RAFile.java
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package org.hsqldb.persist;
import java.io.EOFException;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import org.hsqldb.Database;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.EventLogInterface;
import org.hsqldb.lib.HsqlByteArrayInputStream;
import org.hsqldb.lib.HsqlByteArrayOutputStream;
/**
* This class is a wrapper for a random access file such as that used for
* CACHED table storage.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.7.0
* @since 1.7.2
*/
final class RAFile implements RandomAccessInterface {
static final int DATA_FILE_RAF = 0;
static final int DATA_FILE_NIO = 1;
static final int DATA_FILE_JAR = 2;
static final int DATA_FILE_STORED = 3;
static final int DATA_FILE_SINGLE = 4;
static final int DATA_FILE_TEXT = 5;
//
static final int bufferScale = 13;
static final int bufferSize = 1 << bufferScale;
static final long bufferMask = 0xffffffffffffffffL << bufferScale;
//
final EventLogInterface logger;
final RandomAccessFile file;
final FileDescriptor fileDescriptor;
private final boolean readOnly;
final String fileName;
final byte[] buffer;
final HsqlByteArrayInputStream ba;
final byte[] valueBuffer;
final HsqlByteArrayOutputStream vbao;
final HsqlByteArrayInputStream vbai;
long bufferOffset;
long fileLength;
final boolean extendLength;
//
long seekPosition;
int cacheHit;
/**
* seekPosition is the position in seek() calls or after reading or writing
* realPosition is the file position
*/
static RandomAccessInterface newScaledRAFile(
Database database,
String name,
boolean readonly,
int type)
throws IOException {
if (type == DATA_FILE_JAR) {
return new RAFileInJar(name);
} else if (type == DATA_FILE_TEXT) {
return new RAFile(database.logger, name, readonly, false, true);
} else if (type == DATA_FILE_RAF) {
return new RAFile(database.logger, name, readonly, true, false);
} else {
java.io.File fi = new java.io.File(name);
long length = fi.length();
if (length > database.logger.propNioMaxSize) {
return new RAFile(database.logger, name, readonly, true, false);
}
return new RAFileHybrid(database, name, readonly);
}
}
RAFile(
EventLogInterface logger,
String name,
boolean readonly,
boolean extendLengthToBlock,
boolean commitOnChange)
throws IOException {
this.logger = logger;
this.fileName = name;
this.readOnly = readonly;
this.extendLength = extendLengthToBlock;
String accessMode = readonly
? "r"
: commitOnChange
? "rws"
: "rw";
this.file = new RandomAccessFile(name, accessMode);
buffer = new byte[bufferSize];
ba = new HsqlByteArrayInputStream(buffer);
valueBuffer = new byte[8];
vbao = new HsqlByteArrayOutputStream(valueBuffer);
vbai = new HsqlByteArrayInputStream(valueBuffer);
fileDescriptor = file.getFD();
fileLength = length();
readIntoBuffer();
}
public long length() throws IOException {
return file.length();
}
public void seek(long position) throws IOException {
if (readOnly && fileLength < position) {
throw new IOException("read beyond end of file");
}
seekPosition = position;
}
public long getFilePointer() {
return seekPosition;
}
private void readIntoBuffer() throws IOException {
long filePos = seekPosition & bufferMask;
long readLength = fileLength - filePos;
if (readLength > buffer.length) {
readLength = buffer.length;
}
if (readLength < 0) {
throw new IOException("read beyond end of file");
}
try {
file.seek(filePos);
file.readFully(buffer, 0, (int) readLength);
bufferOffset = filePos;
} catch (IOException e) {
resetPointer();
logger.logWarningEvent(
"Read Error " + filePos + " " + readLength,
e);
throw e;
}
}
public int read() throws IOException {
if (seekPosition >= fileLength) {
return -1;
}
if (seekPosition < bufferOffset
|| seekPosition >= bufferOffset + buffer.length) {
readIntoBuffer();
} else {
cacheHit++;
}
