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postgresql/contrib/tsearch2/rank.c

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/*
* Relevation
* Teodor Sigaev <teodor@sigaev.ru>
*/
#include "postgres.h"
#include <math.h>
#include "access/gist.h"
#include "access/itup.h"
#include "catalog/namespace.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "fmgr.h"
#include "funcapi.h"
#include "nodes/pg_list.h"
#include "storage/bufpage.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "tsvector.h"
#include "query.h"
#include "common.h"
PG_FUNCTION_INFO_V1(rank);
Datum rank(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(rank_def);
Datum rank_def(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(rank_cd);
Datum rank_cd(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(rank_cd_def);
Datum rank_cd_def(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(get_covers);
Datum get_covers(PG_FUNCTION_ARGS);
static float weights[] = {0.1, 0.2, 0.4, 1.0};
#define wpos(wep) ( w[ WEP_GETWEIGHT(wep) ] )
#define RANK_NO_NORM 0x00
#define RANK_NORM_LOGLENGTH 0x01
#define RANK_NORM_LENGTH 0x02
#define RANK_NORM_EXTDIST 0x04
#define RANK_NORM_UNIQ 0x08
#define RANK_NORM_LOGUNIQ 0x10
#define DEF_NORM_METHOD RANK_NO_NORM
static float calc_rank_or(float *w, tsvector * t, QUERYTYPE * q);
static float calc_rank_and(float *w, tsvector * t, QUERYTYPE * q);
/*
* Returns a weight of a word collocation
*/
static float4
word_distance(int4 w)
{
if (w > 100)
return 1e-30;
return 1.0 / (1.005 + 0.05 * exp(((float4) w) / 1.5 - 2));
}
static int
cnt_length(tsvector * t)
{
WordEntry *ptr = ARRPTR(t),
*end = (WordEntry *) STRPTR(t);
int len = 0,
clen;
while (ptr < end)
{
if ((clen = POSDATALEN(t, ptr)) == 0)
len += 1;
else
len += clen;
ptr++;
}
return len;
}
static int4
WordECompareITEM(char *eval, char *qval, WordEntry * ptr, ITEM * item)
{
if (ptr->len == item->length)
return strncmp(
eval + ptr->pos,
qval + item->distance,
item->length);
return (ptr->len > item->length) ? 1 : -1;
}
static WordEntry *
find_wordentry(tsvector * t, QUERYTYPE * q, ITEM * item)
{
WordEntry *StopLow = ARRPTR(t);
WordEntry *StopHigh = (WordEntry *) STRPTR(t);
WordEntry *StopMiddle;
int difference;
/* Loop invariant: StopLow <= item < StopHigh */
while (StopLow < StopHigh)
{
StopMiddle = StopLow + (StopHigh - StopLow) / 2;
difference = WordECompareITEM(STRPTR(t), GETOPERAND(q), StopMiddle, item);
if (difference == 0)
return StopMiddle;
else if (difference < 0)
StopLow = StopMiddle + 1;
else
StopHigh = StopMiddle;
}
return NULL;
}
static char *SortAndUniqOperand = NULL;
static int
compareITEM(const void *a, const void *b)
{
if ((*(ITEM **) a)->length == (*(ITEM **) b)->length)
return strncmp(SortAndUniqOperand + (*(ITEM **) a)->distance,
SortAndUniqOperand + (*(ITEM **) b)->distance,
(*(ITEM **) b)->length);
return ((*(ITEM **) a)->length > (*(ITEM **) b)->length) ? 1 : -1;
}
static ITEM **
SortAndUniqItems(char *operand, ITEM * item, int *size)
{
ITEM **res,
**ptr,
**prevptr;
ptr = res = (ITEM **) palloc(sizeof(ITEM *) * *size);
