Package org.apache.hadoop.hbase.filter

Class SkipFilter

java.lang.Object
org.apache.hadoop.hbase.filter.Filter
org.apache.hadoop.hbase.filter.FilterBase
org.apache.hadoop.hbase.filter.SkipFilter
@Public public class SkipFilter extends FilterBase
A wrapper filter that filters an entire row if any of the Cell checks do not pass.

For example, if all columns in a row represent weights of different things, with the values being the actual weights, and we want to filter out the entire row if any of its weights are zero. In this case, we want to prevent rows from being emitted if a single key is filtered. Combine this filter with a ValueFilter:

scan.setFilter(new SkipFilter(new ValueFilter(CompareOp.NOT_EQUAL, new BinaryComparator(Bytes.toBytes(0)))); Any row which contained a column whose value was 0 will be filtered out (since ValueFilter will not pass that Cell). Without this filter, the other non-zero valued columns in the row would still be emitted.

  • Field Details

  • Constructor Details

  • Method Details

    • getFilter

      public Filter getFilter()

    • reset

      public void reset() throws IOException
      Description copied from class: FilterBase
      Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation. Reset the state of the filter between rows. Concrete implementers can signal a failure condition in their code by throwing an IOException.
      Overrides:
      reset in class FilterBase
      Throws:
      IOException - in case an I/O or an filter specific failure needs to be signaled.

    • changeFR

      private void changeFR(boolean value)

    • filterRowKey

      public boolean filterRowKey(Cell cell) throws IOException
      Description copied from class: Filter
      Filters a row based on the row key. If this returns true, the entire row will be excluded. If false, each KeyValue in the row will be passed to Filter.filterCell(Cell) below. If Filter.filterAllRemaining() returns true, then Filter.filterRowKey(Cell) should also return true. Concrete implementers can signal a failure condition in their code by throwing an IOException.
      Overrides:
      filterRowKey in class FilterBase
      Parameters:
      cell - The first cell coming in the new row
      Returns:
      true, remove entire row, false, include the row (maybe).
      Throws:
      IOException - in case an I/O or an filter specific failure needs to be signaled.

    • filterCell

      public Filter.ReturnCode filterCell(Cell c) throws IOException
      Description copied from class: Filter
      A way to filter based on the column family, column qualifier and/or the column value. Return code is described below. This allows filters to filter only certain number of columns, then terminate without matching ever column. If filterRowKey returns true, filterCell needs to be consistent with it. filterCell can assume that filterRowKey has already been called for the row. If your filter returns ReturnCode.NEXT_ROW, it should return ReturnCode.NEXT_ROW until Filter.reset() is called just in case the caller calls for the next row. Concrete implementers can signal a failure condition in their code by throwing an IOException.
      Overrides:
      filterCell in class Filter
      Parameters:
      c - the Cell in question
      Returns:
      code as described below
      Throws:
      IOException - in case an I/O or an filter specific failure needs to be signaled.
      See Also:

    • transformCell

      public Cell transformCell(Cell v) throws IOException
      Description copied from class: FilterBase
      By default no transformation takes place Give the filter a chance to transform the passed Cell. If the Cell is changed a new Cell object must be returned.

      NOTICE: Filter will be evaluate at server side so the returned Cell must be an ExtendedCell, although it is marked as IA.Private.

      Overrides:
      transformCell in class FilterBase
      Parameters:
      v - the Cell in question
      Returns:
      the changed Cell
      Throws:
      IOException - in case an I/O or an filter specific failure needs to be signaled.
      See Also:

    • filterRow

      public boolean filterRow()
      Description copied from class: FilterBase
      Filters that never filter by rows based on previously gathered state from Filter.filterCell(Cell) can inherit this implementation that never filters a row. Last chance to veto row based on previous Filter.filterCell(Cell) calls. The filter needs to retain state then return a particular value for this call if they wish to exclude a row if a certain column is missing (for example). Concrete implementers can signal a failure condition in their code by throwing an IOException.
      Overrides:
      filterRow in class FilterBase
      Returns:
      true to exclude row, false to include row.

    • hasFilterRow

      public boolean hasFilterRow()
      Description copied from class: FilterBase
      Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing. Primarily used to check for conflicts with scans(such as scans that do not read a full row at a time).
      Overrides:
      hasFilterRow in class FilterBase
      Returns:
      True if this filter actively uses filterRowCells(List) or filterRow().

    • toByteArray

      public byte[] toByteArray() throws IOException
      Returns The filter serialized using pb
      Overrides:
      toByteArray in class FilterBase
      Returns:
      The filter serialized using pb
      Throws:
      IOException - in case an I/O or an filter specific failure needs to be signaled.

    • parseFrom

      public static SkipFilter parseFrom(byte[] pbBytes) throws DeserializationException
      Parse a serialized representation of SkipFilter
      Parameters:
      pbBytes - A pb serialized SkipFilter instance
      Returns:
      An instance of SkipFilter made from bytes
      Throws:
      DeserializationException - if an error occurred
      See Also:

    • areSerializedFieldsEqual

      boolean areSerializedFieldsEqual(Filter o)
      Returns true if and only if the fields of the filter that are serialized are equal to the corresponding fields in other. Used for testing.
      Overrides:
      areSerializedFieldsEqual in class FilterBase
      Returns:
      true if and only if the fields of the filter that are serialized are equal to the corresponding fields in other. Used for testing.

