internal void WriteStartTransaction()
{
if (_fileIdWithTransactionLog == 0)
{
WriteStartOfNewTransactionLogFile();
}
else
{
if (_writerWithTransactionLog == null)
{
_fileWithTransactionLog = FileCollection.GetFile(_fileIdWithTransactionLog);
_writerWithTransactionLog = _fileWithTransactionLog.GetAppenderWriter();
}
if (_writerWithTransactionLog.GetCurrentPosition() > MaxTrLogFileSize)
{
WriteStartOfNewTransactionLogFile();
}
}
_writerWithTransactionLog.WriteUInt8((byte)KVCommandType.TransactionStart);
_writerWithTransactionLog.WriteByteArrayRaw(MagicStartOfTransaction);
}
public ByteBuffer ReadValue(uint valueFileId, uint valueOfs, int valueSize)
{
if (valueSize == 0)
{
return(ByteBuffer.NewEmpty());
}
if (valueFileId == 0)
{
var len = valueSize >> 24;
var buf = new byte[len];
switch (len)
{
case 7:
buf[6] = (byte)(valueOfs >> 24);
goto case 6;
case 6:
buf[5] = (byte)(valueOfs >> 16);
goto case 5;
case 5:
buf[4] = (byte)(valueOfs >> 8);
goto case 4;
case 4:
buf[3] = (byte)valueOfs;
goto case 3;
case 3:
buf[2] = (byte)valueSize;
goto case 2;
case 2:
buf[1] = (byte)(valueSize >> 8);
goto case 1;
case 1:
buf[0] = (byte)(valueSize >> 16);
break;
default:
throw new BTDBException("Corrupted DB");
}
return(ByteBuffer.NewAsync(buf));
}
var compressed = false;
if (valueSize < 0)
{
compressed = true;
valueSize = -valueSize;
}
var result = ByteBuffer.NewAsync(new byte[valueSize]);
var file = FileCollection.GetFile(valueFileId);
file.RandomRead(result.Buffer, 0, valueSize, valueOfs, false);
if (compressed)
{
_compression.DecompressValue(ref result);
}
return(result);
}
// Return true if it is suitable for continuing writing new transactions
bool LoadTransactionLog(uint fileId, uint logOffset)
{
var inlineValueBuf = new byte[MaxValueSizeInlineInMemory];
var stack = new List <NodeIdxPair>();
var collectionFile = FileCollection.GetFile(fileId);
var reader = collectionFile.GetExclusiveReader();
try
{
if (logOffset == 0)
{
FileTransactionLog.SkipHeader(reader);
}
else
{
reader.SkipBlock(logOffset);
}
if (reader.Eof)
{
return(true);
}
var afterTemporaryEnd = false;
while (!reader.Eof)
{
var command = (KVCommandType)reader.ReadUInt8();
if (command == 0 && afterTemporaryEnd)
{
collectionFile.SetSize(reader.GetCurrentPosition() - 1);
return(true);
}
afterTemporaryEnd = false;
switch (command & KVCommandType.CommandMask)
{
case KVCommandType.CreateOrUpdateDeprecated:
case KVCommandType.CreateOrUpdate:
{
if (_nextRoot == null)
{
return(false);
}
var keyLen = reader.ReadVInt32();
var valueLen = reader.ReadVInt32();
var key = new byte[keyLen];
reader.ReadBlock(key);
var keyBuf = ByteBuffer.NewAsync(key);
if ((command & KVCommandType.FirstParamCompressed) != 0)
{
_compression.DecompressKey(ref keyBuf);
}
var ctx = new CreateOrUpdateCtx
{
KeyPrefix = BitArrayManipulation.EmptyByteArray,
Key = keyBuf,
ValueFileId = fileId,
ValueOfs = (uint)reader.GetCurrentPosition(),
ValueSize = (command & KVCommandType.SecondParamCompressed) != 0 ? -valueLen : valueLen
};
if (valueLen <= MaxValueSizeInlineInMemory && (command & KVCommandType.SecondParamCompressed) == 0)
{
reader.ReadBlock(inlineValueBuf, 0, valueLen);
StoreValueInlineInMemory(ByteBuffer.NewSync(inlineValueBuf, 0, valueLen), out ctx.ValueOfs, out ctx.ValueSize);
ctx.ValueFileId = 0;
}
else
{
reader.SkipBlock(valueLen);
}
_nextRoot.CreateOrUpdate(ctx);
}
break;
case KVCommandType.EraseOne:
{
if (_nextRoot == null)
{
return(false);
}
var keyLen = reader.ReadVInt32();
var key = new byte[keyLen];
reader.ReadBlock(key);
var keyBuf = ByteBuffer.NewAsync(key);
if ((command & KVCommandType.FirstParamCompressed) != 0)
{
_compression.DecompressKey(ref keyBuf);
