include/ndbapi/NdbIndexScanOperation.hpp

/*
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    All rights reserved. Use is subject to license terms.

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   it under the terms of the GNU General Public License, version 2.0,
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifndef NdbIndexScanOperation_H
#define NdbIndexScanOperation_H

#include "NdbScanOperation.hpp"

/**
 * @class NdbIndexScanOperation
 * @brief Class of scan operations for use to scan ordered index
 */
class NdbIndexScanOperation : public NdbScanOperation {
#ifndef DOXYGEN_SHOULD_SKIP_INTERNAL
  friend class Ndb;
  friend class NdbTransaction;
  friend class NdbResultSet;
  friend class NdbOperation;
  friend class NdbScanOperation;
  friend class NdbIndexStat;
#endif

public:
  /**
   * readTuples using ordered index
   * This method is used to specify details for an old Api Index Scan
   * operation.
   *
   * @param lock_mode Lock mode
   * @param scan_flags see @ref ScanFlag
   * @param parallel No of fragments to scan in parallel (0=max)
   */
  virtual int readTuples(LockMode lock_mode = LM_Read,
                         Uint32 scan_flags = 0,
			 Uint32 parallel = 0,
			 Uint32 batch = 0);

#ifndef DOXYGEN_SHOULD_SKIP_INTERNAL
  /**
   * readTuples using ordered index
   *
   * @param lock_mode Lock mode
   * @param batch     No of rows to fetch from each fragment at a time
   * @param parallel  No of fragments to scan in parallel
   * @param order_by  Order result set in index order
   * @param order_desc Order descending, ignored unless order_by
   * @param read_range_no Enable reading of range no using @ref get_range_no
   * @returns 0 for success and -1 for failure
   * @see NdbScanOperation::readTuples
   */
  inline int readTuples(LockMode lock_mode,
                        Uint32 batch,
                        Uint32 parallel,
                        bool order_by,
                        bool order_desc = false,
                        bool read_range_no = false,
			bool keyinfo = false,
			bool multi_range = false) {
    Uint32 scan_flags =
      (SF_OrderBy & -(Int32)order_by) |
      (SF_Descending & -(Int32)order_desc) |
      (SF_ReadRangeNo & -(Int32)read_range_no) |
      (SF_KeyInfo & -(Int32)keyinfo) |
      (SF_MultiRange & -(Int32)multi_range);

    return readTuples(lock_mode, scan_flags, parallel, batch);
  }
#endif

  /**
   * Type of ordered index key bound.  The values (0-4) will not change
   * and can be used explicitly (e.g. they could be computed).
   */
  enum BoundType {
    BoundLE = 0,        ///< lower bound
    BoundLT = 1,        ///< lower bound, strict
    BoundGE = 2,        ///< upper bound
    BoundGT = 3,        ///< upper bound, strict
    BoundEQ = 4         ///< equality
  };

  /* Maximum number of ranges that can be supplied to a single
   * NdbIndexScanOperation
   */
  enum {
    MaxRangeNo= 0xfff
  };

  /**
   * Define bound on index key in range scan - old Api.
   *
   * Each index key can have lower and/or upper bound.  Setting the key
   * equal to a value defines both upper and lower bounds.  The bounds
   * can be defined in any order.  Conflicting definitions is an error.
   *
   * For equality, it is better to use BoundEQ instead of the equivalent
   * pair of BoundLE and BoundGE.  This is especially true when table
   * partition key is an initial part of the index key.
   *
   * The sets of lower and upper bounds must be on initial sequences of
   * index keys.  All but possibly the last bound must be non-strict.
   * So "a >= 2 and b > 3" is ok but "a > 2 and b >= 3" is not.
   *
   * The scan may currently return tuples for which the bounds are not
   * satisfied.  For example, "a <= 2 and b <= 3" scans the index up to
   * (a=2, b=3) but also returns any (a=1, b=4).
   *
   * NULL is treated like a normal value which is less than any not-NULL
   * value and equal to another NULL value.  To compare against NULL use
   * setBound with null pointer (0).
   *
   * An index stores also all-NULL keys.  Doing index scan with empty
   * bound set returns all table tuples.
   *
   * @param attr        Attribute name, alternatively:
   * @param type        Type of bound
   * @param value       Pointer to bound value, 0 for NULL
   * @return            0 if successful otherwise -1
   *
   * @note See comment under equal() about data format and length.
   * @note See the two parameter setBound variant for use with NdbRecord
   */
#ifndef DOXYGEN_SHOULD_SKIP_DEPRECATED
  int setBound(const char* attr, int type, const void* value, Uint32 len);
#endif
  int setBound(const char* attr, int type, const void* value);

