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Journalkeeper core raft implementations.
/**
* 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.core.journal;
import io.journalkeeper.core.api.JournalEntry;
import io.journalkeeper.core.api.JournalEntryParser;
import io.journalkeeper.core.api.RaftJournal;
import io.journalkeeper.core.exception.JournalException;
import io.journalkeeper.exceptions.IndexOverflowException;
import io.journalkeeper.exceptions.IndexUnderflowException;
import io.journalkeeper.persistence.BufferPool;
import io.journalkeeper.persistence.JournalPersistence;
import io.journalkeeper.persistence.PersistenceFactory;
import io.journalkeeper.persistence.TooManyBytesException;
import io.journalkeeper.utils.ThreadSafeFormat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* @author LiYue
* Date: 2019-03-15
*/
public class Journal implements RaftJournal, Flushable, Closeable {
private static final Logger logger = LoggerFactory.getLogger(Journal.class);
private static final String PARTITION_PATH = "index";
private static final String INDEX_PATH = "index/all";
public static final int INDEX_STORAGE_SIZE = Long.BYTES;
private static final String JOURNAL_PROPERTIES_PATTERN = "^persistence\\.journal\\.(.*)$";
private static final String INDEX_PROPERTIES_PATTERN = "^persistence\\.index\\.(.*)$";
private static final Properties DEFAULT_JOURNAL_PROPERTIES = new Properties();
private static final Properties DEFAULT_INDEX_PROPERTIES = new Properties();
private final AtomicLong commitIndex = new AtomicLong(0L);
// 写入index时转换用的缓存
private final byte [] indexBytes = new byte [INDEX_STORAGE_SIZE];
private final ByteBuffer indexBuffer = ByteBuffer.wrap(indexBytes);
// 写入index时转换用的缓存
private final byte [] commitIndexBytes = new byte [INDEX_STORAGE_SIZE];
private final ByteBuffer commitIndexBuffer = ByteBuffer.wrap(commitIndexBytes);
static {
DEFAULT_JOURNAL_PROPERTIES.put("file_data_size", String.valueOf(128 * 1024 * 1024));
DEFAULT_JOURNAL_PROPERTIES.put("cached_file_core_count", String.valueOf(3));
DEFAULT_JOURNAL_PROPERTIES.put("cached_file_max_count", String.valueOf(10));
DEFAULT_JOURNAL_PROPERTIES.put("max_dirty_size", String.valueOf(128 * 1024 * 1024));
DEFAULT_INDEX_PROPERTIES.put("file_data_size", String.valueOf(512 * 1024));
DEFAULT_INDEX_PROPERTIES.put("cached_file_core_count", String.valueOf(10));
DEFAULT_INDEX_PROPERTIES.put("cached_file_max_count", String.valueOf(20));
}
private final JournalPersistence indexPersistence;
private final JournalPersistence journalPersistence;
private final Map partitionMap;
private final PersistenceFactory persistenceFactory;
private final BufferPool bufferPool;
private Path basePath = null;
private Properties indexProperties;
private ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
private final JournalEntryParser journalEntryParser;
public Journal(PersistenceFactory persistenceFactory, BufferPool bufferPool, JournalEntryParser journalEntryParser) {
this.indexPersistence = persistenceFactory.createJournalPersistenceInstance();
this.journalPersistence = persistenceFactory.createJournalPersistenceInstance();
this.persistenceFactory = persistenceFactory;
this.journalEntryParser = journalEntryParser;
this.partitionMap = new ConcurrentHashMap<>();
this.bufferPool = bufferPool;
}
@Override
public long minIndex() {
return indexPersistence.min() / INDEX_STORAGE_SIZE;
}
@Override
public long maxIndex() {
return indexPersistence.max() / INDEX_STORAGE_SIZE;
}
@Override
public long minIndex(int partition) {
return getPartitionPersistence(partition).min() / INDEX_STORAGE_SIZE;
}
@Override
public long maxIndex(int partition) {
return getPartitionPersistence(partition).max() / INDEX_STORAGE_SIZE;
}
/**
* 删除给定索引位置之前的数据。
* 不保证给定位置之前的数据全都被物理删除。
* 保证给定位置（含）之后的数据不会被删除。
*
* @param journalSnapshot 给定最小安全索引位置。
