Thanks! Given that, is there any advantage to a "header message" as opposed to just hand-serializing everything in the header?
On Sat, Jul 7, 2018 at 12:45 PM Ilia Mirkin <[email protected]> wrote: > You need explicit lengths. Usually this is done as <header length > varint><header><body>. And the header contains the body length in it. > In Java, there's a CodedInputStream/OutputStream which makes it easy > to consume fixed lengths (push/popLimit) as well as raw varints (as > for the initial header length). Other languages have similar > abstractions. > > On Sat, Jul 7, 2018 at 2:26 PM, John Lilley <[email protected]> wrote: > > I am posting protobuf messages to a message broker, and in order to > identify > > them, I prefix the message bytes with the serialized result of a "header" > > message: > > > > message Header { > > int version = 1; > > string message_type = 2; > > } > > > > It is easy, to concatenate the header+actual message bytes and post the > > resulting block to a queue. But how do I take these apart on the > receiving > > end? Suppose I get a byte-buffer consisting of: > > > > --------------- > > | header | > > --------------- > > | body | > > --------------- > > > > Is it OK to throw this oversized buffer at the Header deserialization? > Will > > the extra bytes hurt anything? > > > > Then, once I extract the Header message, how do I know where the body > > begins? I could turn around and ask the Header object "how big would you > be > > if serialized?". Is that reliable? Is there a better way? > > > > Thanks > > john > > > > -- > > You received this message because you are subscribed to the Google Groups > > "Protocol Buffers" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [email protected]. > > To post to this group, send email to [email protected]. > > Visit this group at https://groups.google.com/group/protobuf. > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/protobuf. For more options, visit https://groups.google.com/d/optout.
