SQLite

/*
** A search constraint.
*/
struct RtreeConstraint {
  int iCoord;                     /* Index of constrained coordinate */
  int op;                         /* Constraining operation */
  double rValue;                  /* Constraint value. */
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
  sqlite3_rtree_geometry *pGeom;  /* Constraint callback argument for a MATCH */
};

/* Possible values for RtreeConstraint.op */
#define RTREE_EQ    0x41
#define RTREE_LE    0x42
#define RTREE_LT    0x43
#define RTREE_GE    0x44

*/
struct RtreeCell {
  i64 iRowid;
  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];
};


/*
** Value for the first field of every RtreeGeomBlob object. The MATCH
** operator tests that the first field of a blob operand matches this
** value to avoid operating on invalid blobs (which could cause a segfault).
*/
#define RTREE_GEOMETRY_MAGIC 0x891245AB

/*
** An instance of this structure must be supplied as a blob argument to
** the right-hand-side of an SQL MATCH operator used to constrain an
** r-tree query.
*/
struct RtreeGeomBlob {
  u32 magic;                      /* Always RTREE_GEOMETRY_MAGIC */
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
  void *pContext;
  int nParam;
  double aParam[1];
};

#ifndef MAX
# define MAX(x,y) ((x) < (y) ? (y) : (x))

/*
** Free the RtreeCursor.aConstraint[] array and its contents.
*/
static void freeCursorConstraints(RtreeCursor *pCsr){
  if( pCsr->aConstraint ){
    int i;                        /* Used to iterate through constraint array */
    for(i=0; i<pCsr->nConstraint; i++){
      sqlite3_rtree_geometry *pGeom = pCsr->aConstraint[i].pGeom;
      if( pGeom ){
        if( pGeom->xDelUser ) pGeom->xDelUser(pGeom->pUser);
        sqlite3_free(pGeom);
      }
    }
    sqlite3_free(pCsr->aConstraint);
    pCsr->aConstraint = 0;

** This function is called to configure the RtreeConstraint object passed
** as the second argument for a MATCH constraint. The value passed as the
** first argument to this function is the right-hand operand to the MATCH
** operator.
*/
static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
  RtreeGeomBlob *p;
  sqlite3_rtree_geometry *pGeom;
  int nBlob;

  /* Check that value is actually a blob. */
  if( !sqlite3_value_type(pValue)==SQLITE_BLOB ) return SQLITE_ERROR;

  /* Check that the blob is roughly the right size. */
  nBlob = sqlite3_value_bytes(pValue);
  if( nBlob<sizeof(RtreeGeomBlob) 
   || ((nBlob-sizeof(RtreeGeomBlob))%sizeof(double))!=0
  ){
    return SQLITE_ERROR;
  }

  pGeom = (sqlite3_rtree_geometry *)sqlite3_malloc(
      sizeof(sqlite3_rtree_geometry) + nBlob
  );
  if( !pGeom ) return SQLITE_NOMEM;
  memset(pGeom, 0, sizeof(sqlite3_rtree_geometry));
  p = (RtreeGeomBlob *)&pGeom[1];

  memcpy(p, sqlite3_value_blob(pValue), nBlob);
  if( p->magic!=RTREE_GEOMETRY_MAGIC 
   || nBlob!=(sizeof(RtreeGeomBlob) + (p->nParam-1)*sizeof(double))
  ){
    sqlite3_free(pGeom);

    void *c = (void *)RTREE_COORD_INT32;
    rc = sqlite3_create_module_v2(db, "rtree_i32", &rtreeModule, c, 0);
  }

  return rc;
}


/*
** A version of sqlite3_free() that can be used as a callback. This is used
** in two places - as the destructor for the blob value returned by the
** invocation of a geometry function, and as the destructor for the geometry
** functions themselves.