* @throws IOException 当发生IO异常时抛出
*/
public void compact(JournalSnapshot journalSnapshot) throws IOException{
if (journalSnapshot.minIndex() <= minIndex()) {
return;
}
if (journalSnapshot.minIndex() > commitIndex()) {
throw new IllegalArgumentException(
String.format("Given snapshot min index %s should less than commit index %s!",
ThreadSafeFormat.formatWithComma(journalSnapshot.minIndex()),
ThreadSafeFormat.formatWithComma(commitIndex())
)
);
}
// 删除分区索引
Map> iterator = partitionMap.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = iterator.next();
int partition = entry.getKey();
JournalPersistence partitionPersistence = entry.getValue();
if (partitionMinIndices.containsKey(partition)) {
long minPartitionIndices = partitionMinIndices.get(entry.getKey());
partitionPersistence.compact(minPartitionIndices * INDEX_STORAGE_SIZE);
} else {
journalPersistence.close();
journalPersistence.delete();
iterator.remove();
}
}
for (Map.Entry entry : partitionMinIndices.entrySet()) {
int partition = entry.getKey();
if (!partitionMap.containsKey(partition)) {
JournalPersistence partitionPersistence = persistenceFactory.createJournalPersistenceInstance();
partitionPersistence.recover(basePath.resolve(PARTITION_PATH).resolve(String.valueOf(partition)),
partitionMinIndices.get(partition) * INDEX_STORAGE_SIZE,
indexProperties);
partitionMap.put(partition, partitionPersistence);
}
}
}
// 删除全局索引
indexPersistence.compact(journalSnapshot.minIndex() * INDEX_STORAGE_SIZE);
// 删除Journal
journalPersistence.compact(journalSnapshot.minOffset());
}
/**
* 追加写入StorageEntry
* @param entry 待写入的entry
* @return entry写入后当前最大全局索引序号
*/
public long append(JournalEntry entry) {
// 记录当前最大位置，也是写入的Journal的offset
long offset = journalPersistence.max();
byte [] serializedEntry = entry.getSerializedBytes();
try {
// 写入Journal header
journalPersistence.append(serializedEntry);
// 写入全局索引
indexBuffer.clear();
indexBuffer.putLong(offset);
indexPersistence.append(indexBytes);
} catch (IOException e) {
throw new JournalException(e);
}
return maxIndex();
}
/**
* 清空整个Journal
*
* @param snapshot 清空后Journal的起始位置
* @throws IOException 发生IO异常时抛出
*/
public void clear(JournalSnapshot snapshot) throws IOException {
commitIndex.set(snapshot.minIndex());
Map> iterator = partitionMap.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = iterator.next();
int partition = entry.getKey();
JournalPersistence partitionPersistence = entry.getValue();
journalPersistence.close();
journalPersistence.delete();
iterator.remove();
}
for (Map.Entry entry : partitionMinIndices.entrySet()) {
int partition = entry.getKey();
JournalPersistence partitionPersistence = persistenceFactory.createJournalPersistenceInstance();
partitionPersistence.recover(basePath.resolve(PARTITION_PATH).resolve(String.valueOf(partition)),
partitionMinIndices.get(partition) * INDEX_STORAGE_SIZE,
indexProperties);
partitionMap.put(partition, partitionPersistence);
}
}
}
/**
* 批量追加写入StorageEntry
* @param entries 待写入的批量entry
* @return 每条entry写入后当前最大全局索引序号
*/
public List append(List entries) {
// 记录当前最大位置，也是写入的Journal的offset
long offset = journalPersistence.max();
long index = maxIndex();
ByteBuffer entryBuffer = ByteBuffer.wrap(new byte[entries.stream().mapToInt(e -> e.getSerializedBytes().length).sum()]);
ByteBuffer indicesBuffer = ByteBuffer.wrap(new byte[entries.size() * INDEX_STORAGE_SIZE]);
List indices = new ArrayList<>(entries.size());
for (JournalEntry entry : entries) {
entryBuffer.put(entry.getSerializedBytes());
indicesBuffer.putLong(offset);
offset += entry.getLength();
indices.add(++index);
}
try {
// 写入Journal header
journalPersistence.append(entryBuffer.array());
// 写入全局索引
indexPersistence.append(indicesBuffer.array());
} catch (IOException e) {
throw new JournalException(e);
}
return indices;
}
// Not thread safe !
