QGIS API Documentation 3.29.0-Master (da8bb1db43)
qgscoordinatereferencesystem_p.h
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1/***************************************************************************
2 qgscoordinatereferencesystem_p.h
3
4 --------------------------------
5 begin : 2016
6 copyright : (C) 2016 by Nyall Dawson
7 email : nyall dot dawson at gmail dot com
8***************************************************************************/
9
10/***************************************************************************
11 * *
12 * This program is free software; you can redistribute it and/or modify *
13 * it under the terms of the GNU General Public License as published by *
14 * the Free Software Foundation; either version 2 of the License, or *
15 * (at your option) any later version. *
16 * *
17 ***************************************************************************/
18#ifndef QGSCOORDINATEREFERENCESYSTEM_PRIVATE_H
19#define QGSCOORDINATEREFERENCESYSTEM_PRIVATE_H
20
22
23//
24// W A R N I N G
25// -------------
26//
27// This file is not part of the QGIS API. It exists purely as an
28// implementation detail. This header file may change from version to
29// version without notice, or even be removed.
30//
31
33
34#include <proj.h>
35#include "qgsprojutils.h"
36#include "qgsreadwritelocker.h"
37
38#ifdef DEBUG
39typedef struct OGRSpatialReferenceHS *OGRSpatialReferenceH;
40#else
41typedef void *OGRSpatialReferenceH;
42#endif
43
44class QgsCoordinateReferenceSystemPrivate : public QSharedData
45{
46 public:
47
48 explicit QgsCoordinateReferenceSystemPrivate()
49 {
50 }
51
52 QgsCoordinateReferenceSystemPrivate( const QgsCoordinateReferenceSystemPrivate &other )
53 : QSharedData( other )
54 , mSrsId( other.mSrsId )
55 , mDescription( other.mDescription )
56 , mProjectionAcronym( other.mProjectionAcronym )
57 , mEllipsoidAcronym( other.mEllipsoidAcronym )
58 , mIsGeographic( other.mIsGeographic )
59 , mMapUnits( other.mMapUnits )
60 , mSRID( other.mSRID )
61 , mAuthId( other.mAuthId )
62 , mIsValid( other.mIsValid )
63 , mCoordinateEpoch( other.mCoordinateEpoch )
64 , mPj()
65 , mProj4( other.mProj4 )
66 , mWktPreferred( other.mWktPreferred )
67 , mAxisInvertedDirty( other.mAxisInvertedDirty )
68 , mAxisInverted( other.mAxisInverted )
69 , mProjObjects()
70 {
71 }
72
73 ~QgsCoordinateReferenceSystemPrivate()
74 {
76 if ( !mProjObjects.empty() || mPj )
77 {
78 locker.changeMode( QgsReadWriteLocker::Write );
79 cleanPjObjects();
80 }
81 }
82
84 long mSrsId = 0;
85
87 QString mDescription;
88
90 QString mProjectionAcronym;
91
93 QString mEllipsoidAcronym;
94
96 bool mIsGeographic = false;
97
100
102 long mSRID = 0;
103
105 QString mAuthId;
106
108 bool mIsValid = false;
109
111 double mCoordinateEpoch = std::numeric_limits< double >::quiet_NaN();
112
113 // this is the "master" proj object, to be used as a template for new proj objects created on different threads ONLY.
114 // Always use threadLocalProjObject() instead of this.
115
116 private:
118 PJ_CONTEXT *mPjParentContext = nullptr;
119
120 void cleanPjObjects()
121 {
122
123 // During destruction of PJ* objects, the errno is set in the underlying
124 // context. Consequently the context attached to the PJ* must still exist !
125 // Which is not necessarily the case currently unfortunately. So
126 // create a temporary dummy context, and attach it to the PJ* before destroying
127 // it
128 PJ_CONTEXT *tmpContext = proj_context_create();
129 for ( auto it = mProjObjects.begin(); it != mProjObjects.end(); ++it )
130 {
131 proj_assign_context( it.value(), tmpContext );
132 proj_destroy( it.value() );
133 }
134 mProjObjects.clear();
135 if ( mPj )
136 {
137 proj_assign_context( mPj.get(), tmpContext );
138 mPj.reset();
139 }
140 proj_context_destroy( tmpContext );
141 }
142
143 public:
144
145 void setPj( QgsProjUtils::proj_pj_unique_ptr obj )
146 {
147 const QgsReadWriteLocker locker( mProjLock, QgsReadWriteLocker::Write );
148 cleanPjObjects();
149
150 mPj = std::move( obj );
151 mPjParentContext = QgsProjContext::get();
152 }
153
154 bool hasPj() const
155 {
156 const QgsReadWriteLocker locker( mProjLock, QgsReadWriteLocker::Read );
157 return static_cast< bool >( mPj );
158 }
159
160 mutable QString mProj4;
161
162 mutable QString mWktPreferred;
163
165 mutable bool mAxisInvertedDirty = false;
166
168 mutable bool mAxisInverted = false;
169
170 private:
171 mutable QReadWriteLock mProjLock{};
172 mutable QMap < PJ_CONTEXT *, PJ * > mProjObjects{};
173
174 public:
175
176 PJ *threadLocalProjObject() const
177 {
178 QgsReadWriteLocker locker( mProjLock, QgsReadWriteLocker::Read );
179 if ( !mPj )
180 return nullptr;
181
182 PJ_CONTEXT *context = QgsProjContext::get();
183 const QMap < PJ_CONTEXT *, PJ * >::const_iterator it = mProjObjects.constFind( context );
184
185 if ( it != mProjObjects.constEnd() )
186 {
187 return it.value();
188 }
189
190 // proj object doesn't exist yet, so we need to create
191 locker.changeMode( QgsReadWriteLocker::Write );
192
193 PJ *res = proj_clone( context, mPj.get() );
194 mProjObjects.insert( context, res );
195 return res;
196 }
197
198 // Only meant to be called by QgsCoordinateReferenceSystem::removeFromCacheObjectsBelongingToCurrentThread()
199 bool removeObjectsBelongingToCurrentThread( PJ_CONTEXT *pj_context )
200 {
201 const QgsReadWriteLocker locker( mProjLock, QgsReadWriteLocker::Write );
202
203 const QMap < PJ_CONTEXT *, PJ * >::iterator it = mProjObjects.find( pj_context );
204 if ( it != mProjObjects.end() )
205 {
206 proj_destroy( it.value() );
207 mProjObjects.erase( it );
208 }
209
210 if ( mPjParentContext == pj_context )
211 {
212 mPj.reset();
213 mPjParentContext = nullptr;
214 }
215
216 return mProjObjects.isEmpty();
217 }
218
219 private:
220 QgsCoordinateReferenceSystemPrivate &operator= ( const QgsCoordinateReferenceSystemPrivate & ) = delete;
221
222};
223
225
226#endif //QGSCOORDINATEREFERENCESYSTEM_PRIVATE_H
static PJ_CONTEXT * get()
Returns a thread local instance of a proj context, safe for use in the current thread.
std::unique_ptr< PJ, ProjPJDeleter > proj_pj_unique_ptr
Scoped Proj PJ object.
Definition: qgsprojutils.h:141
The QgsReadWriteLocker class is a convenience class that simplifies locking and unlocking QReadWriteL...
@ Write
Lock for write.
@ Read
Lock for read.
DistanceUnit
Units of distance.
Definition: qgsunittypes.h:68
@ DistanceUnknownUnit
Unknown distance unit.
Definition: qgsunittypes.h:78
void * OGRSpatialReferenceH
struct PJconsts PJ
struct projCtx_t PJ_CONTEXT