mariadb/sql/spatial.h
Davi Arnaut f317d3a6fb Bug#42733: Type-punning warnings when compiling MySQL --
strict aliasing violations.

Another rather noisy violation of strict aliasing rules
is the spatial code which makes use of stack-based memory
(of type Geometry_buffer) to provide placement for Geometry
objects. Although a placement new is allowed to dynamically
change the type of a object, the object returned by the
new placement was being ignored and the original stack-based
object was being casted to the new type, thus violating strict
aliasing rules.

The solution is to reorganize the code so that the object
returned by the new placement is used instead of casting the
original object. Also, to ensure that the stack-based object
is properly aligned with respect to the objects it provides
placement for, a set of compiler-dependent macros and types
are introduced so that the alignment of objects can be inquired
and specified.

include/Makefile.am:
  Add new header.
include/my_compiler.h:
  Add new header.
include/my_global.h:
  Remove now-unnecessary macros.
sql/spatial.cc:
  Make object creation functions return the object whose type
  was dynamically changed by the new placement.
  
  Move static method from the header in order to avoid having
  to access a forward declaration.
sql/spatial.h:
  Object creation callbacks now take a array of chars as the
  storage area.
  
  Move create_by_typeid to a source file as to not access the
  forward declaration of Geometry_buffer.
  
  Ensure that Geometry_buffer is properly aligned.
sql/sql_show.cc:
  Use newly added aligned storage helper.
2010-07-14 09:27:13 -03:00

