+++ /dev/null
-package org.vamsas.client.simpleclient;
-
-import org.vamsas.client.*;
-
-import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutput;
-import java.io.ObjectOutputStream;
-import java.io.OutputStream;
-import java.util.Vector;
-
-/**
- * Handler for the clientsFile within a vamsas session thread.
- * @author jim
- */
-public class ClientsFile extends ListFile {
- private static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog(ClientsFile.class);
- /**
- * number of my client in list - passed back when a client
- * is added to list, and used (if valid) for quickly
- * looking up presence of client handle in the list.
- */
- private int syncnum = 1;
-
- public ClientsFile(File filelist) throws IOException {
- super(filelist);
- }
-
- /**
- * internal method for getting clientList - ensures a lock has been made but
- * does not release it.
- *
- * @return list of clients
- */
- private ClientHandle[] retrieveClientHandles() {
- if (lockFile()) {
- try {
- ClientHandle[] clients=null;
- if (fileLock.length()>0) {
-
- ObjectInputStream is = new ObjectInputStream(fileLock.getBufferedInputStream(true));
- Object o;
- o=is.readObject();
- if (o!=null) {
- try {
- clients = (ClientHandle[]) o;
- }
- catch (Exception e) {
- System.err.println("Garbage in the clientHandle list "+this.sessionFile);
- }
- }
- }
- return clients;
- } catch (FileNotFoundException e) {
- // TODO Auto-generated catch block
- e.printStackTrace(System.err);
- } catch (Exception e) {
- e.printStackTrace(System.err);
- }
- }
- return null;
- }
- /**
- * get the clientList from the file. May return null if lock failed!
- * @return clientList
- */
- public ClientHandle[] retrieveClientList() {
- if (lockFile()) {
- ClientHandle[] clients = retrieveClientHandles();
- unlockFile();
- return clients;
- }
- return null;
- }
- /**
- * get list from the locked ClientList.
- * @param extantlock
- * @return clientList or null if lock failed (or file was empty)
- */
- public ClientHandle[] retrieveClientList(Lock extantlock) {
- if (lockFile(extantlock)) {
- ClientHandle[] clients = retrieveClientHandles();
- unlockFile();
- return clients;
- }
- return null;
- }
- /**
- * adds clientHandle me to the clientList under an existing lock extantLock.
- * @param me
- * @param extantLock
- * @return client index in list or 0 if lock was invalid or addClient operation failed.
- */
- public int addClient(ClientHandle me, Lock extantLock) {
- return addClient(me, true, extantLock);
- }
-
- /**
- * adds clientHandle me to the clientList under an existing lock.
- * @param me - clientHandle
- * @param disambig - if true then add will fail if an identical clientHandle already exists
- * @param extantLock - existing lock
- * @return client index in list or 0 if addClient (or the lock) failed.
- */
-
- public int addClient(ClientHandle me, boolean disambig, Lock extantLock) {
- if (lockFile(extantLock)) {
- syncnum = addClient(me, disambig);
- unlockFile();
- return syncnum;
- }
- return 0;
- }
-
- /**
- * adds the ClientHandle to the list - if it is not unique, then the
- * ClientHandle object is modified to make it unique in the list. returns the
- * clientNumber for the client in the session.
- *
- * @param me
- * @return
- */
-
- public int addClient(ClientHandle me) {
- syncnum = addClient(me, true);
- unlockFile();
- return syncnum;
- }
-
- /**
- * removes 'me' from the session ClientList without complaint if 'me' isn't in the clientList already.
- * @param me client handle to be removed
- * @param clientlock existing lock passed from watcher.
- */
- public void removeClient(ClientHandle me, Lock clientlock) {
- int mynum=-1;
- if (lockFile(clientlock)) {
- ClientHandle[] clients = retrieveClientHandles();
- if (clients != null) {
- if ((syncnum<=0 || syncnum>clients.length) || clients[syncnum-1]!=me) {
- for (int i = 0, j = clients.length; i < j; i++)
- if (clients[i].equals(me)) {
- mynum=i;
- break;
- }
- } else {
- mynum=syncnum-1;
- }
- if (mynum>-1) {
- ClientHandle[] newlist = new ClientHandle[clients.length - 1];
- for (int k=0,i = 0, j = clients.length; i < j; i++)
- if (i!=mynum)
- newlist[k++] = clients[i];
- if (!putClientList(newlist))
- throw new Error("Failed to write new clientList!"); // failed to put the clientList to disk.
