spgist.h

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/*-------------------------------------------------------------------------
 *
 * spgist.h
 *    Public header file for SP-GiST access method.
 *
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/access/spgist.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef SPGIST_H
#define SPGIST_H

#include "access/amapi.h"
#include "access/xlogreader.h"
#include "lib/stringinfo.h"


/* SPGiST opclass support function numbers */
#define SPGIST_CONFIG_PROC              1
#define SPGIST_CHOOSE_PROC              2
#define SPGIST_PICKSPLIT_PROC           3
#define SPGIST_INNER_CONSISTENT_PROC    4
#define SPGIST_LEAF_CONSISTENT_PROC     5
#define SPGIST_COMPRESS_PROC            6
#define SPGISTNRequiredProc             5
#define SPGISTNProc                     6

/*
 * Argument structs for spg_config method
 */
typedef struct spgConfigIn
{
    Oid         attType;        /* Data type to be indexed */
} spgConfigIn;

typedef struct spgConfigOut
{
    Oid         prefixType;     /* Data type of inner-tuple prefixes */
    Oid         labelType;      /* Data type of inner-tuple node labels */
    Oid         leafType;       /* Data type of leaf-tuple values */
    bool        canReturnData;  /* Opclass can reconstruct original data */
    bool        longValuesOK;   /* Opclass can cope with values > 1 page */
} spgConfigOut;

/*
 * Argument structs for spg_choose method
 */
typedef struct spgChooseIn
{
    Datum       datum;          /* original datum to be indexed */
    Datum       leafDatum;      /* current datum to be stored at leaf */
    int         level;          /* current level (counting from zero) */

    /* Data from current inner tuple */
    bool        allTheSame;     /* tuple is marked all-the-same? */
    bool        hasPrefix;      /* tuple has a prefix? */
    Datum       prefixDatum;    /* if so, the prefix value */
    int         nNodes;         /* number of nodes in the inner tuple */
    Datum      *nodeLabels;     /* node label values (NULL if none) */
} spgChooseIn;

typedef enum spgChooseResultType
{
    spgMatchNode = 1,           /* descend into existing node */
    spgAddNode,                 /* add a node to the inner tuple */
    spgSplitTuple               /* split inner tuple (change its prefix) */
} spgChooseResultType;

typedef struct spgChooseOut
{
    spgChooseResultType resultType; /* action code, see above */
    union
    {
        struct                  /* results for spgMatchNode */
        {
            int         nodeN;  /* descend to this node (index from 0) */
            int         levelAdd;   /* increment level by this much */
            Datum       restDatum;  /* new leaf datum */
        }           matchNode;
        struct                  /* results for spgAddNode */
        {
            Datum       nodeLabel;  /* new node's label */
            int         nodeN;  /* where to insert it (index from 0) */
        }           addNode;
        struct                  /* results for spgSplitTuple */
        {
            /* Info to form new upper-level inner tuple with one child tuple */
            bool        prefixHasPrefix;    /* tuple should have a prefix? */
            Datum       prefixPrefixDatum;  /* if so, its value */
            int         prefixNNodes;   /* number of nodes */
            Datum      *prefixNodeLabels;   /* their labels (or NULL for no
                                             * labels) */
            int         childNodeN; /* which node gets child tuple */

            /* Info to form new lower-level inner tuple with all old nodes */
            bool        postfixHasPrefix;   /* tuple should have a prefix? */
            Datum       postfixPrefixDatum; /* if so, its value */
        }           splitTuple;
    }           result;
} spgChooseOut;

/*
 * Argument structs for spg_picksplit method
 */
typedef struct spgPickSplitIn
{
    int         nTuples;        /* number of leaf tuples */
    Datum      *datums;         /* their datums (array of length nTuples) */
    int         level;          /* current level (counting from zero) */
} spgPickSplitIn;

typedef struct spgPickSplitOut
{
    bool        hasPrefix;      /* new inner tuple should have a prefix? */
    Datum       prefixDatum;    /* if so, its value */

    int         nNodes;         /* number of nodes for new inner tuple */
    Datum      *nodeLabels;     /* their labels (or NULL for no labels) */

    int        *mapTuplesToNodes;   /* node index for each leaf tuple */
    Datum      *leafTupleDatums;    /* datum to store in each new leaf tuple */
} spgPickSplitOut;