/**
* 提交journal，已提交的journal不可变。
* @param index 提交全局索引序号
* @throws IOException 发生IO异常时抛出
*/
public void commit(long index) throws IOException {
long finalCommitIndex;
while ((finalCommitIndex = commitIndex.get()) < index &&
finalCommitIndex < maxIndex() &&
commitIndex.compareAndSet(finalCommitIndex, finalCommitIndex + 1)) {
long offset = readOffset(finalCommitIndex);
JournalEntry header = readEntryHeaderByOffset(offset);
commitIndexBuffer.clear();
commitIndexBuffer.putLong(offset);
appendPartitionIndex(commitIndexBytes, header.getPartition(), header.getBatchSize());
}
}
private JournalEntry readEntryHeaderByOffset(long offset) {
try {
byte [] headerBytes = journalPersistence.read(offset, journalEntryParser.headerLength());
return journalEntryParser.parseHeader(headerBytes);
} catch (IOException e) {
throw new JournalException(e);
}
}
/**
* 获取当前提交的全局索引序号
* @return 当前提交的全局索引序号
*/
public long commitIndex() {
return commitIndex.get();
}
private void appendPartitionIndex(byte [] offset, int partition, int batchSize) throws IOException {
// Create partition which not exists
if(!partitionMap.containsKey(partition)) {
addPartition(partition, 0L);
}
JournalPersistence partitionPersistence = getPartitionPersistence(partition);
if(batchSize > 1) {
byte[] bytes = new byte[batchSize * INDEX_STORAGE_SIZE];
ByteBuffer pb = ByteBuffer.wrap(bytes);
int j = 0;
while (j < batchSize) {
if (j == 0) {
pb.put(offset);
} else {
pb.putLong(-1 * j);
}
j++;
}
partitionPersistence.append(bytes);
} else {
partitionPersistence.append(offset);
}
}
private JournalPersistence getPartitionPersistence(int partition) {
JournalPersistence partitionPersistence = partitionMap.get(partition);
if(null == partitionPersistence) {
throw new NosuchPartitionException(partition);
}
return partitionPersistence;
}
/**
* 批量追加写入序列化之后的StorageEntry，用户RAFT复制时，FOLLOWER写入从LEADER复制过来的entries
* @param storageEntries 从LEADER复制过来的entries
* @return 写入后的最大全局索引序号
*/
public long appendBatchRaw(List storageEntries) {
// 计算索引
long [] offsets = new long[storageEntries.size()];
long offset = journalPersistence.max();
for (int i = 0; i < offsets.length; i++) {
offsets[i] = offset;
offset += storageEntries.get(i).length;
}
try {
// 写入Journal
for (byte [] storageEntry : storageEntries) {
journalPersistence.append(storageEntry);
}
// 写入全局索引
int indexBufferLength = INDEX_STORAGE_SIZE * storageEntries.size();
ByteBuffer indexBuffer = ByteBuffer.allocate(indexBufferLength);
for (long index: offsets) {
indexBuffer.putLong(index);
}
indexBuffer.flip();
try {
indexPersistence.append(indexBuffer.array());
} catch (TooManyBytesException e) {
// 如果批量写入超长，改为单条写入
ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES);
for (long index: offsets) {
buffer.putLong(0, index);
indexPersistence.append(buffer.array());
}
}
// 在commit()提交时才写入分区索引
// appendPartitionIndices(storageEntries, offsets);
} catch (IOException e) {
throw new JournalException(e);
}
return maxIndex();
}
@Override
public JournalEntry readByPartition(int partition, long index) {
JournalPersistence pp = getPartitionPersistence(partition);
long offset = readOffset(pp, index);
long journalOffset;
int relIndex;
if(offset < 0) {
journalOffset = readOffset(pp , index + offset);
relIndex = (int)(-1 * offset);
} else {
journalOffset = offset;
relIndex = 0;
}
JournalEntry journal = readByOffset(journalOffset);
journal.setOffset(relIndex);
return journal;
}
@Override
public List batchReadByPartition(int partition, long startPartitionIndex, int maxSize) {
List list = new LinkedList<>();
int size = 0;
