

@@ -8,13 +8,14 @@ package org.h2.value;
 
 import org.h2.constant.SysProperties;
 import org.h2.util.ByteUtils;
+import org.h2.util.MemoryUtils;
 
 /**
  * Implementation of the BINARY data type.
  */
 public class ValueBytes extends ValueBytesBase {
 
-    private static final ValueBytes EMPTY = new ValueBytes(new byte[0]);
+    private static final ValueBytes EMPTY = new ValueBytes(MemoryUtils.EMPTY_BYTES);
 
     protected ValueBytes(byte[] v) {
         super(v);

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

@@ -11,6 +11,7 @@ import java.sql.SQLException;
 import java.sql.Types;
 
 import org.h2.constant.SysProperties;
+import org.h2.util.MemoryUtils;
 import org.h2.util.ObjectUtils;
 
 /**
@@ -18,7 +19,7 @@ import org.h2.util.ObjectUtils;
  */
 public class ValueJavaObject extends ValueBytesBase {
 
-    private static final ValueJavaObject EMPTY = new ValueJavaObject(new byte[0]);
+    private static final ValueJavaObject EMPTY = new ValueJavaObject(MemoryUtils.EMPTY_BYTES);
 
     protected ValueJavaObject(byte[] v) {
         super(v);

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

@@ -27,6 +27,7 @@ import org.h2.util.ByteUtils;
 import org.h2.util.FileUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.MathUtils;
+import org.h2.util.MemoryUtils;
 import org.h2.util.SmallLRUCache;
 import org.h2.util.StringUtils;
 
@@ -353,11 +354,11 @@ public class ValueLob extends Value {
                 buff = IOUtils.readBytesAndClose(in, -1);
                 len = buff.length;
             } else {
-                buff = ByteUtils.newBytes(len);
+                buff = MemoryUtils.newBytes(len);
                 len = IOUtils.readFully(in, buff, 0, len);
             }
             if (len <= handler.getMaxLengthInplaceLob()) {
-                byte[] small = ByteUtils.newBytes(len);
+                byte[] small = MemoryUtils.newBytes(len);
                 System.arraycopy(buff, 0, small, 0, len);
                 return ValueLob.createSmallLob(Value.BLOB, small);
             }
@@ -723,7 +724,7 @@ public class ValueLob extends Value {
             int len = getBufferSize(handler, compress, Long.MAX_VALUE);
             int tabId = tableId;
             if (type == Value.BLOB) {
-                createFromStream(ByteUtils.newBytes(len), 0, getInputStream(), Long.MAX_VALUE, handler);
+                createFromStream(MemoryUtils.newBytes(len), 0, getInputStream(), Long.MAX_VALUE, handler);
             } else {
                 createFromReader(new char[len], 0, getReader(), Long.MAX_VALUE, handler);
             }