/// <summary>
/// Read key from file for merge.
/// </summary>
/// <remarks>
/// The data is written is 8 bytes aligned.
///
/// Name Type Size
///
/// KeySize int 4
/// Kind byte 1
/// RESERVED 3
/// VersionSequenceNumber long 8
///
/// (DeletedVersion)
/// TimeStamp long 8
///
/// (Inserted || Updated)
/// Offset long 8
/// ValueChecksum ulong 8
/// ValueSize int 4
/// RESERVED 4
///
/// Key TKey N
/// PADDING (N % 8 ==0) ? 0 : 8 - (N % 8)
///
/// RESERVED: Fixed padding that is usable to add fields in future.
/// PADDING: Due to dynamic size, cannot be used for adding fields.
///
/// Note: Larges Key size supported is int.MaxValue in bytes.
/// </remarks>
public KeyData <TKey, TValue> ReadKey <TKey, TValue>(InMemoryBinaryReader memoryBuffer, IStateSerializer <TKey> keySerializer)
{
memoryBuffer.ThrowIfNotAligned();
// This mirrors WriteKey().
var keySize = memoryBuffer.ReadInt32();
var kind = (RecordKind)memoryBuffer.ReadByte();
memoryBuffer.ReadPaddingUntilAligned(true);
var lsn = memoryBuffer.ReadInt64();
long valueOffset = 0;
var valueSize = 0;
ulong valueChecksum = 0;
long TimeStamp = 0;
if (kind == RecordKind.DeletedVersion)
{
TimeStamp = memoryBuffer.ReadInt64();
}
else
{
valueOffset = memoryBuffer.ReadInt64();
valueChecksum = memoryBuffer.ReadUInt64();
valueSize = memoryBuffer.ReadInt32();
memoryBuffer.ReadPaddingUntilAligned(true);
}
// Protection in case the user's key serializer doesn't leave the stream at the correct end point.
var keyPosition = memoryBuffer.BaseStream.Position;
var key = keySerializer.Read(memoryBuffer);
memoryBuffer.BaseStream.Position = keyPosition + keySize;
memoryBuffer.ReadPaddingUntilAligned(false);
TVersionedItem <TValue> value = null;
switch (kind)
{
case RecordKind.DeletedVersion:
value = new TDeletedItem <TValue>(lsn, this.FileId);
break;
case RecordKind.InsertedVersion:
value = new TInsertedItem <TValue>(lsn, this.FileId, valueOffset, valueSize, valueChecksum);
break;
case RecordKind.UpdatedVersion:
value = new TUpdatedItem <TValue>(lsn, this.FileId, valueOffset, valueSize, valueChecksum);
break;
default:
throw new InvalidDataException(string.Format(CultureInfo.CurrentCulture, SR.Error_KeyCheckpointFile_RecordKind, (byte)kind));
}
return(new KeyData <TKey, TValue>(key, value, TimeStamp));
}
public static PropertyChunkMetadata Read(InMemoryBinaryReader reader)
{
reader.ThrowIfNotAligned();
var currentBlockSize = reader.ReadInt32();
reader.ReadPaddingUntilAligned(true);
reader.ThrowIfNotAligned();
return(new PropertyChunkMetadata(currentBlockSize));
}