- }
- }
- unlockFile();
- } else {
- throw new Error("Couldn't get lock for "+((sessionFile==null) ? "Unitialised sessionFile in ClientsFile" : sessionFile.getAbsolutePath()));
- }
- }
- /**
- * Adds a ClientHandle to the ClientList file - optionally disambiguating
- * the ClientHandle (modifes the URN).
- * Note: Caller is left to release the lock on the ClientList.
- * @param me
- * @param disambiguate -
- * flag indicating if the URN for me should be disambiguated to
- * differentiate between sessions.
- * @return index of clientHandle in new list, or -1-position of existing
- * clientHandle (if disambiguate is true)
- */
- protected int addClient(ClientHandle me, boolean disambiguate) {
- int newclient = 0;
- int tries=5;
- while (tries-->0 && !lockFile())
- try { Thread.sleep(1); } catch (Exception e){};
- if (lockFile()) {
- ClientHandle[] clients = retrieveClientHandles();
- if (me.getClientUrn()==null) {
- // TODO: move this into ClientUrn as a standard form method.
- me.setClientUrn("vamsas://"+me.getClientName()+":"+me.getVersion()+"/");
- }
- if (clients == null) {
- clients = new ClientHandle[1];
- clients[0] = me;
- newclient = 1;
- } else {
- int k = 0;
- for (int i = 0, j = clients.length; i < j; i++) {
- if (clients[i].equals(me)) {
- if (disambiguate) {
- while (clients[i].equals(me)) {
- me.setClientUrn(me.getClientUrn() + k++); // TODO: make a better
- // disambiguation of
- // urn.
- }
- } else {
- // will not write the ambiguous clientHandle to disk, just return
- // its index.
- return -1 - i;
- }
- }
- }
- int i, j;
- ClientHandle[] newlist = new ClientHandle[clients.length + 1];
- for (i = 0, j = clients.length; i < j; i++)
- newlist[i] = clients[i];
- newlist[j] = me;
- clients = newlist;
- newclient = j+1;
- }
- if (!putClientList(clients))
- return 0; // failed to put the clientList to disk.
- }
- return newclient;
- }
- /**
- * when set true - get FileNotFoundExceptions on WinXP when writing to locked stream after the backup has been made (via the backupFile method)
- */
- boolean backup=false;
- /**
- * safely writes clients array to the file referred to by sessionFile.
- *
- * @param clients
- * @return true if successful write. Throws Errors otherwise.
- */
- protected boolean putClientList(ClientHandle[] clients) {
- if (lockFile()) {
- File templist=null;
- if (!backup || (templist = backupSessionFile()) != null) {
- int retries=3;
- while (retries-->0) {
- try {
- ObjectOutputStream os =
- new ObjectOutputStream(fileLock.getBufferedOutputStream(true));
- log.debug("About to write "+clients.length+" clientHandles to output stream.");
- os.writeObject(clients);
- os.close();
- // All done - remove the backup.
- if (backup)
- templist.delete();
- templist = null;
- retries=-1;
- } catch (Exception e) {
- System.err
- .println("Serious - problems writing to sessionFile.");
- if (retries>0 && templist != null) {
- System.err.println("Recovering from Backup in "
- + templist.getAbsolutePath());
- templist.renameTo(fileLock.target);
- }
- e.printStackTrace(System.err);
- }
- }
- if (retries>-2) {
- System.err
- .println("Serious - problems writing to sessionFile. Giving Up.");
- return false;
- }
- } else {
- throw new Error(
- "Couldn't create backup of the clientList before writing to it!");
- }
- } else {
- throw new Error("Could not lock the clientList: "
- + ((sessionFile == null) ? "Unitialized ClientsFile"
- : " failed to get lock on " + sessionFile.getAbsolutePath()));
- }
- // successful!
- return true;
- }
-
- public void clearList() {
- if (lockFile()) {
- try {
- FileOutputStream fout = fileLock.getFileOutputStream(true);
- fout.flush();
- fout.close();
- } catch (Exception e) {
- throw new Error("Problems trying to clear clientlist!",e);
-
- }
- }
-
- }
-}
git://source.jalview.org / vamsas.git / blobdiff