/*
* Trivial split: half of entries will be placed on one page
* and another half - to another
*/
static void
fallbackSplit(GistEntryVector *entryvec, GIST_SPLITVEC *v)
{
OffsetNumber i,
maxoff;
BOX *unionL = NULL,
*unionR = NULL;
int nbytes;
maxoff = entryvec->n - 1;
nbytes = (maxoff + 2) * sizeof(OffsetNumber);
v->spl_left = (OffsetNumber *) palloc(nbytes);
v->spl_right = (OffsetNumber *) palloc(nbytes);
v->spl_nleft = v->spl_nright = 0;
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
BOX *cur = DatumGetBoxP(entryvec->vector[i].key);
if (i <= (maxoff - FirstOffsetNumber + 1) / 2)
{
v->spl_left[v->spl_nleft] = i;
if (unionL == NULL)
{
unionL = (BOX *) palloc(sizeof(BOX));
*unionL = *cur;
}
else
adjustBox(unionL, cur);
v->spl_nleft++;
}
else
{
v->spl_right[v->spl_nright] = i;
if (unionR == NULL)
{
unionR = (BOX *) palloc(sizeof(BOX));
*unionR = *cur;
}
else
adjustBox(unionR, cur);
v->spl_nright++;
}
}
if (v->spl_ldatum_exists)
adjustBox(unionL, DatumGetBoxP(v->spl_ldatum));
v->spl_ldatum = BoxPGetDatum(unionL);
if (v->spl_rdatum_exists)
adjustBox(unionR, DatumGetBoxP(v->spl_rdatum));
v->spl_rdatum = BoxPGetDatum(unionR);
v->spl_ldatum_exists = v->spl_rdatum_exists = false;
}
/*
* SP-GiST choose function
*/
Datum
spg_box_quad_choose(PG_FUNCTION_ARGS)
{
spgChooseIn *in = (spgChooseIn *) PG_GETARG_POINTER(0);
spgChooseOut *out = (spgChooseOut *) PG_GETARG_POINTER(1);
BOX *centroid = DatumGetBoxP(in->prefixDatum),
*box = DatumGetBoxP(in->datum);
out->resultType = spgMatchNode;
out->result.matchNode.restDatum = BoxPGetDatum(box);
/* nodeN will be set by core, when allTheSame. */
if (!in->allTheSame)
out->result.matchNode.nodeN = getQuadrant(centroid, box);
PG_RETURN_VOID();
}
Datum
gist_point_compress(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
if (entry->leafkey) /* Point, actually */
{
BOX *box = palloc(sizeof(BOX));
Point *point = DatumGetPointP(entry->key);
GISTENTRY *retval = palloc(sizeof(GISTENTRY));
box->high = box->low = *point;
gistentryinit(*retval, BoxPGetDatum(box),
entry->rel, entry->page, entry->offset, FALSE);
PG_RETURN_POINTER(retval);
}
PG_RETURN_POINTER(entry);
}
/*
* SP-GiST pick-split function
*
* It splits a list of boxes into quadrants by choosing a central 4D
* point as the median of the coordinates of the boxes.
*/
Datum
spg_box_quad_picksplit(PG_FUNCTION_ARGS)
{
spgPickSplitIn *in = (spgPickSplitIn *) PG_GETARG_POINTER(0);
spgPickSplitOut *out = (spgPickSplitOut *) PG_GETARG_POINTER(1);
BOX *centroid;
int median,
i;
double *lowXs = palloc(sizeof(double) * in->nTuples);
double *highXs = palloc(sizeof(double) * in->nTuples);
double *lowYs = palloc(sizeof(double) * in->nTuples);
double *highYs = palloc(sizeof(double) * in->nTuples);
/* Calculate median of all 4D coordinates */
for (i = 0; i < in->nTuples; i++)
{
BOX *box = DatumGetBoxP(in->datums[i]);
lowXs[i] = box->low.x;
highXs[i] = box->high.x;
lowYs[i] = box->low.y;
highYs[i] = box->high.y;
}
qsort(lowXs, in->nTuples, sizeof(double), compareDoubles);
qsort(highXs, in->nTuples, sizeof(double), compareDoubles);
qsort(lowYs, in->nTuples, sizeof(double), compareDoubles);
qsort(highYs, in->nTuples, sizeof(double), compareDoubles);
median = in->nTuples / 2;
centroid = palloc(sizeof(BOX));
centroid->low.x = lowXs[median];
centroid->high.x = highXs[median];
centroid->low.y = lowYs[median];
centroid->high.y = highYs[median];
/* Fill the output */
out->hasPrefix = true;
out->prefixDatum = BoxPGetDatum(centroid);
out->nNodes = 16;
out->nodeLabels = NULL; /* We don't need node labels. */
out->mapTuplesToNodes = palloc(sizeof(int) * in->nTuples);
out->leafTupleDatums = palloc(sizeof(Datum) * in->nTuples);
/*
* Assign ranges to corresponding nodes according to quadrants
* relative to the "centroid" range
*/
for (i = 0; i < in->nTuples; i++)
{
BOX *box = DatumGetBoxP(in->datums[i]);
uint8 quadrant = getQuadrant(centroid, box);
out->leafTupleDatums[i] = BoxPGetDatum(box);
out->mapTuplesToNodes[i] = quadrant;
}
PG_RETURN_VOID();
}
/*
* The GiST PickSplit method
*
* New linear algorithm, see 'New Linear Node Splitting Algorithm for R-tree',
* C.H.Ang and T.C.Tan
*
* This is used for both boxes and points.