532 lines
16 KiB
C++

/* Copyright (C) 2002-2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef _spatial_h
#define _spatial_h
#include <my_compiler.h>
#ifdef HAVE_SPATIAL
const uint SRID_SIZE= 4;
const uint SIZEOF_STORED_DOUBLE= 8;
const uint POINT_DATA_SIZE= SIZEOF_STORED_DOUBLE*2;
const uint WKB_HEADER_SIZE= 1+4;
const uint32 GET_SIZE_ERROR= ((uint32) -1);
struct st_point_2d
{
double x;
double y;
};
struct st_linear_ring
{
uint32 n_points;
st_point_2d points;
};
/***************************** MBR *******************************/
/*
It's ok that a lot of the functions are inline as these are only used once
in MySQL
*/
struct MBR
{
double xmin, ymin, xmax, ymax;
MBR()
{
xmin= ymin= DBL_MAX;
xmax= ymax= -DBL_MAX;
}
MBR(const double xmin_arg, const double ymin_arg,
const double xmax_arg, const double ymax_arg)
:xmin(xmin_arg), ymin(ymin_arg), xmax(xmax_arg), ymax(ymax_arg)
{}
MBR(const st_point_2d &min, const st_point_2d &max)
:xmin(min.x), ymin(min.y), xmax(max.x), ymax(max.y)
{}
inline void add_xy(double x, double y)
{
/* Not using "else" for proper one point MBR calculation */
if (x < xmin)
xmin= x;
if (x > xmax)
xmax= x;
if (y < ymin)
ymin= y;
if (y > ymax)
ymax= y;
}
void add_xy(const char *px, const char *py)
{
double x, y;
float8get(x, px);
float8get(y, py);
add_xy(x,y);
}
void add_mbr(const MBR *mbr)
{
if (mbr->xmin < xmin)
xmin= mbr->xmin;
if (mbr->xmax > xmax)
xmax= mbr->xmax;
if (mbr->ymin < ymin)
ymin= mbr->ymin;
if (mbr->ymax > ymax)
ymax= mbr->ymax;
}
int equals(const MBR *mbr)
{
/* The following should be safe, even if we compare doubles */
return ((mbr->xmin == xmin) && (mbr->ymin == ymin) &&
(mbr->xmax == xmax) && (mbr->ymax == ymax));
}
int disjoint(const MBR *mbr)
{
/* The following should be safe, even if we compare doubles */
return ((mbr->xmin > xmax) || (mbr->ymin > ymax) ||
(mbr->xmax < xmin) || (mbr->ymax < ymin));
}
int intersects(const MBR *mbr)
{
return !disjoint(mbr);
}
int touches(const MBR *mbr)
{
/* The following should be safe, even if we compare doubles */
return ((mbr->xmin == xmax || mbr->xmax == xmin) &&
((mbr->ymin >= ymin && mbr->ymin <= ymax) ||
(mbr->ymax >= ymin && mbr->ymax <= ymax))) ||
((mbr->ymin == ymax || mbr->ymax == ymin) &&
((mbr->xmin >= xmin && mbr->xmin <= xmax) ||
(mbr->xmax >= xmin && mbr->xmax <= xmax)));
}
int within(const MBR *mbr)
{
/* The following should be safe, even if we compare doubles */
return ((mbr->xmin <= xmin) && (mbr->ymin <= ymin) &&
(mbr->xmax >= xmax) && (mbr->ymax >= ymax));
}
int contains(const MBR *mbr)
{
/* The following should be safe, even if we compare doubles */
return ((mbr->xmin >= xmin) && (mbr->ymin >= ymin) &&
(mbr->xmax <= xmax) && (mbr->ymax <= ymax));
}
bool inner_point(double x, double y) const
{
/* The following should be safe, even if we compare doubles */
return (xmin<x) && (xmax>x) && (ymin<y) && (ymax>y);
}
/**
The dimension maps to an integer as:
- Polygon -> 2
- Horizontal or vertical line -> 1
- Point -> 0
- Invalid MBR -> -1
*/
int dimension() const
{
int d= 0;
if (xmin > xmax)
return -1;
else if (xmin < xmax)
d++;
if (ymin > ymax)
return -1;
else if (ymin < ymax)
d++;
return d;
}
int overlaps(const MBR *mbr)
{
/*
overlaps() requires that some point inside *this is also inside
*mbr, and that both geometries and their intersection are of the
same dimension.
*/
int d = dimension();
if (d != mbr->dimension() || d <= 0 || contains(mbr) || within(mbr))
return 0;
MBR intersection(max(xmin, mbr->xmin), max(ymin, mbr->ymin),
min(xmax, mbr->xmax), min(ymax, mbr->ymax));
return (d == intersection.dimension());
}
};
/***************************** Geometry *******************************/
struct Geometry_buffer;
class Geometry
{
public:
Geometry() {} /* Remove gcc warning */
virtual ~Geometry() {} /* Remove gcc warning */
static void *operator new(size_t size, void *buffer)
{
return buffer;
}
static void operator delete(void *ptr, void *buffer)
{}
static void operator delete(void *buffer)
{}
static String bad_geometry_data;
enum wkbType
{
wkb_point= 1,
wkb_linestring= 2,
wkb_polygon= 3,
wkb_multipoint= 4,
wkb_multilinestring= 5,
wkb_multipolygon= 6,
wkb_geometrycollection= 7,
wkb_last=7
};
enum wkbByteOrder
{
wkb_xdr= 0, /* Big Endian */
wkb_ndr= 1 /* Little Endian */
};
/** Callback which creates Geometry objects on top of a given placement. */
typedef Geometry *(*create_geom_t)(char *);
class Class_info
{
public:
LEX_STRING m_name;
int m_type_id;
create_geom_t m_create_func;
Class_info(const char *name, int type_id, create_geom_t create_func);
};
virtual const Class_info *get_class_info() const=0;
virtual uint32 get_data_size() const=0;
virtual bool init_from_wkt(Gis_read_stream *trs, String *wkb)=0;
/* returns the length of the wkb that was read */
virtual uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo,
String *res)=0;
virtual bool get_data_as_wkt(String *txt, const char **end) const=0;
virtual bool get_mbr(MBR *mbr, const char **end) const=0;
virtual bool dimension(uint32 *dim, const char **end) const=0;
virtual int get_x(double *x) const { return -1; }
virtual int get_y(double *y) const { return -1; }
virtual int geom_length(double *len) const { return -1; }
virtual int area(double *ar, const char **end) const { return -1;}
virtual int is_closed(int *closed) const { return -1; }
virtual int num_interior_ring(uint32 *n_int_rings) const { return -1; }
virtual int num_points(uint32 *n_points) const { return -1; }
virtual int num_geometries(uint32 *num) const { return -1; }
virtual int start_point(String *point) const { return -1; }
virtual int end_point(String *point) const { return -1; }
virtual int exterior_ring(String *ring) const { return -1; }
virtual int centroid(String *point) const { return -1; }
virtual int point_n(uint32 num, String *result) const { return -1; }
virtual int interior_ring_n(uint32 num, String *result) const { return -1; }
virtual int geometry_n(uint32 num, String *result) const { return -1; }
public:
static Geometry *create_by_typeid(Geometry_buffer *buffer, int type_id);
static Geometry *construct(Geometry_buffer *buffer,
