static void _writeEnumeratorToEnd <T>(Stream stream,
IEnumerator enumerator, ObjectToBytesConverter <T> converter,
bool validityCheck)
{
var lengthPos = stream.Position;
stream.WriteInt32(0);
stream.WriteInt32(0);
stream.WriteInt64(0);
int len = 0;
do
{
if (enumerator.Current != null)
{
len += stream.WriteObject((T)enumerator.Current, converter, validityCheck);
}
}while (enumerator.MoveNext());
var endPos = stream.Position;
stream.SeekTo(lengthPos);
stream.WriteInt32(len);
stream.WriteInt32(len);
stream.SeekTo(endPos);
}
public static int WriteObject <T>(this Stream stream, T obj, ObjectToBytesConverter <T> converter, bool validityCheck = true)
{
return(stream.WriteByteArray(converter(obj), validityCheck));
}
/// <summary>
/// Writes a set of objects, each of them fetched from an enumerator, to this stream.
/// </summary>
/// <param name="stream">A <see cref="System.IO.Stream"/>.</param>
/// <param name="enumerator">An enumerator used to get each object.</param>
/// <param name="mode">Indicates whether to override existing list or create a new list in the stream.</param>
/// <param name="converter">A delegate used to convert each item in the list to a byte array.</param>
/// <param name="validityCheck">Indicates whether to write a validity-check countersign before the list in the stream.</param>
public static void WriteObjects <T>(this Stream stream, IEnumerator enumerator, WritingMode mode,
ObjectToBytesConverter <T> converter, bool validityCheck = true)
{
if (mode == WritingMode.New)
{
if (validityCheck)
{
stream.WriteCheckCode((Int64)29);
}
if (enumerator.MoveNext())
{
_writeEnumeratorToEnd(stream, enumerator, converter, validityCheck);
}
else
{
stream.WriteInt32(0);
stream.WriteInt32(0);
stream.WriteInt64(0);
}
}
else
{
if (!validityCheck || stream.Check((Int64)29))
{
int i = 0;
bool moreObjs = enumerator.MoveNext();
if (!moreObjs)
{
stream.SkipInt32();
stream.WriteInt32(0);
var next = stream.ReadInt64();
stream.WriteInt64(-Math.Abs(next));
return;
}
while (moreObjs)
{
var len = stream.ReadInt32();
var olen = len;
var usedLenPos = stream.Position;
var usedLen = stream.ReadInt32();
var nextPtrPos = stream.Position;
var next = stream.ReadInt64();
int objLen;
for (; len > 0 && moreObjs; len -= objLen, i++)
{
var b = converter((T)enumerator.Current);
objLen = stream._byteArrayOccupancy(b, validityCheck);
if (objLen > len)
{
break;
}
else
{
stream.WriteByteArray(b, validityCheck);
moreObjs = enumerator.MoveNext();
}
}
var nUsedLen = olen - len;
var currPos = stream.Position;
stream.SeekTo(usedLenPos);
stream.WriteInt32(nUsedLen);
stream.SeekTo(currPos);
if (moreObjs)
{
if (next == 0)
{
stream.SeekTo(nextPtrPos);
stream.WriteInt64(stream.Length);
stream.SeekToEnd();
_writeEnumeratorToEnd(stream, enumerator, converter, validityCheck);
break;
}
else
{
if (next < 0)
{
stream.SeekTo(nextPtrPos);
next = -next;
stream.WriteInt64(next);
}
stream.SeekTo(next);
}
}
else
{
if (next != 0)
{
currPos = stream.Position;
stream.SeekTo(nextPtrPos);
stream.WriteInt64(-Math.Abs(next));
stream.SeekTo(currPos);
break;
}
}
}
}
else
{
throw new InvalidDataException(IOResources.ERR_StreamExtension_DataIrrecognizable);
}
}
}