/*
 * Argument structs for spg_inner_consistent method
 */
typedef struct spgInnerConsistentIn
{
    ScanKey     scankeys;       /* array of operators and comparison values */
    ScanKey     orderbys;       /* array of ordering operators and comparison
                                 * values */
    int         nkeys;          /* length of scankeys array */
    int         norderbys;      /* length of orderbys array */

    Datum       reconstructedValue; /* value reconstructed at parent */
    void       *traversalValue; /* opclass-specific traverse value */
    MemoryContext traversalMemoryContext;   /* put new traverse values here */
    int         level;          /* current level (counting from zero) */
    bool        returnData;     /* original data must be returned? */

    /* Data from current inner tuple */
    bool        allTheSame;     /* tuple is marked all-the-same? */
    bool        hasPrefix;      /* tuple has a prefix? */
    Datum       prefixDatum;    /* if so, the prefix value */
    int         nNodes;         /* number of nodes in the inner tuple */
    Datum      *nodeLabels;     /* node label values (NULL if none) */
} spgInnerConsistentIn;

typedef struct spgInnerConsistentOut
{
    int         nNodes;         /* number of child nodes to be visited */
    int        *nodeNumbers;    /* their indexes in the node array */
    int        *levelAdds;      /* increment level by this much for each */
    Datum      *reconstructedValues;    /* associated reconstructed values */
    void      **traversalValues;    /* opclass-specific traverse values */
    double    **distances;      /* associated distances */
} spgInnerConsistentOut;

/*
 * Argument structs for spg_leaf_consistent method
 */
typedef struct spgLeafConsistentIn
{
    ScanKey     scankeys;       /* array of operators and comparison values */
    ScanKey     orderbys;       /* array of ordering operators and comparison
                                 * values */
    int         nkeys;          /* length of scankeys array */
    int         norderbys;      /* length of orderbys array */

    Datum       reconstructedValue; /* value reconstructed at parent */
    void       *traversalValue; /* opclass-specific traverse value */
    int         level;          /* current level (counting from zero) */
    bool        returnData;     /* original data must be returned? */

    Datum       leafDatum;      /* datum in leaf tuple */
} spgLeafConsistentIn;

typedef struct spgLeafConsistentOut
{
    Datum       leafValue;      /* reconstructed original data, if any */
    bool        recheck;        /* set true if operator must be rechecked */
    bool        recheckDistances;   /* set true if distances must be rechecked */
    double     *distances;      /* associated distances */
} spgLeafConsistentOut;


/* spgutils.c */
extern bytea *spgoptions(Datum reloptions, bool validate);

/* spginsert.c */
extern IndexBuildResult *spgbuild(Relation heap, Relation index,
                                  struct IndexInfo *indexInfo);
extern void spgbuildempty(Relation index);
extern bool spginsert(Relation index, Datum *values, bool *isnull,
                      ItemPointer ht_ctid, Relation heapRel,
                      IndexUniqueCheck checkUnique,
                      struct IndexInfo *indexInfo);

/* spgscan.c */
extern IndexScanDesc spgbeginscan(Relation rel, int keysz, int orderbysz);
extern void spgendscan(IndexScanDesc scan);
extern void spgrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
                      ScanKey orderbys, int norderbys);
extern int64 spggetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
extern bool spggettuple(IndexScanDesc scan, ScanDirection dir);
extern bool spgcanreturn(Relation index, int attno);

/* spgvacuum.c */
extern IndexBulkDeleteResult *spgbulkdelete(IndexVacuumInfo *info,
                                            IndexBulkDeleteResult *stats,
                                            IndexBulkDeleteCallback callback,
                                            void *callback_state);
extern IndexBulkDeleteResult *spgvacuumcleanup(IndexVacuumInfo *info,
                                               IndexBulkDeleteResult *stats);

/* spgvalidate.c */
extern bool spgvalidate(Oid opclassoid);

#endif                          /* SPGIST_H */