long index = startPartitionIndex;
while (size < maxSize) {
JournalEntry batchEntry = readByPartition(partition, index);
int count = batchEntry.getBatchSize() - batchEntry.getOffset();
size += count ;
index += count;
list.add(batchEntry);
}
return list;
}
public JournalEntry read(long index){
return journalEntryParser.parse(readRaw(index));
}
private JournalEntry readByOffset(long offset) {
return journalEntryParser.parse(readRawByOffset(offset));
}
private byte [] readRaw(long index){
readWriteLock.readLock().lock();
checkIndex(index);
try {
long offset = readOffset(index);
return readRawByOffset(offset);
} finally {
readWriteLock.readLock().unlock();
}
}
private byte [] readRawByOffset(long offset) {
readWriteLock.readLock().lock();
try {
int length = readEntryLengthByOffset(offset);
return journalPersistence
.read(offset, length);
} catch (IOException e) {
throw new JournalException(e);
} finally {
readWriteLock.readLock().unlock();
}
}
private int readEntryLengthByOffset(long offset) {
return readEntryHeaderByOffset(offset).getLength();
}
public long readOffset(long index) {
return readOffset(indexPersistence, index);
}
private long readOffset(JournalPersistence indexPersistence , long index) {
try {
byte [] indexBytes = indexPersistence.read(index * INDEX_STORAGE_SIZE, INDEX_STORAGE_SIZE);
return ByteBuffer.wrap(indexBytes).getLong();
} catch (IOException e) {
throw new JournalException(e);
}
}
public List batchRead(long index, int size) {
checkIndex(index);
List list = new ArrayList<>(size);
long i = index;
while (list.size() < size && i < maxIndex()) {
list.add(read(i++));
}
return list;
}
/**
* 批量读取StorageEntry
* @param index 起始索引位置
* @param size 期望读取的条数
* @return 未反序列化的StorageEntry列表。
* @throws IndexUnderflowException 如果 index 小于 minIndex()
* @throws IndexOverflowException 如果index 不小于 maxIndex()
*/
public List readRaw(long index, int size) {
checkIndex(index);
List list = new ArrayList<>(size);
long i = index;
while (list.size() < size && i < maxIndex()) {
list.add(readRaw(i++));
}
return list;
}
/**
* 读取指定索引位置上Entry的Term。
* @param index 索引位置。
* @return Term 任期
* @throws IndexUnderflowException 如果 index 小于 minIndex()
* @throws IndexOverflowException 如果index 不小于 maxIndex()
*/
public int getTerm(long index) {
readWriteLock.readLock().lock();
try {
if(index == -1) return -1;
checkIndex(index);
long offset = readOffset(index);
return readEntryHeaderByOffset(offset).getTerm();
} finally {
readWriteLock.readLock().unlock();
}
}
/**
* 从index位置开始：
* 如果一条已经存在的日志与新的冲突（index 相同但是任期号 term 不同），则删除已经存在的日志和它之后所有的日志
* 添加任何在已有的日志中不存在的条目。
* @param rawEntries 待比较的日志
* @param startIndex 起始位置
* @throws IndexUnderflowException 如果 startIndex 小于 minIndex()
* @throws IndexOverflowException 如果 startIndex 不小于 maxIndex()
*/
public void compareOrAppendRaw(List rawEntries, long startIndex) {
List entries = rawEntries.stream()
.map(journalEntryParser::parse)
.collect(Collectors.toList());
try {
long index = startIndex;
for (int i = 0; i < entries.size(); i++, index++) {
if (index < maxIndex() && getTerm(index) != entries.get(i).getTerm()) {
readWriteLock.writeLock().lock();
try {
truncate(index);
} finally {
readWriteLock.writeLock().unlock();
}
}
if (index == maxIndex()) {
appendBatchRaw(rawEntries.subList(i, entries.size()));
break;
}
}
} catch (IOException e) {
throw new JournalException(e);
}
}
/**
* 从索引index位置开始，截掉后面的数据
* @param index 截取全局索引位置
* @throws IndexUnderflowException 如果 index < minIndex()
* @throws IndexOverflowException 如果 index >= maxIndex()
*/
