/*-------------------------------------------------------------------------
 *
 * partbounds.h
 *
 * Copyright (c) 2007-2018, PostgreSQL Global Development Group
 *
 * src/include/partitioning/partbounds.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PARTBOUNDS_H
#define PARTBOUNDS_H

#include "fmgr.h"
#include "nodes/parsenodes.h"
#include "nodes/pg_list.h"
#include "partitioning/partdefs.h"
#include "utils/relcache.h"


/*
 * PartitionBoundInfoData encapsulates a set of partition bounds. It is
 * usually associated with partitioned tables as part of its partition
 * descriptor, but may also be used to represent a virtual partitioned
 * table such as a partitioned joinrel within the planner.
 *
 * A list partition datum that is known to be NULL is never put into the
 * datums array. Instead, it is tracked using the null_index field.
 *
 * In the case of range partitioning, ndatums will typically be far less than
 * 2 * nparts, because a partition's upper bound and the next partition's lower
 * bound are the same in most common cases, and we only store one of them (the
 * upper bound).  In case of hash partitioning, ndatums will be the same as the
 * number of partitions.
 *
 * For range and list partitioned tables, datums is an array of datum-tuples
 * with key->partnatts datums each.  For hash partitioned tables, it is an array
 * of datum-tuples with 2 datums, modulus and remainder, corresponding to a
 * given partition.
 *
 * The datums in datums array are arranged in increasing order as defined by
 * functions qsort_partition_rbound_cmp(), qsort_partition_list_value_cmp() and
 * qsort_partition_hbound_cmp() for range, list and hash partitioned tables
 * respectively. For range and list partitions this simply means that the
 * datums in the datums array are arranged in increasing order as defined by
 * the partition key's operator classes and collations.
 *
 * In the case of list partitioning, the indexes array stores one entry for
 * each datum-array entry, which is the index of the partition that accepts
 * rows matching that datum.  So nindexes == ndatums.
 *
 * In the case of range partitioning, the indexes array stores one entry per
 * distinct range datum, which is the index of the partition for which that
 * datum is an upper bound (or -1 for a "gap" that has no partition).  It is
 * convenient to have an extra -1 entry representing values above the last
 * range datum, so nindexes == ndatums + 1.
 *
 * In the case of hash partitioning, the number of entries in the indexes
 * array is the same as the greatest modulus amongst all partitions (which
 * is a multiple of all partition moduli), so nindexes == greatest modulus.
 * The indexes array is indexed according to the hash key's remainder modulo
 * the greatest modulus, and it contains either the partition index accepting
 * that remainder, or -1 if there is no partition for that remainder.
 */
typedef struct PartitionBoundInfoData
{
	char		strategy;		/* hash, list or range? */
	int			ndatums;		/* Length of the datums[] array */
	Datum	  **datums;
	PartitionRangeDatumKind **kind; /* The kind of each range bound datum;
									 * NULL for hash and list partitioned
									 * tables */
	int		   *indexes;		/* Partition indexes */
	int			null_index;		/* Index of the null-accepting partition; -1
								 * if there isn't one */
	int			default_index;	/* Index of the default partition; -1 if there
								 * isn't one */
	int			nindexes;		/* Length of the indexes[] array */
} PartitionBoundInfoData;

#define partition_bound_accepts_nulls(bi) ((bi)->null_index != -1)
#define partition_bound_has_default(bi) ((bi)->default_index != -1)

/*
 * When qsort'ing partition bounds after reading from the catalog, each bound
 * is represented with one of the following structs.
 */

/* One bound of a hash partition */
typedef struct PartitionHashBound
{
	int			modulus;
	int			remainder;
	int			index;
} PartitionHashBound;

/* One value coming from some (index'th) list partition */
typedef struct PartitionListValue
{
	int			index;
	Datum		value;
} PartitionListValue;

/* One bound of a range partition */
typedef struct PartitionRangeBound
{
	int			index;
	Datum	   *datums;			/* range bound datums */
	PartitionRangeDatumKind *kind;	/* the kind of each datum */
	bool		lower;			/* this is the lower (vs upper) bound */
} PartitionRangeBound;

extern int	get_hash_partition_greatest_modulus(PartitionBoundInfo b);
extern uint64 compute_partition_hash_value(int partnatts, FmgrInfo *partsupfunc,
							 Datum *values, bool *isnull);
extern List *get_qual_from_partbound(Relation rel, Relation parent,
						PartitionBoundSpec *spec);
extern bool partition_bounds_equal(int partnatts, int16 *parttyplen,
					   bool *parttypbyval, PartitionBoundInfo b1,
					   PartitionBoundInfo b2);
extern PartitionBoundInfo partition_bounds_copy(PartitionBoundInfo src,
					  PartitionKey key);
extern void check_new_partition_bound(char *relname, Relation parent,
						  PartitionBoundSpec *spec);
extern void check_default_partition_contents(Relation parent,
								 Relation defaultRel,
								 PartitionBoundSpec *new_spec);

extern PartitionRangeBound *make_one_partition_rbound(PartitionKey key, int index,
						  List *datums, bool lower);
extern int32 partition_hbound_cmp(int modulus1, int remainder1, int modulus2,
					 int remainder2);
extern int32 partition_rbound_cmp(int partnatts, FmgrInfo *partsupfunc,
					 Oid *partcollation, Datum *datums1,
					 PartitionRangeDatumKind *kind1, bool lower1,
					 PartitionRangeBound *b2);
extern int32 partition_rbound_datum_cmp(FmgrInfo *partsupfunc,
						   Oid *partcollation,
						   Datum *rb_datums, PartitionRangeDatumKind *rb_kind,
						   Datum *tuple_datums, int n_tuple_datums);
extern int partition_list_bsearch(FmgrInfo *partsupfunc,
					   Oid *partcollation,
					   PartitionBoundInfo boundinfo,
					   Datum value, bool *is_equal);
extern int partition_range_bsearch(int partnatts, FmgrInfo *partsupfunc,
						Oid *partcollation,
						PartitionBoundInfo boundinfo,
						PartitionRangeBound *probe, bool *is_equal);
extern int partition_range_datum_bsearch(FmgrInfo *partsupfunc,
							  Oid *partcollation,
							  PartitionBoundInfo boundinfo,
							  int nvalues, Datum *values, bool *is_equal);
extern int partition_hash_bsearch(PartitionBoundInfo boundinfo,
					   int modulus, int remainder);

#endif							/* PARTBOUNDS_H */