001 package org.wdssii.core.fam;
002
003 import java.io.File;
004 import java.io.FilenameFilter;
005 import java.util.ArrayList;
006 import java.util.Arrays;
007 import java.util.List;
008
009 import net.contentobjects.jnotify.JNotify;
010 import net.contentobjects.jnotify.JNotifyException;
011 import net.contentobjects.jnotify.JNotifyListener;
012
013 import org.apache.commons.logging.Log;
014 import org.apache.commons.logging.LogFactory;
015
016 public class FamIndexHelperInotifyImpl implements FamIndexHelper,
017 JNotifyListener {
018
019 private final Log log = LogFactory.getLog(getClass());
020 private List<File> files = new ArrayList<File>();
021 private int wd;
022 private final FilenameFilter filenamePattern;
023
024 /** By default look only at files that end with .fml */
025 public FamIndexHelperInotifyImpl() {
026 this(new FmlFilesOnlyFilter());
027 }
028
029 public FamIndexHelperInotifyImpl(FilenameFilter pattern) {
030 // this will cause a class-load exception if JNotify is not in classpath
031 try{
032 JNotify.removeWatch(-1);
033 } catch (JNotifyException e){
034 // ok
035 }
036 filenamePattern = pattern;
037 }
038
039 @Override
040 public File[] getInitialFiles(String indexDir) {
041 try {
042 // JNotify maps IN_CREATE and IN_MOVED_TO to these constants
043 final int mask = JNotify.FILE_CREATED | JNotify.FILE_RENAMED;
044 this.wd = JNotify.addWatch(indexDir, mask, false, this);
045 if (log.isInfoEnabled()) {
046 log.info("Successfully created inotify watch for " + indexDir
047 + " wd=" + wd);
048 }
049 } catch (JNotifyException e) {
050 log
051 .error("Make sure that the jnotify jar file and .so are in Tomcat's shared/lib");
052 log
053 .error(
054 "Otherwise, you could try using WebIndexDirectoryListingDAO instead",
055 e);
056 throw new UnsupportedOperationException(e);
057 }
058 // existing files
059 File[] files = new File(indexDir).listFiles(filenamePattern);
060 Arrays.sort(files);
061 return files;
062 }
063
064 @Override
065 public synchronized void fileCreated(int watch, String indexDir,
066 String filename) {
067 if (filename != null && filenamePattern.accept(null, filename)) {
068 File f = new File(indexDir, filename);
069 files.add(f);
070 }
071 }
072
073 @Override
074 public synchronized void fileDeleted(int arg0, String arg1, String arg2) {
075 }
076
077 @Override
078 public synchronized void fileModified(int arg0, String arg1, String arg2) {
079 }
080
081 @Override
082 public synchronized void fileRenamed(int wd, String indexDir,
083 String oldName, String newName) {
084 if (newName != null && filenamePattern.accept(null, newName)) {
085 File f = new File(indexDir, newName);
086 files.add(f);
087 }
088 }
089
090 @Override
091 /**
092 * returns new files in watched directory since previous call to this
093 * method.
094 */
095 public synchronized File[] getNewFiles() {
096 File[] newfiles = files.toArray(new File[0]);
097 files.clear(); // start accumulating again
098 return newfiles;
099 }
100
101 /**
102 * De-registers from the watch so that the servlet container does not keep
103 * receiving events.
104 */
105 @Override
106 public void close() {
107 if (wd >= 0) {
108 try {
109 JNotify.removeWatch(wd);
110 if (log.isInfoEnabled()) {
111 log.info("Removed inotify watch wd=" + wd);
112 }
113 } catch (JNotifyException e) {
114 // ok
115 }
116 }
117 }
118
119 @Override
120 public void pruneToMaxSize(long m, long n){
121 // nothing to do
122 }
123 }