org.mapdb20.StoreWAL Maven / Gradle / Ivy
/*
/*
* Copyright (c) 2012 Jan Kotek
*
* 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 org.mapdb20;
import java.io.DataInput;
import java.io.File;
import java.io.IOError;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.Lock;
import java.util.logging.Level;
import static org.mapdb20.DataIO.*;
/**
* Write-Ahead-Log
*/
public class StoreWAL extends StoreCached {
/** 2 byte store version*/
protected static final int WAL_STORE_VERSION = 100;
/** 4 byte file header */
protected static final int WAL_HEADER = (0x8A77<<16) | WAL_STORE_VERSION;
protected static final long WAL_SEAL = 8234892392398238983L;
protected static final int FULL_REPLAY_AFTER_N_TX = 16;
/**
* Contains index table modified in previous transactions.
*/
protected final LongLongMap[] prevLongLongs;
protected final LongLongMap[] currLongLongs;
protected final LongLongMap[] prevDataLongs;
protected final LongLongMap[] currDataLongs;
protected final LongLongMap pageLongStack = new LongLongMap();
protected final List volumes = Collections.synchronizedList(new ArrayList());
/** record WALs, store recid-record pairs. Created during compaction when memory allocator is not available */
protected final List walRec = Collections.synchronizedList(new ArrayList());
protected Volume curVol;
protected int fileNum = -1;
//TODO how to protect concurrrently file offset when file is being swapped?
protected final AtomicLong walOffset = new AtomicLong();
protected Volume headVolBackup;
protected long[] indexPagesBackup;
protected Volume realVol;
protected volatile boolean $_TEST_HACK_COMPACT_PRE_COMMIT_WAIT =false;
protected volatile boolean $_TEST_HACK_COMPACT_POST_COMMIT_WAIT =false;
public StoreWAL(String fileName) {
this(fileName,
fileName == null ? CC.DEFAULT_MEMORY_VOLUME_FACTORY : CC.DEFAULT_FILE_VOLUME_FACTORY,
null,
CC.DEFAULT_LOCK_SCALE,
0,
false, false, null, false,false, false, null,
null, 0L, 0L, false,
0L,
0);
}
public StoreWAL(
String fileName,
Volume.VolumeFactory volumeFactory,
Cache cache,
int lockScale,
int lockingStrategy,
boolean checksum,
boolean compress,
byte[] password,
boolean readonly,
boolean snapshotEnable,
boolean fileLockDisable,
HeartbeatFileLock fileLockHeartbeat,
ScheduledExecutorService executor,
long startSize,
long sizeIncrement,
boolean recidReuseDisable,
long executorScheduledRate,
int writeQueueSize
) {
super(fileName, volumeFactory, cache,
lockScale,
lockingStrategy,
checksum, compress, password, readonly, snapshotEnable, fileLockDisable, fileLockHeartbeat,
executor,
startSize,
sizeIncrement,
recidReuseDisable,
executorScheduledRate,
writeQueueSize);
prevLongLongs = new LongLongMap[this.lockScale];
currLongLongs = new LongLongMap[this.lockScale];
for (int i = 0; i < prevLongLongs.length; i++) {
prevLongLongs[i] = new LongLongMap();
currLongLongs[i] = new LongLongMap();
}
prevDataLongs = new LongLongMap[this.lockScale];
currDataLongs = new LongLongMap[this.lockScale];
for (int i = 0; i < prevDataLongs.length; i++) {
prevDataLongs[i] = new LongLongMap();
currDataLongs[i] = new LongLongMap();
}
}
@Override
protected void initCreate() {
super.initCreate();
indexPagesBackup = indexPages.clone();
realVol = vol;
//make main vol readonly, to make sure it is never overwritten outside WAL replay
vol = new Volume.ReadOnly(vol);
//start new WAL file
walStartNextFile();
}
@Override
public void initOpen(){
//TODO disable readonly feature for this store
realVol = vol;
//replay WAL files
String wal0Name = getWalFileName("0");
String walCompSeal = getWalFileName("c");
boolean walCompSealExists =
