charlesconnell commented on code in PR #6167:
URL: https://github.com/apache/hbase/pull/6167#discussion_r1761050188
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hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncTable.java:
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@@ -676,6 +676,47 @@ interface CoprocessorCallback<R> {
void onError(Throwable error);
}
+ /**
+ * Some coprocessors may support the idea of "partial results." If for some
reason a coprocessor
+ * cannot return all results for a given region in a single response, the
client side can be
+ * designed to recognize this and continuing requesting more results until
they are completely
+ * accumulated in the client.
+ * <p>
+ * It is up to a particular coprocessor implementation and its corresponding
clients to agree on
+ * what it means for results to be incomplete, how this state is
communicated, and how multiple
+ * incomplete results are accumulated together.
+ * <p>
+ * Use this callback when you want to execute a coprocessor call on a range
of regions, and that
+ * coprocessor may return incomplete results for a given region. See also
the docs for
+ * {@link CoprocessorCallback}, which all apply here to its child interface
too.
+ */
+ @InterfaceAudience.Public
+ interface PartialResultCoprocessorCallback<S, R> extends
CoprocessorCallback<R> {
+ /**
+ * Subclasses should implement this to tell AsyncTable whether the given
response is "final" or
+ * whether the AsyncTable should send another request to the coprocessor
to fetch more results
+ * from the given region. This method of fetching more results can be used
many times until
+ * there are no more results to fetch from the region.
+ * @param response The response received from the coprocessor
+ * @param region The region the response came from
+ * @return A ServiceCaller object if the response was not final and
therefore another request is
+ * required to continuing fetching results. null if no more
requests need to be sent to
+ * the region.
+ */
+ ServiceCaller<S, R> getNextCallable(R response, RegionInfo region);
+
+ /**
+ * Subclasses should implement this such that, when the above method
returns non-null, this
+ * method returns the number of milliseconds that AsyncTable should wait
before sending the next
+ * request to the given region. You can use this to create a back-off
behavior to reduce load on
+ * the RegionServer. If that's not desired, you can always return 0.
+ * @param response The response received from the coprocessor
+ * @param region The region the response came from
+ * @return The number of milliseconds to wait.
+ */
+ long getWaitIntervalMs(R response, RegionInfo region);
Review Comment:
No problem, done.
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