*/
Datum
gist_box_picksplit(PG_FUNCTION_ARGS)
{
GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
OffsetNumber i;
OffsetNumber *listL,
*listR,
*listB,
*listT;
BOX *unionL,
*unionR,
*unionB,
*unionT;
int posL,
posR,
posB,
posT;
BOX pageunion;
BOX *cur;
char direction = ' ';
bool allisequal = true;
OffsetNumber maxoff;
int nbytes;
posL = posR = posB = posT = 0;
maxoff = entryvec->n - 1;
cur = DatumGetBoxP(entryvec->vector[FirstOffsetNumber].key);
memcpy((void *) &pageunion, (void *) cur, sizeof(BOX));
/* find MBR */
for (i = OffsetNumberNext(FirstOffsetNumber); i <= maxoff; i = OffsetNumberNext(i))
{
cur = DatumGetBoxP(entryvec->vector[i].key);
if (allisequal && (
pageunion.high.x != cur->high.x ||
pageunion.high.y != cur->high.y ||
pageunion.low.x != cur->low.x ||
pageunion.low.y != cur->low.y
))
allisequal = false;
adjustBox(&pageunion, cur);
}
if (allisequal)
{
/*
* All entries are the same
*/
fallbackSplit(entryvec, v);
PG_RETURN_POINTER(v);
}
nbytes = (maxoff + 2) * sizeof(OffsetNumber);
listL = (OffsetNumber *) palloc(nbytes);
listR = (OffsetNumber *) palloc(nbytes);
listB = (OffsetNumber *) palloc(nbytes);
listT = (OffsetNumber *) palloc(nbytes);
unionL = (BOX *) palloc(sizeof(BOX));
unionR = (BOX *) palloc(sizeof(BOX));
unionB = (BOX *) palloc(sizeof(BOX));
unionT = (BOX *) palloc(sizeof(BOX));
#define ADDLIST( list, unionD, pos, num ) do { \
if ( pos ) { \
if ( (unionD)->high.x < cur->high.x ) (unionD)->high.x = cur->high.x; \
if ( (unionD)->low.x > cur->low.x ) (unionD)->low.x = cur->low.x; \
if ( (unionD)->high.y < cur->high.y ) (unionD)->high.y = cur->high.y; \
if ( (unionD)->low.y > cur->low.y ) (unionD)->low.y = cur->low.y; \
} else { \
memcpy( (void*)(unionD), (void*) cur, sizeof( BOX ) ); \
} \
(list)[pos] = num; \
(pos)++; \
} while(0)
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
cur = DatumGetBoxP(entryvec->vector[i].key);
if (cur->low.x - pageunion.low.x < pageunion.high.x - cur->high.x)
ADDLIST(listL, unionL, posL, i);
else
ADDLIST(listR, unionR, posR, i);
if (cur->low.y - pageunion.low.y < pageunion.high.y - cur->high.y)
ADDLIST(listB, unionB, posB, i);
else
ADDLIST(listT, unionT, posT, i);
}
#define LIMIT_RATIO 0.1
#define _IS_BADRATIO(x,y) ( (y) == 0 || (float)(x)/(float)(y) < LIMIT_RATIO )
#define IS_BADRATIO(x,y) ( _IS_BADRATIO((x),(y)) || _IS_BADRATIO((y),(x)) )
/* bad disposition, try to split by centers of boxes */
if (IS_BADRATIO(posR, posL) && IS_BADRATIO(posT, posB))
{
double avgCenterX = 0.0,
avgCenterY = 0.0;
double CenterX,
CenterY;
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
cur = DatumGetBoxP(entryvec->vector[i].key);
avgCenterX += ((double) cur->high.x + (double) cur->low.x) / 2.0;
avgCenterY += ((double) cur->high.y + (double) cur->low.y) / 2.0;
}
avgCenterX /= maxoff;
avgCenterY /= maxoff;
posL = posR = posB = posT = 0;
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
cur = DatumGetBoxP(entryvec->vector[i].key);