walCompSeal!=null &&
new File(walCompSeal).exists();
if(walCompSealExists ||
(wal0Name!=null &&
new File(wal0Name).exists())){
//fill compaction stuff
for(int i=0;;i++){
String rname = getWalFileName("r"+i);
if(!new File(rname).exists())
break;
walRec.add(volumeFactory.makeVolume(rname, readonly, true));
}
//fill wal files
for(int i=0;;i++){
String wname = getWalFileName(""+i);
if(!new File(wname).exists())
break;
volumes.add(volumeFactory.makeVolume(wname, readonly, true));
}
initOpenPost();
replayWAL();
for(Volume v:walRec){
v.close();
}
walRec.clear();
volumes.clear();
}
//start new WAL file
//TODO do not start if readonly
walStartNextFile();
initOpenPost();
}
@Override
protected void initFailedCloseFiles() {
if(walRec!=null){
for(Volume v:walRec){
if(v!=null && !v.isClosed())
v.close();
}
walRec.clear();
}
if(volumes!=null){
for(Volume v:volumes){
if(v!=null && !v.isClosed())
v.close();
}
volumes.clear();
}
}
protected void initOpenPost() {
super.initOpen();
indexPagesBackup = indexPages.clone();
//make main vol readonly, to make sure it is never overwritten outside WAL replay
//all data are written to realVol
vol = new Volume.ReadOnly(vol);
}
@Override
protected void initHeadVol() {
super.initHeadVol();
//backup headVol
if(headVolBackup!=null && !headVolBackup.isClosed())
headVolBackup.close();
byte[] b = new byte[(int) HEAD_END];
headVol.getData(0, b, 0, b.length);
headVolBackup = new Volume.SingleByteArrayVol(b);
}
protected void walStartNextFile() {
if (CC.ASSERT && !structuralLock.isHeldByCurrentThread())
throw new AssertionError();
fileNum++;
if (CC.ASSERT && fileNum != volumes.size())
throw new DBException.DataCorruption();
String filewal = getWalFileName(""+fileNum);
Volume nextVol;
if (readonly && filewal != null && !new File(filewal).exists()){
nextVol = new Volume.ReadOnly(new Volume.ByteArrayVol(8,0L));
}else {
nextVol = volumeFactory.makeVolume(filewal, readonly, true);
}
nextVol.ensureAvailable(16);
if(!readonly) {
nextVol.putInt(0, WAL_HEADER);
nextVol.putLong(8, makeFeaturesBitmap());
}
walOffset.set(16);
volumes.add(nextVol);
curVol = nextVol;
}
protected String getWalFileName(String ext) {
return fileName==null? null :
fileName+".wal"+"."+ext;
}
protected void walPutLong(long offset, long value){
final int plusSize = +1+8+6;
long walOffset2 = walOffset.getAndAdd(plusSize);
Volume curVol2 = curVol;
//in case of overlap, put Skip Bytes instruction and try again
if(hadToSkip(walOffset2, plusSize)){
walPutLong(offset, value);
return;
}
if(CC.ASSERT && offset>>>48!=0)
throw new DBException.DataCorruption();
curVol2.ensureAvailable(walOffset2+plusSize);
int parity = 1+Long.bitCount(value)+Long.bitCount(offset);
parity &=15;
curVol2.putUnsignedByte(walOffset2, (1 << 4)|parity);
walOffset2+=1;
curVol2.putLong(walOffset2, value);
walOffset2+=8;
curVol2.putSixLong(walOffset2, offset);
}
protected void walPutUnsignedShort(long offset, int value) {
final int plusSize = +1+8;
long walOffset2 = walOffset.getAndAdd(plusSize);
Volume curVol2 = curVol;
//in case of overlap, put Skip Bytes instruction and try again
if(hadToSkip(walOffset2, plusSize)){
walPutUnsignedShort(offset, value);
return;
}
curVol2.ensureAvailable(walOffset2+plusSize);
if(CC.ASSERT && offset>>>48!=0)
throw new DBException.DataCorruption();
offset = (((long)value)<<48) | offset;
int parity = 1+Long.bitCount(offset);
parity &=15;
curVol2.putUnsignedByte(walOffset2, (6 << 4)|parity);
walOffset2+=1;
curVol2.putLong(walOffset2, offset);
}
protected boolean hadToSkip(long walOffset2, int plusSize) {
//does it overlap page boundaries?
