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-rw-r--r--src/backend/access/spgist/spgkdtreeproc.c349
1 files changed, 349 insertions, 0 deletions
diff --git a/src/backend/access/spgist/spgkdtreeproc.c b/src/backend/access/spgist/spgkdtreeproc.c
new file mode 100644
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--- /dev/null
+++ b/src/backend/access/spgist/spgkdtreeproc.c
@@ -0,0 +1,349 @@
+/*-------------------------------------------------------------------------
+ *
+ * spgkdtreeproc.c
+ * implementation of k-d tree over points for SP-GiST
+ *
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/access/spgist/spgkdtreeproc.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/spgist.h"
+#include "access/spgist_private.h"
+#include "access/stratnum.h"
+#include "catalog/pg_type.h"
+#include "utils/builtins.h"
+#include "utils/float.h"
+#include "utils/geo_decls.h"
+
+
+Datum
+spg_kd_config(PG_FUNCTION_ARGS)
+{
+ /* spgConfigIn *cfgin = (spgConfigIn *) PG_GETARG_POINTER(0); */
+ spgConfigOut *cfg = (spgConfigOut *) PG_GETARG_POINTER(1);
+
+ cfg->prefixType = FLOAT8OID;
+ cfg->labelType = VOIDOID; /* we don't need node labels */
+ cfg->canReturnData = true;
+ cfg->longValuesOK = false;
+ PG_RETURN_VOID();
+}
+
+static int
+getSide(double coord, bool isX, Point *tst)
+{
+ double tstcoord = (isX) ? tst->x : tst->y;
+
+ if (coord == tstcoord)
+ return 0;
+ else if (coord > tstcoord)
+ return 1;
+ else
+ return -1;
+}
+
+Datum
+spg_kd_choose(PG_FUNCTION_ARGS)
+{
+ spgChooseIn *in = (spgChooseIn *) PG_GETARG_POINTER(0);
+ spgChooseOut *out = (spgChooseOut *) PG_GETARG_POINTER(1);
+ Point *inPoint = DatumGetPointP(in->datum);
+ double coord;
+
+ if (in->allTheSame)
+ elog(ERROR, "allTheSame should not occur for k-d trees");
+
+ Assert(in->hasPrefix);
+ coord = DatumGetFloat8(in->prefixDatum);
+
+ Assert(in->nNodes == 2);
+
+ out->resultType = spgMatchNode;
+ out->result.matchNode.nodeN =
+ (getSide(coord, in->level % 2, inPoint) > 0) ? 0 : 1;
+ out->result.matchNode.levelAdd = 1;
+ out->result.matchNode.restDatum = PointPGetDatum(inPoint);
+
+ PG_RETURN_VOID();
+}
+
+typedef struct SortedPoint
+{
+ Point *p;
+ int i;
+} SortedPoint;
+
+static int
+x_cmp(const void *a, const void *b)
+{
+ SortedPoint *pa = (SortedPoint *) a;
+ SortedPoint *pb = (SortedPoint *) b;
+
+ if (pa->p->x == pb->p->x)
+ return 0;
+ return (pa->p->x > pb->p->x) ? 1 : -1;
+}
+
+static int
+y_cmp(const void *a, const void *b)
+{
+ SortedPoint *pa = (SortedPoint *) a;
+ SortedPoint *pb = (SortedPoint *) b;
+
+ if (pa->p->y == pb->p->y)
+ return 0;
+ return (pa->p->y > pb->p->y) ? 1 : -1;
+}
+
+
+Datum
+spg_kd_picksplit(PG_FUNCTION_ARGS)
+{
+ spgPickSplitIn *in = (spgPickSplitIn *) PG_GETARG_POINTER(0);
+ spgPickSplitOut *out = (spgPickSplitOut *) PG_GETARG_POINTER(1);
+ int i;
+ int middle;
+ SortedPoint *sorted;
+ double coord;
+
+ sorted = palloc(sizeof(*sorted) * in->nTuples);
+ for (i = 0; i < in->nTuples; i++)
+ {
+ sorted[i].p = DatumGetPointP(in->datums[i]);
