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spgquadtreeproc.c
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1 /*-------------------------------------------------------------------------
2  *
3  * spgquadtreeproc.c
4  * implementation of quad tree over points for SP-GiST
5  *
6  *
7  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * IDENTIFICATION
11  * src/backend/access/spgist/spgquadtreeproc.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 
16 #include "postgres.h"
17 
18 #include "access/spgist.h"
19 #include "access/spgist_private.h"
20 #include "access/stratnum.h"
21 #include "catalog/pg_type.h"
22 #include "utils/builtins.h"
23 #include "utils/float.h"
24 #include "utils/geo_decls.h"
25 
26 Datum
28 {
29  /* spgConfigIn *cfgin = (spgConfigIn *) PG_GETARG_POINTER(0); */
31 
32  cfg->prefixType = POINTOID;
33  cfg->labelType = VOIDOID; /* we don't need node labels */
34  cfg->canReturnData = true;
35  cfg->longValuesOK = false;
37 }
38 
39 #define SPTEST(f, x, y) \
40  DatumGetBool(DirectFunctionCall2(f, PointPGetDatum(x), PointPGetDatum(y)))
41 
42 /*
43  * Determine which quadrant a point falls into, relative to the centroid.
44  *
45  * Quadrants are identified like this:
46  *
47  * 4 | 1
48  * ----+-----
49  * 3 | 2
50  *
51  * Points on one of the axes are taken to lie in the lowest-numbered
52  * adjacent quadrant.
53  */
54 static int16
55 getQuadrant(Point *centroid, Point *tst)
56 {
57  if ((SPTEST(point_above, tst, centroid) ||
58  SPTEST(point_horiz, tst, centroid)) &&
59  (SPTEST(point_right, tst, centroid) ||
60  SPTEST(point_vert, tst, centroid)))
61  return 1;
62 
63  if (SPTEST(point_below, tst, centroid) &&
64  (SPTEST(point_right, tst, centroid) ||
65  SPTEST(point_vert, tst, centroid)))
66  return 2;
67 
68  if ((SPTEST(point_below, tst, centroid) ||
69  SPTEST(point_horiz, tst, centroid)) &&
70  SPTEST(point_left, tst, centroid))
71  return 3;
72 
73  if (SPTEST(point_above, tst, centroid) &&
74  SPTEST(point_left, tst, centroid))
75  return 4;
76 
77  elog(ERROR, "getQuadrant: impossible case");
78  return 0;
79 }
80 
81 /* Returns bounding box of a given quadrant inside given bounding box */
82 static BOX *
83 getQuadrantArea(BOX *bbox, Point *centroid, int quadrant)
84 {
85  BOX *result = (BOX *) palloc(sizeof(BOX));
86 
87  switch (quadrant)
88  {
89  case 1:
90  result->high = bbox->high;
91  result->low = *centroid;
92  break;
93  case 2:
94  result->high.x = bbox->high.x;
95  result->high.y = centroid->y;
96  result->low.x = centroid->x;
97  result->low.y = bbox->low.y;
98  break;
99  case 3:
100  result->high = *centroid;
101  result->low = bbox->low;
102  break;
103  case 4:
104  result->high.x = centroid->x;
105  result->high.y = bbox->high.y;
106  result->low.x = bbox->low.x;
107  result->low.y = centroid->y;
108  break;
109  }
110 
111  return result;
112 }
113 
114 Datum
116 {
119  Point *inPoint = DatumGetPointP(in->datum),
120  *centroid;
121 
122  if (in->allTheSame)
123  {
124  out->resultType = spgMatchNode;
125  /* nodeN will be set by core */
126  out->result.matchNode.levelAdd = 0;
127  out->result.matchNode.restDatum = PointPGetDatum(inPoint);
128  PG_RETURN_VOID();
129  }
130 
131  Assert(in->hasPrefix);
132  centroid = DatumGetPointP(in->prefixDatum);
133 
134  Assert(in->nNodes == 4);
135 
136  out->resultType = spgMatchNode;
137  out->result.matchNode.nodeN = getQuadrant(centroid, inPoint) - 1;
138  out->result.matchNode.levelAdd = 0;
139  out->result.matchNode.restDatum = PointPGetDatum(inPoint);
140 
141  PG_RETURN_VOID();
142 }
143 
144 #ifdef USE_MEDIAN
145 static int
146 x_cmp(const void *a, const void *b, void *arg)
147 {
148  Point *pa = *(Point **) a;
149  Point *pb = *(Point **) b;
150 
151  if (pa->x == pb->x)
152  return 0;
153  return (pa->x > pb->x) ? 1 : -1;
154 }
155 
156 static int
157 y_cmp(const void *a, const void *b, void *arg)
158 {
159  Point *pa = *(Point **) a;
160  Point *pb = *(Point **) b;
161 
162  if (pa->y == pb->y)
163  return 0;
164  return (pa->y > pb->y) ? 1 : -1;
165 }
166 #endif
167 
168 Datum
170 {
173  int i;
174  Point *centroid;
175 
176 #ifdef USE_MEDIAN