if((walOffset2>>>CC.VOLUME_PAGE_SHIFT)==(walOffset2+plusSize)>>>CC.VOLUME_PAGE_SHIFT){
return false; //no, does not, all fine
}
//is there enough space for 4 byte skip N bytes instruction?
while((walOffset2&PAGE_MASK) >= PAGE_SIZE-4 || plusSize<5){
//pad with single byte skip instructions, until end of page is reached
int singleByteSkip = (4<<4)|(Long.bitCount(walOffset2)&15);
curVol.putUnsignedByte(walOffset2++, singleByteSkip);
plusSize--;
if(CC.ASSERT && plusSize<0)
throw new DBException.DataCorruption();
}
//now new page starts, so add skip instruction for remaining bits
int val = (3<<(4+3*8)) | (plusSize-4) | ((Integer.bitCount(plusSize-4)&15)<<(3*8));
curVol.ensureAvailable(walOffset2 + 4);
curVol.putInt(walOffset2, val);
return true;
}
@Override
protected void putDataSingleWithLink(int segment, long offset, long link, byte[] buf, int bufPos, int size) {
if(CC.ASSERT && (size&0xFFFF)!=size)
throw new DBException.DataCorruption();
//TODO optimize so array copy is not necessary, that means to clone and modify putDataSingleWithoutLink method
byte[] buf2 = new byte[size+8];
DataIO.putLong(buf2,0,link);
System.arraycopy(buf,bufPos,buf2,8,size);
putDataSingleWithoutLink(segment,offset,buf2,0,buf2.length);
}
@Override
protected void putDataSingleWithoutLink(int segment, long offset, byte[] buf, int bufPos, int size) {
if(CC.ASSERT && (size&0xFFFF)!=size)
throw new DBException.DataCorruption();
if(CC.ASSERT && (offset%16!=0 && offset!=4))
throw new DBException.DataCorruption();
// if(CC.ASSERT && size%16!=0)
// throw new AssertionError(); //TODO allign record size to 16, and clear remaining bytes
if(CC.ASSERT && segment!=-1)
assertWriteLocked(segment);
if(CC.ASSERT && segment==-1 && !structuralLock.isHeldByCurrentThread())
throw new AssertionError();
final int plusSize = +1+2+6+size;
long walOffset2 = walOffset.getAndAdd(plusSize);
if(hadToSkip(walOffset2, plusSize)){
putDataSingleWithoutLink(segment,offset,buf,bufPos,size);
return;
}
curVol.ensureAvailable(walOffset2+plusSize);
int checksum = 1+Integer.bitCount(size)+Long.bitCount(offset)+sum(buf,bufPos,size);
checksum &= 15;
curVol.putUnsignedByte(walOffset2, (2 << 4)|checksum);
walOffset2+=1;
curVol.putLong(walOffset2, ((long) size) << 48 | offset);
walOffset2+=8;
curVol.putData(walOffset2, buf,bufPos,size);
//TODO assertions
long val = ((long)size)<<48;
val |= ((long)fileNum)<<32;
val |= walOffset2;
(segment==-1?pageLongStack:currDataLongs[segment]).put(offset, val);
}
protected DataInput walGetData(long offset, int segment) {
if (CC.ASSERT && offset % 16 != 0)
throw new DBException.DataCorruption();
long longval = currDataLongs[segment].get(offset);
if(longval==0){
longval = prevDataLongs[segment].get(offset);
}
if(longval==0)
return null;
int arraySize = (int) (longval >>> 48);
int fileNum = (int) ((longval >>> 32) & 0xFFFFL);
long dataOffset = longval & 0xFFFFFFFFL;
Volume vol = volumes.get(fileNum);
return vol.getDataInput(dataOffset, arraySize);
}
@Override
protected long indexValGet(long recid) {
if(CC.ASSERT)
assertReadLocked(recid);
int segment = lockPos(recid);
long offset = recidToOffset(recid);
long ret = currLongLongs[segment].get(offset);
if(ret!=0) {
return ret;
}
ret = prevLongLongs[segment].get(offset);
if(ret!=0)
return ret;
return super.indexValGet(recid);
}
@Override
protected long indexValGetRaw(long recid) {
if(CC.ASSERT)
assertReadLocked(recid);
int segment = lockPos(recid);
long offset = recidToOffset(recid);
long ret = currLongLongs[segment].get(offset);
if(ret!=0) {
