MySQL  8.0.27
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wkb.h
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1 #ifndef SQL_GIS_WKB_H_INCLUDED
2 #define SQL_GIS_WKB_H_INCLUDED
3 
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25 
26 /// @file
27 ///
28 /// This file declares the interface of the WKB parser for geometries and the
29 /// parser for the internal geometry representation.
30 
31 #include <memory> // std::unique_ptr
32 
33 #include "sql/gis/geometries.h"
34 #include "sql/gis/srid.h"
35 
36 class THD;
37 class String;
38 namespace dd {
39 class Spatial_reference_system;
40 }
41 
42 namespace gis {
43 
44 /// Parses an SRID from a little-endian string.
45 ///
46 /// @param[in] str The string.
47 /// @param[in] length Length of the string.
48 /// @param[out] srid The SRID read from the string.
49 ///
50 /// @retval false Success.
51 /// @retval true Error. my_error() has not been called.
52 bool parse_srid(const char *str, std::size_t length, srid_t *srid);
53 
54 ///
55 /// Parses a geometry WKB string and constructs a geometry object.
56 ///
57 /// The geometry is allocated on the heap and ownership is transferred to the
58 /// caller.
59 ///
60 /// If ignore_axis_order is true, the string is assumed to be on the geometry
61 /// storage format, not general WKB. The storage format differs from ordinary
62 /// WKB by having a fixed x=longitude, y=latitude mapping.
63 ///
64 /// @warning This function checks if there are so many nested levels of geometry
65 /// collections that the stack will be exhausted. If that happens, my_error is
66 /// called and the function exits with no geometry value. However, if thd is
67 /// nullptr, this check is disabled, and the caller is responsible for checking
68 /// that there is enough stack to parse the WKB string.
69 ///
70 /// @param[in] thd Thread handle.
71 /// @param srs The SRS of the geometry.
72 /// @param wkb The WKB string.
73 /// @param length Length of the WKB string.
74 /// @param ignore_axis_order Ignore SRS axis order and assume it's always
75 /// long-lat.
76 ///
77 /// @return The geometry. If an error occurred, the return value is a null
78 /// pointer. In case of stack overrun, my_error has been called.
79 std::unique_ptr<Geometry> parse_wkb(THD *thd,
81  const char *wkb, std::size_t length,
82  bool ignore_axis_order = false);
83 
84 /// Parses a little-endian geometry string (SRID + WKB).
85 ///
86 /// The geometry is allocated on the heap and ownership is transferred to the
87 /// caller.
88 ///
89 /// @param[in] thd Thread handle
90 /// @param[in] func_name The function name to use in error messages.
91 /// @param[in] str The geometry string.
92 /// @param[out] srs The spatial reference system of the geometry.
93 /// @param[out] geometry The geometry.
94 /// @param[in] treat_unknown_srid_as_cartesian Whether to treat unknown
95 /// SRIDs as Cartesian. If false, raise an error if the SRID is unknown.
96 ///
97 /// @retval false Success.
98 /// @retval true Error. my_error() has been called.
99 bool parse_geometry(THD *thd, const char *func_name, const String *str,
100  const dd::Spatial_reference_system **srs,
101  std::unique_ptr<Geometry> *geometry,
102  bool treat_unknown_srid_as_cartesian = false);
103 
104 /// Writes a little-endian geometry string (SRID + WKB).
105 ///
106 /// @param[in] srs The SRS of the geometry.
107 /// @param[in] geometry The geometry.
108 /// @param[out] str The string to write the geometry to.
109 ///
110 /// @retval false Success.
111 /// @retval true Error. my_error() has been called.
112 bool write_geometry(const dd::Spatial_reference_system *srs, Geometry &geometry,
113  String *str);
114 
115 } // namespace gis
116 
117 #endif // SQL_GIS_WKB_H_INCLUDED
Definition: spatial.h:214
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:165
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:821
Definition: spatial_reference_system.h:52
This file declares the geometry class hierarchy used by the server as the internal representation of ...
std::string str(const mysqlrouter::ConfigGenerator::Options::Endpoint &ep)
Definition: config_generator.cc:1056
The version of the current data dictionary table definitions.
Definition: dictionary_client.h:42
Definition: area.cc:46
bool length(const dd::Spatial_reference_system *srs, const Geometry *g1, double *length, bool *null) noexcept
Computes the length of linestrings and multilinestrings.
Definition: length.cc:75
bool parse_geometry(THD *thd, const char *func_name, const String *str, const dd::Spatial_reference_system **srs, std::unique_ptr< Geometry > *geometry, bool treat_unknown_srid_as_cartesian)
Parses a little-endian geometry string (SRID + WKB).
Definition: wkb.cc:436
bool parse_srid(const char *str, std::size_t length, srid_t *srid)
Parses an SRID from a little-endian string.
Definition: wkb.cc:428
bool write_geometry(const dd::Spatial_reference_system *srs, Geometry &geometry, String *str)
Writes a little-endian geometry string (SRID + WKB).
Definition: wkb.cc:498
std::unique_ptr< Geometry > parse_wkb(THD *thd, const dd::Spatial_reference_system *srs, const char *wkb, std::size_t length, bool ignore_axis_order)
Parses a geometry WKB string and constructs a geometry object.
Definition: wkb.cc:383
std::uint32_t srid_t
A spatial reference system ID (SRID).
Definition: srid.h:32