ltree.h

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/* contrib/ltree/ltree.h */

#ifndef __LTREE_H__
#define __LTREE_H__

#include "fmgr.h"
#include "tsearch/ts_locale.h"
#include "utils/memutils.h"


/* ltree */

/*
 * We want the maximum length of a label to be encoding-independent, so
 * set it somewhat arbitrarily at 255 characters (not bytes), while using
 * uint16 fields to hold the byte length.
 */
#define LTREE_LABEL_MAX_CHARS 255

/*
 * LOWER_NODE used to be defined in the Makefile via the compile flags.
 * However the MSVC build scripts neglected to do the same which resulted in
 * MSVC builds not using LOWER_NODE.  Since then, the MSVC scripts have been
 * modified to look for -D compile flags in Makefiles, so here, in order to
 * get the historic behavior of LOWER_NODE not being defined on MSVC, we only
 * define it when not building in that environment.  This is important as we
 * want to maintain the same LOWER_NODE behavior after a pg_update.
 */
#ifndef _MSC_VER
#define LOWER_NODE
#endif

typedef struct
{
    uint16      len;            /* label string length in bytes */
    char        name[FLEXIBLE_ARRAY_MEMBER];
} ltree_level;

#define LEVEL_HDRSIZE   (offsetof(ltree_level,name))
#define LEVEL_NEXT(x)   ( (ltree_level*)( ((char*)(x)) + MAXALIGN(((ltree_level*)(x))->len + LEVEL_HDRSIZE) ) )

typedef struct
{
    int32       vl_len_;        /* varlena header (do not touch directly!) */
    uint16      numlevel;       /* number of labels */
    /* Array of maxalign'd ltree_level structs follows: */
    char        data[FLEXIBLE_ARRAY_MEMBER];
} ltree;

#define LTREE_HDRSIZE   MAXALIGN( offsetof(ltree, data) )
#define LTREE_FIRST(x)  ( (ltree_level*)( ((char*)(x))+LTREE_HDRSIZE ) )
#define LTREE_MAX_LEVELS    PG_UINT16_MAX   /* ltree.numlevel is uint16 */


/* lquery */

/* lquery_variant: one branch of some OR'ed alternatives */
typedef struct
{
    int32       val;            /* CRC of label string */
    uint16      len;            /* label string length in bytes */
    uint8       flag;           /* see LVAR_xxx flags below */
    char        name[FLEXIBLE_ARRAY_MEMBER];
} lquery_variant;

/*
 * Note: these macros contain too many MAXALIGN calls and so will sometimes
 * overestimate the space needed for an lquery_variant.  However, we can't
 * change it without breaking on-disk compatibility for lquery.
 */
#define LVAR_HDRSIZE   MAXALIGN(offsetof(lquery_variant, name))
#define LVAR_NEXT(x)    ( (lquery_variant*)( ((char*)(x)) + MAXALIGN(((lquery_variant*)(x))->len) + LVAR_HDRSIZE ) )

#define LVAR_ANYEND 0x01        /* '*' flag: prefix match */
#define LVAR_INCASE 0x02        /* '@' flag: case-insensitive match */
#define LVAR_SUBLEXEME  0x04    /* '%' flag: word-wise match */

/*
 * In an lquery_level, "flag" contains the union of the variants' flags
 * along with possible LQL_xxx flags; so those bit sets can't overlap.
 *
 * "low" and "high" are nominally the minimum and maximum number of matches.
 * However, for backwards compatibility with pre-v13 on-disk lqueries,
 * non-'*' levels (those with numvar > 0) only have valid low/high if the
 * LQL_COUNT flag is set; otherwise those fields are zero, but the behavior
 * is as if they were both 1.
 */
typedef struct
{
    uint16      totallen;       /* total length of this level, in bytes */
    uint16      flag;           /* see LQL_xxx and LVAR_xxx flags */
    uint16      numvar;         /* number of variants; 0 means '*' */
    uint16      low;            /* minimum repeat count */
    uint16      high;           /* maximum repeat count */
    /* Array of maxalign'd lquery_variant structs follows: */
    char        variants[FLEXIBLE_ARRAY_MEMBER];
} lquery_level;