return ret;
}
ret = prevLongLongs[segment].get(offset);
if(ret!=0)
return ret;
return super.indexValGetRaw(recid);
}
@Override
protected void indexValPut(long recid, int size, long offset, boolean linked, boolean unused) {
if(CC.ASSERT)
assertWriteLocked(lockPos(recid));
// if(CC.ASSERT && compactionInProgress)
// throw new AssertionError();
long newVal = composeIndexVal(size, offset, linked, unused, true);
currLongLongs[lockPos(recid)].put(recidToOffset(recid), newVal);
}
@Override
protected void indexLongPut(long offset, long val) {
if(CC.ASSERT && !structuralLock.isHeldByCurrentThread())
throw new AssertionError();
walPutLong(offset,val);
}
@Override
protected long pageAllocate() {
// TODO compaction assertion
// if(CC.ASSERT && compactionInProgress)
// throw new AssertionError();
long storeSize = storeSizeGet();
storeSizeSet(storeSize + PAGE_SIZE);
//TODO clear data on page? perhaps special instruction?
if(CC.ASSERT && storeSize%PAGE_SIZE!=0)
throw new DBException.DataCorruption();
return storeSize;
}
@Override
protected byte[] loadLongStackPage(long pageOffset, boolean willBeModified) {
if (CC.ASSERT && !structuralLock.isHeldByCurrentThread())
throw new AssertionError();
// if(CC.ASSERT && compactionInProgress)
// throw new AssertionError();
//first try to get it from dirty pages in current TX
byte[] page = dirtyStackPages.get(pageOffset);
if (page != null) {
return page;
}
//try to get it from previous TX stored in WAL, but not yet replayed
long walval = pageLongStack.get(pageOffset);
if(walval!=0){
//get file number, offset and size in WAL
int arraySize = (int) (walval >>> 48);
int fileNum = (int) ((walval >>> 32) & 0xFFFFL);
long dataOffset = walval & 0xFFFFFFFFL;
//read and return data
byte[] b = new byte[arraySize];
Volume vol = volumes.get(fileNum);
vol.getData(dataOffset, b, 0, arraySize);
//page is going to be modified, so put it back into dirtyStackPages)
if (willBeModified) {
dirtyStackPages.put(pageOffset, b);
}
return b;
}
//and finally read it from main store
int pageSize = (int) (parity4Get(vol.getLong(pageOffset)) >>> 48);
page = new byte[pageSize];
vol.getData(pageOffset, page, 0, pageSize);
if (willBeModified){
dirtyStackPages.put(pageOffset, page);
}
return page;
}
/** return positions of (possibly) linked record */
@Override
protected long[] offsetsGet(int segment, long indexVal) {;
if(indexVal>>>48==0){
return ((indexVal&MLINKED)!=0) ? null : StoreDirect.EMPTY_LONGS;
}
long[] ret = new long[]{indexVal};
while((ret[ret.length-1]&MLINKED)!=0){
ret = Arrays.copyOf(ret, ret.length + 1);
long oldLink = ret[ret.length-2]&MOFFSET;
//get WAL position from current transaction, or previous (not yet fully replayed) transactions
long val = currDataLongs[segment].get(oldLink);
if(val==0)
val = prevDataLongs[segment].get(oldLink);
if(val!=0) {
//was found in previous position, read link from WAL
int file = (int) ((val>>>32) & 0xFFFFL); // get WAL file number
val = val & 0xFFFFFFFFL; // convert to WAL offset;
val = volumes.get(file).getLong(val);
}else{
//was not found in any transaction, read from main store
val = vol.getLong(oldLink);
}
ret[ret.length-1] = parity3Get(val);
}
if(CC.ASSERT){
offsetsVerify(ret);
}
if (CC.LOG_STORE && LOG.isLoggable(Level.FINEST)) {
LOG.log(Level.FINEST, "indexVal={0}, ret={1}",
new Object[]{Long.toHexString(indexVal), Arrays.toString(ret)});
}
return ret;
}
@Override
protected A get2(long recid, Serializer serializer) {
if (CC.ASSERT)
assertReadLocked(recid);
int segment = lockPos(recid);
//is in write cache?
