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The NetCDF-Java Library is a Java interface to NetCDF files,
as well as to many other types of scientific data formats.
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/*
* Copyright (c) 1998 - 2009. University Corporation for Atmospheric Research/Unidata
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
* written permission is obtained from UCAR/Unidata. The user also
* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package thredds.filesystem;
import thredds.inventory.MCollection;
import thredds.inventory.*;
import java.util.*;
import java.io.IOException;
import net.jcip.annotations.ThreadSafe;
/**
* Implements an MController using a CacheManager.
*
* @author caron
* @since Jun 25, 2009
*/
@ThreadSafe
public class ControllerCaching implements MController {
public static MController makeStandardController(String configFile, String cacheDir) throws IOException {
CacheManager.makeStandardCacheManager(configFile, cacheDir);
CacheManager cm = new CacheManager("directories");
return new ControllerCaching(cm);
}
public static MController makeTestController(String cacheDir) {
CacheManager.makeTestCacheManager( cacheDir);
CacheManager cm = new CacheManager("directories");
return new ControllerCaching(cm);
}
////////////////////////////////////////
private CacheManager cacheManager;
private ControllerCaching(CacheManager cacheManager) {
this.cacheManager = cacheManager;
}
////////////////////////////////////////
@Override
public Iterator getInventoryAll(MCollection mc, boolean recheck) {
String path = mc.getDirectoryName();
if (path.startsWith("file:")) {
path = path.substring(5);
}
CacheDirectory cd = cacheManager.get(path, recheck); // check in cache, else call File.listFiles()
if (cd == null) return null;
if (!cd.isDirectory()) return null;
return new FilteredIterator(mc, new MFileIteratorAll(cd, recheck), false);
}
@Override
public Iterator getInventoryTop(MCollection mc, boolean recheck) {
String path = mc.getDirectoryName();
if (path.startsWith("file:")) {
path = path.substring(5);
}
CacheDirectory cd = cacheManager.get(path, recheck); // check in cache, else call File.listFiles()
if (cd == null) return null;
if (!cd.isDirectory()) return null;
return new FilteredIterator(mc, new MFileIterator(cd), false);
}
@Override
public Iterator getSubdirs(MCollection mc, boolean recheck) {
String path = mc.getDirectoryName();
if (path.startsWith("file:")) {
path = path.substring(5);
}
CacheDirectory cd = cacheManager.get(path, recheck); // check in cache, else call File.listFiles()
if (cd == null) return null;
if (!cd.isDirectory()) return null;
return new FilteredIterator(mc, new MFileIterator(cd), true);
}
@Override
public void close() {
if (cacheManager != null) cacheManager.close();
cacheManager = null;
}
////////////////////////////////////////////////////////////
// handles filtering and removing subdirectories
private class FilteredIterator implements Iterator {
private final Iterator orgIter;
private final MCollection mc;
private final boolean wantDirs;
private MFile next;
FilteredIterator(MCollection mc, Iterator iter, boolean wantDirs) {
this.orgIter = iter;
this.mc = mc;
this.wantDirs = wantDirs;
}
public boolean hasNext() {
next = nextFilteredFile();
return (next != null);
}
public MFile next() {
return next;
}
public void remove() {
throw new UnsupportedOperationException();
}
private MFile nextFilteredFile() {
if (orgIter == null) return null;
if (!orgIter.hasNext()) return null;
MFile pdata = orgIter.next();
while ((pdata.isDirectory() != wantDirs) || !mc.accept(pdata)) { // skip directories, and filter
if (!orgIter.hasNext()) return null;
pdata = orgIter.next();
}
return pdata;
}
}
private class MFileIterator implements Iterator {
final String path;
final List files;
int count = 0;
MFileIterator(CacheDirectory cd) {
this.path = cd.getPath();
this.files = Arrays.asList(cd.getChildren());
}
MFileIterator(String path, List files) {
this.path = path;
this.files = files;
}
public boolean hasNext() {
return count < files.size();
}
public MFile next() {
CacheFile cfile = files.get(count++);
return new MFileCached(path, cfile);
}
public void remove() {
throw new UnsupportedOperationException();
}
}
// recursively scans everything in the directory and in subdirectories, depth first, leaves before subdirs
private class MFileIteratorAll implements Iterator {
final boolean recheck;
final Queue traverse;
Traversal currTraversal;
Iterator currIter;
MFileIteratorAll(CacheDirectory top, boolean recheck) {
traverse = new LinkedList();
currTraversal = new Traversal(top);
this.recheck = recheck;
}
public boolean hasNext() {
if (currIter == null) {
currIter = getNextIterator();
if (currIter == null) {
return false;
}
}
if (!currIter.hasNext()) {
currIter = getNextIterator();
return hasNext();
}
return true;
}
public MFile next() {
return currIter.next();
}
private Iterator getNextIterator() {
if (!currTraversal.leavesAreDone) {
currTraversal.leavesAreDone = true;
return new MFileIterator(currTraversal.dir.getPath(), currTraversal.fileList); // look for leaves in the current directory
} else {
if ((currTraversal.subdirIterator != null) && currTraversal.subdirIterator.hasNext()) { // has subdirs
CacheFile nextDir = currTraversal.subdirIterator.next();
CacheDirectory cd = cacheManager.get(currTraversal.dir.getPath() + "/" + nextDir.getShortName(), recheck); // fetch subdirectory
if (cd == null) { // subdir has disappeared - skip it
return getNextIterator();
}
traverse.add(currTraversal); // keep track of current traversal on queue
currTraversal = new Traversal(cd); // new traversal
return getNextIterator();
} else {
if (traverse.peek() == null) return null; // all done
currTraversal = traverse.remove();
return getNextIterator();
}
}
}
public void remove() {
throw new UnsupportedOperationException();
}
}
private class Traversal {
final CacheDirectory dir;
final List fileList;
Iterator subdirIterator;
boolean leavesAreDone = false;
Traversal(CacheDirectory dir) {
this.dir = dir;
fileList = new ArrayList();
List subdirList = new ArrayList();
for (CacheFile f : dir.getChildren()) {
if (f.isDirectory())
subdirList.add(f);
else
fileList.add(f);
}
if (subdirList.size() > 0)
this.subdirIterator = subdirList.iterator();
}
}
}