CenterX = ((double) cur->high.x + (double) cur->low.x) / 2.0;
CenterY = ((double) cur->high.y + (double) cur->low.y) / 2.0;
if (CenterX < avgCenterX)
ADDLIST(listL, unionL, posL, i);
else if (CenterX == avgCenterX)
{
if (posL > posR)
ADDLIST(listR, unionR, posR, i);
else
ADDLIST(listL, unionL, posL, i);
}
else
ADDLIST(listR, unionR, posR, i);
if (CenterY < avgCenterY)
ADDLIST(listB, unionB, posB, i);
else if (CenterY == avgCenterY)
{
if (posB > posT)
ADDLIST(listT, unionT, posT, i);
else
ADDLIST(listB, unionB, posB, i);
}
else
ADDLIST(listT, unionT, posT, i);
}
if (IS_BADRATIO(posR, posL) && IS_BADRATIO(posT, posB))
{
fallbackSplit(entryvec, v);
PG_RETURN_POINTER(v);
}
}
/* which split more optimal? */
if (Max(posL, posR) < Max(posB, posT))
direction = 'x';
else if (Max(posL, posR) > Max(posB, posT))
direction = 'y';
else
{
Datum interLR = DirectFunctionCall2(rt_box_inter,
BoxPGetDatum(unionL),
BoxPGetDatum(unionR));
Datum interBT = DirectFunctionCall2(rt_box_inter,
BoxPGetDatum(unionB),
BoxPGetDatum(unionT));
double sizeLR,
sizeBT;
sizeLR = size_box(interLR);
sizeBT = size_box(interBT);
if (sizeLR < sizeBT)
direction = 'x';
else
direction = 'y';
}
if (direction == 'x')
chooseLR(v,
listL, posL, unionL,
listR, posR, unionR);
else
chooseLR(v,
listB, posB, unionB,
listT, posT, unionT);
PG_RETURN_POINTER(v);
}
static void
chooseLR(GIST_SPLITVEC *v,
OffsetNumber *list1, int nlist1, BOX *union1,
OffsetNumber *list2, int nlist2, BOX *union2)
{
bool firstToLeft = true;
if (v->spl_ldatum_exists || v->spl_rdatum_exists)
{
if (v->spl_ldatum_exists && v->spl_rdatum_exists)
{
BOX LRl = *union1,
LRr = *union2;
BOX RLl = *union2,
RLr = *union1;
double sizeLR,
sizeRL;
adjustBox(&LRl, DatumGetBoxP(v->spl_ldatum));
adjustBox(&LRr, DatumGetBoxP(v->spl_rdatum));
adjustBox(&RLl, DatumGetBoxP(v->spl_ldatum));
adjustBox(&RLr, DatumGetBoxP(v->spl_rdatum));
sizeLR = size_box(DirectFunctionCall2(rt_box_inter, BoxPGetDatum(&LRl), BoxPGetDatum(&LRr)));
sizeRL = size_box(DirectFunctionCall2(rt_box_inter, BoxPGetDatum(&RLl), BoxPGetDatum(&RLr)));
if (sizeLR > sizeRL)
firstToLeft = false;
}
else
{
float p1,
p2;
GISTENTRY oldUnion,
addon;
gistentryinit(oldUnion, (v->spl_ldatum_exists) ? v->spl_ldatum : v->spl_rdatum,
NULL, NULL, InvalidOffsetNumber, FALSE);
gistentryinit(addon, BoxPGetDatum(union1), NULL, NULL, InvalidOffsetNumber, FALSE);
DirectFunctionCall3(gist_box_penalty, PointerGetDatum(&oldUnion), PointerGetDatum(&addon), PointerGetDatum(&p1));
gistentryinit(addon, BoxPGetDatum(union2), NULL, NULL, InvalidOffsetNumber, FALSE);
DirectFunctionCall3(gist_box_penalty, PointerGetDatum(&oldUnion), PointerGetDatum(&addon), PointerGetDatum(&p2));
if ((v->spl_ldatum_exists && p1 > p2) || (v->spl_rdatum_exists && p1 < p2))
firstToLeft = false;
}
}
if (firstToLeft)
{
v->spl_left = list1;
v->spl_right = list2;
v->spl_nleft = nlist1;
v->spl_nright = nlist2;
if (v->spl_ldatum_exists)
adjustBox(union1, DatumGetBoxP(v->spl_ldatum));
v->spl_ldatum = BoxPGetDatum(union1);