{
Object cached = writeCache[segment].get1(recid);
if (cached != null) {
if(cached==TOMBSTONE2)
return null;
return (A) cached;
}
}
//is in wal?
{
long walval = currLongLongs[segment].get(recidToOffset(recid));
if(walval==0) {
walval = prevLongLongs[segment].get(recidToOffset(recid));
}
if(walval!=0){
//read record from WAL
boolean linked = (walval&MLINKED)!=0;
int size = (int) (walval>>>48);
if(linked && size==0)
return null;
if(size==0){
return deserialize(serializer,0,new DataIO.DataInputByteArray(new byte[0]));
}
if(linked)try {
//read linked record
int totalSize = 0;
byte[] in = new byte[100];
long link = walval;
while((link&MLINKED)!=0){
DataInput in2 = walGetData(link&MOFFSET, segment);
int chunkSize = (int) (link>>>48);
//get value of next link
link = in2.readLong();
//copy data into in
if(in.length>>48);
//copy data into in
if(in.length>>48),in);
}
}
long[] offsets = offsetsGet(lockPos(recid),indexValGet(recid));
if (offsets == null) {
return null; //zero size
}else if (offsets.length==0){
return deserialize(serializer,0,new DataIO.DataInputByteArray(new byte[0]));
}else if (offsets.length == 1) {
//not linked
int size = (int) (offsets[0] >>> 48);
long offset = offsets[0] & MOFFSET;
DataInput in = vol.getDataInput(offset, size);
return deserialize(serializer, size, in);
} else {
//calculate total size
int totalSize = offsetsTotalSize(offsets);
//load data
byte[] b = new byte[totalSize];
int bpos = 0;
for (int i = 0; i < offsets.length; i++) {
int plus = (i == offsets.length - 1)?0:8;
long size = (offsets[i] >>> 48) - plus;
if(CC.ASSERT && (size&0xFFFF)!=size)
throw new DBException.DataCorruption("size mismatch");
long offset = offsets[i] & MOFFSET;
vol.getData(offset + plus, b, bpos, (int) size);
bpos += size;
}
if (CC.ASSERT && bpos != totalSize)
throw new DBException.DataCorruption("size does not match");
DataInput in = new DataIO.DataInputByteArray(b);
return deserialize(serializer, totalSize, in);
}
}
@Override
public void rollback() throws UnsupportedOperationException {
commitLock.lock();
try {
//flush modified records
for (int segment = 0; segment < locks.length; segment++) {
Lock lock = locks[segment].writeLock();
lock.lock();
try {
writeCache[segment].clear();
if(caches!=null) {
caches[segment].clear();
}
} finally {
lock.unlock();
}
}
structuralLock.lock();
try {
dirtyStackPages.clear();
//restore headVol from backup
byte[] b = new byte[(int) HEAD_END];
//TODO use direct copy
headVolBackup.getData(0,b,0,b.length);
headVol.putData(0,b,0,b.length);
indexPages = indexPagesBackup.clone();
} finally {
structuralLock.unlock();
}
}finally {
commitLock.unlock();
}
}
@Override
public void commit() {
commitLock.lock();
try{
//if big enough, do full WAL replay
if(volumes.size()>FULL_REPLAY_AFTER_N_TX) {
