tsvector_op.c

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/*-------------------------------------------------------------------------
 *
 * tsvector_op.c
 *	  operations over tsvector
 *
 * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/backend/utils/adt/tsvector_op.c,v 1.12.2.1 2008/04/08 18:20:34 tgl Exp $
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include "catalog/namespace.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "funcapi.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "tsearch/ts_type.h"
#include "tsearch/ts_utils.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"


typedef struct
{
	WordEntry  *arrb;
	WordEntry  *arre;
	char	   *values;
	char	   *operand;
} CHKVAL;

typedef struct
{
	uint32		cur;
	TSVector	stat;
} StatStorage;

typedef struct
{
	uint32		len;
	uint32		pos;
	uint32		ndoc;
	uint32		nentry;
} StatEntry;

typedef struct
{
	int32		vl_len_;		/* varlena header (do not touch directly!) */
	int4		size;
	int4		weight;
	char		data[1];
} tsstat;

#define STATHDRSIZE (sizeof(int4) * 4)
#define CALCSTATSIZE(x, lenstr) ( (x) * sizeof(StatEntry) + STATHDRSIZE + (lenstr) )
#define STATPTR(x)	( (StatEntry*) ( (char*)(x) + STATHDRSIZE ) )
#define STATSTRPTR(x)	( (char*)(x) + STATHDRSIZE + ( sizeof(StatEntry) * ((TSVector)(x))->size ) )
#define STATSTRSIZE(x)	( VARSIZE((TSVector)(x)) - STATHDRSIZE - ( sizeof(StatEntry) * ((TSVector)(x))->size ) )


static Datum tsvector_update_trigger(PG_FUNCTION_ARGS, bool config_column);


/*
 * Check if datatype is the specified type or equivalent to it.
 *
 * Note: we could just do getBaseType() unconditionally, but since that's
 * a relatively expensive catalog lookup that most users won't need, we
 * try the straight comparison first.
 */
static bool
is_expected_type(Oid typid, Oid expected_type)
{
	if (typid == expected_type)
		return true;
	typid = getBaseType(typid);
	if (typid == expected_type)
		return true;
	return false;
}

/* Check if datatype is TEXT or binary-equivalent to it */
static bool
is_text_type(Oid typid)
{
	/* varchar(n) and char(n) are binary-compatible with text */
	if (typid == TEXTOID || typid == VARCHAROID || typid == BPCHAROID)
		return true;
	/* Allow domains over these types, too */
	typid = getBaseType(typid);
	if (typid == TEXTOID || typid == VARCHAROID || typid == BPCHAROID)
		return true;
	return false;
}


/*
 * Order: haspos, len, word, for all positions (pos, weight)
 */
static int
silly_cmp_tsvector(const TSVector a, const TSVector b)
{
	if (VARSIZE(a) < VARSIZE(b))
		return -1;
	else if (VARSIZE(a) > VARSIZE(b))
		return 1;
	else if (a->size < b->size)
		return -1;
	else if (a->size > b->size)
		return 1;
	else
	{
		WordEntry  *aptr = ARRPTR(a);
		WordEntry  *bptr = ARRPTR(b);
		int			i = 0;
		int			res;


		for (i = 0; i < a->size; i++)
		{
			if (aptr->haspos != bptr->haspos)
			{
				return (aptr->haspos > bptr->haspos) ? -1 : 1;
			}
			else if (aptr->len != bptr->len)
			{
				return (aptr->len > bptr->len) ? -1 : 1;
			}
			else if ((res = strncmp(STRPTR(a) + aptr->pos, STRPTR(b) + bptr->pos, bptr->len)) != 0)
			{
				return res;
			}
			else if (aptr->haspos)
			{
				WordEntryPos *ap = POSDATAPTR(a, aptr);
				WordEntryPos *bp = POSDATAPTR(b, bptr);
				int			j;

				if (POSDATALEN(a, aptr) != POSDATALEN(b, bptr))
					return (POSDATALEN(a, aptr) > POSDATALEN(b, bptr)) ? -1 : 1;

				for (j = 0; j < POSDATALEN(a, aptr); j++)
				{
					if (WEP_GETPOS(*ap) != WEP_GETPOS(*bp))
					{
						return (WEP_GETPOS(*ap) > WEP_GETPOS(*bp)) ? -1 : 1;
					}
					else if (WEP_GETWEIGHT(*ap) != WEP_GETWEIGHT(*bp))
					{
						return (WEP_GETWEIGHT(*ap) > WEP_GETWEIGHT(*bp)) ? -1 : 1;
					}
					ap++, bp++;
				}
			}

			aptr++;
			bptr++;
		}
	}

	return 0;
}

#define TSVECTORCMPFUNC( type, action, ret )			\
Datum													\
tsvector_##type(PG_FUNCTION_ARGS)						\
{														\
	TSVector	a = PG_GETARG_TSVECTOR(0);				\
	TSVector	b = PG_GETARG_TSVECTOR(1);				\
	int			res = silly_cmp_tsvector(a, b);			\
	PG_FREE_IF_COPY(a,0);								\
	PG_FREE_IF_COPY(b,1);								\
	PG_RETURN_##ret( res action 0 );					\
}

