/// <summary>
/// Writes debugging marker if needed
/// </summary>
protected static void WriteEntryMarker(PageableStore store, BuildXLWriter writer)
{
if (store.Debug)
{
writer.Write(EntryMarker);
}
}
public override int Write(PageableStore store, Action <BuildXLWriter> serializer, out bool gotSealed)
{
lock (this)
{
m_stream.Seek(0, SeekOrigin.End);
int start = (int)m_stream.Position;
WriteEntryMarker(store, m_writer);
int depth = m_writer.Depth;
serializer(m_writer);
Contract.Assert(depth == m_writer.Depth);
m_writer.Flush();
// Make sure that whoever may pick up m_buffer concurrently will see the actual buffer contents
Volatile.Write(ref m_buffer, m_stream.GetBuffer());
m_length = (int)m_stream.Length;
m_capacity = m_stream.Capacity;
if (m_stream.Length * 1D / m_capacity > 0.9)
{
Seal();
gotSealed = true;
}
else
{
// Otherwise, make it available for more writes.
gotSealed = false;
}
return(start);
}
}
/// <summary>
/// Read away debugging marker if needed
/// </summary>
protected static void ReadEntryMarker(PageableStore store, BuildXLReader reader)
{
if (store.Debug)
{
uint marker = reader.ReadUInt32();
Contract.Assume(marker == EntryMarker);
}
}
public MemoryPageStream(PageableStore store)
{
Contract.RequiresNotNull(store);
Contract.Requires(store.CanWrite);
Contract.Assume(
store.m_initialBufferSize > 0,
"Initial buffer size for store was 0. This implies an attempt to write to a non-writable store.");
m_stream = new MemoryStream(store.m_initialBufferSize);
m_writer = store.CreateWriter(m_stream, leaveOpen: true);
m_buffer = m_stream.GetBuffer();
}
public override T Read <T>(PageableStore store, int offset, Func <BuildXLReader, T> deserializer)
{
var buffer = GetBuffer();
using (var stream = new MemoryStream(buffer, writable: false, index: offset, count: buffer.Length - offset))
using (var reader = store.CreateReader(stream, leaveOpen: true))
{
ReadEntryMarker(store, reader);
T value = deserializer(reader);
Contract.Assume(reader.Depth == 0);
return(value);
}
}
/// <summary>
/// Writes an item.
/// </summary>
public virtual int Write(PageableStore store, Action <BuildXLWriter> serializer, out bool gotSealed)
{
Contract.Requires(CanWrite);
gotSealed = false;
return(0);
}
/// <summary> /// Reads an item. /// </summary> public abstract T Read <T>(PageableStore store, int offset, Func <BuildXLReader, T> deserializer);