commitFullWALReplay();
return;
}
//move all from current longs to prev
//each segment requires write lock
for(int segment=0;segment MAX_REC_SIZE)
throw new DBException.DataCorruption();
putDataSingleWithoutLink(-1, offset, val, 0, val.length);
}
dirtyStackPages.clear();
}
//update index checksum
headVol.putInt(HEAD_CHECKSUM, headChecksum(headVol));
// flush headVol into WAL
byte[] b = new byte[(int) HEAD_END-4];
//TODO use direct copy
headVol.getData(4, b, 0, b.length);
//put headVol into WAL
putDataSingleWithoutLink(-1, 4L, b, 0, b.length);
//make copy of current headVol
headVolBackup.putData(4, b, 0, b.length);
indexPagesBackup = indexPages.clone();
long finalOffset = walOffset.get();
curVol.ensureAvailable(finalOffset + 1); //TODO overlap here
//put EOF instruction
curVol.putUnsignedByte(finalOffset, (0 << 4) | (Long.bitCount(finalOffset) & 15));
curVol.sync();
//put wal seal
curVol.putLong(8, WAL_SEAL);
curVol.sync();
walStartNextFile();
} finally {
structuralLock.unlock();
}
}finally {
commitLock.unlock();
}
}
protected void commitFullWALReplay() {
if(CC.ASSERT && !commitLock.isHeldByCurrentThread())
throw new AssertionError();
//lock all segment locks
//TODO use series of try..finally statements, perhaps recursion with runnable
for(int i=0;i MAX_REC_SIZE)
throw new DBException.DataCorruption();
putDataSingleWithoutLink(-1, offset, val, 0, val.length);
}
dirtyStackPages.clear();
}
if(CC.ASSERT && dirtyStackPages.size!=0)
throw new AssertionError();
pageLongStack.clear();
//update index checksum
headVol.putInt(HEAD_CHECKSUM, headChecksum(headVol));
// flush headVol into WAL
byte[] b = new byte[(int) HEAD_END-4];
//TODO use direct copy
headVol.getData(4, b, 0, b.length);
//put headVol into WAL
putDataSingleWithoutLink(-1, 4L, b, 0, b.length);
//make copy of current headVol
headVolBackup.putData(4, b, 0, b.length);
indexPagesBackup = indexPages.clone();
long finalOffset = walOffset.get();
curVol.ensureAvailable(finalOffset+1); //TODO overlap here
//put EOF instruction
curVol.putUnsignedByte(finalOffset, (0<<4) | (Long.bitCount(finalOffset)&15));
curVol.sync();
//put wal seal
curVol.putLong(8, WAL_SEAL);
curVol.sync();
//now replay full WAL
replayWAL();
walStartNextFile();
} finally {
structuralLock.unlock();
}
}finally {
for(int i=locks.length-1;i>=0;i--){
locks[i].writeLock().unlock();
}
}
}
protected void replayWAL(){
/*
Init Open for StoreWAL has following phases:
1) check existing files and their seals
2) if compacted file exists, swap it with original
3) if Record WAL files exists, initialize Memory Allocator
4) if Record WAL exists, convert it to WAL
5) replay WAL if any
6) reinitialize memory allocator if replay WAL happened
*/
if(!walRec.isEmpty()){
//convert walRec into WAL log files.
