io.journalkeeper.persistence.local.journal.LocalStoreFile Maven / Gradle / Ivy
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/**
* 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 io.journalkeeper.persistence.local.journal;
import io.journalkeeper.persistence.local.cache.BufferHolder;
import io.journalkeeper.persistence.local.cache.MemoryCacheManager;
import io.journalkeeper.utils.locks.CasLock;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.Cleaner;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.lang.reflect.Method;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedByInterruptException;
import java.nio.channels.FileChannel;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.locks.StampedLock;
/**
* 支持并发、带缓存页、顺序写入的文件
*/
public class LocalStoreFile implements StoreFile, BufferHolder {
private static final Logger logger = LoggerFactory.getLogger(LocalStoreFile.class);
// 缓存页类型
// 只读：
// MAPPED_BUFFER：mmap映射内存镜像文件；
// 读写：
// DIRECT_BUFFER: 数据先写入DirectBuffer，异步刷盘到文件，性能最好；
private final static int MAPPED_BUFFER = 0, DIRECT_BUFFER = 1, NO_BUFFER = -1;
// 文件全局位置
private final long filePosition;
// 文件头长度
private final int headerSize;
// 对应的File
private final File file;
// buffer读写锁：
// 访问(包括读和写）buffer时加读锁；
// 加载、释放buffer时加写锁；
private final StampedLock bufferLock = new StampedLock();
// 文件锁，读写文件时加锁
private final CasLock fileLock = new CasLock();
// 缓存页
private ByteBuffer pageBuffer = null;
private int bufferType = NO_BUFFER;
private MemoryCacheManager bufferPool;
private final int capacity;
private long lastAccessTime = System.currentTimeMillis();
// 当前刷盘位置
private int flushPosition;
// 当前写入位置
private int writePosition = 0;
private long timestamp = -1L;
private AtomicBoolean forced = new AtomicBoolean(false);
private volatile boolean writeClosed = true;
private FileChannel fileChannel;
private RandomAccessFile raf;
LocalStoreFile(long filePosition, File base, int headerSize, MemoryCacheManager bufferPool, int maxFileDataLength) {
this.filePosition = filePosition;
this.headerSize = headerSize;
this.bufferPool = bufferPool;
this.file = new File(base, String.valueOf(filePosition));
if (file.exists() && file.length() > headerSize) {
this.writePosition = (int) (file.length() - headerSize);
this.flushPosition = writePosition;
}
this.capacity = Math.max(maxFileDataLength, (int )(file.length() - headerSize));
}
@Override
public File file() {
return file;
}
@Override
public long position() {
return filePosition;
}
private void loadRoUnsafe() throws IOException {
if (null != pageBuffer) throw new IOException("Buffer already loaded!");
bufferPool.allocateMMap(this);
ByteBuffer loadBuffer;
try (RandomAccessFile raf = new RandomAccessFile(file, "r"); FileChannel fileChannel = raf.getChannel()) {
loadBuffer =
fileChannel.map(FileChannel.MapMode.READ_ONLY, headerSize, file.length() - headerSize);
pageBuffer = loadBuffer;
bufferType = MAPPED_BUFFER;
pageBuffer.clear();
forced.set(true);
} catch (ClosedByInterruptException cie) {
throw cie;
} catch (Throwable t) {
logger.warn("Exception: ", t);
bufferPool.releaseMMap(this);
pageBuffer = null;
throw t;
}
}
private void loadRwUnsafe() throws IOException {
if (bufferType == DIRECT_BUFFER) {
return;
} else if (bufferType == MAPPED_BUFFER) {
unloadUnsafe();
}
ByteBuffer buffer = bufferPool.allocateDirect(capacity, this);
loadDirectBuffer(buffer);
writeClosed = false;
}
private void loadDirectBuffer(ByteBuffer buffer) throws IOException {
boolean needLoadFileContent = file.exists() && file.length() > headerSize;
boolean writeTimestamp = !file.exists();
// 打开文件描述符
raf = new RandomAccessFile(file, "rw");
fileChannel = raf.getChannel();
if (writeTimestamp) {
// 第一次创建文件写入头部预留128字节中0位置开始的前8字节长度:文件创建时间戳
writeTimestamp();
}
if (needLoadFileContent) {
logger.warn("Reload file for write! size: {}, file: {}.", file.length(), file);
fileChannel.position(headerSize);
int length;
do {
length = fileChannel.read(buffer);
} while (length > 0);
buffer.clear();
}
this.pageBuffer = buffer;
bufferType = DIRECT_BUFFER;
}
public long timestamp() {
if (timestamp == -1L) {
// 文件存在初始化时间戳
readTimestamp();
}