#define LQL_HDRSIZE MAXALIGN( offsetof(lquery_level,variants) )
#define LQL_NEXT(x) ( (lquery_level*)( ((char*)(x)) + MAXALIGN(((lquery_level*)(x))->totallen) ) )
#define LQL_FIRST(x)    ( (lquery_variant*)( ((char*)(x))+LQL_HDRSIZE ) )

#define LQL_NOT     0x10        /* level has '!' (NOT) prefix */
#define LQL_COUNT   0x20        /* level is non-'*' and has repeat counts */

#ifdef LOWER_NODE
#define FLG_CANLOOKSIGN(x) ( ( (x) & ( LQL_NOT | LVAR_ANYEND | LVAR_SUBLEXEME ) ) == 0 )
#else
#define FLG_CANLOOKSIGN(x) ( ( (x) & ( LQL_NOT | LVAR_ANYEND | LVAR_SUBLEXEME | LVAR_INCASE ) ) == 0 )
#endif
#define LQL_CANLOOKSIGN(x) FLG_CANLOOKSIGN( ((lquery_level*)(x))->flag )

typedef struct
{
    int32       vl_len_;        /* varlena header (do not touch directly!) */
    uint16      numlevel;       /* number of lquery_levels */
    uint16      firstgood;      /* number of leading simple-match levels */
    uint16      flag;           /* see LQUERY_xxx flags below */
    /* Array of maxalign'd lquery_level structs follows: */
    char        data[FLEXIBLE_ARRAY_MEMBER];
} lquery;

#define LQUERY_HDRSIZE   MAXALIGN( offsetof(lquery, data) )
#define LQUERY_FIRST(x)   ( (lquery_level*)( ((char*)(x))+LQUERY_HDRSIZE ) )
#define LQUERY_MAX_LEVELS   PG_UINT16_MAX   /* lquery.numlevel is uint16 */

#define LQUERY_HASNOT       0x01

#define ISALNUM(x)  ( t_isalpha(x) || t_isdigit(x)  || ( pg_mblen(x) == 1 && t_iseq((x), '_') ) )

/* full text query */

/*
 * item in polish notation with back link
 * to left operand
 */
typedef struct ITEM
{
    int16       type;
    int16       left;
    int32       val;
    uint8       flag;
    /* user-friendly value */
    uint8       length;
    uint16      distance;
} ITEM;

/*
 *Storage:
 *      (len)(size)(array of ITEM)(array of operand in user-friendly form)
 */
typedef struct
{
    int32       vl_len_;        /* varlena header (do not touch directly!) */
    int32       size;
    char        data[FLEXIBLE_ARRAY_MEMBER];
} ltxtquery;

#define HDRSIZEQT       MAXALIGN(VARHDRSZ + sizeof(int32))
#define COMPUTESIZE(size,lenofoperand)  ( HDRSIZEQT + (size) * sizeof(ITEM) + (lenofoperand) )
#define LTXTQUERY_TOO_BIG(size,lenofoperand) \
    ((size) > (MaxAllocSize - HDRSIZEQT - (lenofoperand)) / sizeof(ITEM))
#define GETQUERY(x)  (ITEM*)( (char*)(x)+HDRSIZEQT )
#define GETOPERAND(x)   ( (char*)GETQUERY(x) + ((ltxtquery*)x)->size * sizeof(ITEM) )

#define ISOPERATOR(x) ( (x)=='!' || (x)=='&' || (x)=='|' || (x)=='(' || (x)==')' )

#define END                     0
#define ERR                     1
#define VAL                     2
#define OPR                     3
#define OPEN                    4
#define CLOSE                   5
#define VALTRUE                 6   /* for stop words */
#define VALFALSE                7


