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Timebase Common utilities and collections
/*
* Copyright 2021 EPAM Systems, Inc
*
* See the NOTICE file distributed with this work for additional information
* regarding copyright ownership. 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.
*/
package com.epam.deltix.util.lang;
import com.epam.deltix.gflog.api.Log;
import com.epam.deltix.gflog.api.LogFactory;
import java.io.*;
import java.lang.management.*;
import java.net.*;
import java.security.*;
import java.util.*;
import java.util.prefs.Preferences;
import java.lang.reflect.*;
/** Set of useful methods */
public class Util {
public static final boolean IS64BIT = "64".equals(System.getProperty("sun.arch.data.model"));
public static final boolean IS32BIT = "32".equals(System.getProperty("sun.arch.data.model"));
public static final String LOGGER_NAME = "deltix.util";
private static final Log LOG = LogFactory.getLog(Util.class);
public static final boolean IS_WINDOWS_OS = System.getProperty ("path.separator").equals(";");
public static final String NATIVE_LINE_BREAK = System.getProperty("line.separator");
public static final String[] EMPTY_STRING_ARRAY = {};
public static final boolean QUIET = Boolean.getBoolean("quiet");
public static void collectLocalFiles(String path, Collection files) {
File file = new File(path);
if (file.isDirectory()) {
String[] children = file.list();
if (children == null) {
// Either dir does not exist or is not a directory
} else {
for (String filename : children) {
collectLocalFiles(file.getAbsolutePath() + File.separator + filename, files);
}
}
} else {
files.add(file.getAbsolutePath());
}
}
public static void collectLocalFiles(String path, Collection files, Filter filter) {
File file = new File(path);
if (filter.accept(file)) {
if (file.isDirectory()) {
String[] children = file.list();
if (children == null) {
// Either dir does not exist or is not a directory
} else {
for (String filename : children) {
collectLocalFiles(file.getAbsolutePath() + File.separator + filename, files, filter);
}
}
} else {
files.add(file.getAbsolutePath());
}
}
}
public static int doubleUntilAtLeast (int a, int limit) {
if (a == 0)
return limit;
while (a < limit)
a = a << 1;
return (a);
}
/**
* Returns the sign of a - b
*/
public static int compare (long a, long b) {
return a > b ? 1 : (a == b ? 0 : -1);
}
/**
* Returns the sign of a - b
*/
public static int compare (double a, double b) {
double diff = a - b;
if (diff < 0)
return (-1);
if (diff > 0)
return (1);
return (0);
}
/**
* Compare two CharSequences for equality. A null equals null.
*/
public static boolean equals (CharSequence s1, CharSequence s2) {
return (compare (s1, s2, true) == 0);
}
/**
* Compare two CharSequences for equality. A null equals null.
*/
public static boolean equals (CharSequence s1, CharSequence s2, int maxLength) {
return (compare (s1, s2, maxLength, true) == 0);
}
/**
* Compare two CharSequences. A null argument is always less than a non-null argument
* and is equal to another null argument.
*
* @param fast When true, use a fast algorithm, which makes a
* char sequence greater than another if it is longer.
* When false, performs lexicographic comparison.
*/
public static int compare (CharSequence s1, CharSequence s2, boolean fast) {
return (compare (s1, s2, 0, fast));
}
/**
* Compare two CharSequences. A null argument is always less than a non-null argument
* and is equal to another null argument.
*
* @param maxLength Only compare the first maxLength characters.
* Send 0 to unlimit.
* @param fast When true, use a fast algorithm, which makes a
* char sequence greater than another if it is longer.
* When false, performs lexicographic comparison.
