Лабораторная работа №21 / serpent.tar / serpent-as-submitted / floppy3 / src / Serpent / Serpent_Properties

// $Id: $
//
// $Log: $
// Revision 1.0 1998/04/10 raif
// + start of history.
//
// $Endlog$
/*
* Copyright (c) 1997, 1998 Systemics Ltd on behalf of
* the Cryptix Development Team. All rights reserved.
*/
package Serpent;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.PrintStream;
import java.util.Enumeration;
import java.util.Properties;

/**
* This class acts as a central repository for an algorithm specific
* properties.<p>
*
* <b>Copyright</b> &copy; 1997, 1998
* <a href="http://www.systemics.com/">Systemics Ltd</a> on behalf of the
* <a href="http://www.systemics.com/docs/cryptix/">Cryptix Development Team</a>.
* <br>All rights reserved.<p>
*
* <b>$Revision: $</b>
* @author David Hopwood
* @author Jill Baker
* @author Raif S. Naffah
*/
public class Serpent_Properties // implicit no-argument constructor
{
// Constants and variables with relevant static code
//...........................................................................

static final boolean GLOBAL_DEBUG = false;

static final String ALGORITHM = "Serpent";
static final double VERSION = 0.1;
static final String FULL_NAME = ALGORITHM + " ver. " + VERSION;
static final String NAME = "Serpent_Properties";

/**
* The (algorithm).properties file containing algorithm-specific
* properties. Only the 'lib' folder/directory in (java.home) is
* searched for this properties file.
*/
static final Properties properties = new Properties();

/** Default properties in case .properties file was not found. */
private static final String[][] DEFAULT_PROPERTIES = {
{"Trace.Serpent_Algorithm", "true"},
{"Debug.Level.*", "1"},
{"Debug.Level.Serpent_Algorithm", "9"},
};

static {
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Looking for " + ALGORITHM + " properties");
String it = ALGORITHM + ".properties";
InputStream is = Serpent_Properties.class.getResourceAsStream(it);
boolean ok = is != null;
if (ok)
try {
properties.load(is);
is.close();
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Properties file loaded OK...");
} catch (Exception x) {
ok = false;
}
if (!ok) {
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": WARNING: Unable to load \"" + it + "\" from CLASSPATH.");
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Will use default values instead...");
int n = DEFAULT_PROPERTIES.length;
for (int i = 0; i < n; i++)
properties.put(
DEFAULT_PROPERTIES[i][0], DEFAULT_PROPERTIES[i][1]);
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Default properties now set...");
}
}


// Properties methods (excluding load and save, which are deliberately not
// supported).
//...........................................................................

/** Get the value of a property for this algorithm. */
public static String getProperty (String key) {
return properties.getProperty(key);
}

/**
* Get the value of a property for this algorithm, or return
* <i>value</i> if the property was not set.
*/
public static String getProperty (String key, String value) {
return properties.getProperty(key, value);
}

/** List algorithm properties to the PrintStream <i>out</i>. */
public static void list (PrintStream out) {
list(new PrintWriter(out, true));
}

/** List algorithm properties to the PrintWriter <i>out</i>. */
public static void list (PrintWriter out) {
out.println("#");
out.println("# ----- Begin "+ALGORITHM+" properties -----");
out.println("#");
String key, value;
Enumeration enum = properties.propertyNames();
while (enum.hasMoreElements()) {
key = (String) enum.nextElement();
value = getProperty(key);
out.println(key + " = " + value);
}
out.println("#");
out.println("# ----- End "+ALGORITHM+" properties -----");
}

// public synchronized void load(InputStream in) throws IOException {}

public static Enumeration propertyNames() {
return properties.propertyNames();
}

// public void save (OutputStream os, String comment) {}


// Developer support: Tracing and debugging enquiry methods (package-private)
//...........................................................................

/**
* Return true if tracing is requested for a given class.<p>
*
* User indicates this by setting the tracing <code>boolean</code>
* property for <i>label</i> in the <code>(algorithm).properties</code>
* file. The property's key is "<code>Trace.<i>label</i></code>".<p>
*
* @param label The name of a class.
* @return True iff a boolean true value is set for a property with
* the key <code>Trace.<i>label</i></code>.
*/
static boolean isTraceable (String label) {
String s = getProperty("Trace." + label);
if (s == null)
return false;
return new Boolean(s).booleanValue();
}

/**
* Return the debug level for a given class.<p>
*
* User indicates this by setting the numeric property with key
* "<code>Debug.Level.<i>label</i></code>".<p>
*
* If this property is not set, "<code>Debug.Level.*</code>" is looked up
* next. If neither property is set, or if the first property found is
* not a valid decimal integer, then this method returns 0.
*
* @param label The name of a class.
* @return The required debugging level for the designated class.
*/
static int getLevel(String label) {
String s = getProperty("Debug.Level." + label);
if (s == null) {
s = getProperty("Debug.Level.*");
if (s == null)
return 0;
}
try {
return Integer.parseInt(s);
} catch (NumberFormatException e) {
return 0;
}
}

/**
* Return the PrintWriter to which tracing and debugging output is to
* be sent.<p>
*
* User indicates this by setting the property with key <code>Output</code>
* to the literal <code>out</code> or <code>err</code>.<p>
*
* By default or if the set value is not allowed, <code>System.err</code>
* will be used.
*/
static PrintWriter getOutput() {
PrintWriter pw;
String name = getProperty("Output");
if (name != null && name.equals("out"))
pw = new PrintWriter(System.out, true);
else
pw = new PrintWriter(System.err, true);
return pw;
}
}