private void truncate(long index) throws IOException {
long journalOffset = readOffset(index);
truncatePartitions(journalOffset);
indexPersistence.truncate(index * INDEX_STORAGE_SIZE);
journalPersistence.truncate(journalOffset);
// 安全更新commitIndex
long finalCommitIndex;
while ((finalCommitIndex = commitIndex.get()) > maxIndex() &&
!commitIndex.compareAndSet(finalCommitIndex, maxIndex())) {
Thread.yield();
}
}
private void truncatePartitions(long journalOffset) throws IOException {
for (JournalPersistence partitionPersistence : partitionMap.values()) {
long position = partitionPersistence.max() - INDEX_STORAGE_SIZE;
while (position > partitionPersistence.min()) {
long offset = readOffset(partitionPersistence, position / INDEX_STORAGE_SIZE );
if(offset < journalOffset) {
break;
}
position -= INDEX_STORAGE_SIZE;
}
partitionPersistence.truncate(position <= partitionPersistence.min()? 0L : position + INDEX_STORAGE_SIZE);
}
}
/**
* 从指定path恢复Journal。
* 1. 删除journal或者index文件末尾可能存在的不完整的数据。
* 2. 以Journal为准，修复全局索引和分区索引：删除多余的索引，并创建缺失的索引。
* @param path 恢复目录
* @param commitIndex 当前journal提交全局索引
* @param journalSnapshot 快照
* @param properties 属性
* @throws IOException 发生IO异常时抛出
*/
public void recover(Path path, long commitIndex, JournalSnapshot journalSnapshot, Properties properties) throws IOException {
this.basePath = path;
Path indexPath = path.resolve(INDEX_PATH);
Path partitionPath = path.resolve(PARTITION_PATH);
Properties journalProperties = replacePropertiesNames(properties,
JOURNAL_PROPERTIES_PATTERN, DEFAULT_JOURNAL_PROPERTIES);
journalPersistence.recover(path, journalSnapshot.minOffset(), journalProperties);
// 截掉末尾半条数据
truncateJournalTailPartialEntry();
indexProperties = replacePropertiesNames(properties,
INDEX_PROPERTIES_PATTERN, DEFAULT_INDEX_PROPERTIES);
indexPersistence.recover(indexPath, journalSnapshot.minIndex() * INDEX_STORAGE_SIZE, indexProperties);
// 截掉末尾半条数据
indexPersistence.truncate(indexPersistence.max() - indexPersistence.max() % INDEX_STORAGE_SIZE);
// 删除多余的索引
truncateExtraIndices();
// 创建缺失的索引
buildMissingIndices();
checkAndSetCommitIndex(commitIndex);
// 恢复分区索引
recoverPartitions(partitionPath, journalSnapshot.partitionMinIndices(), indexProperties);
flush();
logger.info("Journal recovered, minIndex: {}, maxIndex: {}, partitions: {}, path: {}.",
minIndex(), maxIndex(), partitionMap.keySet(), path.toAbsolutePath().toString());
}
private void checkAndSetCommitIndex(long commitIndex) {
this.commitIndex.set(commitIndex);
if(this.commitIndex.get() < minIndex() ) {
logger.info("Journal commitIndex {} should be not less than minIndex {}, set commitIndex to {}.",
this.commitIndex.get(), minIndex(), minIndex());
this.commitIndex.set(minIndex());
} else if ( this.commitIndex.get() > maxIndex()) {
logger.info("Journal commitIndex {} should be not greater than maxIndex {}, set commitIndex to {}.",
this.commitIndex.get(), maxIndex(), maxIndex());
this.commitIndex.set(maxIndex());
}
}
private void recoverPartitions(Path partitionPath, Map partitionIndices, Properties properties) throws IOException {
Map lastIndexedOffsetMap = new HashMap<>(partitionIndices.size());
for (Map.Entry entry : partitionIndices.entrySet()) {
int partition = entry.getKey();
long lastIncludedIndex = entry.getValue();
JournalPersistence pp = persistenceFactory.createJournalPersistenceInstance();
pp.recover(partitionPath.resolve(String.valueOf(partition)), lastIncludedIndex * INDEX_STORAGE_SIZE, properties);
// 截掉末尾半条数据
pp.truncate(pp.max() - pp.max() % INDEX_STORAGE_SIZE);
truncateTailPartialBatchIndices(pp);