*/
public static int compare (
CharSequence s1,
CharSequence s2,
int maxLength,
boolean fast
)
{
if (s1 == null)
if (s2 == null)
return (0);
else
return (-1);
else if (s2 == null)
return (1);
else if (s1 == s2)
return (0);
else {
int len1 = s1.length ();
int len2 = s2.length ();
if (maxLength > 0) {
if (maxLength < len1)
len1 = maxLength;
if (maxLength < len2)
len2 = maxLength;
}
int diff = len1 - len2;
if (fast && diff != 0)
return (diff);
int minLength = diff > 0 ? len2 : len1;
for (int ii = 0; ii < minLength; ii++) {
int cdiff = s1.charAt (ii) - s2.charAt (ii);
if (cdiff != 0)
return (cdiff);
}
return (diff);
}
}
public static int fastCompare (CharSequence s1, CharSequence s2) {
int len1 = s1.length ();
int len2 = s2.length ();
int diff = len1 - len2;
if (diff != 0)
return (diff);
for (int ii = 0; ii < len1; ii++) {
int cdiff = s1.charAt (ii) - s2.charAt (ii);
if (cdiff != 0)
return (cdiff);
}
return (diff);
}
public static > T max (T a, T b) {
if (a == null)
return (b);
if (b == null)
return (a);
return (a.compareTo (b) > 0 ? a : b);
}
public static > T min (T a, T b) {
if (a == null)
return (b);
if (b == null)
return (a);
return (a.compareTo (b) < 0 ? a : b);
}
public static void writeNullableString (String s, DataOutput os)
throws IOException
{
os.writeBoolean (s == null);
if (s != null)
os.writeUTF (s);
}
public static String readNullableString (DataInput is)
throws IOException
{
if (is.readBoolean ())
return (null);
return (is.readUTF ());
}
/**
* Loads and instantiates the specified class using the no-argument constructor
*/
public static Object newInstance (String className, Object ... args)
throws ClassNotFoundException, InstantiationException, IllegalAccessException,
IllegalArgumentException, NoSuchMethodException, InvocationTargetException
{
return (newInstance (Class.forName (className), args));
}
/**
* Call a static method of the specified class. Figure out the method
* signature from the types of the supplied arguments (which must not contain
* null elements).
*/
public static Object callStaticMethod (
String className,
String methodName,
Object ... args
)
throws
ClassNotFoundException,
NoSuchMethodException,
InvocationTargetException,
IllegalAccessException
{
Class c = Class.forName (className);
Class [] paramTypes = new Class [args.length];
for (int ii = 0; ii < args.length; ii++)
paramTypes [ii] = args [ii].getClass ();
Method m = c.getDeclaredMethod (methodName, paramTypes);
m.setAccessible (true);
return (m.invoke (null, args));
}
/**
* Call a method of the specified class. Figure out the method
* signature from the types of the supplied arguments (which must not contain
* null elements).
*/
public static Object callNonStaticMethod (
Object object,
String methodName,
Object ... args
)
throws
ClassNotFoundException,
NoSuchMethodException,
InvocationTargetException,
IllegalAccessException
{
Class [] paramTypes = new Class [args.length];
for (int ii = 0; ii < args.length; ii++)
paramTypes [ii] = args [ii].getClass ();
Method m = object.getClass ().getDeclaredMethod (methodName, paramTypes);
m.setAccessible (true);
return (m.invoke (object, args));
}
/**
* Call a method of the specified class. Unlike {@linkplain #callNonStaticMethod} figures out the method
* signature from the types of the supplied arguments using recursive look up of the types base classes
*/
public static Object callNonStaticMethodRecursive (
Object object,
String methodName,
Object ... args
)
throws
ClassNotFoundException,
NoSuchMethodException,
InvocationTargetException,
IllegalAccessException
{
final Method[] mm = object.getClass().getDeclaredMethods();
if (mm == null || mm.length == 0)
throw new NoSuchMethodException(object.getClass().getName() + "." + methodName);
Class[] paramTypes = new Class[args.length];
for (int ii = 0; ii < args.length; ii++)
paramTypes[ii] = args[ii].getClass();
m1:
for (Method method : mm) {
if (method.getName().equals(methodName)) {
final Class[] types = method.getParameterTypes();
for (int i = 0; i < types.length; i++) {
Class type = types[i];
if (type != paramTypes[i] && !type.isAssignableFrom(paramTypes[i]))
continue m1;
}
method.setAccessible(true);
return (method.invoke(object, args));
}
}
throw new NoSuchMethodException(object.getClass().getName() + "." + methodName + " " + Util.printArray(paramTypes));
}
@SuppressWarnings ("unchecked")
public static void setFieldValue (
Object object,
String fieldName,
Object value
)
throws
NoSuchFieldException,
IllegalAccessException
{
if (object == null)