177  /* Use the median values of x and y as the centroid point */
178  Point **sorted;
179 
180  sorted = palloc(sizeof(*sorted) * in->nTuples);
181  for (i = 0; i < in->nTuples; i++)
182  sorted[i] = DatumGetPointP(in->datums[i]);
183 
184  centroid = palloc(sizeof(*centroid));
185 
186  qsort(sorted, in->nTuples, sizeof(*sorted), x_cmp);
187  centroid->x = sorted[in->nTuples >> 1]->x;
188  qsort(sorted, in->nTuples, sizeof(*sorted), y_cmp);
189  centroid->y = sorted[in->nTuples >> 1]->y;
190 #else
191  /* Use the average values of x and y as the centroid point */
192  centroid = palloc0(sizeof(*centroid));
193 
194  for (i = 0; i < in->nTuples; i++)
195  {
196  centroid->x += DatumGetPointP(in->datums[i])->x;
197  centroid->y += DatumGetPointP(in->datums[i])->y;
198  }
199 
200  centroid->x /= in->nTuples;
201  centroid->y /= in->nTuples;
202 #endif
203 
204  out->hasPrefix = true;
205  out->prefixDatum = PointPGetDatum(centroid);
206 
207  out->nNodes = 4;
208  out->nodeLabels = NULL; /* we don't need node labels */
209 
210  out->mapTuplesToNodes = palloc(sizeof(int) * in->nTuples);
211  out->leafTupleDatums = palloc(sizeof(Datum) * in->nTuples);
212 
213  for (i = 0; i < in->nTuples; i++)
214  {
215  Point *p = DatumGetPointP(in->datums[i]);
216  int quadrant = getQuadrant(centroid, p) - 1;
217 
218  out->leafTupleDatums[i] = PointPGetDatum(p);
219  out->mapTuplesToNodes[i] = quadrant;
220  }
221 
222  PG_RETURN_VOID();
223 }
224 
225 
226 Datum
228 {
231  Point *centroid;
232  BOX infbbox;
233  BOX *bbox = NULL;
234  int which;
235  int i;
236 
237  Assert(in->hasPrefix);
238  centroid = DatumGetPointP(in->prefixDatum);
239 
240  /*
241  * When ordering scan keys are specified, we've to calculate distance for
242  * them. In order to do that, we need calculate bounding boxes for all
243  * children nodes. Calculation of those bounding boxes on non-zero level
244  * require knowledge of bounding box of upper node. So, we save bounding
245  * boxes to traversalValues.
246  */
247  if (in->norderbys > 0)
248  {
249  out->distances = (double **) palloc(sizeof(double *) * in->nNodes);
250  out->traversalValues = (void **) palloc(sizeof(void *) * in->nNodes);
251 
252  if (in->level == 0)
253  {
254  double inf = get_float8_infinity();
255 
256  infbbox.high.x = inf;
257  infbbox.high.y = inf;
258  infbbox.low.x = -inf;
259  infbbox.low.y = -inf;
260  bbox = &infbbox;
261  }
262  else
263  {
264  bbox = in->traversalValue;
265  Assert(bbox);
266  }
267  }
268 
269  if (in->allTheSame)
270  {
271  /* Report that all nodes should be visited */
272  out->nNodes = in->nNodes;
273  out->nodeNumbers = (int *) palloc(sizeof(int) * in->nNodes);
274  for (i = 0; i < in->nNodes; i++)
275  {
276  out->nodeNumbers[i] = i;
277 
278  if (in->norderbys > 0)
279  {
281 
282  /* Use parent quadrant box as traversalValue */
283  BOX *quadrant = box_copy(bbox);
284 
285  MemoryContextSwitchTo(oldCtx);
286 
287  out->traversalValues[i] = quadrant;
288  out->distances[i] = spg_key_orderbys_distances(BoxPGetDatum(quadrant), false,
289  in->orderbys, in->norderbys);
290  }
291  }
292  PG_RETURN_VOID();
293  }
294 
295  Assert(in->nNodes == 4);
296 
297  /* "which" is a bitmask of quadrants that satisfy all constraints */
298  which = (1 << 1) | (1 << 2) | (1 << 3) | (1 << 4);
299 
300  for (i = 0; i < in->nkeys; i++)
301  {
302  Point *query = DatumGetPointP(in->scankeys[i].sk_argument);
303  BOX *boxQuery;
304 
305  switch (in->scankeys[i].sk_strategy)
306  {
308  if (SPTEST(point_right, centroid, query))
309  which &= (1 << 3) | (1 << 4);
310  break;
312  if (SPTEST(point_left, centroid, query))
313  which &= (1 << 1) | (1 << 2);
314  break;
316  which &= (1 << getQuadrant(centroid, query));
317  break;
320  if (SPTEST(point_above, centroid, query))
321  which &= (1 << 2) | (1 << 3);
322  break;
325  if (SPTEST(point_below, centroid, query))
326  which &= (1 << 1) | (1 << 4);
327  break;
329 
330  /*
331  * For this operator, the query is a box not a point. We
332  * cheat to the extent of assuming that DatumGetPointP won't
333  * do anything that would be bad for a pointer-to-box.