if (v->spl_rdatum_exists)
adjustBox(union2, DatumGetBoxP(v->spl_rdatum));
v->spl_rdatum = BoxPGetDatum(union2);
}
else
{
v->spl_left = list2;
v->spl_right = list1;
v->spl_nleft = nlist2;
v->spl_nright = nlist1;
if (v->spl_ldatum_exists)
adjustBox(union2, DatumGetBoxP(v->spl_ldatum));
v->spl_ldatum = BoxPGetDatum(union2);
if (v->spl_rdatum_exists)
adjustBox(union1, DatumGetBoxP(v->spl_rdatum));
v->spl_rdatum = BoxPGetDatum(union1);
}
v->spl_ldatum_exists = v->spl_rdatum_exists = false;
}
/*
** The GiST PickSplit method
** New linear algorithm, see 'New Linear Node Splitting Algorithm for R-tree',
** C.H.Ang and T.C.Tan
*/
Datum
gbox_picksplit(PG_FUNCTION_ARGS)
{
bytea *entryvec = (bytea *) PG_GETARG_POINTER(0);
GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
OffsetNumber i;
OffsetNumber *listL,
*listR,
*listB,
*listT;
BOX *unionL,
*unionR,
*unionB,
*unionT;
int posL,
posR,
posB,
posT;
BOX pageunion;
BOX *cur;
char direction = ' ';
bool allisequal = true;
OffsetNumber maxoff;
int nbytes;
posL = posR = posB = posT = 0;
maxoff = ((VARSIZE(entryvec) - VARHDRSZ) / sizeof(GISTENTRY)) - 1;
cur = DatumGetBoxP(((GISTENTRY *) VARDATA(entryvec))[FirstOffsetNumber].key);
memcpy((void *) &pageunion, (void *) cur, sizeof(BOX));
/* find MBR */
for (i = OffsetNumberNext(FirstOffsetNumber); i <= maxoff; i = OffsetNumberNext(i))
{
cur = DatumGetBoxP(((GISTENTRY *) VARDATA(entryvec))[i].key);
if (allisequal == true && (
pageunion.high.x != cur->high.x ||
pageunion.high.y != cur->high.y ||
pageunion.low.x != cur->low.x ||
pageunion.low.y != cur->low.y
))
allisequal = false;
if (pageunion.high.x < cur->high.x)
pageunion.high.x = cur->high.x;
if (pageunion.low.x > cur->low.x)
pageunion.low.x = cur->low.x;
if (pageunion.high.y < cur->high.y)
pageunion.high.y = cur->high.y;
if (pageunion.low.y > cur->low.y)
pageunion.low.y = cur->low.y;
}
nbytes = (maxoff + 2) * sizeof(OffsetNumber);
listL = (OffsetNumber *) palloc(nbytes);
listR = (OffsetNumber *) palloc(nbytes);
unionL = (BOX *) palloc(sizeof(BOX));
unionR = (BOX *) palloc(sizeof(BOX));
if (allisequal)
{
cur = DatumGetBoxP(((GISTENTRY *) VARDATA(entryvec))[OffsetNumberNext(FirstOffsetNumber)].key);
if (memcmp((void *) cur, (void *) &pageunion, sizeof(BOX)) == 0)
{
v->spl_left = listL;
v->spl_right = listR;
v->spl_nleft = v->spl_nright = 0;
memcpy((void *) unionL, (void *) &pageunion, sizeof(BOX));
memcpy((void *) unionR, (void *) &pageunion, sizeof(BOX));
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
if (i <= (maxoff - FirstOffsetNumber + 1) / 2)
{
v->spl_left[v->spl_nleft] = i;
v->spl_nleft++;
}
else
{
v->spl_right[v->spl_nright] = i;
v->spl_nright++;
}
}
v->spl_ldatum = BoxPGetDatum(unionL);
v->spl_rdatum = BoxPGetDatum(unionR);
PG_RETURN_POINTER(v);
}
}
listB = (OffsetNumber *) palloc(nbytes);
listT = (OffsetNumber *) palloc(nbytes);
unionB = (BOX *) palloc(sizeof(BOX));
unionT = (BOX *) palloc(sizeof(BOX));
#define ADDLIST( list, unionD, pos, num ) do { \
if ( pos ) { \