throw new NullPointerException(fieldName);
Field f = findFieldByName (object, fieldName);
if (f == null)
throw new NoSuchFieldException (fieldName + " in " + object.getClass ());
f.setAccessible (true);
final Class type = f.getType();
if (type.isPrimitive()) {
if (value == null)
throw new IllegalArgumentException("Attempt to set NULL value to a field of primitive type (" + f.getDeclaringClass().getSimpleName() + "." + fieldName + ")");
if (type == long.class)
f.setLong(object, ((Number) value).longValue ());
else if (type == int.class)
f.setInt(object, ((Number) value).intValue ());
else if (type == short.class)
f.setInt(object, ((Number) value).shortValue ());
else if (type == byte.class)
f.setInt(object, ((Number) value).byteValue ());
else if (type == double.class)
f.setDouble(object, ((Number) value).doubleValue ());
else if (type == float.class)
f.setDouble(object, ((Number) value).doubleValue ());
else if (type == boolean.class)
f.setBoolean(object, (Boolean) value);
else
throw new IllegalArgumentException("field type is not supported " + type);
} else {
if (type.isEnum () && value instanceof String)
value = Enum.valueOf ((Class ) type, (String) value);
f.set(object, value);
}
}
/**
* Find class field hierarchically by name
*/
public static Field findFieldByName(Object object, String fieldName) {
Field f = null;
for (
Class c = object.getClass ();
c != Object.class;
c = c.getSuperclass ()
)
{
try {
f = c.getDeclaredField(fieldName);
break;
} catch (NoSuchFieldException x) {
}
}
return f;
}
/**
* Call a constructor of the specified class. Figure out the method
* signature from the types of the supplied arguments (which must not contain
* null elements).
*/
public static T newInstance (
Class clazz,
Object ... args
)
throws ClassNotFoundException, NoSuchMethodException,
InstantiationException, IllegalAccessException,
IllegalArgumentException, InvocationTargetException
{
Constructor m;
int numArgs = args.length;
if (numArgs == 0)
m = clazz.getDeclaredConstructor ();
else {
Class [] paramTypes = new Class [numArgs];
for (int ii = 0; ii < numArgs; ii++)
paramTypes [ii] = args [ii].getClass ();
m = clazz.getDeclaredConstructor (paramTypes);
}
m.setAccessible (true);
return (m.newInstance (args));
}
public static T newInstanceNoX (
Class clazz,
Object ... args
)
{
try {
return (newInstance (clazz, args));
} catch (RuntimeException x) {
throw x;
} catch (Error x) {
throw x;
} catch (Throwable other) {
throw new RuntimeException (clazz.getName () + " instantiation failed", other);
}
}
public static Object newInstanceNoX (
String className,
Object ... args
)
{
try {
return (newInstance (className, args));
} catch (RuntimeException x) {
throw x;
} catch (Error x) {
throw x;
} catch (Throwable other) {
throw new RuntimeException (className + " instantiation failed", other);
}
}
public static Runnable methodRunnable (final Object obj, String methodName) {
Method m = null;
Class cls = obj.getClass ();
while (true) {
try {
m = cls.getDeclaredMethod (methodName);
break;
} catch (NoSuchMethodException x) {
cls = cls.getSuperclass ();
if (cls == null)
throw new RuntimeException(x);
// continue
}
}
assert m != null;
m.setAccessible(true);
final Method fm = m;
return (
new Runnable() {
public void run() {
try {
fm.invoke(obj);
} catch (IllegalArgumentException | InvocationTargetException | IllegalAccessException x) {
throw new RuntimeException(x);
}
}
}
);
}
@SuppressWarnings("unchecked")
public static T unwrap (T instance) {
while (instance instanceof Wrapper)
instance = ((Wrapper)instance).getNestedInstance();
return instance;
}
@SuppressWarnings("unchecked")
public static T unwrap (Object instance, Class upToClass) {
boolean found = false;
while (!(found = instance.getClass() == upToClass) &&
instance instanceof Wrapper)
instance = ((Wrapper)instance).getNestedInstance();
return found ? (T) instance : null;
}
/**
* Gets to the bottom of the exception.
*/
public static Throwable unwrap (Throwable ex) {
Throwable result = ex;
while (result != null) {
Throwable nested;
nested = result.getCause ();
if (nested == null)
break;
result = nested;
}
return result;
}
/**
* Same as System.getProperty (prop, def), but returns
* null if access to system properties is prohibited.
*/
public static String getSysProp (String prop, String def) {
try {
return (System.getProperty (prop, def));
} catch (java.security.AccessControlException acx) {
return (null);
}
}
/**
* Same as System.getProperty (prop), but returns
* null if access to system properties is prohibited.
