mjsax commented on a change in pull request #10810: URL: https://github.com/apache/kafka/pull/10810#discussion_r644509797
########## File path: streams/src/main/java/org/apache/kafka/streams/processor/ProcessorContext.java ########## @@ -158,32 +165,52 @@ Cancellable schedule(final Duration interval, void commit(); /** - * Returns the topic name of the current input record; could be null if it is not - * available (for example, if this method is invoked from the punctuate call). + * Returns the topic name of the current input record; could be {@code null} if it is not + * available. + * + * <p> For example, if this method is invoked within a punctuate callback, or while processing a + * record that was forwarded by a punctuation callback, the record won't have an associated topic. + * Another example is + * {@link org.apache.kafka.streams.kstream.KTable#transformValues(ValueTransformerWithKeySupplier, String...)} + * (and siblings), that do not always guarantee to provide a valid topic name, as they might be + * executed "out-of-band" due to some internal optimizations applied by the Kafka Streams DSL. * * @return the topic name */ String topic(); /** - * Returns the partition id of the current input record; could be -1 if it is not - * available (for example, if this method is invoked from the punctuate call). + * Returns the partition id of the current input record; could be {@code -1} if it is not + * available. + * + * <p> For example, if this method is invoked within a punctuate callback, or while processing a + * record that was forwarded by a punctuation callback the record won't have an associated partition id. + * Another example is + * {@link org.apache.kafka.streams.kstream.KTable#transformValues(ValueTransformerWithKeySupplier, String...)} + * (and siblings), that do not always guarantee to provide a valid partition id, as they might be + * executed "out-of-band" due to some internal optimizations applied by the Kafka Streams DSL. * * @return the partition id */ int partition(); /** - * Returns the offset of the current input record; could be -1 if it is not - * available (for example, if this method is invoked from the punctuate call). + * Returns the offset of the current input record; could be {@code -1} if it is not + * available. + * + * <p> For example, if this method is invoked within a punctuate callback, or while processing a + * record that was forwarded by a punctuation callback, the record won't have an associated offset. + * Another example is + * {@link org.apache.kafka.streams.kstream.KTable#transformValues(ValueTransformerWithKeySupplier, String...)} + * (and siblings), that do not always guarantee to provide a valid offset, as they might be + * executed "out-of-band" due to some internal optimizations applied by the Kafka Streams DSL. * * @return the offset */ long offset(); /** - * Returns the headers of the current input record; could be null if it is not - * available (for example, if this method is invoked from the punctuate call). + * Returns the headers of the current input record. Review comment: While I think `headers` should never be `null`, they could still be empty. Not sure to what extend this must be documented? For punctuation "forwards" it seems obvious (similar if one would not set a key or value...), and for the new `Record` api it's even more obvious. For the `KTable#transformValues` "ValueGetter" case, it's a little different though. Might be worth to repeat here? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org