/* $Id$ */
package ibis.ipl.impl;
import ibis.ipl.IbisProperties;
import ibis.util.TypedProperties;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Properties;
/**
* Represents a location on which an Ibis instance runs. This is the
* data type returned by {@link IbisIdentifier#location()}.
* It represents a number of levels, for instance hostname, domain,
* in that order, t.i., from detailed to coarse.
*/
public final class Location implements ibis.ipl.Location {
private static final Location universe = new Location(new String[0]);
private static final long serialVersionUID = 1L;
/** Separates level names in a string representation of the location. */
public static final String SEPARATOR = "@";
/** The names of the levels. */
private String levelNames[];
/** Coded form. */
private transient byte[] codedForm;
private transient Location parent = null;
/**
* Constructs a location object from the specified level names.
* @param levels the level names.
*/
public Location(String[] levels) {
levelNames = new String[levels.length];
for (int i = 0; i < levels.length; i++) {
levelNames[i] = levels[i];
}
codedForm = computeCodedForm();
}
/**
* Constructs a location object from the specified string, in which
* level names are separated by the separator character.
* @param s the specified string.
*/
public Location(String s) {
if (s.equals("")) {
levelNames = new String[0];
} else {
levelNames = s.split(SEPARATOR);
}
codedForm = computeCodedForm();
}
/**
* Constructs a <code>Location</code> from the specified coded form.
* @param codedForm the coded form.
* @exception IOException is thrown in case of trouble.
*/
public Location(byte[] codedForm) throws IOException {
this(codedForm, 0, codedForm.length);
}
/**
* Constructs a <code>Location</code> from the specified coded form,
* at a particular offset and size.
* @param codedForm the coded form.
* @param offset offset in the coded form.
* @param size size of the coded form.
* @exception IOException is thrown in case of trouble.
*/
public Location(byte[] codedForm, int offset, int size)
throws IOException {
this(new DataInputStream(
new ByteArrayInputStream(codedForm, offset, size)));
}
/**
* Reads a <code>Location</code> from the specified input stream.
* @param dis the input stream.
* @exception IOException is thrown in case of trouble.
*/
public Location(DataInput dis) throws IOException {
this(dis.readUTF());
}
/**
* Returns the coded form of this <code>Location</code>.
* @return the coded form.
*/
public byte[] toBytes() {
if (codedForm == null) {
codedForm = computeCodedForm();
}
return codedForm.clone();
}
private byte[] computeCodedForm() {
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(bos);
dos.writeUTF(toString());
dos.close();
return bos.toByteArray();
} catch(Exception e) {
// Should not happen. Ignore.
return null;
}
}
/**
* Adds coded form of this <code>Location</code> to the specified
* output stream.
* @param dos the output stream.
* @exception IOException is thrown in case of trouble.
*/
public void writeTo(DataOutput dos) throws IOException {
if (codedForm == null) {
codedForm = computeCodedForm();
}
dos.write(codedForm);
}
public int numberOfLevels() {
return levelNames.length;
}
public String[] getLevels() {
return levelNames.clone();
}
public String getLevel(int level) {
return levelNames[level];
}
public int numberOfMatchingLevels(ibis.ipl.Location o) {
int n1 = o.numberOfLevels();
for (int i = levelNames.length-1; i >= 0; i--) {
n1--;
if (n1 < 0 || ! levelNames[i].equals(o.getLevel(n1))) {
return levelNames.length-1-i;
}
}
return levelNames.length;
}
public boolean equals(Object o) {
if (! (o instanceof ibis.ipl.impl.Location)) {
return false;
}
Location l = (Location) o;
if (l.levelNames.length != levelNames.length) {
return false;
}
return numberOfMatchingLevels(l) == levelNames.length;
}
public int hashCode() {
int retval = 0;
for (int i = 0; i < levelNames.length; i++) {
retval += levelNames[i].hashCode();
}
return retval;
}
/**
* Method to retreive a default location, consisting of the domain and
* hostname of this machine.
* @param props properties.