+ sorted[i].i = i;
+ }
+
+ qsort(sorted, in->nTuples, sizeof(*sorted),
+ (in->level % 2) ? x_cmp : y_cmp);
+ middle = in->nTuples >> 1;
+ coord = (in->level % 2) ? sorted[middle].p->x : sorted[middle].p->y;
+
+ out->hasPrefix = true;
+ out->prefixDatum = Float8GetDatum(coord);
+
+ out->nNodes = 2;
+ out->nodeLabels = NULL; /* we don't need node labels */
+
+ out->mapTuplesToNodes = palloc(sizeof(int) * in->nTuples);
+ out->leafTupleDatums = palloc(sizeof(Datum) * in->nTuples);
+
+ /*
+ * Note: points that have coordinates exactly equal to coord may get
+ * classified into either node, depending on where they happen to fall in
+ * the sorted list. This is okay as long as the inner_consistent function
+ * descends into both sides for such cases. This is better than the
+ * alternative of trying to have an exact boundary, because it keeps the
+ * tree balanced even when we have many instances of the same point value.
+ * So we should never trigger the allTheSame logic.
+ */
+ for (i = 0; i < in->nTuples; i++)
+ {
+ Point *p = sorted[i].p;
+ int n = sorted[i].i;
+
+ out->mapTuplesToNodes[n] = (i < middle) ? 0 : 1;
+ out->leafTupleDatums[n] = PointPGetDatum(p);
+ }
+
+ PG_RETURN_VOID();
+}
+
+Datum
+spg_kd_inner_consistent(PG_FUNCTION_ARGS)
+{
+ spgInnerConsistentIn *in = (spgInnerConsistentIn *) PG_GETARG_POINTER(0);
+ spgInnerConsistentOut *out = (spgInnerConsistentOut *) PG_GETARG_POINTER(1);
+ double coord;
+ int which;
+ int i;
+ BOX bboxes[2];
+
+ Assert(in->hasPrefix);
+ coord = DatumGetFloat8(in->prefixDatum);
+
+ if (in->allTheSame)
+ elog(ERROR, "allTheSame should not occur for k-d trees");
+
+ Assert(in->nNodes == 2);
+
+ /* "which" is a bitmask of children that satisfy all constraints */
+ which = (1 << 1) | (1 << 2);
+
+ for (i = 0; i < in->nkeys; i++)
+ {
+ Point *query = DatumGetPointP(in->scankeys[i].sk_argument);
+ BOX *boxQuery;
+
+ switch (in->scankeys[i].sk_strategy)
+ {
+ case RTLeftStrategyNumber:
+ if ((in->level % 2) != 0 && FPlt(query->x, coord))
+ which &= (1 << 1);
+ break;
+ case RTRightStrategyNumber:
+ if ((in->level % 2) != 0 && FPgt(query->x, coord))
+ which &= (1 << 2);
+ break;
+ case RTSameStrategyNumber:
+ if ((in->level % 2) != 0)
+ {
+ if (FPlt(query->x, coord))
+ which &= (1 << 1);
+ else if (FPgt(query->x, coord))
+ which &= (1 << 2);
+ }
+ else
+ {
+ if (FPlt(query->y, coord))
+ which &= (1 << 1);
+ else if (FPgt(query->y, coord))
+ which &= (1 << 2);
+ }
+ break;
+ case RTBelowStrategyNumber:
+ case RTOldBelowStrategyNumber:
+ if ((in->level % 2) == 0 && FPlt(query->y, coord))
+ which &= (1 << 1);
+ break;
+ case RTAboveStrategyNumber:
+ case RTOldAboveStrategyNumber:
+ if ((in->level % 2) == 0 && FPgt(query->y, coord))
+ which &= (1 << 2);
+ break;
+ case RTContainedByStrategyNumber:
+
+ /*
+ * For this operator, the query is a box not a point. We
+ * cheat to the extent of assuming that DatumGetPointP won't
+ * do anything that would be bad for a pointer-to-box.
