/*
* eXist Open Source Native XML Database
* Copyright (C) 2013 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.source;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import org.exist.dom.persistent.BinaryDocument;
import org.exist.dom.persistent.DocumentImpl;
import org.exist.dom.QName;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
import org.exist.security.Subject;
import org.exist.security.internal.aider.UnixStylePermissionAider;
import org.exist.storage.DBBroker;
import org.exist.storage.lock.Lock.LockMode;
import org.exist.xmldb.XmldbURI;
/**
* Source implementation that reads from a binary resource
* stored in the database.
*
* @author wolf
*/
public class DBSource extends AbstractSource {
private final BinaryDocument doc;
private final XmldbURI key;
private final long lastModified;
private String encoding = "UTF-8";
private final boolean checkEncoding;
private final DBBroker broker;
public DBSource(final DBBroker broker, final BinaryDocument doc, final boolean checkXQEncoding) {
this.broker = broker;
this.doc = doc;
this.key = doc.getURI();
this.lastModified = doc.getMetadata().getLastModified();
this.checkEncoding = checkXQEncoding;
}
@Override
public String path() {
return getDocumentPath().toString();
}
@Override
public String type() {
return "DB";
}
/* (non-Javadoc)
* @see org.exist.source.Source#getKey()
*/
@Override
public Object getKey() {
return key;
}
public XmldbURI getDocumentPath() {
return key;
}
public long getLastModified() {
return lastModified;
}
/* (non-Javadoc)
* @see org.exist.source.Source#isValid()
*/
@Override
public int isValid(final DBBroker broker) {
DocumentImpl d = null;
int result;
try {
d = broker.getXMLResource(key, LockMode.READ_LOCK);
if(d == null) {
result = INVALID;
} else if(d.getMetadata().getLastModified() > lastModified) {
result = INVALID;
} else {
result = VALID;
}
} catch(final PermissionDeniedException pde) {
result = INVALID;
} finally {
if(d != null) {
d.getUpdateLock().release(LockMode.READ_LOCK);
}
}
return result;
}
/* (non-Javadoc)
* @see org.exist.source.Source#isValid(org.exist.source.Source)
*/
@Override
public int isValid(final Source other) {
final int result;
if(!(other instanceof DBSource)) {
result = INVALID;
} else if(((DBSource)other).getLastModified() > lastModified) {
result = INVALID;
} else {
result = VALID;
}
return result;
}
/* (non-Javadoc)
* @see org.exist.source.Source#getReader()
*/
@Override
public Reader getReader() throws IOException {
final InputStream is = broker.getBinaryResource(doc);
final BufferedInputStream bis = new BufferedInputStream(is);
bis.mark(64);
checkEncoding(bis);
bis.reset();
return new InputStreamReader(bis, encoding);
}
@Override
public InputStream getInputStream() throws IOException {
return broker.getBinaryResource(doc);
}
/* (non-Javadoc)
* @see org.exist.source.Source#getContent()
*/
@Override
public String getContent() throws IOException {
final InputStream raw = broker.getBinaryResource(doc);
final long binaryLength = broker.getBinaryResourceSize(doc);
if(binaryLength > (long)Integer.MAX_VALUE) {
throw new IOException("Resource too big to be read using this method.");
}
final byte [] data = new byte[(int)binaryLength];
raw.read(data);
raw.close();
final ByteArrayInputStream is = new ByteArrayInputStream(data);
checkEncoding(is);
return new String(data, encoding);
}
@Override
public QName isModule() throws IOException {
final InputStream raw = broker.getBinaryResource(doc);
final long binaryLength = broker.getBinaryResourceSize(doc);
if(binaryLength > (long)Integer.MAX_VALUE) {
throw new IOException("Resource too big to be read using this method.");
}
final byte [] data = new byte[(int)binaryLength];
raw.read(data);
raw.close();
final ByteArrayInputStream is = new ByteArrayInputStream(data);
return getModuleDecl(is);
}
private void checkEncoding(final InputStream is) throws IOException {
if(checkEncoding) {
final String checkedEnc = guessXQueryEncoding(is);
if(checkedEnc != null) {
encoding = checkedEnc;
}
}
}
@Override
public String toString() {
return doc.getDocumentURI();
}
@Override
public void validate(final Subject subject, final int mode) throws PermissionDeniedException {
//TODO This check should not even be here! Its up to the database to refuse access not requesting source
if(!doc.getPermissions().validate(subject, mode)) {
final String modeStr = new UnixStylePermissionAider(mode).toString();
throw new PermissionDeniedException("Subject '" + subject.getName() + "' does not have '" + modeStr + "' access to resource '" + doc.getURI() + "'.");
}
}
public Permission getPermissions() {
return doc.getPermissions();
}
}