* @param adds addresses to use as a source of the hostname (may be null).
* @return the default location of this machine.
*/
public static Location defaultLocation(Properties props, InetAddress [] adds) {
// If the user has specified one or more preferred IP addresses, we'll
// try to resolve those first.
String fullHostName = null;
if (adds != null && adds.length >= 0) {
for (InetAddress a : adds) {
fullHostName = a.getCanonicalHostName();
if (fullHostName.length() > 0 && Character.isJavaIdentifierStart(fullHostName.charAt(0))) {
break;
}
fullHostName = null;
}
}
// NOTE: This may result in a unusable location when the hostname
// of the machine is set to a crappy value (as on DAS-3).
if (fullHostName == null) {
try {
InetAddress a = InetAddress.getLocalHost();
fullHostName = a.getCanonicalHostName();
} catch(IOException e) {
fullHostName = "Unknown location";
}
}
String[] split = fullHostName.split("\\.");
TypedProperties p = new TypedProperties(props);
String s = p.getProperty(IbisProperties.LOCATION);
if (s == null) {
s = DEFAULT_LOCATION;
}
char[] buf = s.toCharArray();
StringBuffer b = new StringBuffer();
// Find words between '%' delimiters, and replace them with the required value.
// If the word is not recognized, it is left untouched (including the
// '%').
for (int i = 0; i < buf.length; i++) {
if (buf[i] != '%') {
b.append(buf[i]);
} else if (i == buf.length-1) {
b.append('%');
} else if (buf[i+1] == '%') {
b.append('%');
i++;
} else {
StringBuffer keyBuffer = new StringBuffer();
String key = null;
for (int j = i+1; j < buf.length; j++) {
if (buf[j] != '%') {
keyBuffer.append(buf[j]);
} else {
key = keyBuffer.toString();
i = j;
break;
}
}
if (key == null) {
b.append('%');
b.append(keyBuffer);
i = buf.length - 1;
break;
}
if (key.equals("HOSTNAME")) {
b.append(split[0]);
} else if (key.equals("DOMAIN") || key.equals("FLAT_DOMAIN")) {
for (int j = 1; j < split.length; j++) {
b.append(split[j]);
if (j < split.length-1) {
b.append(key.equals("DOMAIN") ? SEPARATOR : ':');
}
}
} else if (key.equals("PID")) {
int pid = -1;
try {
pid = Integer.parseInt(( new File("/proc/self")).getCanonicalFile().getName());
} catch (Throwable e) {
// ignore. No pid available.
}
b.append(pid);
} else {
// Unrecognized key, just leave it alone.
b.append('%');
b.append(key);
b.append('%');
}
}
}
return new Location(b.toString());
}
public String toString() {
String retval = "";
for (int i = 0; i < levelNames.length; i++) {
if (i != 0) {
retval += SEPARATOR;
}
retval += levelNames[i];
}
return retval;
}
public int compareTo(ibis.ipl.Location o) {
int n = o.numberOfLevels();
for (int i = levelNames.length-1; i >= 0; i--) {
n--;
if (n < 0) {
return 1;
}
int cmp = levelNames[i].compareTo(o.getLevel(n));
if (cmp != 0) {
return cmp;
}
}
if (n == 0) {
return 0;
}
return -1;
}
public ibis.ipl.Location getParent() {
if (parent == null) {
if (levelNames.length <= 1) {
parent = universe;
} else {
String[] names = new String[levelNames.length-1];
for (int i = 1; i < levelNames.length; i++) {
names[i-1] = levelNames[i];
}
parent = new Location(names);
}
}
return parent;
}
public Iterator<String> iterator() {
return new Iter();
}
private class Iter implements Iterator<String> {
int index = levelNames.length;
public boolean hasNext() {
return index > 0;
}
public String next() {
if (hasNext()) {
return levelNames[--index];
}
throw new NoSuchElementException("Iterator exhausted");
}
public void remove() {
throw new UnsupportedOperationException("remove() not supported");
}
}
}