MINOR: Clarify ReadOnlyWindowStore's time range behaviour
Highlight that the range in `fetch` is inclusive of both `timeFrom` and `timeTo`
Author: Damian Guy
Reviewers: Michael G. Noll Matthias J. Sax Ismael Juma
Closes from dguy/minor-window-fetch-java-doc
@@ -32,6 +32,25 @@ public interface ReadOnlyWindowStore<K, V> {
/**
* Get all the key-value pairs with the given key and the time range from all
* the existing windows.
+ * <p>
+ * The time range is inclusive and applies to the starting timestamp of the window.
+ * For example, if we have the following windows:
+ * <p>
+ * <pre>
+ * +-------------------------------+
+ * | key | start time | end time |
+ * +-------+------------+----------+
+ * | A | 10 | 20 |
+ * +-------+------------+----------+
+ * | A | 15 | 25 |
+ * +-------+------------+----------+
+ * | A | 20 | 30 |
+ * +-------+------------+----------+
+ * | A | 25 | 35 |
+ * +--------------------------------
+ * </pre>
+ * And we call {@code store.fetch("A", 10, 20)} then the results will contain the first
+ * three windows from the table above, i.e., all those where 10 <= start time <= 20.
*
* @return an iterator over key-value pairs {@code <timestamp, value>}
* @throws InvalidStateStoreException if the store is not initialized