while ((*size)--)
{
if (item->type == VAL)
{
*ptr = item;
ptr++;
}
item++;
}
*size = ptr - res;
if (*size < 2)
return res;
SortAndUniqOperand = operand;
qsort(res, *size, sizeof(ITEM **), compareITEM);
ptr = res + 1;
prevptr = res;
while (ptr - res < *size)
{
if (compareITEM((void *) ptr, (void *) prevptr) != 0)
{
prevptr++;
*prevptr = *ptr;
}
ptr++;
}
*size = prevptr + 1 - res;
return res;
}
static WordEntryPos POSNULL[] = {
0,
0
};
static float
calc_rank_and(float *w, tsvector * t, QUERYTYPE * q)
{
uint16 **pos;
int i,
k,
l,
p;
WordEntry *entry;
WordEntryPos *post,
*ct;
int4 dimt,
lenct,
dist;
float res = -1.0;
ITEM **item;
int size = q->size;
item = SortAndUniqItems(GETOPERAND(q), GETQUERY(q), &size);
if (size < 2)
{
pfree(item);
return calc_rank_or(w, t, q);
}
pos = (uint16 **) palloc(sizeof(uint16 *) * q->size);
memset(pos, 0, sizeof(uint16 *) * q->size);
*(uint16 *) POSNULL = lengthof(POSNULL) - 1;
WEP_SETPOS(POSNULL[1], MAXENTRYPOS - 1);
for (i = 0; i < size; i++)
{
entry = find_wordentry(t, q, item[i]);
if (!entry)
continue;
if (entry->haspos)
pos[i] = (uint16 *) _POSDATAPTR(t, entry);
else
pos[i] = (uint16 *) POSNULL;
dimt = *(uint16 *) (pos[i]);
post = (WordEntryPos *) (pos[i] + 1);
for (k = 0; k < i; k++)
{
if (!pos[k])
continue;
lenct = *(uint16 *) (pos[k]);
ct = (WordEntryPos *) (pos[k] + 1);
for (l = 0; l < dimt; l++)
{
for (p = 0; p < lenct; p++)
{
dist = Abs((int) WEP_GETPOS(post[l]) - (int) WEP_GETPOS(ct[p]));
if (dist || (dist == 0 && (pos[i] == (uint16 *) POSNULL || pos[k] == (uint16 *) POSNULL)))
{
float curw;
if (!dist)
dist = MAXENTRYPOS;
curw = sqrt(wpos(post[l]) * wpos(ct[p]) * word_distance(dist));
res = (res < 0) ? curw : 1.0 - (1.0 - res) * (1.0 - curw);
}
}
}
}
}
pfree(pos);
pfree(item);
return res;
}
static float
calc_rank_or(float *w, tsvector * t, QUERYTYPE * q)
{
WordEntry *entry;
WordEntryPos *post;
int4 dimt,
j,
i;
float res = 0.0;
ITEM **item;
int size = q->size;
*(uint16 *) POSNULL = lengthof(POSNULL) - 1;
item = SortAndUniqItems(GETOPERAND(q), GETQUERY(q), &size);
for (i = 0; i < size; i++)
{
float resj,
wjm;
int4 jm;
entry = find_wordentry(t, q, item[i]);
if (!entry)
continue;
if (entry->haspos)
{
dimt = POSDATALEN(t, entry);
post = POSDATAPTR(t, entry);
}
else
{
dimt = *(uint16 *) POSNULL;
post = POSNULL + 1;
}
resj = 0.0;
wjm = -1.0;
jm = 0;
for (j = 0; j < dimt; j++)
{
resj = resj + wpos(post[j]) / ((j + 1) * (j + 1));
if (wpos(post[j]) > wjm)
{
wjm = wpos(post[j]);
jm = j;
}
}
/*
limit (sum(i/i^2),i->inf) = pi^2/6
resj = sum(wi/i^2),i=1,noccurence,
wi - should be sorted desc,
don't sort for now, just choose maximum weight. This should be corrected
Oleg Bartunov
*/
res = res + (wjm + resj - wjm / ((jm + 1) * (jm + 1))) / 1.64493406685;
}
if (size > 0)
res = res / size;
pfree(item);
return res;
}
static float
calc_rank(float *w, tsvector * t, QUERYTYPE * q, int4 method)
{
ITEM *item = GETQUERY(q);
float res = 0.0;
int len;
if (!t->size || !q->size)
return 0.0;
res = (item->type != VAL && item->val == (int4) '&') ?