+ */
+ boxQuery = DatumGetBoxP(in->scankeys[i].sk_argument);
+
+ if ((in->level % 2) != 0)
+ {
+ if (FPlt(boxQuery->high.x, coord))
+ which &= (1 << 1);
+ else if (FPgt(boxQuery->low.x, coord))
+ which &= (1 << 2);
+ }
+ else
+ {
+ if (FPlt(boxQuery->high.y, coord))
+ which &= (1 << 1);
+ else if (FPgt(boxQuery->low.y, coord))
+ which &= (1 << 2);
+ }
+ break;
+ default:
+ elog(ERROR, "unrecognized strategy number: %d",
+ in->scankeys[i].sk_strategy);
+ break;
+ }
+
+ if (which == 0)
+ break; /* no need to consider remaining conditions */
+ }
+
+ /* We must descend into the children identified by which */
+ out->nNodes = 0;
+
+ /* Fast-path for no matching children */
+ if (!which)
+ PG_RETURN_VOID();
+
+ out->nodeNumbers = (int *) palloc(sizeof(int) * 2);
+
+ /*
+ * When ordering scan keys are specified, we've to calculate distance for
+ * them. In order to do that, we need calculate bounding boxes for both
+ * children nodes. Calculation of those bounding boxes on non-zero level
+ * require knowledge of bounding box of upper node. So, we save bounding
+ * boxes to traversalValues.
+ */
+ if (in->norderbys > 0)
+ {
+ BOX infArea;
+ BOX *area;
+
+ out->distances = (double **) palloc(sizeof(double *) * in->nNodes);
+ out->traversalValues = (void **) palloc(sizeof(void *) * in->nNodes);
+
+ if (in->level == 0)
+ {
+ float8 inf = get_float8_infinity();
+
+ infArea.high.x = inf;
+ infArea.high.y = inf;
+ infArea.low.x = -inf;
+ infArea.low.y = -inf;
+ area = &infArea;
+ }
+ else
+ {
+ area = (BOX *) in->traversalValue;
+ Assert(area);
+ }
+
+ bboxes[0].low = area->low;
+ bboxes[1].high = area->high;
+
+ if (in->level % 2)
+ {
+ /* split box by x */
+ bboxes[0].high.x = bboxes[1].low.x = coord;
+ bboxes[0].high.y = area->high.y;
+ bboxes[1].low.y = area->low.y;
+ }
+ else
+ {
+ /* split box by y */
+ bboxes[0].high.y = bboxes[1].low.y = coord;
+ bboxes[0].high.x = area->high.x;
+ bboxes[1].low.x = area->low.x;
+ }
+ }
+
+ for (i = 1; i <= 2; i++)
+ {
+ if (which & (1 << i))
+ {
+ out->nodeNumbers[out->nNodes] = i - 1;
+
+ if (in->norderbys > 0)
+ {
+ MemoryContext oldCtx = MemoryContextSwitchTo(in->traversalMemoryContext);
+ BOX *box = box_copy(&bboxes[i - 1]);
+
+ MemoryContextSwitchTo(oldCtx);
+
+ out->traversalValues[out->nNodes] = box;
+
+ out->distances[out->nNodes] = spg_key_orderbys_distances(BoxPGetDatum(box), false,
+ in->orderbys, in->norderbys);
+ }
+
+ out->nNodes++;
+ }
+ }
+
+ /* Set up level increments, too */
+ out->levelAdds = (int *) palloc(sizeof(int) * 2);
+ out->levelAdds[0] = 1;
+ out->levelAdds[1] = 1;
+
+ PG_RETURN_VOID();
+}
+
+/*
+ * spg_kd_leaf_consistent() is the same as spg_quad_leaf_consistent(),
+ * since we support the same operators and the same leaf data type.
+ * So we just borrow that function.
+ */
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