You can see the two pass reader here https://stackoverflow.com/questions/20666594/how-can-i-push-bytes-into-a-reader-in-go
But yea, the basic premise is that you buffer the data so you can rewind if needed Are you certain it is reading to the end to return EOF? It may be returning eof once the parsing fails. Otherwise I would expect this is being decoded wrong - eg the mime type or encoding type should tell you the correct format before you start decoding. > On Jan 12, 2025, at 2:46 PM, Rory Campbell-Lange <r...@campbell-lange.net> > wrote: > > Thanks for the suggestion of a ReadSeeker to wrap an io.Reader. > > My google fu must be deserting me. I can find PushbackReader implementations > in Java, but the only similar thing for Go I could find was > https://gitlab.com/osaki-lab/iowrapper. If you have a specific recommendation > for a ReadSeeker wrapper to an io.Reader that would be great to know. > > Since the base64 decoding error I'm looking for is an EOF, I guess the > wrapper approach will not work when the EOF byte position is > than the > io.ReadSeeker buffer size. > > Rory > >> On 12/01/25, robert engels (reng...@ix.netcom.com) wrote: >> create a ReadSeeker that wraps the Reader providing the buffering (mark & >> reset) - normally the buffer only needs to be large enough to detect the >> format contained in the Reader. >> >> You can search Google for PushbackReader in Go and you’ll get a basic >> implementation. >> >>> On Jan 12, 2025, at 12:52 PM, Rory Campbell-Lange <r...@campbell-lange.net> >>> wrote: > ... >>> I'm attempting to rationalise the process [of avoiding reading email parts >>> into byte slices] by simply wrapping the provided io.Reader with the >>> necessary decoders to reduce memory usage and unnecessary processing. >>> >>> The wrapping strategy seems to work ok. However there is a particular issue >>> in detecting base64.StdEncoding versus base64.RawStdEncoding, which >>> requires draining the io.Reader using base64.StdEncoding and (based on the >>> current implementation) switching to base64.RawStdEncoding if an >>> io.ErrUnexpectedEOF is found. >>> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/golang-nuts/DD0C1480-D237-447A-B978-78FC8951FE05%40ix.netcom.com.