return timestamp;
}
private void readTimestamp() {
ByteBuffer timeBuffer = ByteBuffer.allocate(8);
try (RandomAccessFile raf = new RandomAccessFile(file, "r"); FileChannel fileChannel = raf.getChannel()) {
fileChannel.position(0);
fileChannel.read(timeBuffer);
} catch (Exception e) {
logger.warn("Exception: ", e);
} finally {
timestamp = timeBuffer.getLong(0);
}
}
private void writeTimestamp() {
ByteBuffer timeBuffer = ByteBuffer.allocate(8);
long creationTime = System.currentTimeMillis();
timeBuffer.putLong(0, creationTime);
try (RandomAccessFile raf = new RandomAccessFile(file, "rw"); FileChannel fileChannel = raf.getChannel()) {
fileChannel.position(0);
fileChannel.write(timeBuffer);
} catch (Exception e) {
logger.warn("Exception:", e);
} finally {
timestamp = creationTime;
}
}
@Override
public boolean unload() {
long stamp = bufferLock.writeLock();
try {
if (isClean()) {
unloadUnsafe();
return true;
} else {
return false;
}
} finally {
bufferLock.unlockWrite(stamp);
}
}
@Override
public void forceUnload() {
long stamp = bufferLock.writeLock();
try {
unloadUnsafe();
} finally {
bufferLock.unlockWrite(stamp);
}
}
@Override
public boolean hasPage() {
return this.bufferType != NO_BUFFER;
}
@Override
public ByteBuffer read(int position, int length) throws IOException {
touch();
long stamp = bufferLock.readLock();
try {
while (!hasPage()) {
long ws = bufferLock.tryConvertToWriteLock(stamp);
if (ws != 0L) {
// 升级成写锁成功
stamp = ws;
loadRoUnsafe();
} else {
bufferLock.unlockRead(stamp);
stamp = bufferLock.writeLock();
}
}
long rs = bufferLock.tryConvertToReadLock(stamp);
if (rs != 0L) {
stamp = rs;
}
ByteBuffer byteBuffer = pageBuffer.asReadOnlyBuffer();
byteBuffer.position(position);
byteBuffer.limit(writePosition);
ByteBuffer dest = ByteBuffer.allocate(Math.min(length, byteBuffer.remaining()));
if (length < byteBuffer.remaining()) {
byteBuffer.limit(byteBuffer.position() + length);
}
dest.put(byteBuffer);
dest.flip();
return dest;
} finally {
bufferLock.unlock(stamp);
}
}
@Override
public Long readLong(int position) throws IOException{
touch();
long stamp = bufferLock.readLock();
try {
while (!hasPage()) {
long ws = bufferLock.tryConvertToWriteLock(stamp);
if (ws != 0L) {
// 升级成写锁成功
stamp = ws;
loadRoUnsafe();
} else {
bufferLock.unlockRead(stamp);
stamp = bufferLock.writeLock();
}
}
long rs = bufferLock.tryConvertToReadLock(stamp);
if (rs != 0L) {
stamp = rs;
}
return pageBuffer.getLong(position);
} finally {
bufferLock.unlock(stamp);
}
}
// Not thread safe!
private int appendToPageBuffer(ByteBuffer byteBuffer) {
pageBuffer.position(writePosition);
int writeLength = byteBuffer.remaining();
pageBuffer.put(byteBuffer);
writePosition += writeLength;
return writeLength;
}
// Not thread safe!
private int appendToPageBuffer(List byteBuffers) {
pageBuffer.position(writePosition);
int writeLength = 0;
for (ByteBuffer byteBuffer : byteBuffers) {
writeLength += byteBuffer.remaining();
pageBuffer.put(byteBuffer);
}
writePosition += writeLength;
return writeLength;
}
@Override
public int append(ByteBuffer byteBuffer) throws IOException {
touch();
long stamp = bufferLock.readLock();
try {
while (bufferType != DIRECT_BUFFER) {
long ws = bufferLock.tryConvertToWriteLock(stamp);
if (ws != 0L) {
// 升级成写锁成功
stamp = ws;
loadRwUnsafe();
} else {
bufferLock.unlockRead(stamp);
stamp = bufferLock.writeLock();
}
}
long rs = bufferLock.tryConvertToReadLock(stamp);
if (rs != 0L) {
stamp = rs;
}
return appendToPageBuffer(byteBuffer);
} finally {
bufferLock.unlock(stamp);
}
}
@Override
public int append(List byteBuffers) throws IOException {
touch();
long stamp = bufferLock.readLock();
try {
while (bufferType != DIRECT_BUFFER) {
long ws = bufferLock.tryConvertToWriteLock(stamp);
if (ws != 0L) {
// 升级成写锁成功
stamp = ws;
loadRwUnsafe();
} else {
bufferLock.unlockRead(stamp);
stamp = bufferLock.writeLock();
}
}
long rs = bufferLock.tryConvertToReadLock(stamp);
if (rs != 0L) {
stamp = rs;
}
return appendToPageBuffer(byteBuffers);
} finally {
bufferLock.unlock(stamp);
}
}
private void touch() {
lastAccessTime = System.currentTimeMillis();
}
/**
* 刷盘
*/
// Not thread safe!
