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Add the sqlite3_rtree_query_callback() API to the RTree virtual table.

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(Cherrypick from the sessions branch.)

FossilOrigin-Name: af2cbe64adab5f9e3b0f3da00d06428088589d7f
This commit is contained in:
drh
2014-04-28 17:56:19 +00:00
parent 1f8bb4b0a8
commit 65e6b0dd12
14 changed files with 1425 additions and 801 deletions
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200
src/test_rtree.c
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@@ -35,6 +35,8 @@ struct Circle {
double centerx;
double centery;
double radius;
double mxArea;
int eScoreType;
};
/*
@@ -50,11 +52,7 @@ static void circle_del(void *p){
static int circle_geom(
sqlite3_rtree_geometry *p,
int nCoord,
#ifdef SQLITE_RTREE_INT_ONLY
sqlite3_int64 *aCoord,
#else
double *aCoord,
#endif
sqlite3_rtree_dbl *aCoord,
int *pRes
){
int i; /* Iterator variable */
@@ -62,7 +60,12 @@ static int circle_geom(
double xmin, xmax; /* X dimensions of box being tested */
double ymin, ymax; /* X dimensions of box being tested */
if( p->pUser==0 ){
xmin = aCoord[0];
xmax = aCoord[1];
ymin = aCoord[2];
ymax = aCoord[3];
pCircle = (Circle *)p->pUser;
if( pCircle==0 ){
/* If pUser is still 0, then the parameter values have not been tested
** for correctness or stored into a Circle structure yet. Do this now. */
@@ -108,14 +111,9 @@ static int circle_geom(
pCircle->aBox[1].xmax = pCircle->centerx - pCircle->radius;
pCircle->aBox[1].ymin = pCircle->centery;
pCircle->aBox[1].ymax = pCircle->centery;
pCircle->mxArea = (xmax - xmin)*(ymax - ymin) + 1.0;
}
pCircle = (Circle *)p->pUser;
xmin = aCoord[0];
xmax = aCoord[1];
ymin = aCoord[2];
ymax = aCoord[3];
/* Check if any of the 4 corners of the bounding-box being tested lie
** inside the circular region. If they do, then the bounding-box does
** intersect the region of interest. Set the output variable to true and
@@ -154,6 +152,170 @@ static int circle_geom(
return SQLITE_OK;
}
/*
** Implementation of "circle" r-tree geometry callback using the
** 2nd-generation interface that allows scoring.
*/
static int circle_query_func(sqlite3_rtree_query_info *p){
int i; /* Iterator variable */
Circle *pCircle; /* Structure defining circular region */
double xmin, xmax; /* X dimensions of box being tested */
double ymin, ymax; /* X dimensions of box being tested */
int nWithin = 0; /* Number of corners inside the circle */
xmin = p->aCoord[0];
xmax = p->aCoord[1];
ymin = p->aCoord[2];
ymax = p->aCoord[3];
pCircle = (Circle *)p->pUser;
if( pCircle==0 ){
/* If pUser is still 0, then the parameter values have not been tested
** for correctness or stored into a Circle structure yet. Do this now. */
/* This geometry callback is for use with a 2-dimensional r-tree table.
** Return an error if the table does not have exactly 2 dimensions. */
if( p->nCoord!=4 ) return SQLITE_ERROR;
/* Test that the correct number of parameters (4) have been supplied,
** and that the parameters are in range (that the radius of the circle
** radius is greater than zero). */
if( p->nParam!=4 || p->aParam[2]<0.0 ) return SQLITE_ERROR;
/* Allocate a structure to cache parameter data in. Return SQLITE_NOMEM
** if the allocation fails. */
pCircle = (Circle *)(p->pUser = sqlite3_malloc(sizeof(Circle)));
if( !pCircle ) return SQLITE_NOMEM;
p->xDelUser = circle_del;
/* Record the center and radius of the circular region. One way that
** tested bounding boxes that intersect the circular region are detected
** is by testing if each corner of the bounding box lies within radius
** units of the center of the circle. */
pCircle->centerx = p->aParam[0];
pCircle->centery = p->aParam[1];
pCircle->radius = p->aParam[2];
pCircle->eScoreType = (int)p->aParam[3];