TSVECTORCMPFUNC(lt, <, BOOL);
TSVECTORCMPFUNC(le, <=, BOOL);
TSVECTORCMPFUNC(eq, ==, BOOL);
TSVECTORCMPFUNC(ge, >=, BOOL);
TSVECTORCMPFUNC(gt, >, BOOL);
TSVECTORCMPFUNC(ne, !=, BOOL);
TSVECTORCMPFUNC(cmp, +, INT32);

Datum
tsvector_strip(PG_FUNCTION_ARGS)
{
	TSVector	in = PG_GETARG_TSVECTOR(0);
	TSVector	out;
	int			i,
				len = 0;
	WordEntry  *arrin = ARRPTR(in),
			   *arrout;
	char	   *cur;

	for (i = 0; i < in->size; i++)
		len += arrin[i].len;

	len = CALCDATASIZE(in->size, len);
	out = (TSVector) palloc0(len);
	SET_VARSIZE(out, len);
	out->size = in->size;
	arrout = ARRPTR(out);
	cur = STRPTR(out);
	for (i = 0; i < in->size; i++)
	{
		memcpy(cur, STRPTR(in) + arrin[i].pos, arrin[i].len);
		arrout[i].haspos = 0;
		arrout[i].len = arrin[i].len;
		arrout[i].pos = cur - STRPTR(out);
		cur += arrout[i].len;
	}

	PG_FREE_IF_COPY(in, 0);
	PG_RETURN_POINTER(out);
}

Datum
tsvector_length(PG_FUNCTION_ARGS)
{
	TSVector	in = PG_GETARG_TSVECTOR(0);
	int4		ret = in->size;

	PG_FREE_IF_COPY(in, 0);
	PG_RETURN_INT32(ret);
}

Datum
tsvector_setweight(PG_FUNCTION_ARGS)
{
	TSVector	in = PG_GETARG_TSVECTOR(0);
	char		cw = PG_GETARG_CHAR(1);
	TSVector	out;
	int			i,
				j;
	WordEntry  *entry;
	WordEntryPos *p;
	int			w = 0;

	switch (cw)
	{
		case 'A':
		case 'a':
			w = 3;
			break;
		case 'B':
		case 'b':
			w = 2;
			break;
		case 'C':
		case 'c':
			w = 1;
			break;
		case 'D':
		case 'd':
			w = 0;
			break;
		default:
			/* internal error */
			elog(ERROR, "unrecognized weight: %d", cw);
	}

	out = (TSVector) palloc(VARSIZE(in));
	memcpy(out, in, VARSIZE(in));
	entry = ARRPTR(out);
	i = out->size;
	while (i--)
	{
		if ((j = POSDATALEN(out, entry)) != 0)
		{
			p = POSDATAPTR(out, entry);
			while (j--)
			{
				WEP_SETWEIGHT(*p, w);
				p++;
			}
		}
		entry++;
	}

	PG_FREE_IF_COPY(in, 0);
	PG_RETURN_POINTER(out);
}

static int
compareEntry(char *ptra, WordEntry *a, char *ptrb, WordEntry *b)
{
	if (a->len == b->len)
	{
		return strncmp(
					   ptra + a->pos,
					   ptrb + b->pos,
					   a->len);
	}
	return (a->len > b->len) ? 1 : -1;
}

/*
 * Add positions from src to dest after offsetting them by maxpos.
 * Return the number added (might be less than expected due to overflow)
 */
static int4
add_pos(TSVector src, WordEntry *srcptr,
		TSVector dest, WordEntry *destptr,
		int4 maxpos)
{
	uint16	   *clen = &_POSVECPTR(dest, destptr)->npos;
	int			i;
	uint16		slen = POSDATALEN(src, srcptr),
				startlen;
	WordEntryPos *spos = POSDATAPTR(src, srcptr),
			   *dpos = POSDATAPTR(dest, destptr);

	if (!destptr->haspos)
		*clen = 0;