  /**
   * Define bound on index key in range scan using index column id.
   * See the other setBound() method for details.
   */
#ifndef DOXYGEN_SHOULD_SKIP_DEPRECATED
  int setBound(Uint32 anAttrId, int type, const void* aValue, Uint32 len);
#endif
  int setBound(Uint32 anAttrId, int type, const void* aValue);

  /**
   * This method is called to separate sets of bounds (ranges) when
   * defining an Index Scan with multiple ranges
   * It can only be used with scans defined using the SF_MultiRange
   * scan flag.
   * For NdbRecord, ranges are specified using the IndexBound structure
   * and the setBound() API.
   * If an index scan has more than one range then end_of_bound must be
   * called after every range, including the last.
   * If the SF_ReadRangeNo flag is set then the range_no supplied when
   * the range is defined will be associated with each row returned from
   * that range.  This can be obtained by calling get_range_no().
   * If SF_ReadRangeNo and SF_OrderBy flags are provided then range_no
   * values must be strictly increasing (i.e. starting at zero and
   * getting larger by 1 for each range specified).  This is to ensure
   * that rows are returned in order.
   */
  int end_of_bound(Uint32 range_no= 0);

  /**
   * Return range number for current row, as defined in the IndexBound
   * structure used when the scan was defined.
   * Only available if the SF_ReadRangeNo and SF_MultiRange flags were
   * set in the ScanOptions::scan_flags structure passed to scanIndex().
   */
  int get_range_no();

  /* Structure used to describe index scan bounds, for NdbRecord scans. */
  struct IndexBound {
    /* Row containing lower bound, or NULL for scan from the start. */
    const char *low_key;
    /* Number of columns in lower bound, for bounding by partial prefix. */
    Uint32 low_key_count;
    /* True for less-than-or-equal, false for strictly less-than. */
    bool low_inclusive;
    /* Row containing upper bound, or NULL for scan to the end. */
    const char * high_key;
    /* Number of columns in upper bound, for bounding by partial prefix. */
    Uint32 high_key_count;
    /* True for greater-than-or-equal, false for strictly greater-than. */
    bool high_inclusive;
    /*
      Value to identify this bound, may be read with get_range_no().
      Must be <= MaxRangeNo (set to zero if not using range_no).
      Note that for ordered scans, the range_no must be strictly increasing
      for each range, or the result set will not be sorted correctly.
    */
    Uint32 range_no;
  };

  /**
   * Add a range to an NdbRecord defined Index scan
   *
   * This method is called to add a range to an IndexScan operation
   * which has been defined with a call to NdbTransaction::scanIndex().
   * To add more than one range, the index scan operation must have been
   * defined with the the SF_MultiRange flag set.
   *
   * Where multiple numbered ranges are defined with multiple calls to
   * setBound, and the scan is ordered, the range number for each range
   * must be larger than the range number for the previously defined range.
   *
   * When the application knows that rows in-range will only be found in
   * a particular partition, a PartitionSpecification can be supplied.
   * This may be used to limit the scan to a single partition, improving
   * system efficiency
   * The sizeOfPartInfo parameter should be set to the
   * sizeof(PartitionSpec) to enable backwards compatibility.
   *
   * @param key_record NdbRecord structure for the key the index is
   *        defined on
   * @param bound The bound to add
   * @param partInfo Extra information to enable a reduced set of
   *        partitions to be scanned.
   * @param sizeOfPartInfo
   *
   * @return 0 for Success, other for Failure.
   */
  int setBound(const NdbRecord *key_record,
               const IndexBound& bound);
  int setBound(const NdbRecord *key_record,
               const IndexBound& bound,
               const Ndb::PartitionSpec* partInfo,
               Uint32 sizeOfPartInfo= 0);

  /**
   * Return size of data, in 32-bit words, that will be send to data nodes for
   * all bounds added so far with setBound().
   *
   * This method is only available for NdbRecord index scans.
   */
  int getCurrentKeySize();

  /**
   * Is current scan sorted?
   */
  bool getSorted() const { return m_ordered; }

  /**
   * Is current scan sorted descending?
   */
  bool getDescending() const { return m_descending; }

private:
  NdbIndexScanOperation(Ndb* aNdb);
  virtual ~NdbIndexScanOperation();

  int processIndexScanDefs(LockMode lm,
                           Uint32 scan_flags,
                           Uint32 parallel,
                           Uint32 batch);
  int scanIndexImpl(const NdbRecord *key_record,
                    const NdbRecord *result_record,
                    NdbOperation::LockMode lock_mode,
                    const unsigned char *result_mask,
                    const NdbIndexScanOperation::IndexBound *bound,
                    const NdbScanOperation::ScanOptions *options,
                    Uint32 sizeOfOptions);