/* Define two bounding box regions. The first, aBox[0], extends to
** infinity in the X dimension. It covers the same range of the Y dimension
** as the circular region. The second, aBox[1], extends to infinity in
** the Y dimension and is constrained to the range of the circle in the
** X dimension.
**
** Then imagine each box is split in half along its short axis by a line
** that intersects the center of the circular region. A bounding box
** being tested can be said to intersect the circular region if it contains
** points from each half of either of the two infinite bounding boxes.
*/
pCircle->aBox[0].xmin = pCircle->centerx;
pCircle->aBox[0].xmax = pCircle->centerx;
pCircle->aBox[0].ymin = pCircle->centery + pCircle->radius;
pCircle->aBox[0].ymax = pCircle->centery - pCircle->radius;
pCircle->aBox[1].xmin = pCircle->centerx + pCircle->radius;
pCircle->aBox[1].xmax = pCircle->centerx - pCircle->radius;
pCircle->aBox[1].ymin = pCircle->centery;
pCircle->aBox[1].ymax = pCircle->centery;
pCircle->mxArea = 200.0*200.0;
}
/* Check if any of the 4 corners of the bounding-box being tested lie
** inside the circular region. If they do, then the bounding-box does
** intersect the region of interest. Set the output variable to true and
** return SQLITE_OK in this case. */
for(i=0; i<4; i++){
double x = (i&0x01) ? xmax : xmin;
double y = (i&0x02) ? ymax : ymin;
double d2;
d2 = (x-pCircle->centerx)*(x-pCircle->centerx);
d2 += (y-pCircle->centery)*(y-pCircle->centery);
if( d2<(pCircle->radius*pCircle->radius) ) nWithin++;
}
/* Check if the bounding box covers any other part of the circular region.
** See comments above for a description of how this test works. If it does
** cover part of the circular region, set the output variable to true
** and return SQLITE_OK. */
if( nWithin==0 ){
for(i=0; i<2; i++){
if( xmin<=pCircle->aBox[i].xmin
&& xmax>=pCircle->aBox[i].xmax
&& ymin<=pCircle->aBox[i].ymin
&& ymax>=pCircle->aBox[i].ymax
){
nWithin = 1;
break;
}
}
}
if( pCircle->eScoreType==1 ){
/* Depth first search */
p->rScore = p->iLevel;
}else if( pCircle->eScoreType==2 ){
/* Breadth first search */
p->rScore = 100 - p->iLevel;
}else if( pCircle->eScoreType==3 ){
/* Depth-first search, except sort the leaf nodes by area with
** the largest area first */
if( p->iLevel==1 ){
p->rScore = 1.0 - (xmax-xmin)*(ymax-ymin)/pCircle->mxArea;
if( p->rScore<0.01 ) p->rScore = 0.01;
}else{
p->rScore = 0.0;
}
}else if( pCircle->eScoreType==4 ){
/* Depth-first search, except exclude odd rowids */
p->rScore = p->iLevel;
if( p->iRowid&1 ) nWithin = 0;
}else{
/* Breadth-first search, except exclude odd rowids */
p->rScore = 100 - p->iLevel;
if( p->iRowid&1 ) nWithin = 0;
}
if( nWithin==0 ){
p->eWithin = NOT_WITHIN;
}else if( nWithin>=4 ){
p->eWithin = FULLY_WITHIN;
}else{
p->eWithin = PARTLY_WITHIN;
}
return SQLITE_OK;
}
/*
** Implementation of "breadthfirstsearch" r-tree geometry callback using the
** 2nd-generation interface that allows scoring.
**
** ... WHERE id MATCH breadthfirstsearch($x0,$x1,$y0,$y1) ...
**
** It returns all entries whose bounding boxes overlap with $x0,$x1,$y0,$y1.
*/
static int bfs_query_func(sqlite3_rtree_query_info *p){
double x0,x1,y0,y1; /* Dimensions of box being tested */
double bx0,bx1,by0,by1; /* Boundary of the query function */
if( p->nParam!=4 ) return SQLITE_ERROR;
x0 = p->aCoord[0];
x1 = p->aCoord[1];
y0 = p->aCoord[2];
y1 = p->aCoord[3];
bx0 = p->aParam[0];
bx1 = p->aParam[1];
by0 = p->aParam[2];
by1 = p->aParam[3];
p->rScore = 100 - p->iLevel;
if( p->eParentWithin==FULLY_WITHIN ){
p->eWithin = FULLY_WITHIN;
}else if( x0>=bx0 && x1<=bx1 && y0>=by0 && y1<=by1 ){
p->eWithin = FULLY_WITHIN;
}else if( x1>=bx0 && x0<=bx1 && y1>=by0 && y0<=by1 ){
p->eWithin = PARTLY_WITHIN;
}else{
p->eWithin = NOT_WITHIN;
}
return SQLITE_OK;
}
/* END of implementation of "circle" geometry callback.
**************************************************************************
*************************************************************************/
@@ -194,11 +356,7 @@ static int gHere = 42;
static int cube_geom(
sqlite3_rtree_geometry *p,
int nCoord,
#ifdef SQLITE_RTREE_INT_ONLY
sqlite3_int64 *aCoord,
#else
double *aCoord,
#endif
sqlite3_rtree_dbl *aCoord,
int *piRes
){
Cube *pCube = (Cube *)p->pUser;
@@ -293,6 +451,14 @@ static int register_circle_geom(
}
if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
rc = sqlite3_rtree_geometry_callback(db, "circle", circle_geom, 0);
if( rc==SQLITE_OK ){
rc = sqlite3_rtree_query_callback(db, "Qcircle",
circle_query_func, 0, 0);
}
if( rc==SQLITE_OK ){
rc = sqlite3_rtree_query_callback(db, "breadthfirstsearch",
bfs_query_func, 0, 0);
}
Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
#endif
return TCL_OK;