calc_rank_and(w, t, q) : calc_rank_or(w, t, q);
if (res < 0)
res = 1e-20;
if ( (method & RANK_NORM_LOGLENGTH) && t->size>0 )
res /= log((double) (cnt_length(t) + 1)) / log(2.0);
if ( method & RANK_NORM_LENGTH ) {
len = cnt_length(t);
if ( len>0 )
res /= (float) len;
}
if ( (method & RANK_NORM_UNIQ) && t->size > 0 )
res /= (float)( t->size );
if ( (method & RANK_NORM_LOGUNIQ) && t->size > 0 )
res /= log((double) (t->size + 1)) / log(2.0);
return res;
}
Datum
rank(PG_FUNCTION_ARGS)
{
ArrayType *win = (ArrayType *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
tsvector *txt = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
QUERYTYPE *query = (QUERYTYPE *) PG_DETOAST_DATUM(PG_GETARG_DATUM(2));
int method = DEF_NORM_METHOD;
float res = 0.0;
float ws[lengthof(weights)];
float4 *arrdata;
int i;
if (ARR_NDIM(win) != 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array of weight must be one-dimensional")));
if (ARRNELEMS(win) < lengthof(weights))
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array of weight is too short")));
if (ARR_HASNULL(win))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array of weight must not contain nulls")));
arrdata = (float4 *) ARR_DATA_PTR(win);
for (i = 0; i < lengthof(weights); i++)
{
ws[i] = (arrdata[i] >= 0) ? arrdata[i] : weights[i];
if (ws[i] > 1.0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("weight out of range")));
}
if (PG_NARGS() == 4)
method = PG_GETARG_INT32(3);
res = calc_rank(ws, txt, query, method);
PG_FREE_IF_COPY(win, 0);
PG_FREE_IF_COPY(txt, 1);
PG_FREE_IF_COPY(query, 2);
PG_RETURN_FLOAT4(res);
}
Datum
rank_def(PG_FUNCTION_ARGS)
{
tsvector *txt = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
QUERYTYPE *query = (QUERYTYPE *) PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
float res = 0.0;
int method = DEF_NORM_METHOD;
if (PG_NARGS() == 3)
method = PG_GETARG_INT32(2);
res = calc_rank(weights, txt, query, method);
PG_FREE_IF_COPY(txt, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_FLOAT4(res);
}
typedef struct
{
ITEM **item;
int16 nitem;
bool needfree;
uint8 wclass;
int32 pos;
} DocRepresentation;
static int
compareDocR(const void *a, const void *b)
{
if (((DocRepresentation *) a)->pos == ((DocRepresentation *) b)->pos)
return 0;
return (((DocRepresentation *) a)->pos > ((DocRepresentation *) b)->pos) ? 1 : -1;
}
static bool
checkcondition_ITEM(void *checkval, ITEM * val)
{
return (bool) (val->istrue);
}
static void
reset_istrue_flag(QUERYTYPE * query)
{
ITEM *item = GETQUERY(query);
int i;
/* reset istrue flag */
for (i = 0; i < query->size; i++)
{
if (item->type == VAL)
item->istrue = 0;
item++;
}
}
typedef struct {
int pos;
int p;
int q;
DocRepresentation *begin;
DocRepresentation *end;
} Extention;
static bool
Cover(DocRepresentation * doc, int len, QUERYTYPE * query, Extention *ext)
{
DocRepresentation *ptr;
int lastpos = ext->pos;
int i;
bool found = false;
reset_istrue_flag(query);
ext->p = 0x7fffffff;
ext->q = 0;
ptr = doc + ext->pos;
/* find upper bound of cover from current position, move up */
while (ptr - doc < len)
{
for (i = 0; i < ptr->nitem; i++)
ptr->item[i]->istrue = 1;
if (TS_execute(GETQUERY(query), NULL, false, checkcondition_ITEM))
{
if (ptr->pos > ext->q)
{
ext->q = ptr->pos;
ext->end = ptr;
lastpos = ptr - doc;
found = true;
}
break;
}
ptr++;
}
if (!found)
return false;
reset_istrue_flag(query);
ptr = doc + lastpos;
/* find lower bound of cover from founded upper bound, move down */
while (ptr >= doc)
{
for (i = 0; i < ptr->nitem; i++)
ptr->item[i]->istrue = 1;
if (TS_execute(GETQUERY(query), NULL, true, checkcondition_ITEM))
{
if (ptr->pos < ext->p) {
ext->begin = ptr;
ext->p = ptr->pos;