int val = buffer[(int) (seekPosition - bufferOffset)] & 0xff;
seekPosition++;
return val;
}
public long readLong() throws IOException {
vbai.reset();
read(valueBuffer, 0, 8);
return vbai.readLong();
}
public int readInt() throws IOException {
vbai.reset();
read(valueBuffer, 0, 4);
return vbai.readInt();
}
public void read(byte[] b, int offset, int length) throws IOException {
try {
if (seekPosition + length > fileLength) {
throw new EOFException();
}
if (length > buffer.length
&& (seekPosition < bufferOffset
|| seekPosition >= bufferOffset + buffer.length)) {
file.seek(seekPosition);
file.readFully(b, offset, length);
seekPosition += length;
return;
}
if (seekPosition < bufferOffset
|| seekPosition >= bufferOffset + buffer.length) {
readIntoBuffer();
} else {
cacheHit++;
}
ba.reset();
if (seekPosition - bufferOffset
!= ba.skip(seekPosition - bufferOffset)) {
throw new EOFException();
}
int bytesRead = ba.read(b, offset, length);
seekPosition += bytesRead;
if (bytesRead < length) {
file.seek(seekPosition);
file.readFully(b, offset + bytesRead, length - bytesRead);
seekPosition += (length - bytesRead);
}
} catch (IOException e) {
resetPointer();
logger.logWarningEvent("failed to read a byte array", e);
throw e;
}
}
public void write(byte[] b, int off, int length) throws IOException {
try {
file.seek(seekPosition);
if (seekPosition < bufferOffset + buffer.length
&& seekPosition + length > bufferOffset) {
writeToBuffer(b, off, length);
}
file.write(b, off, length);
seekPosition += length;
if (!extendLength && fileLength < seekPosition) {
fileLength = seekPosition;
}
} catch (IOException e) {
resetPointer();
logger.logWarningEvent("failed to write a byte array", e);
throw e;
}
}
public void writeInt(int i) throws IOException {
vbao.reset();
vbao.writeInt(i);
write(valueBuffer, 0, 4);
}
public void writeLong(long i) throws IOException {
vbao.reset();
vbao.writeLong(i);
write(valueBuffer, 0, 8);
}
public void close() throws IOException {
file.close();
}
public boolean isReadOnly() {
return readOnly;
}
public boolean ensureLength(long newLength) {
if (newLength <= fileLength) {
return true;
}
try {
extendLength(newLength);
} catch (IOException e) {
return false;
}
return true;
}
public boolean setLength(long newLength) {
try {
file.setLength(newLength);
file.seek(0);
fileLength = file.length();
seekPosition = 0;
readIntoBuffer();
return true;
} catch (Throwable t) {
return false;
}
}
public void synch() {
try {
fileDescriptor.sync();
} catch (Throwable t) {
try {
fileDescriptor.sync();
} catch (Throwable tt) {
logger.logSevereEvent("RA file sync error ", tt);
throw Error.error(t, ErrorCode.FILE_IO_ERROR, null);
}
}
}
private int writeToBuffer(byte[] b, int off, int len) {
int count = ArrayUtil.copyBytes(
seekPosition - off,
b,
off,
len,
bufferOffset,
buffer,
buffer.length);
return count;
}
private long getExtendLength(long position) {
if (!extendLength) {
return position;
}
int scaleUp;
if (position < 256 * 1024) {
scaleUp = 2;
} else if (position < 1024 * 1024) {
scaleUp = 6;
} else if (position < 32 * 1024 * 1024) {
scaleUp = 8;
} else {
scaleUp = 12;
}
position = ArrayUtil.getBinaryNormalisedCeiling(
position,
bufferScale + scaleUp);
return position;
}
/**
* Some old JVM's do not allow seek beyond end of file, so zeros must be written
* first in that case. Reported by bohgammer@users in Open Disucssion
* Forum.
*/
private void extendLength(long position) throws IOException {
long newSize = getExtendLength(position);
if (newSize > fileLength) {
try {
file.seek(newSize - 1);
file.write(0);
fileLength = newSize;
} catch (IOException e) {
logger.logWarningEvent("data file enlarge failed ", e);
throw e;
}
}
}
private void resetPointer() {
try {
seekPosition = 0;
fileLength = length();
bufferOffset = -buffer.length; // invalid buffer
} catch (Throwable e) {}
}
}