I guess the issue, though, is that MessageSet is meant to represent a set of messages even prior to their being published. As a result it is not necessarily the case that there is an offset yet. Likewise it is possible to write a single message set twice to two separate topics. I guess a fully correct modeling would have MessageSet which implements Iterator[Message] and PublishedMessageSet[MessageAndOffsetInfo] (probably need to work on the name) which represents a chunk of a published log. This might be a bit of overkill, though.
-Jay On Mon, Apr 2, 2012 at 7:55 AM, Prashanth Menon <prashanth.men...@gmail.com> wrote: > My two cents here: > > Agreed on the getters and the errorCode: the former is unncessary and the > latter should be solved with the new fetch response. With respect to the > initialOffset, from the writer perspective it seems unnecessary. It's only > really used from the consumer perspective as a convenience to iterate over > the messages tieing each to an offset (ie. MessageAndOffset). A simple > solution would be have MessageSet iterate over its Message and to pull out > the initialOffset into a new class that wraps a MessageSet and an > initialOffset that consumers use allowing simple iteration over > MessageAndOffset? This will probably make the API cleaner. > > - Prashanth > > On Fri, Mar 30, 2012 at 8:53 PM, Jun Rao <jun...@gmail.com> wrote: > >> Yes, they should all be fixable with the new consumer response object. >> Could you open a jira to track this? >> >> Thanks, >> >> Jun >> >> On Fri, Mar 30, 2012 at 2:17 PM, Jay Kreps <jay.kr...@gmail.com> wrote: >> >> > There are a number of methods on ByteBufferMessageSet: >> > def getInitialOffset = initialOffset >> > def getBuffer = buffer >> > def getErrorCode = errorCode >> > def getSerialized(): ByteBuffer = buffer >> > >> > We don't generally have getters in kafka, since it automatically adds >> > them. Is there a reason for these? >> > >> > Also, there is no documentation on getSerialized() which does the same >> > thing as getBuffer(). >> > >> > Also why does a message set have an initial offset? Isn't it the case >> > that a messageset is independent of a particular offset to which it >> > might be written? >> > >> > It isn't clear to me why a MessageSet would have an error code at all. >> > It is a set of messages, that is what it is. Error codes are something >> > that have to do with APIs...did we just stick that in for convenience? >> > >> > I have a feeling that some of this was stuck in due to not having a >> > proper consumer response object in which to put the fields maybe. Now >> > that we have that in 0.8 can we clean this up? I feel if we junk up >> > these core classes we will soon have a real mess on our hands... >> > >> > -Jay >> > >>
