/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002-2006
* Sleepycat Software. All rights reserved.
*
* $Id: LogUtils.java,v 1.1 2006/05/06 08:59:59 ckaestne Exp $
*/
package com.sleepycat.je.log;
import java.nio.ByteBuffer;
import java.sql.Timestamp;
import javax.transaction.xa.Xid;
/**
* This class holds convenience methods for marshalling internal JE data to and
* from the log.
*/
public class LogUtils {
/* Storage sizes for int, long in log. */
public static final int SHORT_BYTES = 2;
public static final int INT_BYTES = 4;
public static final int LONG_BYTES = 8;
public static final int UNSIGNED_INT_BYTES = 4;
private static final boolean DEBUG = false;
/*
* We can return the same byte[] for 0 length arrays.
*/
public static final byte[] ZERO_LENGTH_BYTE_ARRAY = new byte[0];
/**
* Marshall a long into the next 4 bytes in this buffer. Necessary when the
* long is used to hold an unsigned int.
*/
public static void writeUnsignedInt(ByteBuffer buf, long value) {
buf.put((byte) (value >>> 0));
buf.put((byte) (value >>> 8));
buf.put((byte) (value >>> 16));
buf.put((byte) (value >>> 24));
}
/**
* Unmarshall the next four bytes which hold an unsigned int into a long.
*/
public static long getUnsignedInt(ByteBuffer buf) {
long ret = (buf.get() & 0xFFL) << 0;
ret += (buf.get() & 0xFFL) << 8;
ret += (buf.get() & 0xFFL) << 16;
ret += (buf.get() & 0xFFL) << 24;
return ret;
}
/*
* Marshall objects.
*/
/**
* Write a short into the log.
*/
public static void writeShort(ByteBuffer logBuf, short i) {
byte b = (byte) ((i >> 0) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 8) & 0xff);
logBuf.put(b);
}
/**
* Read a short from the log.
*/
public static short readShort(ByteBuffer logBuf) {
return (short) (((logBuf.get() & 0xFF) << 0) +
((logBuf.get() & 0xFF) << 8));
}
/**
* Write an int into the log.
*/
public static void writeInt(ByteBuffer logBuf, int i) {
byte b = (byte) ((i >> 0) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 8) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 16) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 24) & 0xff);
logBuf.put(b);
}
/**
* Read a int from the log.
*/
public static int readInt(ByteBuffer logBuf) {
int ret = (logBuf.get() & 0xFF) << 0;
ret += (logBuf.get() & 0xFF) << 8;
ret += (logBuf.get() & 0xFF) << 16;
ret += (logBuf.get() & 0xFF) << 24;
return ret;
}
/**
* @return log storage size for a byteArray.
*/
public static int getIntLogSize() {
return INT_BYTES;
}
/**
* Write an int into the log in MSB order. Used for ordered keys.
*/
public static void writeIntMSB(ByteBuffer logBuf, int i) {
byte b = (byte) ((i >> 24) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 16) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 8) & 0xff);
logBuf.put(b);
b = (byte) ((i >> 0) & 0xff);
logBuf.put(b);
}
/**
* Read a int from the log in MSB order. Used for ordered keys.
*/
public static int readIntMSB(ByteBuffer logBuf) {
int ret = (logBuf.get() & 0xFF) << 24;
ret += (logBuf.get() & 0xFF) << 16;
ret += (logBuf.get() & 0xFF) << 8;
ret += (logBuf.get() & 0xFF) << 0;
return ret;
}
/**
* Write a long into the log.
*/
public static void writeLong(ByteBuffer logBuf, long l) {
byte b =(byte) (l >>> 0);
logBuf.put(b);
b =(byte) (l >>> 8);
logBuf.put(b);
b =(byte) (l >>> 16);
logBuf.put(b);
b =(byte) (l >>> 24);
logBuf.put(b);
b =(byte) (l >>> 32);
logBuf.put(b);
b =(byte) (l >>> 40);
logBuf.put(b);
b =(byte) (l >>> 48);
logBuf.put(b);
b =(byte) (l >>> 56);
logBuf.put(b);
}
/**
* Read a long from the log.
*/
public static long readLong(ByteBuffer logBuf) {
long ret = (logBuf.get() & 0xFFL) << 0;
ret += (logBuf.get() & 0xFFL) << 8;
ret += (logBuf.get() & 0xFFL) << 16;
ret += (logBuf.get() & 0xFFL) << 24;
ret += (logBuf.get() & 0xFFL) << 32;
ret += (logBuf.get() & 0xFFL) << 40;
ret += (logBuf.get() & 0xFFL) << 48;
ret += (logBuf.get() & 0xFFL) << 56;
return ret;
}
/**
* @return log storage size for a byteArray.
*/
public static int getLongLogSize() {
return LONG_BYTES;
}
/**
* Write a byte array into the log. The size is stored first as an integer.
*/
public static void writeByteArray(ByteBuffer logBuf,
byte[] b) {
/* Write the length. */
writeInt(logBuf, b.length);
/* Add the data itself. */
logBuf.put(b); // data
}
/**
* Read a byte array from the log. The size is stored first as an integer.
*/
public static byte[] readByteArray(ByteBuffer logBuf) {
int size = readInt(logBuf); // how long is it?
if (DEBUG) {
System.out.println("pos = " + logBuf.position() +
" byteArray is " + size + " on read");
}
if (size == 0) {
return ZERO_LENGTH_BYTE_ARRAY;
}
byte[] b = new byte[size];
logBuf.get(b); // read it out
return b;
}
/**
* @return log storage size for a byteArray
*/
public static int getByteArrayLogSize(byte[] b) {
return INT_BYTES + b.length;
}
/**
* Write a string into the log. The size is stored first as an integer.
