internal ReadOnlySpan <byte> EncodeBatch(KeyValuePair <byte[], ResultCacheEntry>[] operations)
{
if (operations.Length == 0)
{
throw new ArgumentException("Zero size batch", nameof(operations));
}
long maxSize = 0;
maxSize += 8; // sequence
maxSize += 4 * operations.Length; // count
foreach (KeyValuePair <byte[], ResultCacheEntry> entry in operations)
{
maxSize += 1; // op code
maxSize += 10; // varint max
maxSize += entry.Key.Length;
if (entry.Value.ResultState == ResultState.Exist)
{
maxSize += 10; // varint max
maxSize += entry.Value.Data?.Length ?? 0;
}
}
Span <byte> data = new byte[maxSize]; // big enough to contain all data regardless of size
var writer = new SpanWriter(data);
// write sequence
writer.Write((ulong)operations.First().Value.Sequence);
// write operations count
writer.Write((uint)operations.Length);
foreach (KeyValuePair <byte[], ResultCacheEntry> operation in operations)
{
byte[] key = operation.Key;
ResultCacheEntry entry = operation.Value;
// write op type (byte)
writer.Write(entry.ResultState == ResultState.Exist ? (byte)OperationType.Value : (byte)OperationType.Delete);
// write key
writer.WriteLengthPrefixed(key);
if (entry.ResultState == ResultState.Exist)
{
// write data
writer.WriteLengthPrefixed(entry.Data);
}
}
return(data.Slice(0, writer.Position));
}
public static Span <byte> EncodeVersion(Version version)
{
var array = new byte[4096];
var buffer = new Span <byte>(array);
var writer = new SpanWriter(buffer);
// case Manifest.LogTagType.Comparator:
if (!string.IsNullOrEmpty(version.Comparator))
{
writer.WriteVarLong((ulong)LogTagType.Comparator);
writer.Write(version.Comparator);
}
// case Manifest.LogTagType.LogNumber:
{
writer.WriteVarLong((ulong)LogTagType.LogNumber);
writer.WriteVarLong((ulong)version.LogNumber);
}
// case Manifest.LogTagType.PrevLogNumber:
{
writer.WriteVarLong((ulong)LogTagType.PrevLogNumber);
writer.WriteVarLong((ulong)version.PreviousLogNumber);
}
// case Manifest.LogTagType.NextFileNumber:
{
writer.WriteVarLong((ulong)LogTagType.NextFileNumber);
writer.WriteVarLong((ulong)version.NextFileNumber);
}
// case Manifest.LogTagType.LastSequence:
{
writer.WriteVarLong((ulong)LogTagType.LastSequence);
writer.WriteVarLong((ulong)version.LastSequenceNumber);
}
// case Manifest.LogTagType.CompactPointer:
if (version.CompactPointers.Count > 0)
{
foreach (KeyValuePair <int, byte[]> pointer in version.CompactPointers)
{
writer.WriteVarLong((ulong)LogTagType.CompactPointer);
writer.WriteVarLong((ulong)pointer.Key);
writer.WriteLengthPrefixed(pointer.Value);
}
}
// case Manifest.LogTagType.DeletedFile:
//if (version.DeletedFiles.Count > 0)
//{
// foreach (KeyValuePair<int, List<ulong>> files in version.DeletedFiles)
// {
// foreach (ulong fileNumber in files.Value)
// {
// writer.WriteVarLong((ulong) LogTagType.DeletedFile);
// writer.WriteVarLong((ulong) files.Key);
// writer.WriteVarLong(fileNumber);
// }
// }
//}
// case Manifest.LogTagType.NewFile:
if (version.Levels.Count > 0)
{
foreach (KeyValuePair <int, List <FileMetadata> > files in version.Levels)
{
int level = files.Key;
foreach (FileMetadata fileMeta in files.Value)
{
writer.WriteVarLong((ulong)LogTagType.NewFile);
//int level = (int) reader.ReadVarLong();
writer.WriteVarLong((ulong)level);
//ulong fileNumber = reader.ReadVarLong();
writer.WriteVarLong((ulong)fileMeta.FileNumber);
//ulong fileSize = reader.ReadVarLong();
writer.WriteVarLong((ulong)fileMeta.FileSize);
//var smallest = reader.ReadLengthPrefixedBytes();
writer.WriteLengthPrefixed(fileMeta.SmallestKey);
//var largest = reader.ReadLengthPrefixedBytes();
writer.WriteLengthPrefixed(fileMeta.LargestKey);
}
}
}
int length = writer.Position;
return(buffer.Slice(0, length).ToArray());
}