contiki/tools/coffee-manager/se/sics/coffee/CoffeeFS.java
2012-01-28 03:34:16 +01:00

201 lines
5.8 KiB
Java

/*
* Copyright (c) 2009, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @author Nicolas Tsiftes
*
*/
package se.sics.coffee;
import java.io.*;
import java.util.Map;
import java.util.TreeMap;
public class CoffeeFS {
private CoffeeImage image;
private CoffeeConfiguration conf;
private int currentPage;
private Map<String, CoffeeFile> files;
private static final int INVALID_PAGE = -1;
public CoffeeFS(CoffeeImage image) throws IOException {
this.image = image;
conf = image.getConfiguration();
currentPage = 0;
files = new TreeMap<String, CoffeeFile>();
while(currentPage < (conf.fsSize / conf.pageSize)) {
CoffeeHeader header = readHeader(currentPage);
if (header.isActive() && !header.isLog()) {
CoffeeFile file = new CoffeeFile(this, header);
files.put(file.getName(), file);
}
currentPage = nextFile(header, currentPage);
}
}
private int pageCount(long size) {
int headerSize = conf.nameLength + conf.pageTypeSize * 2 + 6;
return (int)(size + headerSize + conf.pageSize - 1) / conf.pageSize;
}
private int findFreeExtent(int pages) throws IOException {
CoffeeHeader header;
int currentPage = 0;
int start = INVALID_PAGE;
while(currentPage < (conf.fsSize / conf.pageSize)) {
header = readHeader(currentPage);
if (header.isFree()) {
if (start == INVALID_PAGE) {
start = currentPage;
}
currentPage = nextFile(header, currentPage);
if (start + pages <= currentPage) {
return start;
}
} else {
start = INVALID_PAGE;
currentPage = nextFile(header, currentPage);
}
}
return INVALID_PAGE;
}
public CoffeeImage getImage() {
return image;
}
public CoffeeConfiguration getConfiguration() {
return conf;
}
public CoffeeHeader readHeader(int page) throws IOException {
byte[] bytes = new byte[conf.nameLength + conf.pageTypeSize * 2 + 6];
image.read(bytes, bytes.length, page * conf.pageSize);
CoffeeHeader header = new CoffeeHeader(this, page, bytes);
return header;
}
public void writeHeader(CoffeeHeader header) throws IOException {
byte[] bytes = header.toRawHeader();
image.write(bytes, bytes.length, header.getPage() * conf.pageSize);
}
private int nextFile(CoffeeHeader header, int page) {
if (header.isFree()) {
return page + conf.pagesPerSector & ~(conf.pagesPerSector - 1);
} else if (header.isIsolated()) {
return page + 1;
}
return page + header.maxPages;
}
public final Map<String, CoffeeFile> getFiles() {
return files;
}
public CoffeeFile insertFile(String filename) throws IOException {
return insertFile(new File(filename));
}
public CoffeeFile insertFile(File file) throws IOException {
CoffeeFile coffeeFile;
try {
FileInputStream input = new FileInputStream(file);
int allocatePages = pageCount(file.length());
int start = findFreeExtent(allocatePages);
if (start == INVALID_PAGE) {
return null;
}
CoffeeHeader header = new CoffeeHeader(this, start);
header.setName(file.getName());
header.setReservedSize(allocatePages);
header.allocate();
coffeeFile = new CoffeeFile(this, header);
writeHeader(header);
coffeeFile.insertContents(input);
input.close();
return coffeeFile;
} catch (FileNotFoundException e) {
}
return null;
}
public void removeFile(String filename)
throws CoffeeFileException, IOException {
CoffeeFile file = files.get(filename);
if (file == null) {
throw new CoffeeFileException("Coffee: attempt to remove inexistent file");
}
file.remove();
writeHeader(file.getHeader());
files.remove(file.getName());
}
public boolean extractFile(String filename) throws IOException {
return extractFile(filename, new File(filename));
}
public boolean extractFile(String fileInCoffee, File fileOnDisk) throws IOException {
CoffeeFile file = files.get(fileInCoffee);
if (file == null) {
return false;
}
file.saveContents(fileOnDisk);
return true;
}
public static class CoffeeException extends RuntimeException {
private static final long serialVersionUID = 1146474084441011154L;
public CoffeeException(String message) {
super("Coffee error: " + message);
}
}
public static class CoffeeFileException extends RuntimeException {
private static final long serialVersionUID = -2954553141887245203L;
public CoffeeFileException(String message) {
super("Coffee file error: " + message);
}
}
}