*/
public static String getSysProp (String prop) {
try {
return (System.getProperty (prop));
} catch (java.security.AccessControlException acx) {
return (null);
}
}
public static URL getResource (String path)
throws MalformedURLException
{
if (path.indexOf (":") > 0)
return (new URL (path));
else
return (Util.class.getClassLoader ().getResource (path));
}
public static URL getResourceNoX (String path) {
try {
return (getResource (path));
} catch (MalformedURLException mux) {
LOG.error ("Error getting resource '%s': %s").with(path).with(mux);
return (null);
}
}
public static void handleException (Throwable x) {
LOG.error ("Ignoring (but Logging) Exception %s").with(x);
}
public static void logException (String message, Throwable x) {
LOG.error ("%s %s").with(message).with(x);
}
/**
* Closes a Closeable without throwing an exception. Checks for null.
* Allows to do:
*
* stream = Util.close(stream);
*
* instead of:
*
* Util.close(stream);
* stream = null;
*
* if required
*/
public static T close (T closeable) {
if (closeable != null)
try {
closeable.close ();
} catch (Exception x) {
handleException (x);
}
return null;
}
public static void closeAll(Iterable values) {
for (Disposable value : values) {
Util.close(value);
}
}
/**
* @return true if two arrays contain identical bytes
*/
public static boolean arrayequals (
byte [] arr1,
int off1,
int len1,
byte [] arr2,
int off2,
int len2
)
{
if (len1 != len2)
return false;
if (arr1 == arr2 && off1 == off2)
return true;
for (int i=0; i 0)
ps.print (".");
ps.print (bytes [offset + jj] & 0xFF);
}
}
public static void arraydump (
StringBuffer sb,
byte [] bytes,
int offset,
int n
)
{
for (int jj = 0; jj < n; jj++) {
if (jj > 0)
sb.append (".");
sb.append (bytes [offset + jj] & 0xFF);
}
}
public static String arraydump (
byte [] bytes,
int offset,
int n
)
{
StringBuffer sb = new StringBuffer ();
arraydump (sb, bytes, offset, n);
return (sb.toString ());
}
/**
* returns obj == null ? 1 : obj.hashCode ()
*/
public static int xhashCode (Object obj) {
return (obj == null ? 1 : obj.hashCode ());
}
public static int hashCode (long value) {
return ((int) (value ^ (value >>> 32)));
}
public static int hashCode (double value) {
return (hashCode (Double.doubleToLongBits (value)));
}
/**
* Adds up hash codes of all array elements, plus array length.
*/
public static int arrayHashCode (Object [] arr) {
if (arr == null)
return (0);
int ret = arr.length;
for (int ii = 0; ii < arr.length; ii++)
ret += xhashCode (arr [ii]);
return (ret);
}
public static > int xcompare (T o1, T o2) {
if (o1 == null)
if (o2 == null)
return (0);
else
return (-1);
else if (o2 == null)
return (1);
else
return (o1.compareTo (o2));
}
/**
* Method identical to "obj1.equals(obj2)", it also handles null values.
*/
public static boolean xequals(Object obj1, Object obj2)
{
return (obj1 == obj2 || obj1 != null && obj2 != null && obj1.equals (obj2));
}
/**
* Given a Class object, attempts to find its .class location
* Returns null if no such definition can be found. Use for testing/debugging only.
* @param clazz class to lookup
* @return URL that points to the class definition [null if not found].