*/
static void doSqlite3Free(void *p){
  sqlite3_free(p);
}

typedef struct GeomCallbackCtx GeomCallbackCtx;
struct GeomCallbackCtx {
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
  void *pContext;
};

/*
** Each call to sqlite3_rtree_geometry_callback() creates an ordinary SQLite
** scalar user function. This C function is the callback used for all such
** registered SQL functions.
**
** The scalar user functions return a blob that is interpreted by r-tree
** table MATCH operators.
*/
static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
  GeomCallbackCtx *pGeomCtx = (GeomCallbackCtx *)sqlite3_user_data(ctx);
  RtreeGeomBlob *pBlob;
  int nBlob;

  nBlob = sizeof(RtreeGeomBlob) + (nArg-1)*sizeof(double);
  pBlob = (RtreeGeomBlob *)sqlite3_malloc(nBlob);

    for(i=0; i<nArg; i++){
      pBlob->aParam[i] = sqlite3_value_double(aArg[i]);
    }
    sqlite3_result_blob(ctx, pBlob, nBlob, doSqlite3Free);
  }
}

/*
** Register a new geometry function for use with the r-tree MATCH operator.
*/
int sqlite3_rtree_geometry_callback(
  sqlite3 *db,
  const char *zGeom,
  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *),
  void *pContext
){
  GeomCallbackCtx *pGeomCtx;      /* Context object for new user-function */

  /* Allocate and populate the context object. */
  pGeomCtx = (GeomCallbackCtx *)sqlite3_malloc(sizeof(GeomCallbackCtx));
  if( !pGeomCtx ) return SQLITE_NOMEM;

/*
** 2010 August 30
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#ifndef _SQLITE3RTREE_H_
#define _SQLITE3RTREE_H_

#include <sqlite3.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;

/*
** Register a geometry callback named zGeom that can be used as part of an
** R-Tree geometry query as follows:
**
**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
*/
int sqlite3_rtree_geometry_callback(
  sqlite3 *db,
  const char *zGeom,
  int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes),
  void *pContext
);


/*
** A pointer to a structure of the following type is passed as the first
** argument to callbacks registered using rtree_geometry_callback().
*/
struct sqlite3_rtree_geometry {
  void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
  int nParam;                     /* Size of array aParam[] */
  double *aParam;                 /* Parameters passed to SQL geom function */
  void *pUser;                    /* Callback implementation user data */
  void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
};


#ifdef __cplusplus
}  /* end of the 'extern "C"' block */




#endif





#endif  /* ifndef _SQLITE3RTREE_H_ */

** coordinates as follows:
**
**   cube(x, y, z, width, height, depth)
**
** The width, height and depth parameters must all be greater than zero.
*/
static int cube_geom(
  sqlite3_rtree_geometry *p,
  int nCoord, 
  double *aCoord, 
  int *piRes
){
  Cube *pCube = (Cube *)p->pUser;

  assert( p->pContext==(void *)&gHere );

close $in

# Set up patterns for recognizing API declarations.
#
set varpattern {^[a-zA-Z][a-zA-Z_0-9 *]+sqlite3_[_a-zA-Z0-9]+(\[|;| =)}
set declpattern {^ *[a-zA-Z][a-zA-Z_0-9 ]+ \**sqlite3_[_a-zA-Z0-9]+\(}

# Process the src/sqlite.h.in ext/rtree/sqlite3rtree.h files.
#
foreach file [list $TOP/src/sqlite.h.in $TOP/ext/rtree/sqlite3rtree.h] {
  set in [open $file]
  while {![eof $in]} {
  
    set line [gets $in]

    # File sqlite3rtree.h contains a line "#include <sqlite3.h>". Omit this
    # line when copying sqlite3rtree.h into sqlite3.h.
    #
    if {[string match {*#include*<sqlite3.h>*} $line]} continue
  
    regsub -- --VERS--           $line $zVersion line
    regsub -- --VERSION-NUMBER-- $line $nVersion line
    regsub -- --SOURCE-ID--      $line "$zDate $zUuid" line
  
    if {[regexp {define SQLITE_EXTERN extern} $line]} {
      puts $line
      puts [gets $in]
      puts ""
      puts "#ifndef SQLITE_API"
      puts "# define SQLITE_API"
      puts "#endif"
      set line ""
    }
  
    if {([regexp $varpattern $line] && ![regexp {^ *typedef} $line])
     || ([regexp $declpattern $line])
    } {
      set line "SQLITE_API $line"
    }
    puts $line
  }
  close $in
}