*/
public static void writeString(ByteBuffer logBuf,
String stringVal) {
writeByteArray(logBuf, stringVal.getBytes());
}
/**
* Read a string from the log. The size is stored first as an integer.
*/
public static String readString(ByteBuffer logBuf) {
return new String(readByteArray(logBuf));
}
/**
* @return log storage size for a string
*/
public static int getStringLogSize(String s) {
return INT_BYTES + s.length();
}
/**
* Write a timestamp into the log.
*/
public static void writeTimestamp(ByteBuffer logBuf,
Timestamp time) {
writeLong(logBuf, time.getTime());
}
/**
* Read a timestamp from the log.
*/
public static Timestamp readTimestamp(ByteBuffer logBuf) {
long millis = readLong(logBuf);
return new Timestamp(millis);
}
/**
* @return log storage size for a timestamp
*/
public static int getTimestampLogSize() {
return LONG_BYTES;
}
/**
* Write a boolean into the log.
*/
public static void writeBoolean(ByteBuffer logBuf,
boolean bool) {
byte val = bool ? (byte) 1 : (byte) 0;
logBuf.put(val);
}
/**
* Read a boolean from the log.
*/
public static boolean readBoolean(ByteBuffer logBuf) {
byte val = logBuf.get();
return (val == (byte) 1) ? true : false;
}
/**
* @return log storage size for a boolean.
*/
public static int getBooleanLogSize() {
return 1;
}
/*
* Dumping support.
*/
public static boolean dumpBoolean(ByteBuffer itemBuffer, StringBuffer sb,
String tag) {
sb.append("<");
sb.append(tag);
sb.append(" exists = \"");
boolean exists = readBoolean(itemBuffer);
sb.append(exists);
if (exists) {
sb.append("\">");
} else {
/* Close off the tag, we're done. */
sb.append("\"/>");
}
return exists;
}
/**
* The byte[]'s in Xid's are known to be 255 or less in length. So instead
* of using read/writeByteArray(), we can save 6 bytes per record by making
* the byte[] length be 1 byte instead of 4.
*/
public static int getXidSize(Xid xid) {
byte[] gid = xid.getGlobalTransactionId();
byte[] bqual = xid.getBranchQualifier();
return
INT_BYTES + // FormatId
1 + // gxid length byte
1 + // bqual length byte
(gid == null ? 0 : gid.length) + // gid bytes
(bqual == null ? 0 : bqual.length); // bqual bytes
}
/*
* Xid.gid[] and bqual[] can't be longer than 64 bytes so we can get away
* with writing the length in one byte, rather than 4.
*/
public static void writeXid(ByteBuffer logBuf, Xid xid) {
byte[] gid = xid.getGlobalTransactionId();
byte[] bqual = xid.getBranchQualifier();
writeInt(logBuf, xid.getFormatId());
if (gid == null) {
logBuf.put((byte) -1);
} else {
logBuf.put((byte) (gid.length));
logBuf.put(gid);
}
if (bqual == null) {
logBuf.put((byte) -1);
} else {
logBuf.put((byte) (bqual.length));
logBuf.put(bqual);
}
}
/*
* Xid.gid[] and bqual[] can't be longer than 64 bytes so we can get away
* with writing the length in one byte, rather than 4.
*/
public static Xid readXid(ByteBuffer logBuf) {
int formatId = readInt(logBuf);
int gidLen = logBuf.get();
byte[] gid = null;
if (gidLen >= 0) {
gid = new byte[gidLen];
logBuf.get(gid);
}
int bqualLen = logBuf.get();
byte[] bqual = null;
if (bqualLen >= 0) {
bqual = new byte[bqualLen];
logBuf.get(bqual);
}
return new XidImpl(formatId, gid, bqual);
}
public static class XidImpl implements Xid {
private int formatId;
private byte[] gid;
private byte[] bqual;
/* public for unit tests. */
public XidImpl(int formatId, byte[] gid, byte[] bqual) {
this.formatId = formatId;
this.gid = gid;
this.bqual = bqual;
}
public int getFormatId() {
return formatId;
}
public byte[] getGlobalTransactionId() {
return gid;
}
public byte[] getBranchQualifier() {
return bqual;
}
public boolean equals(Object o) {
if (!(o instanceof XidImpl)) {
return false;
}
XidImpl xid = (XidImpl) o;
if (xid.getFormatId() != formatId) {
return false;
}
if (compareByteArrays(xid.getGlobalTransactionId(), gid) &&
compareByteArrays(xid.getBranchQualifier(), bqual)) {
return true;
}
return false;
}
public int hashCode() {
int code = formatId;
if (gid != null) {
for (int i = 0; i < gid.length; i++) {
code += gid[i];
}
}
if (bqual != null) {
for (int i = 0; i < bqual.length; i++) {
code += bqual[i];
}
}
return code;
}
private boolean compareByteArrays(byte[] b1, byte[] b2) {
if (b1 == null ||
b2 == null) {
return b1 == b2;
}
if (b1.length != b2.length) {
return false;
}
for (int i = 0; i < b1.length; i++) {
if (b1[i] != b2[i]) {
return false;
}
}
return true;
}
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("<Xid formatId=\"").append(formatId);
sb.append("\" gTxnId=\"");
if (gid == null) {
sb.append("null");
} else {
sb.append(new String(gid));
}
sb.append("\" bqual=\"");
if (bqual == null) {
sb.append("null");
} else {
sb.append(new String(bqual));
}
sb.append("\"/>");
return sb.toString();
}
}
}