//memory allocator was not available at the time of compaction
structuralLock.lock();
try {
walStartNextFile();
}finally {
structuralLock.unlock();
}
for(Volume wr:walRec){
if(wr.length()==0)
break;
wr.ensureAvailable(16); //TODO this should not be here, Volume should be already mapped if file existsi
if(wr.getLong(8)!=StoreWAL.WAL_SEAL)
break;
long pos = 16;
for(;;) {
int instr = wr.getUnsignedByte(pos++);
if (instr >>> 4 == 0) {
//EOF
break;
} else if (instr >>> 4 != 5) {
//TODO failsafe with corrupted wal
throw new DBException.DataCorruption("Invalid instruction in WAL REC" + (instr >>> 4));
}
long recid = wr.getSixLong(pos);
pos += 6;
int size = wr.getInt(pos);
//TODO zero size, null records, tombstone
pos += 4;
byte[] arr = new byte[size]; //TODO reuse array if bellow certain size
wr.getData(pos, arr, 0, size);
pos += size;
update(recid, arr, Serializer.BYTE_ARRAY_NOSIZE);
}
}
List l = new ArrayList(walRec);
walRec.clear();
commitFullWALReplay();
//delete all wr files
for(Volume wr:l){
File f = wr.getFile();
wr.close();
wr.deleteFile();
if(f!=null && f.exists() && !f.delete()){
LOG.warning("Could not delete WAL REC file: "+f);
}
}
walRec.clear();
}
replayWALInstructionFiles();
}
private void replayWALInstructionFiles() {
if(CC.ASSERT && !structuralLock.isHeldByCurrentThread())
throw new AssertionError();
if(CC.ASSERT && !commitLock.isHeldByCurrentThread())
throw new AssertionError();
file:for(Volume wal:volumes){
if(wal.length()<16 || wal.getLong(8)!=WAL_SEAL) {
break file;
//TODO better handling for corrupted logs
}
long pos = 16;
for(;;) {
int checksum = wal.getUnsignedByte(pos++);
int instruction = checksum>>>4;
checksum = (checksum&15);
if (instruction == 0) {
//EOF
if((Long.bitCount(pos-1)&15) != checksum)
throw new InternalError("WAL corrupted");
continue file;
} else if (instruction == 1) {
//write long
long val = wal.getLong(pos);
pos += 8;
long offset = wal.getSixLong(pos);
pos += 6;
if(((1+Long.bitCount(val)+Long.bitCount(offset))&15)!=checksum)
throw new InternalError("WAL corrupted");
realVol.ensureAvailable(offset+8);
realVol.putLong(offset, val);
} else if (instruction == 2) {
//write byte[]
int dataSize = wal.getUnsignedShort(pos);
pos += 2;
long offset = wal.getSixLong(pos);
pos += 6;
byte[] data = new byte[dataSize];
wal.getData(pos, data, 0, data.length);
pos += data.length;
if(((1+Integer.bitCount(dataSize)+Long.bitCount(offset)+sum(data))&15)!=checksum)
throw new InternalError("WAL corrupted");
//TODO direct transfer
realVol.ensureAvailable(offset+data.length);
realVol.putData(offset, data, 0, data.length);
} else if (instruction == 3) {
//skip N bytes
int skipN = wal.getInt(pos - 1) & 0xFFFFFF; //read 3 bytes
if((Integer.bitCount(skipN)&15) != checksum)
throw new InternalError("WAL corrupted");
pos += 3 + skipN;
} else if (instruction == 4) {
//skip single byte
if((Long.bitCount(pos-1)&15) != checksum)
throw new InternalError("WAL corrupted");
} else if (instruction == 6) {
//write two bytes
long s = wal.getLong(pos);
pos+=8;
if(((1+Long.bitCount(s))&15) != checksum)
throw new InternalError("WAL corrupted");
long offset = s&0xFFFFFFFFFFFFL;
realVol.ensureAvailable(offset + 2);
realVol.putUnsignedShort(offset, (int) (s>>>48));
}else{
throw new InternalError("WAL corrupted, unknown instruction");
}
}
}
realVol.sync();
//destroy old wal files
for(Volume wal:volumes){
if(!wal.isClosed()) {
wal.truncate(0);
wal.close();
}
wal.deleteFile();
}
fileNum = -1;
curVol = null;
volumes.clear();
}
private int sum(byte[] data) {
int ret = 0;
for(byte b:data){
ret+=b;
}
return Math.abs(ret);
}
private int sum(byte[] buf, int bufPos, int size) {
int ret = 0;
size+=bufPos;
while(bufPos © 2015 - 2025 Weber Informatics LLC | Privacy Policy