nes-proj/tools/coffee-manager/org/contikios/coffee/CoffeeHeader.java

204 lines
5.2 KiB
Java
Raw Normal View History

/*
* 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 org.contikios.coffee;
class CoffeeHeader {
2012-01-28 02:34:16 +00:00
private final CoffeeConfiguration conf;
private final int page;
private static final int HDR_FLAG_VALID = 0x1;
private static final int HDR_FLAG_ALLOCATED = 0x2;
private static final int HDR_FLAG_OBSOLETE = 0x4;
private static final int HDR_FLAG_MODIFIED = 0x8;
private static final int HDR_FLAG_LOG = 0x10;
private static final int HDR_FLAG_ISOLATED = 0x20;
int logPage;
int logRecords;
int logRecordSize;
int maxPages;
String name;
2012-01-28 02:34:16 +00:00
private int flags;
public CoffeeHeader(CoffeeFS coffeeFS, int page) {
this.page = page;
conf = coffeeFS.getConfiguration();
}
public CoffeeHeader(CoffeeFS coffeeFS, int page, byte[] bytes) {
2012-01-28 02:34:16 +00:00
this(coffeeFS, page);
processRawHeader(bytes);
}
2012-01-28 02:34:16 +00:00
private int getInt(byte[] bytes, int index) {
return (bytes[index] & 0xff) + ((bytes[index + 1] & 0xff) << 8);
}
private void processRawHeader(byte[] bytes) {
int index = 0;
logPage = getPageValue(bytes, 0);
index += conf.pageTypeSize;
2012-01-28 02:34:16 +00:00
logRecords = getInt(bytes, index);
index += 2;
2012-01-28 02:34:16 +00:00
logRecordSize = getInt(bytes, index);
index += 2;
maxPages = getPageValue(bytes, index);
index += conf.pageTypeSize;
index++; // Skip deprecated EOF hint field.
2012-01-28 02:34:16 +00:00
flags = bytes[index] & 0xff;
index++;
name = new String(bytes).substring(index,
2012-01-28 02:34:16 +00:00
index + conf.nameLength);
int nullCharOffset = name.indexOf(0);
if (nullCharOffset >= 0) {
name = name.substring(0, nullCharOffset);
}
}
private byte[] setPageValue(int page) {
byte[] bytes = new byte[conf.pageTypeSize];
for (int i = conf.pageTypeSize - 1; i >= 0; i--) {
bytes[i] = (byte) (page >> (8 * i));
}
return bytes;
}
private int getPageValue(byte[] bytes, int offset) {
int page = 0;
for (int i = 0; i < conf.pageTypeSize; i++) {
2012-01-28 02:34:16 +00:00
page |= (bytes[offset + i] & 0xff) << (8 * i);
}
return page;
}
public byte[] toRawHeader() {
byte[] bytes = new byte[2 * conf.pageTypeSize +
2012-01-28 02:34:16 +00:00
conf.nameLength + 6];
int index = 0;
System.arraycopy(setPageValue(logPage), 0, bytes, 0,
conf.pageTypeSize);
index += conf.pageTypeSize;
bytes[index++] = (byte) (logRecords >> 8);
bytes[index++] = (byte) logRecords;
bytes[index++] = (byte) (logRecordSize >> 8);
bytes[index++] = (byte) logRecordSize;
System.arraycopy(setPageValue(maxPages), 0, bytes, index,
conf.pageTypeSize);
index += conf.pageTypeSize;
bytes[index++] = 0; // Deprecated EOF hint field.
2012-01-28 02:34:16 +00:00
bytes[index++] = (byte) flags;
byte[] nameBytes = name.getBytes();
2012-01-28 02:34:16 +00:00
int copyLength = nameBytes.length > conf.nameLength ?
conf.nameLength : nameBytes.length;
System.arraycopy(nameBytes, 0, bytes, index, copyLength);
return bytes;
}
public int rawLength() {
2012-01-28 02:34:16 +00:00
return 2 * conf.pageTypeSize + conf.nameLength + 6;
}
public int getPage() {
return page;
}
public boolean isValid() {
2012-01-28 02:34:16 +00:00
return (flags & HDR_FLAG_VALID) != 0;
}
public boolean isAllocated() {
2012-01-28 02:34:16 +00:00
return (flags & HDR_FLAG_ALLOCATED) != 0;
}
public boolean isObsolete() {
2012-01-28 02:34:16 +00:00
return (flags & HDR_FLAG_OBSOLETE) != 0;
}
public boolean isModified() {
2012-01-28 02:34:16 +00:00
return (flags & HDR_FLAG_MODIFIED) != 0;
}
public boolean isIsolated() {
2012-01-28 02:34:16 +00:00
return (flags & HDR_FLAG_ISOLATED) != 0;
}
public boolean isLog() {
2012-01-28 02:34:16 +00:00
return (flags & HDR_FLAG_LOG) != 0;
}
public boolean isFree() {
return !isAllocated();
}
public boolean isActive() {
return isAllocated() && !isObsolete() && !isIsolated();
}
public void allocate() {
2012-01-28 02:34:16 +00:00
flags |= HDR_FLAG_ALLOCATED;
}
public void makeObsolete() {
2012-01-28 02:34:16 +00:00
flags |= HDR_FLAG_OBSOLETE;
}
public void setName(String name) {
this.name = name;
}
public void setReservedSize(int pages) {
maxPages = pages;
}
public int getReservedSize() {
return maxPages;
}
}