On Wed, Apr 4, 2018 at 4:32 PM, <[email protected]> wrote:
>
> Would Base64Decoder work gracefully with chunking? Looking at below code
> which I slapped together from the Wiki example on chunking and with Jeff's
> help re EndOfFile (which I just did not see above the screen and only tried
> to search for in the Wiki and source code), I have this question: once the
> MeterFilter starts slicing and dicing the input, and feeding to the
> Base64Decoder, would the later be smart enough to process successfully? It
> seems that from every 3 input bytes Base64Decoder has to recover 2 data
> bytes. Does it mean that chunk size for this scenario has to be a multiple
> of 3?
>
>
> MeterFilter meter;
> StreamTransformationFilter
> decryptorFilter((StreamTransformation&)decryptor);
> Base64Decoder base64Dec;
>
> FileSource source(sourceStream, false);
> FileSink sink(destStream);
>
> source.Attach(new Redirector(decryptorFilter));
> if (Base64Encode)
> {
> decryptorFilter.Attach(new Redirector(base64Dec));
> base64Dec.Attach(new Redirector(meter)); // meter filter
> feeding base64 decryptor? will this work?
> }
> else
> {
> decryptorFilter.Attach(new Redirector(meter));
> }
> meter.Attach(new Redirector(sink));
>
> word64 processed = 0;
>
> while (!FileUtil::EndOfFile(source) &&
> !source.SourceExhausted())
> {
> source.Pump(ChunkSize); // so hear we would have to
> adjust ChunkSize to the nearest greater multiple of 3?
> decryptorFilter.Flush(false);
>
> processed += ChunkSize;
>
> if (ProgressCallback != nullptr)
> {
> if (processed % (ProgressEvery) == 0)
> {
> ProgressCallback(meter.GetTotalBytes());
> }
> }
> }
What happens in reality is, you do this at the application layer:
source.Pump(ChunkSize);
You pump data into the attached
transformation/{encoder|encryptor|decoder|decryption|...} filter. The
filter then buffers your requests and flushes them at 4096 bytes or
when it gets a MessageEnd() signal.
I can't find the reference at the moment at the moment. When I do I'll
post it to the wiki page.
Jeff
Jeff
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