Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.lz4 / src / net / jpountz / util / UnsafeUtils.java

diff --git a/bundles/org.simantics.lz4/src/net/jpountz/util/UnsafeUtils.java b/bundles/org.simantics.lz4/src/net/jpountz/util/UnsafeUtils.java
new file mode 100644 (file)
index 0000000..30231ef
--- /dev/null
+++ b/bundles/org.simantics.lz4/src/net/jpountz/util/UnsafeUtils.java
@@ -0,0 +1,147 @@
+package net.jpountz.util;
+
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import static net.jpountz.util.Utils.NATIVE_BYTE_ORDER;
+
+import java.lang.reflect.Field;
+import java.nio.ByteOrder;
+
+import sun.misc.Unsafe;
+
+public enum UnsafeUtils {
+  ;
+
+  private static final Unsafe UNSAFE;
+  private static final long BYTE_ARRAY_OFFSET;
+  private static final int BYTE_ARRAY_SCALE;
+  private static final long INT_ARRAY_OFFSET;
+  private static final int INT_ARRAY_SCALE;
+  private static final long SHORT_ARRAY_OFFSET;
+  private static final int SHORT_ARRAY_SCALE;
+  
+  static {
+    try {
+      Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
+      theUnsafe.setAccessible(true);
+      UNSAFE = (Unsafe) theUnsafe.get(null);
+      BYTE_ARRAY_OFFSET = UNSAFE.arrayBaseOffset(byte[].class);
+      BYTE_ARRAY_SCALE = UNSAFE.arrayIndexScale(byte[].class);
+      INT_ARRAY_OFFSET = UNSAFE.arrayBaseOffset(int[].class);
+      INT_ARRAY_SCALE = UNSAFE.arrayIndexScale(int[].class);
+      SHORT_ARRAY_OFFSET = UNSAFE.arrayBaseOffset(short[].class);
+      SHORT_ARRAY_SCALE = UNSAFE.arrayIndexScale(short[].class);
+    } catch (IllegalAccessException e) {
+      throw new ExceptionInInitializerError("Cannot access Unsafe");
+    } catch (NoSuchFieldException e) {
+      throw new ExceptionInInitializerError("Cannot access Unsafe");
+    } catch (SecurityException e) {
+      throw new ExceptionInInitializerError("Cannot access Unsafe");
+    }
+  }
+
+  public static void checkRange(byte[] buf, int off) {
+    SafeUtils.checkRange(buf, off);
+  }
+
+  public static void checkRange(byte[] buf, int off, int len) {
+    SafeUtils.checkRange(buf, off, len);
+  }
+
+  public static void checkLength(int len) {
+    SafeUtils.checkLength(len);
+  }
+
+  public static byte readByte(byte[] src, int srcOff) {
+    return UNSAFE.getByte(src, BYTE_ARRAY_OFFSET + BYTE_ARRAY_SCALE * srcOff);
+  }
+
+  public static void writeByte(byte[] src, int srcOff, byte value) {
+    UNSAFE.putByte(src, BYTE_ARRAY_OFFSET + BYTE_ARRAY_SCALE * srcOff, (byte) value);
+  }
+
+  public static void writeByte(byte[] src, int srcOff, int value) {
+    writeByte(src, srcOff, (byte) value);
+  }
+
+  public static long readLong(byte[] src, int srcOff) {
+    return UNSAFE.getLong(src, BYTE_ARRAY_OFFSET + srcOff);
+  }
+
+  public static long readLongLE(byte[] src, int srcOff) {
+    long i = readLong(src, srcOff);
+    if (NATIVE_BYTE_ORDER == ByteOrder.BIG_ENDIAN) {
+      i = Long.reverseBytes(i);
+    }
+    return i;
+  }
+
+  public static void writeLong(byte[] dest, int destOff, long value) {
+    UNSAFE.putLong(dest, BYTE_ARRAY_OFFSET + destOff, value);
+  }
+
+  public static int readInt(byte[] src, int srcOff) {
+    return UNSAFE.getInt(src, BYTE_ARRAY_OFFSET + srcOff);
+  }
+
+  public static int readIntLE(byte[] src, int srcOff) {
+    int i = readInt(src, srcOff);
+    if (NATIVE_BYTE_ORDER == ByteOrder.BIG_ENDIAN) {
+      i = Integer.reverseBytes(i);
+    }
+    return i;
+  }
+
+  public static void writeInt(byte[] dest, int destOff, int value) {
+    UNSAFE.putInt(dest, BYTE_ARRAY_OFFSET + destOff, value);
+  }
+
+  public static short readShort(byte[] src, int srcOff) {
+    return UNSAFE.getShort(src, BYTE_ARRAY_OFFSET + srcOff);
+  }
+
+  public static int readShortLE(byte[] src, int srcOff) {
+    short s = readShort(src, srcOff);
+    if (NATIVE_BYTE_ORDER == ByteOrder.BIG_ENDIAN) {
+      s = Short.reverseBytes(s);
+    }
+    return s & 0xFFFF;
+  }
+
+  public static void writeShort(byte[] dest, int destOff, short value) {
+    UNSAFE.putShort(dest, BYTE_ARRAY_OFFSET + destOff, value);
+  }
+
+  public static void writeShortLE(byte[] buf, int off, int v) {
+    writeByte(buf, off, (byte) v);
+    writeByte(buf, off + 1, (byte) (v >>> 8));
+  }
+
+  public static int readInt(int[] src, int srcOff) {
+    return UNSAFE.getInt(src, INT_ARRAY_OFFSET + INT_ARRAY_SCALE * srcOff);
+  }
+
+  public static void writeInt(int[] dest, int destOff, int value) {
+    UNSAFE.putInt(dest, INT_ARRAY_OFFSET + INT_ARRAY_SCALE * destOff, value);
+  }
+
+  public static int readShort(short[] src, int srcOff) {
+    return UNSAFE.getShort(src, SHORT_ARRAY_OFFSET + SHORT_ARRAY_SCALE * srcOff) & 0xFFFF;
+  }
+
+  public static void writeShort(short[] dest, int destOff, int value) {
+    UNSAFE.putShort(dest, SHORT_ARRAY_OFFSET + SHORT_ARRAY_SCALE * destOff, (short) value);
+  }
+}