internal static int GetRecordLength(ArrayHeader header)
{
var len = header.OverallLength / header.RecordCount;
if (len > int.MaxValue || len < 1)
{
throw new InvalidOperationException();
}
return((int)len);
}
public override DatabaseBuilder AddArray <T, TKey>(
IConstSizeSerializer <T> serializer,
Func <Database, IEnumerable <T> > elements,
Func <T, TKey> selector,
IComparer <TKey>?comparer)
{
try
{
var headerPosition = stream.Position;
// write a dummy header
var dummyHeaderBytes = new ArrayHeader(serializer).AsBytes();
stream.Write(dummyHeaderBytes);
var elementLength = serializer.ElementSize;
Utility.EnsureArrayOfMinimalSize(ref buffer, elementLength);
long elementCount = 0;
var elementsEnumerable = elements(db);
if (comparer != null)
{
elementsEnumerable = elementsEnumerable.OrderBy(selector, comparer);
}
foreach (var element in elementsEnumerable)
{
serializer.TrySerialize(element, buffer.AsSpan(), out _);
stream.Write(buffer, 0, elementLength);
elementCount++;
}
var pastEndPosition = stream.Position;
stream.Seek(headerPosition, SeekOrigin.Begin);
var arrayHeader = new ArrayHeader(serializer)
{
OverallLength = elementLength * elementCount,
RecordCount = elementCount,
StartsAt = headerPosition + dummyHeaderBytes.Length,
EndsAt = pastEndPosition,
Type = 1
};
stream.Write(arrayHeader.AsBytes());
stream.Seek(pastEndPosition, SeekOrigin.Begin);
headers.Add(arrayHeader);
}
catch
{
stream.Dispose();
db.Dispose();
throw;
}
return(this);
}
private ArrayHeader ReadNextHeader <T>(ISerializer <T> serializer)
where T : notnull
{
var preHeaderPosition = stream.Position;
var header = new ArrayHeader(serializer);
var buffer = new byte[sizeof(long)];
stream.ReadFully(buffer);
header.RecordCount = BitConverter.ToInt64(buffer, 0);
stream.ReadFully(buffer);
header.OverallLength = BitConverter.ToInt64(buffer, 0);
stream.ReadFully(buffer);
header.Type = BitConverter.ToInt64(buffer, 0);
// TODO: validate header
var headerBytes = header.AsBytes();
header.StartsAt = preHeaderPosition + headerBytes.Length;
header.EndsAt = header.StartsAt + header.OverallLength;
stream.Seek(header.EndsAt, SeekOrigin.Begin);
return(header);
}
public override DatabaseBuilder AddIndirectArray <T, TKey>(
ISerializer <T> serializer,
Func <Database, IEnumerable <T> > elements,
Func <T, TKey> selector,
IComparer <TKey>?comparer)
{
try
{
var headerPosition = stream.Position;
// write a dummy header
var dummyHeaderBytes = new ArrayHeader(serializer).AsBytes();
stream.Write(dummyHeaderBytes);
var pointersArrayOffsetPosition = stream.Position;
stream.Write(BitConverter.GetBytes(0L));
var dataStartPosition = stream.Position;
long elementCount = 0;
// TODO: less lazy way
var offsetList = new List <long>();
var elementsEnumerable = elements(db);
if (comparer != null)
{
elementsEnumerable = elementsEnumerable.OrderBy(selector, comparer);
}
foreach (var element in elementsEnumerable)
{
int actualLength;
while (!serializer.TrySerialize(element, buffer.AsSpan(), out actualLength))
{
Utility.Reallocate(ref buffer);
}
offsetList.Add(stream.Position - dataStartPosition);
stream.Write(BitConverter.GetBytes(actualLength));
stream.Write(buffer, 0, actualLength);
elementCount++;
}
var pointerArrayPosition = stream.Position;
stream.Position += elementCount * sizeof(long);
var pastEndPosition = stream.Position;
stream.Seek(headerPosition, SeekOrigin.Begin);
var arrayHeader = new ArrayHeader(serializer)
{
OverallLength = pastEndPosition - pointersArrayOffsetPosition,
RecordCount = elementCount,
StartsAt = pointersArrayOffsetPosition,
EndsAt = pastEndPosition,
Type = 2
};
stream.Write(arrayHeader.AsBytes());
stream.Write(BitConverter.GetBytes(pointerArrayPosition - pointersArrayOffsetPosition));
stream.Seek(pointerArrayPosition, SeekOrigin.Begin);
foreach (var off in offsetList)
{
stream.Write(BitConverter.GetBytes(off));
}
stream.Seek(pastEndPosition, SeekOrigin.Begin);
headers.Add(arrayHeader);
}
catch
{
stream.Dispose();
db.Dispose();
throw;
}
return(this);
}