*/
public static URL getClassLocation(final Class clazz)
{
URL url = null;
if (clazz == null)
throw new IllegalArgumentException ("Class in undefined");
ProtectionDomain pd = clazz.getProtectionDomain ();
String resource = clazz.getName ().replace ('.', '/').concat (".class");
// java.lang.Class contract does not specify if 'pd' can ever be null, but anyway
if (pd != null) {
if (pd.getCodeSource () != null)
url = pd.getCodeSource ().getLocation ();
if (url != null) {
// Convert a code source location into a full class file location
if ("file".equals (url.getProtocol ())) {
try {
String form = url.toExternalForm();
if (form.endsWith (".jar") || form.endsWith (".zip"))
url = new URL ("jar:" + form + "!/" + resource);
else if (new File (url.getFile ()).isDirectory ())
url = new URL (url, resource);
} catch (MalformedURLException ignore) {
// ignore
}
}
}
}
if (url == null) {
// Try to find 'clazz' definition as a resource; this is not
// documented to be legal, but Sun's implementations seem to allow this:
ClassLoader clsLoader = clazz.getClassLoader ();
url = clsLoader != null ? clsLoader.getResource (resource) : ClassLoader.getSystemResource (resource);
}
return url;
}
/**
* Return string byte length (encoded as UTF8),
* same as s.getBytes("UTF8").length but faster
*/
public static int strlenUTF8(String s)
{
int i, len = s.length (), cnt = 0;
for (i = 0; i < len; i++) {
char ch = s.charAt (i);
if (ch <= 0x7F) {
cnt += 1;
} else if (ch <= 0x7FF) {
cnt += 2;
} else if (ch <= 0x7FFF) {
cnt += 3;
} else if (ch <= 0x7FFFF) {
cnt += 4;
} else {
throw new RuntimeException ("Character is a way too big: " + Long.toHexString (ch));
}
}
return cnt;
}
private static long mLastUsedMemory;
private static long mLastTotalMemory;
/**
* Prints current memory usage and memory usage delta to System.out.
*/
public static synchronized void dumpMemoryUsage(String msgText)
{
System.gc ();
System.runFinalization ();
System.gc ();
long freeMemory = Runtime.getRuntime ().freeMemory ();
long totalMemory = Runtime.getRuntime ().totalMemory ();
StringBuffer msg = new StringBuffer (256);
msg.append ("(M)");
if (msgText != null) {
msg.append (" [");
msg.append (msgText);
msg.append (']');
}
msg.append (" JVM Memory: ");
msg.append (freeMemory * 100 / totalMemory);
msg.append ("% free.");
if (mLastTotalMemory != totalMemory) {
msg.append (" (*) Total memory changed to: ");
msg.append (totalMemory);
mLastTotalMemory = totalMemory;
}
long newUsedMemory = totalMemory - freeMemory;
msg.append (" Used memory change: ");
msg.append (newUsedMemory - mLastUsedMemory);
msg.append (" bytes");
mLastUsedMemory = newUsedMemory;
System.out.println (msg.toString ());
}
/**
* Return a comma separated list of elements or "null".
* @param array - array to print
*/
public static String printArray(Object[] array)
{
if (array == null)
return "null";
StringBuffer sb = new StringBuffer ("[");
if (array.length > 0) {
sb.append (array[0]);
for (int i = 1; i < array.length; i++) {
sb.append (", ");
sb.append (array[i]);
}
}
sb.append ("]");
return sb.toString ();
}
/**
* @return stack trace of given throwable as String
*/
public static String printStackTrace (Throwable t) {
StringWriter swr = new StringWriter (512);
PrintWriter pwr = new PrintWriter (swr);
t.printStackTrace(pwr);
pwr.close();
return swr.toString();
}
public static String printStackTrace(StackTraceElement[] stack) {
final int stackSize = stack.length;
if (stackSize > 0) {
final StringBuilder sb = new StringBuilder();
for (int i = 0; i < stackSize; i++) {
sb.append(stack[i]);
if (i < stackSize - 1)
sb.append("\n\t");
}
return sb.toString();
}
return "";
}
public static Map getAllStackTraces() {
ThreadMXBean bean = ManagementFactory.getThreadMXBean();
Map traces = Thread.getAllStackTraces();
Map info = new HashMap();
for (Thread thread : traces.keySet())
info.put(thread, bean.getThreadInfo(new long[] {thread.getId()}, true, true)[0]);
return info;
}
public static String getThreadStackTrace(Thread thread, ThreadInfo info) {
StringBuilder sb = new StringBuilder("\"" + thread.getName() + "\"" +
(thread.isDaemon() ? " daemon" : "") + " priority=" + thread.getPriority());
if (info.getLockName() != null)
sb.append(" on ").append(info.getLockName());
if (info.getLockOwnerName() != null)
sb.append(" owned by \"" + info.getLockOwnerName() + "\" id=" + info.getLockOwnerId());
// if (isSuspended()) {
// sb.append(" (suspended)");
// }
// if (isInNative()) {
// sb.append(" (in native)");
// }
sb.append('\n');
sb.append("Thread State: ").append(thread.getState()).append("\n");