334  */
335  boxQuery = DatumGetBoxP(in->scankeys[i].sk_argument);
336 
338  PointerGetDatum(boxQuery),
339  PointerGetDatum(centroid))))
340  {
341  /* centroid is in box, so all quadrants are OK */
342  }
343  else
344  {
345  /* identify quadrant(s) containing all corners of box */
346  Point p;
347  int r = 0;
348 
349  p = boxQuery->low;
350  r |= 1 << getQuadrant(centroid, &p);
351  p.y = boxQuery->high.y;
352  r |= 1 << getQuadrant(centroid, &p);
353  p = boxQuery->high;
354  r |= 1 << getQuadrant(centroid, &p);
355  p.x = boxQuery->low.x;
356  r |= 1 << getQuadrant(centroid, &p);
357 
358  which &= r;
359  }
360  break;
361  default:
362  elog(ERROR, "unrecognized strategy number: %d",
363  in->scankeys[i].sk_strategy);
364  break;
365  }
366 
367  if (which == 0)
368  break; /* no need to consider remaining conditions */
369  }
370 
371  out->levelAdds = palloc(sizeof(int) * 4);
372  for (i = 0; i < 4; ++i)
373  out->levelAdds[i] = 1;
374 
375  /* We must descend into the quadrant(s) identified by which */
376  out->nodeNumbers = (int *) palloc(sizeof(int) * 4);
377  out->nNodes = 0;
378 
379  for (i = 1; i <= 4; i++)
380  {
381  if (which & (1 << i))
382  {
383  out->nodeNumbers[out->nNodes] = i - 1;
384 
385  if (in->norderbys > 0)
386  {
388  BOX *quadrant = getQuadrantArea(bbox, centroid, i);
389 
390  MemoryContextSwitchTo(oldCtx);
391 
392  out->traversalValues[out->nNodes] = quadrant;
393 
394  out->distances[out->nNodes] = spg_key_orderbys_distances(BoxPGetDatum(quadrant), false,
395  in->orderbys, in->norderbys);
396  }
397 
398  out->nNodes++;
399  }
400  }
401 
402  PG_RETURN_VOID();
403 }
404 
405 
406 Datum
408 {
411  Point *datum = DatumGetPointP(in->leafDatum);
412  bool res;
413  int i;
414 
415  /* all tests are exact */
416  out->recheck = false;
417 
418  /* leafDatum is what it is... */
419  out->leafValue = in->leafDatum;
420 
421  /* Perform the required comparison(s) */
422  res = true;
423  for (i = 0; i < in->nkeys; i++)
424  {
425  Point *query = DatumGetPointP(in->scankeys[i].sk_argument);
426 
427  switch (in->scankeys[i].sk_strategy)
428  {
430  res = SPTEST(point_left, datum, query);
431  break;
433  res = SPTEST(point_right, datum, query);
434  break;
436  res = SPTEST(point_eq, datum, query);
437  break;
440  res = SPTEST(point_below, datum, query);
441  break;
444  res = SPTEST(point_above, datum, query);
445  break;
447 
448  /*
449  * For this operator, the query is a box not a point. We
450  * cheat to the extent of assuming that DatumGetPointP won't
451  * do anything that would be bad for a pointer-to-box.
