void CompactOnePureValueFileIteration(ref StructList <uint> toRemoveFileIds)
{
_cancellation.ThrowIfCancellationRequested();
_writerBytesPerSecondLimiter = new BytesPerSecondLimiter(_keyValueDB.CompactorWriteBytesPerSecondLimit);
var writer = _keyValueDB.StartPureValuesFile(out var valueFileId);
var firstIteration = true;
while (true)
{
var wastefulFileId =
FindMostWastefulFile(firstIteration
? uint.MaxValue
: _keyValueDB.MaxTrLogFileSize - writer.GetCurrentPositionWithoutWriter());
firstIteration = false;
if (wastefulFileId == 0)
{
break;
}
MoveValuesContent(writer, wastefulFileId, valueFileId);
if (_fileStats.GetOrFakeValueRef(wastefulFileId).IsFreeToDelete())
{
toRemoveFileIds.Add(wastefulFileId);
}
_fileStats.GetOrFakeValueRef(wastefulFileId) = new FileStat(0);
}
var valueFile = _keyValueDB.FileCollection.GetFile(valueFileId);
valueFile !.HardFlushTruncateSwitchToReadOnlyMode();
_keyValueDB.Logger?.CompactionCreatedPureValueFile(valueFileId, valueFile.GetSize(),
(uint)_newPositionMap.Count, 28 * (ulong)_newPositionMap.EnsureCapacity(0)
);
}
void MoveValuesContent(ISpanWriter writer, uint wastefulFileId, uint pvlFileId)
{
const uint blockSize = 256 * 1024;
var wastefulStream = _keyValueDB.FileCollection.GetFile(wastefulFileId);
var totalSize = wastefulStream !.GetSize();
var blocks = (int)((totalSize + blockSize - 1) / blockSize);
var wasteInMemory = new byte[blocks][];
var pos = 0UL;
var readLimiter = new BytesPerSecondLimiter(_keyValueDB.CompactorReadBytesPerSecondLimit);
for (var i = 0; i < blocks; i++)
{
_cancellation.ThrowIfCancellationRequested();
wasteInMemory[i] = new byte[blockSize];
var readSize = totalSize - pos;
if (readSize > blockSize)
{
readSize = blockSize;
}
wastefulStream.RandomRead(wasteInMemory[i].AsSpan(0, (int)readSize), pos, true);
pos += readSize;
readLimiter.Limit(pos);
}
_keyValueDB.IterateRoot(_root, (valueFileId, valueOfs, valueSize) =>
{
if (valueFileId != wastefulFileId)
{
return;
}
var size = (uint)Math.Abs(valueSize);
_newPositionMap.Add(((ulong)wastefulFileId << 32) | valueOfs,
((ulong)pvlFileId << 32) + (ulong)writer.GetCurrentPositionWithoutWriter());
pos = valueOfs;
while (size > 0)
{
_cancellation.ThrowIfCancellationRequested();
var blockId = pos / blockSize;
var blockStart = pos % blockSize;
var writeSize = (uint)(blockSize - blockStart);
if (writeSize > size)
{
writeSize = size;
}
writer.WriteBlockWithoutWriter(
ref MemoryMarshal.GetReference(wasteInMemory[blockId].AsSpan((int)blockStart, (int)writeSize)),
writeSize);
size -= writeSize;
pos += writeSize;
_writerBytesPerSecondLimiter.Limit((ulong)writer.GetCurrentPositionWithoutWriter());
}
});
}
