private static void EndSubItem(SubItemToken token, ProtoWriter writer, PrefixStyle style)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
if (writer.wireType != WireType.None)
{
throw CreateException(writer);
}
int value = (int)token.value64;
if (writer.depth <= 0)
{
throw CreateException(writer);
}
if (writer.depth-- > RecursionCheckDepth)
{
writer.PopRecursionStack();
}
writer.packedFieldNumber = 0; // ending the sub-item always wipes packed encoding
if (value < 0)
{ // group - very simple append
WriteHeaderCore(-value, WireType.EndGroup, writer);
writer.wireType = WireType.None;
return;
}
// so we're backfilling the length into an existing sequence
int len;
switch (style)
{
case PrefixStyle.Fixed32:
len = (int)((writer.ioIndex - value) - 4);
ProtoWriter.WriteInt32ToBuffer(len, writer.ioBuffer, value);
break;
case PrefixStyle.Fixed32BigEndian:
len = (int)((writer.ioIndex - value) - 4);
byte[] buffer = writer.ioBuffer;
ProtoWriter.WriteInt32ToBuffer(len, buffer, value);
// and swap the byte order
byte b = buffer[value];
buffer[value] = buffer[value + 3];
buffer[value + 3] = b;
b = buffer[value + 1];
buffer[value + 1] = buffer[value + 2];
buffer[value + 2] = b;
break;
case PrefixStyle.Base128:
// string - complicated because we only reserved one byte;
// if the prefix turns out to need more than this then
// we need to shuffle the existing data
len = (int)((writer.ioIndex - value) - 1);
int offset = 0;
uint tmp = (uint)len;
while ((tmp >>= 7) != 0)
{
offset++;
}
if (offset == 0)
{
writer.ioBuffer[value] = (byte)(len & 0x7F);
}
else
{
DemandSpace(offset, writer);
byte[] blob = writer.ioBuffer;
Helpers.BlockCopy(blob, value + 1, blob, value + 1 + offset, len);
tmp = (uint)len;
do
{
blob[value++] = (byte)((tmp & 0x7F) | 0x80);
} while ((tmp >>= 7) != 0);
blob[value - 1] = (byte)(blob[value - 1] & ~0x80);
writer.position64 += offset;
writer.ioIndex += offset;
}
break;
default:
throw new ArgumentOutOfRangeException("style");
}
// and this object is no longer a blockage - also flush if sensible
const int ADVISORY_FLUSH_SIZE = 1024;
if (--writer.flushLock == 0 && writer.ioIndex >= ADVISORY_FLUSH_SIZE)
{
ProtoWriter.Flush(writer);
}
}