StackTraceElement[] stackTrace = info.getStackTrace();
for (int i = 0; i < stackTrace.length; i++) {
StackTraceElement ste = stackTrace[i];
sb.append("\tat " + ste.toString());
sb.append('\n');
LockInfo lock = info.getLockInfo();
if (i == 0 && lock != null) {
Thread.State ts = info.getThreadState();
switch (ts) {
case BLOCKED:
sb.append("\t- blocked on ").append(lock);
sb.append('\n');
break;
case WAITING:
sb.append("\t- waiting on ").append(lock);
sb.append('\n');
break;
case TIMED_WAITING:
sb.append("\t- waiting on ").append(lock);
sb.append('\n');
break;
default:
}
}
for (MonitorInfo mi : info.getLockedMonitors()) {
if (mi.getLockedStackDepth() == i) {
sb.append("\t- locked " + mi);
sb.append('\n');
}
}
}
LockInfo[] locks = info.getLockedSynchronizers();
if (locks.length > 0) {
sb.append("\n\tLocked ownable synchronizers:");
sb.append('\n');
for (LockInfo li : locks) {
sb.append("\t- ").append(li.toString());
sb.append('\n');
}
}
sb.append('\n');
return sb.toString();
}
public static void printStackTraces () {
Map threads = Util.getAllStackTraces ();
for (Map.Entry e : threads.entrySet ())
System.out.println (Util.getThreadStackTrace (e.getKey (), e.getValue ()));
}
public static RuntimeException asRuntimeException(Throwable exception) {
if (exception instanceof RuntimeException)
return (RuntimeException) exception;
else if (exception instanceof Error)
throw (Error) exception;
else
return new RuntimeException(exception);
}
public static T findCause(Throwable error, Class causeClass) {
while (error != null) {
if (causeClass.isInstance(error))
return causeClass.cast(error);
error = error.getCause();
}
return null;
}
/** @return Array of all interfaces implemented by given class (calls cls.getInterfaces() recursively), never null */
public static Class [] getClassInterfaces (Class cls) {
List result = new ArrayList ();
if (cls.isInterface())
result.add (cls);
Class c = cls;
while (c != null) {
Class [] interfaces = c.getInterfaces();
for (int i = 0; i < interfaces.length; i++) {
Class cc = interfaces [i];
if ( ! result.contains(cc)) // joined multi inheritance
result.add(cc);
}
c = c.getSuperclass();
}
return result.toArray(new Class [result.size()]);
}
/** @return true if given cls is instanceof interface specified by className */
public static boolean isntanceOf (Class cls, String className) {
Class c = cls;
while (c != null) {
if (className.equals(c.getName()))
return true;
Class [] interfaces = c.getInterfaces();
for (int i = 0; i < interfaces.length; i++) {
if (className.equals(interfaces [i].getName()))
return true;
}
c = c.getSuperclass();
}
return false;
}
/**
* @param propName System property name
* @param defaultValue default value
* @param minValue minimum value (inclusive) or Long.MIN_VALUE
* @param maxValue maximum value (inclusive) or Long.MAX_VALUE
* @return long property value
*/
public static long getLongSystemProperty (String propName, long defaultValue, long minValue, long maxValue) {
long result =
Long.parseLong(System.getProperty (propName, String.valueOf (defaultValue)));
if (result < minValue) {
LOG.error ("Property \"%s\" cannot be less than %s").with(propName).with(minValue);
result = minValue;
}
if (result > maxValue) {
LOG.error ("Property \"%s\" cannot be more than %s").with(propName).with(maxValue);
result = maxValue;
}
return result;
}
public static long getLongSystemProperty (String propName, long defaultValue) {
return getLongSystemProperty(propName, defaultValue, Long.MIN_VALUE, Long.MAX_VALUE);
}
public static int getIntSystemProperty (String propName, int defaultValue, int minValue, int maxValue) {
return (int) getLongSystemProperty(propName, defaultValue, minValue, maxValue);
}
/**
* @param propName System property name
* @param defaultValue default value
* @param minValue minimum value (inclusive) or Double.MIN_VALUE
* @param maxValue maximum value (inclusive) or Double.MAX_VALUE
* @return double property value
*/
public static double getDoubleSystemProperty (String propName, double defaultValue, double minValue, double maxValue) {
double result =
Double.parseDouble(System.getProperty (propName, String.valueOf (defaultValue)));
if (result < minValue) {
LOG.error ("Property \"%s\" cannot be less than %s").with(propName).with(minValue);
result = minValue;
}
if (result > maxValue) {
LOG.error ("Property \"%s\" cannot be more than %s").with(propName).with(maxValue);
result = maxValue;
}
return result;
}
/**
* Return the length of the specified array, or 0 if the array is null.