    • getHintForRejectedRow

      public Cell getHintForRejectedRow(Cell firstRowCell) throws IOException
      Description copied from class: FilterBase
      Filters that cannot provide a seek hint after row-key rejection can inherit this no-op implementation. Subclasses whose row-key logic (e.g. a range pointer advanced inside FilterBase.filterRowKey(Cell)) makes a better seek target available should override this. Provides a seek hint to bypass row-by-row scanning after Filter.filterRowKey(Cell) rejects a row. When filterRowKey returns true the scan pipeline would normally iterate through every remaining cell in the rejected row one-by-one (via nextRow()) before moving on. If the filter can determine a better forward position — for example, the next range boundary in a MultiRowRangeFilter — it should return that target cell here, allowing the scanner to seek directly past the unwanted rows.

      Contract:

      • Only called after Filter.filterRowKey(Cell) has returned true for the same firstRowCell.
      • Implementations may use state that was set during Filter.filterRowKey(Cell) (e.g. an updated range pointer), but must not invoke Filter.filterCell(Cell) logic — the caller guarantees that filterCell has not been called for this row.
      • The returned Cell, if non-null, must be an ExtendedCell because filters are evaluated on the server side.
      • Returning null (the default) falls through to the existing nextRow() behaviour, preserving full backward compatibility.
      • For reversed scans (Scan.isReversed()), the hint must point to a smaller row key (earlier in reverse-scan direction). The scanner validates hint direction and falls back to nextRow() if the hint does not advance in the scan direction.
      • Composite filter support: FilterList (both MUST_PASS_ALL and MUST_PASS_ONE), SkipFilter, and WhileMatchFilter delegate this method to their sub-filters and merge the results. For AND (MUST_PASS_ALL), only sub-filters whose filterRowKey individually returned true are consulted, and the farthest (maximal-step) hint among them is returned. For OR (MUST_PASS_ONE), the nearest hint is returned only when every non-terminated sub-filter provides one — any null collapses the OR result to null.
      Overrides:
      getHintForRejectedRow in class FilterBase
      Parameters:
      firstRowCell - the first cell encountered in the rejected row; contains the row key that was passed to filterRowKey
      Returns:
      a Cell representing the earliest position the scanner should seek to, or 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 Also:

    • getSkipHint

      public Cell getSkipHint(Cell skippedCell) throws IOException
      Description copied from class: FilterBase
      Filters that cannot provide a structural-skip seek hint can inherit this no-op implementation. Subclasses with purely configuration-driven, stateless hint computation (e.g. a fixed column range or fuzzy-row pattern) may override this to avoid cell-by-cell advancement when the time-range, column, or version gate fires. Provides a seek hint for cells that are structurally skipped by the scan pipeline before Filter.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 filterCell call sequence), it should return that position here so the scanner can seek ahead instead of advancing one cell at a time.

      Contract:

      • May be called for cells that have never been passed to Filter.filterCell(Cell).
      • Implementations must not 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.
      • The returned Cell, if non-null, must be an ExtendedCell because filters are evaluated on the server side.
      • Returning null (the default) falls through to the existing structural skip/seek behaviour, preserving full backward compatibility.
      • For reversed scans, the returned cell must have a smaller row key (i.e., earlier in reverse-scan direction) than the skippedCell. Hints that do not advance in the scan direction are silently ignored.
      • Composite filter support: FilterList (both MUST_PASS_ALL and MUST_PASS_ONE), SkipFilter, and WhileMatchFilter delegate this method to their sub-filters and merge the results (maximal step for AND; for OR, the nearest hint is returned only when every non-terminated sub-filter provides one — any null collapses the OR result to null).
      Overrides:
      getSkipHint in class FilterBase
      Parameters:
      skippedCell - the cell that was rejected by the time-range, column, or version gate before filterCell could be consulted
      Returns:
      a Cell representing the earliest position the scanner should seek to, or null if this filter cannot provide a better position than the structural hint
      Throws:
      IOException - in case an I/O or filter-specific failure needs to be signaled
      See Also:

    • isFamilyEssential

      public boolean isFamilyEssential(byte[] name) throws IOException
      Description copied from class: FilterBase
      By default, we require all scan's column families to be present. Our subclasses may be more precise. Check that given column family is essential for filter to check row. Most filters always return true here. But some could have more sophisticated logic which could significantly reduce scanning process by not even touching columns until we are 100% sure that it's data is needed in result. Concrete implementers can signal a failure condition in their code by throwing an IOException.
      Overrides:
      isFamilyEssential in class FilterBase
      Throws:
      IOException - in case an I/O or an filter specific failure needs to be signaled.

    • toString

      public String toString()
      Description copied from class: FilterBase
      Return filter's info for debugging and logging purpose.
      Overrides:
      toString in class FilterBase

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object