  /* Structure used to collect information about an IndexBound
   * as it is provided by the old Api setBound() calls
   */
public:
  struct OldApiBoundInfo
  {
    Uint32 highestKey;
    bool highestSoFarIsStrict;
    Uint32 keysPresentBitmap;
    char* key;
  };

private:
  struct OldApiScanRangeDefinition
  {
    /* OldApiBoundInfo used during definition
     * IndexBound used once bound defined
     * Todo : For heavy old Api use, consider splitting
     * to allow NdbRecAttr use without malloc
     */
    union {
      struct {
        OldApiBoundInfo lowBound;
        OldApiBoundInfo highBound;
      } oldBound;

      IndexBound ib;
    };
    /* Space for key bounds
     *   Low bound from offset 0
     *   High bound from offset key_record->m_row_size
     */
    char space[1];
  };

  int setBoundHelperOldApi(OldApiBoundInfo& boundInfo,
                           Uint32 maxKeyRecordBytes,
                           Uint32 index_attrId,
                           Uint32 valueLen,
                           bool inclusive,
                           Uint32 byteOffset,
                           Uint32 nullbit_byte_offset,
                           Uint32 nullbit_bit_in_byte,
                           const void *aValue);

  int setBound(const NdbColumnImpl*, int type, const void* aValue);
  int buildIndexBoundOldApi(int range_no);
  const IndexBound* getIndexBoundFromRecAttr(NdbRecAttr* recAttr);
  void releaseIndexBoundsOldApi();
  int ndbrecord_insert_bound(const NdbRecord *key_record,
                             Uint32 column_index,
                             const char *row,
                             Uint32 bound_type,
                             Uint32*& firstWordOfBound);
  int insert_open_bound(const NdbRecord* key_record,
                        Uint32*& firstWordOfBound);

  virtual int equal_impl(const NdbColumnImpl*, const char*);
  virtual NdbRecAttr* getValue_impl(const NdbColumnImpl*, char*);

  int getDistKeyFromRange(const NdbRecord* key_record,
                          const NdbRecord* result_record,
                          const char* row,
                          Uint32* distKey);
  void fix_get_values();
  int next_result_ordered(bool fetchAllowed, bool forceSend = false);
  int next_result_ordered_ndbrecord(const char * & out_row,
                                    bool fetchAllowed,
                                    bool forceSend);
  void ordered_insert_receiver(Uint32 start, NdbReceiver *receiver);
  int ordered_send_scan_wait_for_all(bool forceSend);
  int send_next_scan_ordered(Uint32 idx);
  int compare(Uint32 key, Uint32 cols, const NdbReceiver*, const NdbReceiver*);
  Uint32 m_sort_columns;

  /* Number of IndexBounds for this scan (NdbRecord only) */
  Uint32 m_num_bounds;
  /* Most recently added IndexBound's range number */
  Uint32 m_previous_range_num;

  /* Old Scan API range information
   * List of RecAttr structures containing OldApiScanRangeDefinition
   * structures
   * currentRangeOldApi is range currently being defined (if any)
   * Once defined (end_of_bound() / execute()) they are added to
   * the list between first/lastRangeOldApi
   */
  NdbRecAttr* firstRangeOldApi;
  NdbRecAttr* lastRangeOldApi;
  NdbRecAttr* currentRangeOldApi;

  friend struct Ndb_free_list_t<NdbIndexScanOperation>;

private:
  NdbIndexScanOperation(const NdbIndexScanOperation&); // Not impl.
  NdbIndexScanOperation&operator=(const NdbIndexScanOperation&);
};

inline
int
NdbIndexScanOperation::setBound(const char* attr, int type, const void* value,
                                Uint32 len)
{
  (void)len;  // unused
  return setBound(attr, type, value);
}

inline
int
NdbIndexScanOperation::setBound(Uint32 anAttrId, int type, const void* value,
                                Uint32 len)
{
  (void)len;  // unused
  return setBound(anAttrId, type, value);
}

/**
 *   Compare keys of  the current records of two NdbReceiver objects.
 * @param r1 holds the first record to compare.
 * @param r2 holds the second record to compare.
 * @param key_record specifies the keys to compare.
 * @param result_record specifies the format of full records.
 * @param descending if true, descending sort order is to be used.
 * @param read_range_no if true, range numbers will first be compared, and then keys if range numbers are the same for both records.
 * @return -1 if r1<r2, 0 if r1=r2, 1 if r1> r2 (reversed when using 'descending').
 **/
int compare_ndbrecord(const NdbReceiver *r1,
                      const NdbReceiver *r2,
                      const NdbRecord *key_record,
                      const NdbRecord *result_record,
                      bool descending,
                      bool read_range_no);
#endif