*/
public static int arraylen (Object [] array) {
return (array == null ? 0 : array.length);
}
/**
* Append the element to the specified array, returning a new array of the same
* type. If the array is null, and the element is not, construct an array of
* components whose type is that of the element.
*
* @exception IllegalArgumentException If both arguments are null.
*/
public static T [] arrayadd (T [] array, T newObject) {
return (arrayadd (array, arraylen (array), newObject));
}
/**
* Insert the element into the specified array, returning a new array of the same
* type. If the array is null, and the element is not, construct an array of
* components whose type is that of the element.
*
* @exception IllegalArgumentException
* If both arguments are null.
* @exception ArrayIndexOutOfBoundsException
* If atIdx is greater than array length.
*/
@SuppressWarnings("unchecked")
public static T [] arrayadd (T [] array, int atIdx, T newObject) {
if (array == null && newObject == null)
throw new IllegalArgumentException ("array == null && newObject == null");
int oldDim = arraylen (array);
if (atIdx < 0 || atIdx > oldDim)
throw new ArrayIndexOutOfBoundsException (atIdx);
Class compType =
array == null ?
newObject.getClass () :
array.getClass ().getComponentType ();
Object [] ret = (Object []) Array.newInstance (compType, oldDim + 1);
if (array != null) {
System.arraycopy (array, 0, ret, 0, atIdx);
System.arraycopy (array, atIdx, ret, atIdx + 1, oldDim - atIdx);
}
ret [atIdx] = newObject;
return (T[])ret;
}
/**
* Remove an element from the specified array, returning a new array of the same
* type.
*
* @exception ArrayIndexOutOfBoundsException
* If atIdx is out of bounds.
*/
@SuppressWarnings ("unchecked")
public static T [] arraydel (T [] array, int atIdx) {
int oldDim = array.length;
if (atIdx < 0 || atIdx >= oldDim)
throw new ArrayIndexOutOfBoundsException (atIdx);
Class compType = array.getClass ().getComponentType ();
T [] ret = (T []) Array.newInstance (compType, oldDim - 1);
int shiftIdx = atIdx + 1;
System.arraycopy (array, 0, ret, 0, atIdx);
System.arraycopy (array, shiftIdx, ret, atIdx, oldDim - shiftIdx);
return (ret);
}
/**
* Find an element in the specified array that equals to the specified element
* and remove it. If element is not found, return array.
*/
public static T [] arraydel (T [] array, Object elem) {
int idx = indexOf (array, elem);
if (idx < 0)
return (array);
return (arraydel (array, idx));
}
/**
* Find an element in the specified array that equals to the specified element
* and return its index, or -1 if not found.
*/
public static int indexOf (Object [] array, Object elem) {
int len = arraylen (array);
for (int ii = 0; ii < len; ii++)
if (xequals (array [ii], elem))
return (ii);
return (-1);
}
/**
* Find an element in the specified array that equals to the specified element
* and return its index, or -1 if not found.
*/
public static boolean contains (Object [] array, Object elem) {
return (indexOf (array, elem) >= 0);
}
/**
* Find the index of the minimum element. Returns -1 if array is empty.
*/
public static int indexOfMinMax (T [] array, Comparator comp, int order) {
int len = arraylen (array);
if (len == 0)
return (-1);
int idx = 0;
T minmax = array [0];
for (int ii = 1; ii < len; ii++) {
T cur = array [ii];
if (comp.compare (cur, minmax) * order > 0) {
minmax = cur;
idx = ii;
}
}
return (idx);
}
/**
* Find the index of the minimum element. Returns -1 if array is empty.