const char *data, uint32 data_len);
static Geometry *create_from_wkt(Geometry_buffer *buffer,
Gis_read_stream *trs, String *wkt,
bool init_stream=1);
static Geometry *create_from_wkb(Geometry_buffer *buffer, const char *wkb,
uint32 len, String *res);
int as_wkt(String *wkt, const char **end)
{
uint32 len= (uint) get_class_info()->m_name.length;
if (wkt->reserve(len + 2, 512))
return 1;
wkt->qs_append(get_class_info()->m_name.str, len);
wkt->qs_append('(');
if (get_data_as_wkt(wkt, end))
return 1;
wkt->qs_append(')');
return 0;
}
inline void set_data_ptr(const char *data, uint32 data_len)
{
m_data= data;
m_data_end= data + data_len;
}
inline void shift_wkb_header()
{
m_data+= WKB_HEADER_SIZE;
}
bool envelope(String *result) const;
static Class_info *ci_collection[wkb_last+1];
protected:
static Class_info *find_class(int type_id)
{
return ((type_id < wkb_point) || (type_id > wkb_last)) ?
NULL : ci_collection[type_id];
}
static Class_info *find_class(const char *name, uint32 len);
const char *append_points(String *txt, uint32 n_points,
const char *data, uint32 offset) const;
bool create_point(String *result, const char *data) const;
bool create_point(String *result, double x, double y) const;
const char *get_mbr_for_points(MBR *mbr, const char *data, uint offset)
const;
inline bool no_data(const char *cur_data, uint32 data_amount) const
{
return (cur_data + data_amount > m_data_end);
}
const char *m_data;
const char *m_data_end;
};
/***************************** Point *******************************/
class Gis_point: public Geometry
{
public:
Gis_point() {} /* Remove gcc warning */
virtual ~Gis_point() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int get_xy(double *x, double *y) const
{
const char *data= m_data;
if (no_data(data, SIZEOF_STORED_DOUBLE * 2))
return 1;
float8get(*x, data);
float8get(*y, data + SIZEOF_STORED_DOUBLE);
return 0;
}
int get_x(double *x) const
{
if (no_data(m_data, SIZEOF_STORED_DOUBLE))
return 1;
float8get(*x, m_data);
return 0;
}
int get_y(double *y) const
{
const char *data= m_data;
if (no_data(data, SIZEOF_STORED_DOUBLE * 2)) return 1;
float8get(*y, data + SIZEOF_STORED_DOUBLE);
return 0;
}
bool dimension(uint32 *dim, const char **end) const
{
*dim= 0;
*end= 0; /* No default end */
return 0;
}
const Class_info *get_class_info() const;
};
/***************************** LineString *******************************/
class Gis_line_string: public Geometry
{
public:
Gis_line_string() {} /* Remove gcc warning */
virtual ~Gis_line_string() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int geom_length(double *len) const;
int is_closed(int *closed) const;
int num_points(uint32 *n_points) const;
int start_point(String *point) const;
int end_point(String *point) const;
int point_n(uint32 n, String *result) const;
bool dimension(uint32 *dim, const char **end) const
{
*dim= 1;
*end= 0; /* No default end */
return 0;
}
const Class_info *get_class_info() const;
};
/***************************** Polygon *******************************/
class Gis_polygon: public Geometry
{
public:
Gis_polygon() {} /* Remove gcc warning */
virtual ~Gis_polygon() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int area(double *ar, const char **end) const;
int exterior_ring(String *result) const;
int num_interior_ring(uint32 *n_int_rings) const;
int interior_ring_n(uint32 num, String *result) const;
int centroid_xy(double *x, double *y) const;
int centroid(String *result) const;
bool dimension(uint32 *dim, const char **end) const
{
*dim= 2;
*end= 0; /* No default end */
return 0;
}
const Class_info *get_class_info() const;
};
/***************************** MultiPoint *******************************/
class Gis_multi_point: public Geometry
{
public:
Gis_multi_point() {} /* Remove gcc warning */
virtual ~Gis_multi_point() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int num_geometries(uint32 *num) const;
int geometry_n(uint32 num, String *result) const;
bool dimension(uint32 *dim, const char **end) const
{
*dim= 0;
*end= 0; /* No default end */
return 0;
}
const Class_info *get_class_info() const;
};
/***************************** MultiLineString *******************************/
class Gis_multi_line_string: public Geometry
{
public:
Gis_multi_line_string() {} /* Remove gcc warning */
virtual ~Gis_multi_line_string() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int num_geometries(uint32 *num) const;
int geometry_n(uint32 num, String *result) const;
int geom_length(double *len) const;
int is_closed(int *closed) const;
bool dimension(uint32 *dim, const char **end) const
{
*dim= 1;
*end= 0; /* No default end */
return 0;
}
const Class_info *get_class_info() const;
};
/***************************** MultiPolygon *******************************/
class Gis_multi_polygon: public Geometry
{
public:
Gis_multi_polygon() {} /* Remove gcc warning */
virtual ~Gis_multi_polygon() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int num_geometries(uint32 *num) const;
int geometry_n(uint32 num, String *result) const;
int area(double *ar, const char **end) const;
int centroid(String *result) const;
bool dimension(uint32 *dim, const char **end) const
{
*dim= 2;
*end= 0; /* No default end */
return 0;
}
const Class_info *get_class_info() const;
};
/*********************** GeometryCollection *******************************/
class Gis_geometry_collection: public Geometry
{
public:
Gis_geometry_collection() {} /* Remove gcc warning */
virtual ~Gis_geometry_collection() {} /* Remove gcc warning */
uint32 get_data_size() const;
bool init_from_wkt(Gis_read_stream *trs, String *wkb);
uint init_from_wkb(const char *wkb, uint len, wkbByteOrder bo, String *res);
bool get_data_as_wkt(String *txt, const char **end) const;
bool get_mbr(MBR *mbr, const char **end) const;
int num_geometries(uint32 *num) const;
int geometry_n(uint32 num, String *result) const;
bool dimension(uint32 *dim, const char **end) const;
const Class_info *get_class_info() const;
};
struct Geometry_buffer : public
my_aligned_storage<sizeof(Gis_point), MY_ALIGNOF(Gis_point)> {};
#endif /*HAVE_SPATAIAL*/
#endif