/* use in array iterator */
Datum       ltree_isparent(PG_FUNCTION_ARGS);
Datum       ltree_risparent(PG_FUNCTION_ARGS);
Datum       ltq_regex(PG_FUNCTION_ARGS);
Datum       ltq_rregex(PG_FUNCTION_ARGS);
Datum       lt_q_regex(PG_FUNCTION_ARGS);
Datum       lt_q_rregex(PG_FUNCTION_ARGS);
Datum       ltxtq_exec(PG_FUNCTION_ARGS);
Datum       ltxtq_rexec(PG_FUNCTION_ARGS);
Datum       _ltq_regex(PG_FUNCTION_ARGS);
Datum       _ltq_rregex(PG_FUNCTION_ARGS);
Datum       _lt_q_regex(PG_FUNCTION_ARGS);
Datum       _lt_q_rregex(PG_FUNCTION_ARGS);
Datum       _ltxtq_exec(PG_FUNCTION_ARGS);
Datum       _ltxtq_rexec(PG_FUNCTION_ARGS);
Datum       _ltree_isparent(PG_FUNCTION_ARGS);
Datum       _ltree_risparent(PG_FUNCTION_ARGS);

/* Concatenation functions */
Datum       ltree_addltree(PG_FUNCTION_ARGS);
Datum       ltree_addtext(PG_FUNCTION_ARGS);
Datum       ltree_textadd(PG_FUNCTION_ARGS);

/* Util function */
Datum       ltree_in(PG_FUNCTION_ARGS);

bool        ltree_execute(ITEM *curitem, void *checkval,
                          bool calcnot, bool (*chkcond) (void *checkval, ITEM *val));

int         ltree_compare(const ltree *a, const ltree *b);
bool        inner_isparent(const ltree *c, const ltree *p);
bool        compare_subnode(ltree_level *t, char *q, int len,
                            int (*cmpptr) (const char *, const char *, size_t), bool anyend);
ltree      *lca_inner(ltree **a, int len);
int         ltree_strncasecmp(const char *a, const char *b, size_t s);

/* fmgr macros for ltree objects */
#define DatumGetLtreeP(X)           ((ltree *) PG_DETOAST_DATUM(X))
#define DatumGetLtreePCopy(X)       ((ltree *) PG_DETOAST_DATUM_COPY(X))
#define PG_GETARG_LTREE_P(n)        DatumGetLtreeP(PG_GETARG_DATUM(n))
#define PG_GETARG_LTREE_P_COPY(n)   DatumGetLtreePCopy(PG_GETARG_DATUM(n))

#define DatumGetLqueryP(X)          ((lquery *) PG_DETOAST_DATUM(X))
#define DatumGetLqueryPCopy(X)      ((lquery *) PG_DETOAST_DATUM_COPY(X))
#define PG_GETARG_LQUERY_P(n)       DatumGetLqueryP(PG_GETARG_DATUM(n))
#define PG_GETARG_LQUERY_P_COPY(n)  DatumGetLqueryPCopy(PG_GETARG_DATUM(n))

#define DatumGetLtxtqueryP(X)           ((ltxtquery *) PG_DETOAST_DATUM(X))
#define DatumGetLtxtqueryPCopy(X)       ((ltxtquery *) PG_DETOAST_DATUM_COPY(X))
#define PG_GETARG_LTXTQUERY_P(n)        DatumGetLtxtqueryP(PG_GETARG_DATUM(n))
#define PG_GETARG_LTXTQUERY_P_COPY(n)   DatumGetLtxtqueryPCopy(PG_GETARG_DATUM(n))

/* GiST support for ltree */

#define SIGLEN_MAX      GISTMaxIndexKeySize
#define SIGLEN_DEFAULT  (2 * sizeof(int32))
#define BITBYTE 8
#define SIGLEN  (sizeof(int32) * SIGLENINT)
#define SIGLENBIT(siglen) ((siglen) * BITBYTE)

typedef unsigned char *BITVECP;

#define LOOPBYTE(siglen) \
            for(i = 0; i < (siglen); i++)