}
break;
}
ptr--;
}
if (ext->p <= ext->q)
{
/*
* set position for next try to next lexeme after begining of founded
* cover
*/
ext->pos = (ptr - doc) + 1;
return true;
}
ext->pos++;
return Cover(doc, len, query, ext);
}
static DocRepresentation *
get_docrep(tsvector * txt, QUERYTYPE * query, int *doclen)
{
ITEM *item = GETQUERY(query);
WordEntry *entry;
WordEntryPos *post;
int4 dimt,
j,
i;
int len = query->size * 4,
cur = 0;
DocRepresentation *doc;
*(uint16 *) POSNULL = lengthof(POSNULL) - 1;
doc = (DocRepresentation *) palloc(sizeof(DocRepresentation) * len);
SortAndUniqOperand = GETOPERAND(query);
reset_istrue_flag(query);
for (i = 0; i < query->size; i++)
{
if (item[i].type != VAL || item[i].istrue)
continue;
entry = find_wordentry(txt, query, &(item[i]));
if (!entry)
continue;
if (entry->haspos)
{
dimt = POSDATALEN(txt, entry);
post = POSDATAPTR(txt, entry);
}
else
{
dimt = *(uint16 *) POSNULL;
post = POSNULL + 1;
}
while (cur + dimt >= len)
{
len *= 2;
doc = (DocRepresentation *) repalloc(doc, sizeof(DocRepresentation) * len);
}
for (j = 0; j < dimt; j++)
{
if (j == 0)
{
ITEM *kptr,
*iptr = item + i;
int k;
doc[cur].needfree = false;
doc[cur].nitem = 0;
doc[cur].item = (ITEM **) palloc(sizeof(ITEM *) * query->size);
for (k = 0; k < query->size; k++)
{
kptr = item + k;
if (k == i || (item[k].type == VAL && compareITEM(&kptr, &iptr) == 0))
{
doc[cur].item[doc[cur].nitem] = item + k;
doc[cur].nitem++;
kptr->istrue = 1;
}
}
}
else
{
doc[cur].needfree = false;
doc[cur].nitem = doc[cur - 1].nitem;
doc[cur].item = doc[cur - 1].item;
}
doc[cur].pos = WEP_GETPOS(post[j]);
doc[cur].wclass = WEP_GETWEIGHT(post[j]);
cur++;
}
}
*doclen = cur;
if (cur > 0)
{
if (cur > 1)
qsort((void *) doc, cur, sizeof(DocRepresentation), compareDocR);
return doc;
}
pfree(doc);
return NULL;
}
static float4
calc_rank_cd(float4 *arrdata, tsvector *txt, QUERYTYPE *query, int method) {
DocRepresentation *doc;
int len,
i,
doclen = 0;
Extention ext;
double Wdoc = 0.0;
double invws[lengthof(weights)];
double SumDist=0.0, PrevExtPos=0.0, CurExtPos=0.0;
int NExtent=0;
for (i = 0; i < lengthof(weights); i++)
{
invws[i] = ((double)((arrdata[i] >= 0) ? arrdata[i] : weights[i]));
if (invws[i] > 1.0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("weight out of range")));
invws[i] = 1.0/invws[i];
}
doc = get_docrep(txt, query, &doclen);
if (!doc)
return 0.0;
MemSet( &ext, 0, sizeof(Extention) );
while (Cover(doc, doclen, query, &ext)) {
double Cpos = 0.0;
double InvSum = 0.0;
DocRepresentation *ptr = ext.begin;
while ( ptr<=ext.end ) {
InvSum += invws[ ptr->wclass ];
ptr++;
}
Cpos = ((double)( ext.end-ext.begin+1 )) / InvSum;
Wdoc += Cpos / ( (double)(( 1 + (ext.q - ext.p) - (ext.end - ext.begin) )) );
CurExtPos = ((double)(ext.q + ext.p))/2.0;
if ( NExtent>0 && CurExtPos > PrevExtPos /* prevent devision by zero in a case of multiple lexize */ )
SumDist += 1.0/( CurExtPos - PrevExtPos );
PrevExtPos = CurExtPos;
NExtent++;
}
if ( (method & RANK_NORM_LOGLENGTH) && txt->size > 0 )
Wdoc /= log((double) (cnt_length(txt) + 1));
if ( method & RANK_NORM_LENGTH ) {
len = cnt_length(txt);
if ( len>0 )
Wdoc /= (double) len;
}
if ( (method & RANK_NORM_EXTDIST) && SumDist > 0 )
Wdoc /= ((double)NExtent) / SumDist;
if ( (method & RANK_NORM_UNIQ) && txt->size > 0 )
Wdoc /= (double)( txt->size );
if ( (method & RANK_NORM_LOGUNIQ) && txt->size > 0 )
Wdoc /= log((double) (txt->size + 1)) / log(2.0);
for (i = 0; i < doclen; i++)
if (doc[i].needfree)
pfree(doc[i].item);
pfree(doc);
return (float4)Wdoc;
}
Datum
rank_cd(PG_FUNCTION_ARGS)
{
ArrayType *win = (ArrayType *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
tsvector *txt = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
