Bluetooth, Wifi Direct, HTTP request/responses via broken proxies, smoke signals... basically anything that is a stream rather than a file.
Right, NFC NDEF and QR codes are not affected, so we can skip the delimiter for these mediums. On 01/26/2014 10:24 PM, Mike Hearn wrote: > Which medium is this an issue for? As you note, for files and HTTP > responses it's not a problem in practice. i'd guess nor for NFC tags nor > QR codes. > > > On Sun, Jan 26, 2014 at 10:11 PM, Andreas Schildbach > <andr...@schildbach.de <mailto:andr...@schildbach.de>> wrote: > > I'm experimenting with BIP70/71 (payment protocol) usage in face to face > payments (more on that soon). > > I've excountered an issue with the protobuf format. Protobufs are not > self-delimiting. That means if you're reading from an undelimited > stream, you will read endlessly because you don't know how much to read. > > The current BIP70 implementations probably work because they're reading > either from a file or from an HTTP resource which sets the > Content-Length header. Trouble is the Content-Length header is optional, > and also there are many kinds of streams that don't have this built-in > delimiting mechanism. > > The Java protobuf API solves this by offering delimited I/O, like > > payment.writeDelimitedTo(os); > > This writes the size of the message as a varint before writing the data. > I don't know about protobuf implementations for other languages but I'd > expect them to offer something compatible. > > However, this leading varint is an incompatible change and would need to > be added to the spec. > > I specifically encountered this with PaymentMessage and PaymentACK, but > it might be a good idea to apply this to all messages if any. Open for > discussion. > > > > ------------------------------------------------------------------------------ > CenturyLink Cloud: The Leader in Enterprise Cloud Services. > Learn Why More Businesses Are Choosing CenturyLink Cloud For > Critical Workloads, Development Environments & Everything In Between. > Get a Quote or Start a Free Trial Today. > > http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > <mailto:Bitcoin-development@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > > > > > ------------------------------------------------------------------------------ > CenturyLink Cloud: The Leader in Enterprise Cloud Services. > Learn Why More Businesses Are Choosing CenturyLink Cloud For > Critical Workloads, Development Environments & Everything In Between. > Get a Quote or Start a Free Trial Today. > http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk > > > > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