#define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
#define GETBITBYTE(x,i) ( ((unsigned char)(x)) >> i & 0x01 )
#define CLRBIT(x,i)   GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
#define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITBYTE ) )
#define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITBYTE )) & 0x01 )

#define HASHVAL(val, siglen) (((unsigned int)(val)) % SIGLENBIT(siglen))
#define HASH(sign, val, siglen) SETBIT((sign), HASHVAL(val, siglen))

/*
 * type of index key for ltree. Tree are combined B-Tree and R-Tree
 * Storage:
 *  Leaf pages
 *      (len)(flag)(ltree)
 *  Non-Leaf
 *               (len)(flag)(sign)(left_ltree)(right_ltree)
 *      ALLTRUE: (len)(flag)(left_ltree)(right_ltree)
 *
 */

typedef struct
{
    int32       vl_len_;        /* varlena header (do not touch directly!) */
    uint32      flag;
    char        data[FLEXIBLE_ARRAY_MEMBER];
} ltree_gist;

#define LTG_ONENODE 0x01
#define LTG_ALLTRUE 0x02
#define LTG_NORIGHT 0x04

#define LTG_HDRSIZE MAXALIGN(VARHDRSZ + sizeof(uint32))
#define LTG_SIGN(x) ( (BITVECP)( ((char*)(x))+LTG_HDRSIZE ) )
#define LTG_NODE(x) ( (ltree*)( ((char*)(x))+LTG_HDRSIZE ) )
#define LTG_ISONENODE(x) ( ((ltree_gist*)(x))->flag & LTG_ONENODE )
#define LTG_ISALLTRUE(x) ( ((ltree_gist*)(x))->flag & LTG_ALLTRUE )
#define LTG_ISNORIGHT(x) ( ((ltree_gist*)(x))->flag & LTG_NORIGHT )
#define LTG_LNODE(x, siglen)    ( (ltree*)( ( ((char*)(x))+LTG_HDRSIZE ) + ( LTG_ISALLTRUE(x) ? 0 : (siglen) ) ) )
#define LTG_RENODE(x, siglen)   ( (ltree*)( ((char*)LTG_LNODE(x, siglen)) + VARSIZE(LTG_LNODE(x, siglen))) )
#define LTG_RNODE(x, siglen)    ( LTG_ISNORIGHT(x) ? LTG_LNODE(x, siglen) : LTG_RENODE(x, siglen) )

#define LTG_GETLNODE(x, siglen) ( LTG_ISONENODE(x) ? LTG_NODE(x) : LTG_LNODE(x, siglen) )
#define LTG_GETRNODE(x, siglen) ( LTG_ISONENODE(x) ? LTG_NODE(x) : LTG_RNODE(x, siglen) )

extern ltree_gist *ltree_gist_alloc(bool isalltrue, BITVECP sign, int siglen,
                                    ltree *left, ltree *right);

/* GiST support for ltree[] */

#define LTREE_ASIGLEN_DEFAULT   (7 * sizeof(int32))
#define LTREE_ASIGLEN_MAX       GISTMaxIndexKeySize
#define LTREE_GET_ASIGLEN()     (PG_HAS_OPCLASS_OPTIONS() ? \
                                 ((LtreeGistOptions *) PG_GET_OPCLASS_OPTIONS())->siglen : \
                                 LTREE_ASIGLEN_DEFAULT)
#define ASIGLENBIT(siglen)      ((siglen) * BITBYTE)

#define ALOOPBYTE(siglen) \
            for (i = 0; i < (siglen); i++)

#define AHASHVAL(val, siglen) (((unsigned int)(val)) % ASIGLENBIT(siglen))
#define AHASH(sign, val, siglen) SETBIT((sign), AHASHVAL(val, siglen))

/* gist_ltree_ops and gist__ltree_ops opclass options */
typedef struct
{
    int32       vl_len_;        /* varlena header (do not touch directly!) */
    int         siglen;         /* signature length in bytes */
} LtreeGistOptions;

/* type of key is the same to ltree_gist */

#endif