QUERYTYPE *query = (QUERYTYPE *) PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(2));
int method = DEF_NORM_METHOD;
float4 res;
if (ARR_NDIM(win) != 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array of weight must be one-dimensional")));
if (ARRNELEMS(win) < lengthof(weights))
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array of weight is too short")));
if (ARR_HASNULL(win))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array of weight must not contain nulls")));
if (PG_NARGS() == 4)
method = PG_GETARG_INT32(3);
res = calc_rank_cd( (float4 *) ARR_DATA_PTR(win), txt, query, method);
PG_FREE_IF_COPY(win, 0);
PG_FREE_IF_COPY(txt, 1);
PG_FREE_IF_COPY(query, 2);
PG_RETURN_FLOAT4(res);
}
Datum
rank_cd_def(PG_FUNCTION_ARGS)
{
tsvector *txt = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
QUERYTYPE *query = (QUERYTYPE *) PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(1));
float4 res;
res = calc_rank_cd( weights, txt, query, (PG_NARGS() == 3) ? PG_GETARG_DATUM(2) : DEF_NORM_METHOD);
PG_FREE_IF_COPY(txt, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_FLOAT4(res);
}
/**************debug*************/
typedef struct
{
char *w;
int2 len;
int2 pos;
int2 start;
int2 finish;
} DocWord;
static int
compareDocWord(const void *a, const void *b)
{
if (((DocWord *) a)->pos == ((DocWord *) b)->pos)
return 0;
return (((DocWord *) a)->pos > ((DocWord *) b)->pos) ? 1 : -1;
}
Datum
get_covers(PG_FUNCTION_ARGS)
{
tsvector *txt = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
QUERYTYPE *query = (QUERYTYPE *) PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(1));
WordEntry *pptr = ARRPTR(txt);
int i,
dlen = 0,
j,
cur = 0,
len = 0,
rlen;
DocWord *dw,
*dwptr;
text *out;
char *cptr;
DocRepresentation *doc;
int olddwpos = 0;
int ncover = 1;
Extention ext;
doc = get_docrep(txt, query, &rlen);
if (!doc)
{
out = palloc(VARHDRSZ);
VARATT_SIZEP(out) = VARHDRSZ;
PG_FREE_IF_COPY(txt, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_POINTER(out);
}
for (i = 0; i < txt->size; i++)
{
if (!pptr[i].haspos)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("no pos info")));
dlen += POSDATALEN(txt, &(pptr[i]));
}
dwptr = dw = palloc(sizeof(DocWord) * dlen);
memset(dw, 0, sizeof(DocWord) * dlen);
for (i = 0; i < txt->size; i++)
{
WordEntryPos *posdata = POSDATAPTR(txt, &(pptr[i]));
for (j = 0; j < POSDATALEN(txt, &(pptr[i])); j++)
{
dw[cur].w = STRPTR(txt) + pptr[i].pos;
dw[cur].len = pptr[i].len;
dw[cur].pos = WEP_GETPOS(posdata[j]);
cur++;
}
len += (pptr[i].len + 1) * (int) POSDATALEN(txt, &(pptr[i]));
}
qsort((void *) dw, dlen, sizeof(DocWord), compareDocWord);
MemSet( &ext, 0, sizeof(Extention) );
while (Cover(doc, rlen, query, &ext))
{
dwptr = dw + olddwpos;
while (dwptr->pos < ext.p && dwptr - dw < dlen)
dwptr++;
olddwpos = dwptr - dw;
dwptr->start = ncover;
while (dwptr->pos < ext.q + 1 && dwptr - dw < dlen)
dwptr++;
(dwptr - 1)->finish = ncover;
len += 4 /* {}+two spaces */ + 2 * 16 /* numbers */ ;
ncover++;
}
out = palloc(VARHDRSZ + len);
cptr = ((char *) out) + VARHDRSZ;
dwptr = dw;
while (dwptr - dw < dlen)
{
if (dwptr->start)
{
sprintf(cptr, "{%d ", dwptr->start);
cptr = strchr(cptr, '\0');
}
memcpy(cptr, dwptr->w, dwptr->len);
cptr += dwptr->len;
*cptr = ' ';
cptr++;
if (dwptr->finish)
{
sprintf(cptr, "}%d ", dwptr->finish);
cptr = strchr(cptr, '\0');
}
dwptr++;
}
VARATT_SIZEP(out) = cptr - ((char *) out);
pfree(dw);
for (i = 0; i < rlen; i++)
if (doc[i].needfree)
pfree(doc[i].item);
pfree(doc);
PG_FREE_IF_COPY(txt, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_POINTER(out);
}
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