Umeshkumar9414 commented on code in PR #8464:
URL: https://github.com/apache/hbase/pull/8464#discussion_r3612821894
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hbase-client/src/main/java/org/apache/hadoop/hbase/filter/Filter.java:
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@@ -219,6 +223,85 @@ public enum ReturnCode {
*/
abstract public Cell getNextCellHint(final Cell currentCell) throws
IOException;
+ /**
+ * Provides a seek hint to bypass row-by-row scanning after {@link
#filterRowKey(Cell)} rejects a
+ * row. When {@code filterRowKey} returns {@code true} the scan pipeline
would normally iterate
+ * through every remaining cell in the rejected row one-by-one (via {@code
nextRow()}) before
+ * moving on. If the filter can determine a better forward position — for
example, the next range
+ * boundary in a {@code MultiRowRangeFilter} — it should return that target
cell here, allowing
+ * the scanner to seek directly past the unwanted rows.
+ * <p>
+ * Contract:
+ * <ul>
+ * <li>Only called after {@link #filterRowKey(Cell)} has returned {@code
true} for the same
+ * {@code firstRowCell}.</li>
+ * <li>Implementations may use state that was set during {@link
#filterRowKey(Cell)} (e.g. an
+ * updated range pointer), but <strong>must not</strong> invoke {@link
#filterCell(Cell)} logic —
+ * the caller guarantees that {@code filterCell} has not been called for
this row.</li>
+ * <li>The returned {@link Cell}, if non-null, must be an
+ * {@link org.apache.hadoop.hbase.ExtendedCell} because filters are
evaluated on the server
+ * side.</li>
+ * <li>Returning {@code null} (the default) falls through to the existing
{@code nextRow()}
+ * behaviour, preserving full backward compatibility.</li>
+ * <li>For reversed scans ({@link
org.apache.hadoop.hbase.client.Scan#isReversed()}), the hint
+ * must point to a <em>smaller</em> row key (earlier in reverse-scan
direction). The scanner
+ * validates hint direction and falls back to {@code nextRow()} if the hint
does not advance in
+ * the scan direction.</li>
+ * <li><strong>Composite filter limitation:</strong> {@code FilterList},
{@code SkipFilter}, and
+ * {@code WhileMatchFilter} do not currently delegate this method to wrapped
sub-filters. Hints
+ * from filters used inside these wrappers will be silently ignored.</li>
+ * </ul>
+ * @param firstRowCell the first cell encountered in the rejected row;
contains the row key that
+ * was passed to {@code filterRowKey}
+ * @return a {@link Cell} representing the earliest position the scanner
should seek to, or
+ * {@code null} if this filter cannot provide a better position than
a sequential skip
+ * @throws IOException in case an I/O or filter-specific failure needs to be
signaled
+ * @see #filterRowKey(Cell)
+ */
+ public Cell getHintForRejectedRow(final Cell firstRowCell) throws
IOException {
+ return null;
+ }
+
+ /**
+ * Provides a seek hint for cells that are structurally skipped by the scan
pipeline
+ * <em>before</em> {@link #filterCell(Cell)} is ever reached. The pipeline
short-circuits on
+ * several criteria — time-range mismatch, column-set exclusion, and
version-limit exhaustion —
+ * and in each case the filter is bypassed entirely. When an implementation
can compute a
+ * meaningful forward position purely from the cell's coordinates (without
needing the
+ * {@code filterCell} call sequence), it should return that position here so
the scanner can seek
+ * ahead instead of advancing one cell at a time.
+ * <p>
+ * Contract:
+ * <ul>
+ * <li>May be called for cells that have <strong>never</strong> been passed
to
+ * {@link #filterCell(Cell)}.</li>
+ * <li>Implementations <strong>must not</strong> modify any filter state;
this method is treated
+ * as logically stateless. Only filters whose hint computation is based
solely on immutable
+ * configuration (e.g. a fixed column range or a fuzzy-row pattern) should
override this.</li>
+ * <li>The returned {@link Cell}, if non-null, must be an
+ * {@link org.apache.hadoop.hbase.ExtendedCell} because filters are
evaluated on the server
Review Comment:
does this comment still apply ?
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