}
long keyIndex;
var findResult = _nextRoot.FindKey(stack, out keyIndex, BitArrayManipulation.EmptyByteArray, keyBuf);
if (findResult == FindResult.Exact)
{
_nextRoot.EraseRange(keyIndex, keyIndex);
}
}
break;
case KVCommandType.EraseRange:
{
if (_nextRoot == null)
{
return(false);
}
var keyLen1 = reader.ReadVInt32();
var keyLen2 = reader.ReadVInt32();
var key = new byte[keyLen1];
reader.ReadBlock(key);
var keyBuf = ByteBuffer.NewAsync(key);
if ((command & KVCommandType.FirstParamCompressed) != 0)
{
_compression.DecompressKey(ref keyBuf);
}
long keyIndex1;
var findResult = _nextRoot.FindKey(stack, out keyIndex1, BitArrayManipulation.EmptyByteArray, keyBuf);
if (findResult == FindResult.Previous)
{
keyIndex1++;
}
key = new byte[keyLen2];
reader.ReadBlock(key);
keyBuf = ByteBuffer.NewAsync(key);
if ((command & KVCommandType.SecondParamCompressed) != 0)
{
_compression.DecompressKey(ref keyBuf);
}
long keyIndex2;
findResult = _nextRoot.FindKey(stack, out keyIndex2, BitArrayManipulation.EmptyByteArray, keyBuf);
if (findResult == FindResult.Next)
{
keyIndex2--;
}
_nextRoot.EraseRange(keyIndex1, keyIndex2);
}
break;
case KVCommandType.TransactionStart:
if (!reader.CheckMagic(MagicStartOfTransaction))
{
return(false);
}
_nextRoot = LastCommited.NewTransactionRoot();
break;
case KVCommandType.CommitWithDeltaUlong:
unchecked // overflow is expected in case commitUlong is decreasing but that should be rare
{
_nextRoot.CommitUlong += reader.ReadVUInt64();
}
goto case KVCommandType.Commit;
case KVCommandType.Commit:
_nextRoot.TrLogFileId = fileId;
_nextRoot.TrLogOffset = (uint)reader.GetCurrentPosition();
_lastCommited = _nextRoot;
_nextRoot = null;
break;
case KVCommandType.Rollback:
_nextRoot = null;
break;
case KVCommandType.EndOfFile:
return(false);
case KVCommandType.TemporaryEndOfFile:
_lastCommited.TrLogFileId = fileId;
_lastCommited.TrLogOffset = (uint)reader.GetCurrentPosition();
afterTemporaryEnd = true;
break;
default:
_nextRoot = null;
return(false);
}
}
return(afterTemporaryEnd);
}
catch (EndOfStreamException)
{
_nextRoot = null;
return(false);
}
}
bool LoadKeyIndex(uint fileId, IKeyIndex info)
{
try
{
var reader = FileCollection.GetFile(fileId).GetExclusiveReader();
FileKeyIndex.SkipHeader(reader);
var keyCount = info.KeyValueCount;
_nextRoot.TrLogFileId = info.TrLogFileId;
_nextRoot.TrLogOffset = info.TrLogOffset;
_nextRoot.CommitUlong = info.CommitUlong;
if (info.Compression == KeyIndexCompression.Old)
{
_nextRoot.BuildTree(keyCount, () =>
{
var keyLength = reader.ReadVInt32();
var key = ByteBuffer.NewAsync(new byte[Math.Abs(keyLength)]);
reader.ReadBlock(key);
if (keyLength < 0)
{
_compression.DecompressKey(ref key);
}
return(new BTreeLeafMember
{
Key = key.ToByteArray(),
ValueFileId = reader.ReadVUInt32(),
ValueOfs = reader.ReadVUInt32(),
ValueSize = reader.ReadVInt32()
});
});
}
else
{
if (info.Compression != KeyIndexCompression.None)
{
return(false);
}
var prevKey = ByteBuffer.NewEmpty();
_nextRoot.BuildTree(keyCount, () =>
{
var prefixLen = (int)reader.ReadVUInt32();
var keyLengthWithoutPrefix = (int)reader.ReadVUInt32();
var key = ByteBuffer.NewAsync(new byte[prefixLen + keyLengthWithoutPrefix]);
Array.Copy(prevKey.Buffer, prevKey.Offset, key.Buffer, key.Offset, prefixLen);
reader.ReadBlock(key.SubBuffer(prefixLen));
prevKey = key;
return(new BTreeLeafMember
{
Key = key.ToByteArray(),
ValueFileId = reader.ReadVUInt32(),
ValueOfs = reader.ReadVUInt32(),
ValueSize = reader.ReadVInt32()
});
});
}
if (reader.Eof)
{
return(true);
}
if (reader.ReadInt32() == EndOfIndexFileMarker)
{
return(true);
}
return(false);
}
catch (Exception)
{
return(false);
}
}