partitionMap.put(partition, pp);
lastIndexedOffsetMap.put(partition, getLastIndexedOffset(pp));
}
// 重建缺失的分区索引
long offset = lastIndexedOffsetMap.values().stream().mapToLong(l -> l).min().orElse(journalPersistence.min());
// 只创建已提交的分区索引
long commitOffset = commitIndex.get() == maxIndex() ? journalPersistence.max() :
readOffset(commitIndex.get());
// 创建缺失的索引
while (offset < commitOffset) {
JournalEntry header = readEntryHeaderByOffset(offset);
int length = readEntryLengthByOffset(offset);
if(offset > lastIndexedOffsetMap.get(header.getPartition())) {
indexBuffer.clear();
indexBuffer.putLong(offset);
appendPartitionIndex(indexBytes, header.getPartition(), header.getBatchSize());
}
offset += length;
}
// 删除未提交部分的分区索引
for (Integer partition : partitionIndices.keySet()) {
JournalPersistence partitionPersistence = partitionMap.get(partition);
long partitionIndex = partitionPersistence.max() / INDEX_STORAGE_SIZE - 1;
while (partitionIndex * INDEX_STORAGE_SIZE >= partitionPersistence.min()) {
long journalOffset = readOffset(partitionPersistence, partitionIndex);
if (journalOffset < commitOffset) {
break;
}
partitionIndex--;
}
partitionIndex += 1;
partitionPersistence.truncate(partitionIndex * INDEX_STORAGE_SIZE);
}
}
private long getLastIndexedOffset(JournalPersistence pp) {
// 读出最后一条索引对应的Journal Offset
long lastIndexedOffset = journalPersistence.min();
if (pp.max() > 0) {
long lastIndex = pp.max() / INDEX_STORAGE_SIZE - 1;
long lastOffset = readOffset(pp, lastIndex);
if (lastOffset < 0) {
long firstIndexOfBatchEntries = lastIndex + lastOffset;
lastIndexedOffset = readOffset(pp, firstIndexOfBatchEntries);
} else {
lastIndexedOffset = lastOffset;
}
}
return lastIndexedOffset;
}
private void truncateTailPartialBatchIndices(JournalPersistence pp) throws IOException {
if(pp.max() > pp.min()) {
// 如果最后一条索引是批消息的索引，需要检查其完整性
long lastIndex = pp.max() / INDEX_STORAGE_SIZE - 1;
long lastOffset = readOffset(pp, lastIndex);
// 如果是批消息检查这一批消息的索引的完整性，如不完整直接截掉这个批消息的已存储的所有索引
if (lastOffset < 0) {
long firstIndexOfBatchEntries = lastIndex + lastOffset;
long batchEntriesOffset = readOffset(pp, firstIndexOfBatchEntries);
JournalEntry header = readEntryHeaderByOffset(batchEntriesOffset);
if ((lastIndex - 1) * -1 < header.getBatchSize()) {
pp.truncate(firstIndexOfBatchEntries * INDEX_STORAGE_SIZE);
}
}
}
}
private Properties replacePropertiesNames(Properties properties, String fromNameRegex, Properties defaultProperties){
Properties jp = new Properties(defaultProperties);
properties.stringPropertyNames().forEach(k -> {
String name = k.replaceAll(fromNameRegex, "$1");
jp.setProperty(name, properties.getProperty(k));
});
return jp;
}
private void buildMissingIndices() throws IOException {
// 找到最新一条没有索引位置
long indexOffset;
if (indexPersistence.max() - INDEX_STORAGE_SIZE >= indexPersistence.min()) {
long offset = readOffset(indexPersistence.max() / INDEX_STORAGE_SIZE - 1);
int length = readEntryLengthByOffset(offset);
indexOffset = offset + length;
} else {
indexOffset = journalPersistence.min();
}
// 创建索引
List indices = new LinkedList<>();
while (indexOffset < journalPersistence.max()) {
indices.add(indexOffset);
indexOffset += readEntryLengthByOffset(indexOffset);
}
// 写入索引
if(!indices.isEmpty()) {
ByteBuffer buffer = bufferPool.allocate(indices.size() * INDEX_STORAGE_SIZE);
indices.forEach(buffer::putLong);
buffer.flip();
indexPersistence.append(buffer.array());
bufferPool.release(buffer);
}
}
private void truncateExtraIndices() throws IOException {
long position = indexPersistence.max();
