public static IOutputStream <TDst> Transform <TSrc, TDst>(this IOutputStream <TSrc> stream, ITransformation <TSrc, TDst> transformation, int readBufSize = 1024)
{
//Encoding.UTF8.GetBytes(str, strPos, charsToBuffer, intBuf, 0);
return(CreateOutput <TDst>(() => {
var inBuf = new TSrc[readBufSize];
var inBufPos = 0;
var inBufCnt = 0;
IStreamReader <TSrc> reader = null;
if (stream != null)
{
reader = stream.CreateReader();
}
return new AnonymousStreamReader <TDst>((buf, ofs, cnt) => {
var totalBytesCopied = 0;
while (cnt > 0)
{
var bytesCopied = transformation.Copy(buf, ofs, cnt);
if (bytesCopied > 0)
{
ofs += bytesCopied;
cnt -= bytesCopied;
totalBytesCopied += bytesCopied;
}
else
{
Action process = () => {
var itemsProcessed = transformation.Process(inBuf, inBufPos, inBufCnt);
inBufCnt -= itemsProcessed;
inBufPos += itemsProcessed;
};
if (inBufCnt > 0)
{
process();
}
else
{
if (reader == null)
{
return totalBytesCopied;
}
inBufPos = 0;
//try {
inBufCnt = reader.Read(inBuf, 0, inBuf.Length);
//} catch (Exception err) {
//inBufCnt = 0;
//try {
// reader.Dispose();
//} finally {
// reader = null;
//}
//}
if (inBufCnt > 0)
{
process();
}
else
{
try {
reader.Dispose();
} finally {
reader = null;
}
return totalBytesCopied;
}
}
}
}
return totalBytesCopied;
});
}));
}