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Jodd Core tools and huge number of utilities.
// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
package jodd.util;
import sun.misc.Unsafe;
import java.lang.reflect.Field;
import java.nio.Buffer;
import java.nio.ByteBuffer;
/**
* Simplified netty class.
* Thanx: Stephane Landelle!
*
* @see https://github.com/netty/netty/blob/master/common/src/main/java/io/netty/util/internal/PlatformDependent.java
*/
final class PlatformInternal {
private static final Unsafe UNSAFE;
private PlatformInternal() {
}
static {
ByteBuffer direct = ByteBuffer.allocateDirect(1);
Field addressField;
try {
addressField = Buffer.class.getDeclaredField("address");
addressField.setAccessible(true);
if (addressField.getLong(ByteBuffer.allocate(1)) != 0) {
// A heap buffer must have 0 address.
addressField = null;
}
else {
if (addressField.getLong(direct) == 0) {
// A direct buffer must have non-zero address.
addressField = null;
}
}
}
catch (Throwable t) {
// Failed to access the address field.
addressField = null;
}
Unsafe unsafe;
if (addressField != null) {
try {
Field unsafeField = Unsafe.class.getDeclaredField("theUnsafe");
unsafeField.setAccessible(true);
unsafe = (Unsafe) unsafeField.get(null);
}
catch (Throwable cause) {
// Unsafe.copyMemory(Object, long, Object, long, long) unavailable.
unsafe = null;
}
}
else {
// If we cannot access the address of a direct buffer, there's no point of using unsafe.
// Let's just pretend unsafe is unavailable for overall simplicity.
unsafe = null;
}
UNSAFE = unsafe;
}
static boolean hasUnsafe() {
return UNSAFE != null;
}
// ---------------------------------------------------------------- string
private static final long STRING_VALUE_FIELD_OFFSET;
private static final long STRING_OFFSET_FIELD_OFFSET;
private static final long STRING_COUNT_FIELD_OFFSET;
static {
long stringValueFieldOffset = -1L;
long stringOffsetFieldOffset = -1L;
long stringCountFieldOffset = -1L;
if (UNSAFE != null) {
try {
// this should be:
stringValueFieldOffset = UNSAFE.objectFieldOffset(String.class.getDeclaredField("value"));
// try also:
stringOffsetFieldOffset = UNSAFE.objectFieldOffset(String.class.getDeclaredField("offset"));
stringCountFieldOffset = UNSAFE.objectFieldOffset(String.class.getDeclaredField("count"));
} catch (Throwable ignore) {
}
}
STRING_VALUE_FIELD_OFFSET = stringValueFieldOffset;
STRING_OFFSET_FIELD_OFFSET = stringOffsetFieldOffset;
STRING_COUNT_FIELD_OFFSET = stringCountFieldOffset;
}
/**
* Returns String characters in most performing way.
* If possible, the inner char[]
will be returned.
* If not, toCharArray()
will be called.
* Returns null
when argument is null
.
*/
static char[] unsafeGetChars(String string) {
char[] value = (char[]) UNSAFE.getObject(string, STRING_VALUE_FIELD_OFFSET);
if (STRING_OFFSET_FIELD_OFFSET != -1) {
// old String version with offset and count
int offset = UNSAFE.getInt(string, STRING_OFFSET_FIELD_OFFSET);
int count = UNSAFE.getInt(string, STRING_COUNT_FIELD_OFFSET);
if (offset == 0 && count == value.length) {
// no need to copy
return value;
} else {
char[] result = new char[count];
System.arraycopy(value, offset, result, 0, count);
return result;
}
} else {
return value;
}
}
static String unsafeCreateString(char[] chars) {
String mutable = new String();
UNSAFE.putObject(mutable, STRING_VALUE_FIELD_OFFSET, chars);
if (STRING_COUNT_FIELD_OFFSET != -1) {
UNSAFE.putInt(mutable, STRING_COUNT_FIELD_OFFSET, chars.length);
}
return mutable;
}
}