public static Footer DecodeFrom(Slice slice)
{
uint startOffset = slice.Offset;
uint startLength = slice.Length;
uint magic_lo = Coding.DecodeFixed32(slice.NewSlice(kEncodedLength - 8, 4));
uint magic_hi = Coding.DecodeFixed32(slice.NewSlice(kEncodedLength - 4, 4));
ulong magic = (unchecked ((ulong)magic_hi) << 32) | unchecked ((ulong)magic_lo);
if (magic != kTableMagicNumber)
{
throw new Exception("not an sstable (bad magic number)");
}
var metaIndexHandle = BlockHandle.DecodeFrom(slice);
var indexHandle = BlockHandle.DecodeFrom(slice);
slice.Update(startOffset + kEncodedLength, startLength - kEncodedLength);
return(new Footer(metaIndexHandle, indexHandle));
}
public void Add(Record record)
{
var actionDict = new Action <Slice>[]
{
Error,
ReadComparator,
ReadLogNumber,
ReadNextFileNumber,
ReadLastSequence,
ReadCompactPointer,
ReadDeletedFiled,
ReadNewFile,
Error,
ReadPrevLogNumber,
};
var slice = new Slice(record.Bytes);
while (slice.Length > 0)
{
var type = Coding.DecodeVarint32(slice);
actionDict[type].Invoke(slice);
}
}
private void ReadPrevLogNumber(Slice slice)
{
m_prevLogNumber = Coding.DecodeVarint64(slice);
m_hasPrevLogNumber = true;
}
private void ReadDeletedFiled(Slice slice)
{
var level = Coding.DecodeVarint32(slice);
var fileNr = Coding.DecodeVarint64(slice);
}
private void ReadCompactPointer(Slice slice)
{
var level = Coding.DecodeVarint32(slice);
var pointer = Coding.DecodeLengthPrefixed(slice);
}
private void ReadLastSequence(Slice slice)
{
m_lastSequence = Coding.DecodeVarint64(slice);
m_hasLastSequence = true;
}
private void ReadNextFileNumber(Slice slice)
{
m_nextFileNumber = Coding.DecodeVarint64(slice);
m_hasNextFileNumber = true;
}
private void ReadLogNumber(Slice slice)
{
m_logNumber = Coding.DecodeVarint64(slice);
m_hasLogNumber = true;
}