//noinspection StatementWithEmptyBody
while ((position -= INDEX_STORAGE_SIZE) >= indexPersistence.min() && readOffset(position / INDEX_STORAGE_SIZE) >= journalPersistence.max()) {}
indexPersistence.truncate(position + INDEX_STORAGE_SIZE);
}
private void truncateJournalTailPartialEntry() throws IOException {
// 找最后的连续2条记录
long position = journalPersistence.max() - journalEntryParser.headerLength();
long lastEntryPosition = -1; // 最后连续2条记录中后面那条的位置
JournalEntry lastEntryHeader = null;
while (position >= journalPersistence.min()) {
try {
JournalEntry header = readByOffset(position);
// 找到一条记录的开头位置
if(lastEntryPosition < 0) { // 之前是否已经找到一条？
// 这是倒数第一条，记录之
lastEntryPosition = position;
lastEntryHeader = header;
if(lastEntryPosition == journalPersistence.min()) {
// 只有一条完整的记录也认为OK，保留之。
truncatePartialEntry(lastEntryPosition, lastEntryHeader);
return;
}
} else {
// 这是倒数第二条
if(position + header.getLength() == lastEntryPosition) {
// 找到最后2条中位置较小的那条，并且较小那条的位置+长度==较大那条的位置
truncatePartialEntry(lastEntryPosition, lastEntryHeader);
return;
} else { // 之前找到的那个第一条是假的（小概率会出现Entry中恰好也有连续2个字节等于MAGIC）
lastEntryPosition = position;
lastEntryHeader = header;
}
}
} catch (Exception ignored) {}
position --;
}
// 找到最小位置了，啥也没找到，直接清空所有数据。
journalPersistence.truncate(journalPersistence.min());
}
private void truncatePartialEntry(long lastEntryPosition, JournalEntry lastEntryHeader) throws IOException {
// 判断最后一条是否完整
if(lastEntryPosition + lastEntryHeader.getLength() <= journalPersistence.max()) {
// 完整，截掉后面的部分
journalPersistence.truncate(lastEntryPosition + lastEntryHeader.getLength());
} else {
// 不完整，直接截掉这条数据
journalPersistence.truncate(lastEntryPosition);
}
}
/**
* 将所有内存中的Journal和Index写入磁盘。
*/
@Override
public void flush() {
long flushed;
do {
flushed = Stream.concat(Stream.of(journalPersistence, indexPersistence), partitionMap.values().stream())
.filter(p -> p.flushed() < p.max())
.peek(p -> {
try {
p.flush();
} catch (IOException e) {
logger.warn("Flush {} exception: ", p.getBasePath(), e);
throw new JournalException(e);
}
}).count();
} while (flushed > 0);
}
public boolean isDirty() {
return Stream.concat(Stream.of(journalPersistence, indexPersistence), partitionMap.values().stream())
.anyMatch(p -> p.flushed() < p.max());}
private void checkIndex(long index) {
long position = index * INDEX_STORAGE_SIZE;
if(position < indexPersistence.min()) {
throw new IndexUnderflowException();
}
if(position >= indexPersistence.max()) {
throw new IndexOverflowException();
}
}
public void rePartition(Set partitions) {
try {
synchronized (partitionMap) {
for (int partition : partitions) {
if (!partitionMap.containsKey(partition)) {
addPartition(partition, 0L);
}
}
List toBeRemoved = new ArrayList<>();
for (Map.Entry entry : partitionMap.entrySet()) {
if (!partitions.contains(entry.getKey())) {
toBeRemoved.add(entry.getKey());
}
}
for (Integer partition : toBeRemoved) {
removePartition(partition);
}
logger.info("Journal repartitioned, partitions: {}, path: {}.",
partitionMap.keySet(), basePath.toAbsolutePath().toString());
}
} catch (IOException e) {
throw new JournalException(e);
}
}
@Override
public long queryIndexByTimestamp(int partition, long timestamp) {
try {
if (partitionMap.containsKey(partition)) {
JournalPersistence indexStore = partitionMap.get(partition);
long searchedIndex = binarySearchByTimestamp(timestamp, indexStore, indexStore.min() / INDEX_STORAGE_SIZE, indexStore.max() / INDEX_STORAGE_SIZE - 1);
// 考虑到有可能出现连续n条消息时间相同，找到这n条消息的第一条
while (searchedIndex - 1 >= indexStore.min() && timestamp <= getStorageTimestamp(indexStore, searchedIndex - 1)) {