if ( unionD->high.x < cur->high.x ) unionD->high.x = cur->high.x; \
if ( unionD->low.x > cur->low.x ) unionD->low.x = cur->low.x; \
if ( unionD->high.y < cur->high.y ) unionD->high.y = cur->high.y; \
if ( unionD->low.y > cur->low.y ) unionD->low.y = cur->low.y; \
} else { \
memcpy( (void*)unionD, (void*) cur, sizeof( BOX ) ); \
} \
list[pos] = num; \
(pos)++; \
} while(0)
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
cur = DatumGetBoxP(((GISTENTRY *) VARDATA(entryvec))[i].key);
if (cur->low.x - pageunion.low.x < pageunion.high.x - cur->high.x)
ADDLIST(listL, unionL, posL, i);
else
ADDLIST(listR, unionR, posR, i);
if (cur->low.y - pageunion.low.y < pageunion.high.y - cur->high.y)
ADDLIST(listB, unionB, posB, i);
else
ADDLIST(listT, unionT, posT, i);
}
/* bad disposition, sort by ascending and resplit */
if ((posR == 0 || posL == 0) && (posT == 0 || posB == 0))
{
KBsort *arr = (KBsort *) palloc(sizeof(KBsort) * maxoff);
posL = posR = posB = posT = 0;
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
arr[i - 1].key = DatumGetBoxP(((GISTENTRY *) VARDATA(entryvec))[i].key);
arr[i - 1].pos = i;
}
qsort(arr, maxoff, sizeof(KBsort), compare_KB);
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
cur = arr[i - 1].key;
if (cur->low.x - pageunion.low.x < pageunion.high.x - cur->high.x)
ADDLIST(listL, unionL, posL, arr[i - 1].pos);
else if (cur->low.x - pageunion.low.x == pageunion.high.x - cur->high.x)
{
if (posL > posR)
ADDLIST(listR, unionR, posR, arr[i - 1].pos);
else
ADDLIST(listL, unionL, posL, arr[i - 1].pos);
}
else
ADDLIST(listR, unionR, posR, arr[i - 1].pos);
if (cur->low.y - pageunion.low.y < pageunion.high.y - cur->high.y)
ADDLIST(listB, unionB, posB, arr[i - 1].pos);
else if (cur->low.y - pageunion.low.y == pageunion.high.y - cur->high.y)
{
if (posB > posT)
ADDLIST(listT, unionT, posT, arr[i - 1].pos);
else
ADDLIST(listB, unionB, posB, arr[i - 1].pos);
}
else
ADDLIST(listT, unionT, posT, arr[i - 1].pos);
}
pfree(arr);
}
/* which split more optimal? */
if (Max(posL, posR) < Max(posB, posT))
direction = 'x';
else if (Max(posL, posR) > Max(posB, posT))
direction = 'y';
else
{
Datum interLR = DirectFunctionCall2(rt_box_inter,
BoxPGetDatum(unionL),
BoxPGetDatum(unionR));
Datum interBT = DirectFunctionCall2(rt_box_inter,
BoxPGetDatum(unionB),
BoxPGetDatum(unionT));
float sizeLR,
sizeBT;
sizeLR = size_box(interLR);
sizeBT = size_box(interBT);
if (sizeLR < sizeBT)
direction = 'x';
else
direction = 'y';
}
if (direction == 'x')
{
pfree(unionB);
pfree(listB);
pfree(unionT);
pfree(listT);
v->spl_left = listL;
v->spl_right = listR;
v->spl_nleft = posL;
v->spl_nright = posR;
v->spl_ldatum = BoxPGetDatum(unionL);
v->spl_rdatum = BoxPGetDatum(unionR);
}
else
{
pfree(unionR);
pfree(listR);
pfree(unionL);
pfree(listL);
v->spl_left = listB;
v->spl_right = listT;
v->spl_nleft = posB;
v->spl_nright = posT;
v->spl_ldatum = BoxPGetDatum(unionB);
v->spl_rdatum = BoxPGetDatum(unionT);
}
PG_RETURN_POINTER(v);
}