@Override
public int flush() throws IOException {
long stamp = bufferLock.readLock();
try {
if (writePosition > flushPosition && fileLock.tryLock()) {
try {
if (!file.exists()) {
// 第一次创建文件写入头部预留128字节中0位置开始的前8字节长度:文件创建时间戳
writeTimestamp();
}
return flushPageBuffer();
} finally {
fileLock.unlock();
}
}
return 0;
} finally {
bufferLock.unlockRead(stamp);
}
}
private void ensureOpen() {
if (fileChannel == null || !fileChannel.isOpen()) {
throw new IllegalStateException(
String.format(
"File %s is not open!", file.getAbsolutePath()
)
);
}
}
private int flushPageBuffer() throws IOException {
ensureOpen();
int flushEnd = writePosition;
ByteBuffer flushBuffer = pageBuffer.asReadOnlyBuffer();
flushBuffer.position(flushPosition);
flushBuffer.limit(flushEnd);
fileChannel.position(headerSize + flushPosition);
int flushSize = flushEnd - flushPosition;
while (flushBuffer.hasRemaining()) {
fileChannel.write(flushBuffer);
}
flushPosition = flushEnd;
return flushSize;
}
// Not thread safe!
@Override
public void rollback(int position) throws IOException {
long stamp = bufferLock.writeLock();
try {
if (position < writePosition) {
writePosition = position;
}
if (position < flushPosition) {
fileLock.waitAndLock();
try {
flushPosition = position;
if (fileChannel != null && fileChannel.isOpen()) {
fileChannel.truncate(position + headerSize);
} else {
try (RandomAccessFile raf = new RandomAccessFile(file, "rw"); FileChannel fileChannel = raf.getChannel()) {
fileChannel.truncate(position + headerSize);
}
}
} finally {
fileLock.unlock();
}
}
} finally {
bufferLock.unlockWrite(stamp);
}
}
@Override
public boolean isClean() {
return flushPosition >= writePosition;
}
@Override
public int writePosition() {
return writePosition;
}
@Override
public int fileDataSize() {
return Math.max((int) file.length() - headerSize, 0);
}
@Override
public int flushPosition() {
return flushPosition;
}
@Override
public long lastAccessTime() {
return lastAccessTime;
}
private void unloadUnsafe() {
if (MAPPED_BUFFER == this.bufferType) {
unloadMappedBuffer();
} else if (DIRECT_BUFFER == this.bufferType) {
unloadDirectBuffer();
}
try {
closeFileChannel();
} catch (IOException e) {
logger.warn("Close file {} exception: ", file.getAbsolutePath(), e);
}
writeClosed = true;
}
private void unloadDirectBuffer() {
final ByteBuffer direct = pageBuffer;
pageBuffer = null;
this.bufferType = NO_BUFFER;
if (null != direct) bufferPool.releaseDirect(direct, this);
}
private void unloadMappedBuffer() {
try {
final Buffer mapped = pageBuffer;
pageBuffer = null;
this.bufferType = NO_BUFFER;
if (null != mapped) {
Method getCleanerMethod;
getCleanerMethod = mapped.getClass().getMethod("cleaner");
getCleanerMethod.setAccessible(true);
Cleaner cleaner = (Cleaner) getCleanerMethod.invoke(mapped, new Object[0]);
cleaner.clean();
}
bufferPool.releaseMMap(this);
} catch (Exception e) {
logger.warn("Release direct buffer exception: ", e);
}
}
@Override
public int size() {
return capacity;
}
@Override
public boolean isFree() {
return isClean();
}
@Override
public boolean evict() {
return unload();
}
@Override
public void closeWrite() {
writeClosed = true;
}
@Override
public boolean writable() {
return bufferType == DIRECT_BUFFER && !writeClosed;
}
private void closeFileChannel() throws IOException {
force();
if (null != fileChannel) {
fileChannel.close();
}
if (null != raf) {
raf.close();
}
}
@Override
public void force() throws IOException {
if(forced.compareAndSet(false, true)) {
fileLock.waitAndLock();
ensureOpen();
try {
fileChannel.force(true);
} catch (Throwable t) {
forced.set(false);
throw t;
} finally {
fileLock.unlock();
}
}
}
}