searchedIndex--;
}
return searchedIndex;
}
} catch (Throwable e) {
logger.warn("Query index by timestamp exception: ", e);
}
return -1L;
}
// 折半查找
private long binarySearchByTimestamp(long timestamp,
JournalPersistence indexStore,
long leftIndexInclude,
long rightIndexInclude) {
if (rightIndexInclude <= leftIndexInclude) {
return -1L;
}
if (timestamp <= getStorageTimestamp(indexStore, leftIndexInclude)) {
return leftIndexInclude;
}
if (timestamp >= getStorageTimestamp(indexStore, rightIndexInclude)) {
return rightIndexInclude;
}
if (leftIndexInclude + 1 == rightIndexInclude) {
return leftIndexInclude;
}
long mid = leftIndexInclude + (rightIndexInclude - leftIndexInclude) / 2;
long midTimestamp = getStorageTimestamp(indexStore, mid);
if (timestamp < midTimestamp) {
return binarySearchByTimestamp(timestamp, indexStore, leftIndexInclude, mid);
} else {
return binarySearchByTimestamp(timestamp, indexStore, mid, rightIndexInclude);
}
}
private long getStorageTimestamp(
JournalPersistence indexStore,
long index) {
JournalEntry header = readEntryHeaderByOffset(readOffset(indexStore, index));
return header.getTimestamp();
}
@Override
public Set getPartitions() {
return new HashSet<>(partitionMap.keySet());
}
public void addPartition(int partition) throws IOException {
addPartition(partition, 0L);
}
public void addPartition(int partition, long minIndex) throws IOException {
synchronized (partitionMap) {
if (!partitionMap.containsKey(partition)) {
JournalPersistence partitionPersistence = persistenceFactory.createJournalPersistenceInstance();
partitionPersistence.recover(
basePath.resolve(PARTITION_PATH).resolve(String.valueOf(partition)),
minIndex * INDEX_STORAGE_SIZE,
indexProperties);
partitionMap.put(partition, partitionPersistence);
}
}
}
public void removePartition(int partition) throws IOException {
synchronized (partitionMap) {
JournalPersistence removedPersistence;
if ((removedPersistence = partitionMap.remove(partition)) != null) {
logger.info("Partition removed: {}, journal: {}.", partition, basePath.toAbsolutePath().toString());
removedPersistence.close();
removedPersistence.delete();
}
}
}
@Override
public void close() throws IOException {
for (JournalPersistence persistence : partitionMap.values()) {
persistence.close();
}
indexPersistence.close();
journalPersistence.close();
}
// For monitor only
public long flushedIndex() {
return indexPersistence.flushed() / INDEX_STORAGE_SIZE;
}
public JournalPersistence getJournalPersistence() {
return journalPersistence;
}
public JournalPersistence getIndexPersistence() {
return indexPersistence;
}
public Map getPartitionMap() {
return Collections.unmodifiableMap(partitionMap);
}
public long maxOffset() {
return journalPersistence.max();
}
public Map calcPartitionIndices(long journalOffset) {
Map partitionIndices = new HashMap<>(partitionMap.size());
for (Map.Entry entry : partitionMap.entrySet()) {
int partition = entry.getKey();
JournalPersistence partitionPersistence = entry.getValue();
long index = maxIndex(partition);
while (--index >= minIndex(partition)) {
long offset = readOffset(partitionPersistence, index);
if (offset < journalOffset) {
break;
}
}
partitionIndices.put(partition, index + 1);
}
return partitionIndices;
}
@Override
public String toString() {
return "Journal{" +
"commitIndex=" + commitIndex +
", indexPersistence=" + indexPersistence +
", journalPersistence=" + journalPersistence +
", partitionMap=" + partitionMap +
", basePath=" + basePath +
'}';
}
}