452  */
453  res = SPTEST(box_contain_pt, query, datum);
454  break;
455  default:
456  elog(ERROR, "unrecognized strategy number: %d",
457  in->scankeys[i].sk_strategy);
458  break;
459  }
460 
461  if (!res)
462  break;
463  }
464 
465  if (res && in->norderbys > 0)
466  /* ok, it passes -> let's compute the distances */
468  in->orderbys, in->norderbys);
469 
470  PG_RETURN_BOOL(res);
471 }
signed short int16
Definition: c.h:416
#define RTOldAboveStrategyNumber
Definition: stratnum.h:80
Datum spg_quad_picksplit(PG_FUNCTION_ARGS)
static BOX * getQuadrantArea(BOX *bbox, Point *centroid, int quadrant)
Definition: geo_decls.h:140
Datum datum
Definition: spgist.h:55
bool hasPrefix
Definition: spgist.h:61
static float8 get_float8_infinity(void)
Definition: float.h:93
bool canReturnData
Definition: spgist.h:46
float8 x
Definition: geo_decls.h:98
Datum * leafTupleDatums
Definition: spgist.h:126
#define RTLeftStrategyNumber
Definition: stratnum.h:51
Datum * datums
Definition: spgist.h:113
#define PointerGetDatum(X)
Definition: postgres.h:556
Datum box_contain_pt(PG_FUNCTION_ARGS)
Definition: geo_ops.c:3207
ScanKey orderbys
Definition: spgist.h:135
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
void * traversalValue
Definition: spgist.h:141
Datum prefixDatum
Definition: spgist.h:62
#define RTContainedByStrategyNumber
Definition: stratnum.h:58
#define PG_GETARG_POINTER(n)
Definition: fmgr.h:276
#define RTOldBelowStrategyNumber
Definition: stratnum.h:79
#define RTBelowStrategyNumber
Definition: stratnum.h:60
Datum spg_quad_leaf_consistent(PG_FUNCTION_ARGS)
Datum point_below(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1897
Datum point_right(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1879
struct spgChooseOut::@47::@48 matchNode
MemoryContext traversalMemoryContext
Definition: spgist.h:142
#define ERROR
Definition: elog.h:43
ScanKey orderbys
Definition: spgist.h:170
Datum * nodeLabels
Definition: spgist.h:123
StrategyNumber sk_strategy
Definition: skey.h:68
ScanKey scankeys
Definition: spgist.h:169
Datum point_left(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1870
double * distances
Definition: spgist.h:188
#define SPTEST(f, x, y)
#define DatumGetBool(X)
Definition: postgres.h:393
#define RTSameStrategyNumber
Definition: stratnum.h:56
static int16 getQuadrant(Point *centroid, Point *tst)
void ** traversalValues
Definition: spgist.h:160
static int x_cmp(const void *a, const void *b)
Definition: spgkdtreeproc.c:85
union spgChooseOut::@47 result
int nNodes
Definition: spgist.h:63
Point low
Definition: geo_decls.h:142
Datum spg_quad_inner_consistent(PG_FUNCTION_ARGS)
void * palloc0(Size size)
Definition: mcxt.c:981
#define PG_RETURN_BOOL(x)
Definition: fmgr.h:359
bool longValuesOK
Definition: spgist.h:47
uintptr_t Datum
Definition: postgres.h:367
double ** distances
Definition: spgist.h:161
Datum point_vert(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1906
Oid prefixType
Definition: spgist.h:43
spgChooseResultType resultType
Definition: spgist.h:76
BOX * box_copy(BOX *orig)
Definition: spgproc.c:82
Datum spg_quad_choose(PG_FUNCTION_ARGS)
#define BoxPGetDatum(X)
Definition: geo_decls.h:198
#define PG_RETURN_VOID()
Definition: fmgr.h:349
#define RTAboveStrategyNumber
Definition: stratnum.h:61
#define Assert(condition)
Definition: c.h:800
float8 y
Definition: geo_decls.h:98
#define RTRightStrategyNumber
Definition: stratnum.h:55
#define DatumGetPointP(X)
Definition: geo_decls.h:175
bool hasPrefix
Definition: spgist.h:119
ScanKey scankeys
Definition: spgist.h:134
#define DatumGetBoxP(X)
Definition: geo_decls.h:197
Point high
Definition: geo_decls.h:142
Datum point_horiz(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1915
void * palloc(Size size)
Definition: mcxt.c:950
double * spg_key_orderbys_distances(Datum key, bool isLeaf, ScanKey orderbys, int norderbys)
Definition: spgproc.c:63
Datum point_eq(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1924
#define elog(elevel,...)
Definition: elog.h:228
Oid labelType
Definition: spgist.h:44
int i
int * mapTuplesToNodes
Definition: spgist.h:125
Datum point_above(PG_FUNCTION_ARGS)
Definition: geo_ops.c:1888
bool allTheSame
Definition: spgist.h:60
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Definition: spgist.h:120
#define PG_FUNCTION_ARGS
Definition: fmgr.h:193
Datum spg_quad_config(PG_FUNCTION_ARGS)
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Definition: port.h:497
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Definition: skey.h:72
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Definition: fmgr.h:628
#define PointPGetDatum(X)
Definition: geo_decls.h:176
static int y_cmp(const void *a, const void *b)
Definition: spgkdtreeproc.c:96