	startlen = *clen;
	for (i = 0;
		 i < slen && *clen < MAXNUMPOS &&
		 (*clen == 0 || WEP_GETPOS(dpos[*clen - 1]) != MAXENTRYPOS - 1);
		 i++)
	{
		WEP_SETWEIGHT(dpos[*clen], WEP_GETWEIGHT(spos[i]));
		WEP_SETPOS(dpos[*clen], LIMITPOS(WEP_GETPOS(spos[i]) + maxpos));
		(*clen)++;
	}

	if (*clen != startlen)
		destptr->haspos = 1;
	return *clen - startlen;
}


Datum
tsvector_concat(PG_FUNCTION_ARGS)
{
	TSVector	in1 = PG_GETARG_TSVECTOR(0);
	TSVector	in2 = PG_GETARG_TSVECTOR(1);
	TSVector	out;
	WordEntry  *ptr;
	WordEntry  *ptr1,
			   *ptr2;
	WordEntryPos *p;
	int			maxpos = 0,
				i,
				j,
				i1,
				i2,
				dataoff;
	char	   *data,
			   *data1,
			   *data2;

	ptr = ARRPTR(in1);
	i = in1->size;
	while (i--)
	{
		if ((j = POSDATALEN(in1, ptr)) != 0)
		{
			p = POSDATAPTR(in1, ptr);
			while (j--)
			{
				if (WEP_GETPOS(*p) > maxpos)
					maxpos = WEP_GETPOS(*p);
				p++;
			}
		}
		ptr++;
	}

	ptr1 = ARRPTR(in1);
	ptr2 = ARRPTR(in2);
	data1 = STRPTR(in1);
	data2 = STRPTR(in2);
	i1 = in1->size;
	i2 = in2->size;
	/* conservative estimate of space needed */
	out = (TSVector) palloc0(VARSIZE(in1) + VARSIZE(in2));
	SET_VARSIZE(out, VARSIZE(in1) + VARSIZE(in2));
	out->size = in1->size + in2->size;
	ptr = ARRPTR(out);
	data = STRPTR(out);
	dataoff = 0;
	while (i1 && i2)
	{
		int			cmp = compareEntry(data1, ptr1, data2, ptr2);

		if (cmp < 0)
		{						/* in1 first */
			ptr->haspos = ptr1->haspos;
			ptr->len = ptr1->len;
			memcpy(data + dataoff, data1 + ptr1->pos, ptr1->len);
			ptr->pos = dataoff;
			dataoff += ptr1->len;
			if (ptr->haspos)
			{
				dataoff = SHORTALIGN(dataoff);
				memcpy(data + dataoff, _POSVECPTR(in1, ptr1), POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16));
				dataoff += POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16);
			}

			ptr++;
			ptr1++;
			i1--;
		}
		else if (cmp > 0)
		{						/* in2 first */
			ptr->haspos = ptr2->haspos;
			ptr->len = ptr2->len;
			memcpy(data + dataoff, data2 + ptr2->pos, ptr2->len);
			ptr->pos = dataoff;
			dataoff += ptr2->len;
			if (ptr->haspos)
			{
				int			addlen = add_pos(in2, ptr2, out, ptr, maxpos);

				if (addlen == 0)
					ptr->haspos = 0;
				else
				{
					dataoff = SHORTALIGN(dataoff);
					dataoff += addlen * sizeof(WordEntryPos) + sizeof(uint16);
				}
			}

			ptr++;
			ptr2++;
			i2--;
		}
		else
		{
			ptr->haspos = ptr1->haspos | ptr2->haspos;
			ptr->len = ptr1->len;
			memcpy(data + dataoff, data1 + ptr1->pos, ptr1->len);
			ptr->pos = dataoff;
			dataoff += ptr1->len;
			if (ptr->haspos)
			{
				if (ptr1->haspos)
				{
					dataoff = SHORTALIGN(dataoff);
					memcpy(data + dataoff, _POSVECPTR(in1, ptr1), POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16));
					dataoff += POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16);
					if (ptr2->haspos)
						dataoff += add_pos(in2, ptr2, out, ptr, maxpos) * sizeof(WordEntryPos);
				}
				else	/* must have ptr2->haspos */
				{
					int			addlen = add_pos(in2, ptr2, out, ptr, maxpos);

					if (addlen == 0)
						ptr->haspos = 0;
					else
					{
						dataoff = SHORTALIGN(dataoff);
						dataoff += addlen * sizeof(WordEntryPos) + sizeof(uint16);
					}
				}
			}

			ptr++;
			ptr1++;
			ptr2++;
			i1--;
			i2--;
		}
	}

	while (i1)
	{
		ptr->haspos = ptr1->haspos;
		ptr->len = ptr1->len;
		memcpy(data + dataoff, data1 + ptr1->pos, ptr1->len);
		ptr->pos = dataoff;
		dataoff += ptr1->len;
		if (ptr->haspos)