*/
public static > int indexOfMinMax (T [] array, int order) {
int len = arraylen (array);
if (len == 0)
return (-1);
int idx = 0;
T minmax = array [0];
for (int ii = 1; ii < len; ii++) {
T cur = array [ii];
if (cur.compareTo (minmax) * order > 0) {
minmax = cur;
idx = ii;
}
}
return (idx);
}
public static void format (
StringBuffer out,
Object obj,
Justification j,
int width,
String clip
)
{
String s = obj.toString ();
int length = s.length ();
int diff = width - length;
if (diff < 0) {
int clipLength = clip.length ();
int showLength = width - clipLength;
if (showLength > 0) {
out.append (s, 0, showLength);
showLength = 0;
}
out.append (clip, 0, clipLength + showLength);
}
else {
int lpad, rpad;
switch (j) {
case LEFT: lpad = diff; rpad = 0; break;
case RIGHT: rpad = diff; lpad = 0; break;
case CENTER: lpad = diff / 2; rpad = diff - lpad; break;
default: throw new RuntimeException ("Unrecognized: " + j);
}
for (int ii = 0; ii < lpad; ii++)
out.append (" ");
out.append (s);
for (int ii = 0; ii < rpad; ii++)
out.append (" ");
}
}
/**
* Creates a string that is a copy of the specified char sequence
* without calling CharSequence.toString ().
*/
public static String toString (CharSequence cs) {
return (cs.getClass () == String.class ? (String) cs : new StringBuilder (cs).toString ());
}
/**
* Creates a string that is a copy of the specified char sequence
* without calling CharSequence.toString (). Supports null argument.
*/
public static String toNullableString (CharSequence cs) {
return (cs == null) ? null : toString(cs);
}
/**
* Replicates the String.hashCode () logic for arbitrary CharSequence instances.
* Returns 0 for null.
*/
public static int hashCode (CharSequence cs) {
if (cs == null)
return (0);
if (cs.getClass () == String.class) // String caches hash code
return (cs.hashCode ());
int len = cs.length ();
int hc = 0;
for (int i = 0; i < len; i++)
hc = 31 * hc + cs.charAt (i);
return (hc);
}
public static boolean isBoxedPrimitive (Class c) {
return (
c == Boolean.class || c == Character.class ||
c == Byte.class || c == Short.class ||
c == Integer.class || c == Long.class ||
c == Float.class || c == Double.class
);
}
public static Class toBoxed (Class c) {
if (c == boolean.class)
return (Boolean.class);
if (c == char.class)
return (Character.class);
if (c == byte.class)
return (Byte.class);
if (c == short.class)
return (Short.class);
if (c == int.class)
return (Integer.class);
if (c == long.class)
return (Long.class);
if (c == float.class)
return (Float.class);
if (c == double.class)
return (Double.class);
return (c);
}
public static String getPackagePrefix (Class cls) {
String qname = cls.getName ();
String sname = cls.getSimpleName ();
assert qname.endsWith (sname);
return (qname.substring (0, qname.length () - sname.length ()));
}
public static long getAvailableMemory () {
final Runtime rt = Runtime.getRuntime ();
return (rt.maxMemory () - rt.totalMemory () + rt.freeMemory ());
}
public static long fractionOfAvailableMemory (double k) {
final Runtime rt = Runtime.getRuntime();
final long maxMem = rt.maxMemory();
final long freeMem = rt.freeMemory();
final long currentMem = rt.totalMemory();
final long usedMem = currentMem - freeMem;
final long availMem = maxMem - usedMem;
final long mem = (long) (availMem * k);
return (mem);
}
public static int availableMemoryPercent () {
final Runtime rt = Runtime.getRuntime();
final long maxMem = rt.maxMemory();
final long freeMem = rt.freeMemory();
final long currentMem = rt.totalMemory();
final long usedMem = currentMem - freeMem;
final long availMem = maxMem - usedMem;
return (int) (availMem * 100 / maxMem);
}
public static boolean asAdministrator () {
// attempt to set a preference
try {
final String path = "/deltix/dummyPref";
final Preferences prefs = Preferences.systemRoot ().node (path);
prefs.putLong ("dummyKey",
System.currentTimeMillis ());
prefs.flush ();
return true;
} catch (final Exception e) {
return false;
}
}
public static HashMap newHashMap(int size) {
return new HashMap(1 + (int) (size/0.75));
}
public static String getPackage (String className) {
int dot = className.lastIndexOf ('.');
return (dot < 0 ? "" : className.substring (0, dot));
}
public static String getSimpleName (String className) {
int dot = className.lastIndexOf ('.');
return (dot < 0 ? className : className.substring (dot + 1));
}
}