/*
* Copyright 2000-2014 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.intellij.util.io;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.util.SystemProperties;
import java.io.IOException;
import java.io.RandomAccessFile;
/**
* Replacement of RandomAccessFile("rw") with shadow file pointer / size, valid when file manipulations happen in with this class only.
* Note that sharing policy is the same as RandomAccessFile
*/
class RandomAccessFileWithLengthAndSizeTracking extends RandomAccessFile {
private static final Logger LOG = Logger.getInstance(RandomAccessFileWithLengthAndSizeTracking.class.getName());
private static final boolean doAssertions = SystemProperties.getBooleanProperty("idea.do.random.access.wrapper.assertions", false);
private final String myPath;
private volatile long mySize;
private volatile long myPointer;
public RandomAccessFileWithLengthAndSizeTracking(String name) throws IOException {
super(name, "rw");
mySize = super.length();
myPath = name;
if (LOG.isDebugEnabled()) {
LOG.debug("Inst:" + this + "," + Thread.currentThread() + "," + getClass().getClassLoader());
}
}
@Override
public void seek(long pos) throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Seek:" + this + "," + Thread.currentThread() + "," + pos + "," + myPointer + "," + mySize);
}
if (doAssertions) {
checkSizeAndPointerAssertions();
}
if (myPointer == pos) {
return;
}
super.seek(pos);
myPointer = pos;
}
@Override
public long length() throws IOException {
if (doAssertions) {
checkSizeAndPointerAssertions();
}
return mySize;
}
@Override
public void write(int b) throws IOException {
write(new byte[]{ (byte)(b & 0xFF)});
}
private void checkSizeAndPointerAssertions() throws IOException {
if (myPointer != super.getFilePointer()) {
assert false;
}
if (mySize != super.length()) {
assert false;
}
}
@Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("write:" + this + "," + Thread.currentThread() + "," + len + "," + myPointer + "," + mySize);
}
if (doAssertions) {
checkSizeAndPointerAssertions();
}
long pointer = myPointer;
super.write(b, off, len);
if (pointer == 0) { // first write can introduce extra bytes, reload the position to avoid position tracking problem, e.g. IDEA-106306
pointer = super.getFilePointer();
} else {
pointer += len;
}
myPointer = pointer;
mySize = Math.max(pointer, mySize);
if (LOG.isDebugEnabled()) {
LOG.debug("after write:" + this + "," + Thread.currentThread() + "," + myPointer + "," + mySize );
}
if (doAssertions) {
checkSizeAndPointerAssertions();
}
}
@Override
public void setLength(long newLength) throws IOException {
if (doAssertions) {
checkSizeAndPointerAssertions();
}
super.setLength(newLength);
mySize = newLength;
if (doAssertions) {
checkSizeAndPointerAssertions();
}
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("read:" + this + "," + Thread.currentThread() + "," + len + "," + myPointer );
}
if (doAssertions) {
checkSizeAndPointerAssertions();
}
int read = super.read(b, off, len);
if (read != -1) myPointer += read;
if (doAssertions) {
checkSizeAndPointerAssertions();
}
return read;
}
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
@Override
public int read() throws IOException {
int read = super.read();
++myPointer;
if (doAssertions) {
checkSizeAndPointerAssertions();
}
return read;
}
@Override
public long getFilePointer() throws IOException {
if (doAssertions) {
checkSizeAndPointerAssertions();
}
return myPointer;
}
@Override
public int skipBytes(int n) throws IOException {
int i = super.skipBytes(n);
if (doAssertions) {
checkSizeAndPointerAssertions();
}
return i;
}
@Override
public void close() throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Closed:" + this + "," + Thread.currentThread() );
}
super.close();
}
@Override
public String toString() {
return myPath + "@" + Integer.toHexString(hashCode());
}
}