Merge pull request #3662 from OSGeo/backport-3661-to-9.2

[Backport 9.2] [Performance regression fix] Fix slowness on proj_trans() on WGS 84 <--> NAD83 conversions
OSGeo · Mar 11, 2023 · 1ef29f0 · 1ef29f0
2 parents 1bb2656 + c7f93e2
commit 1ef29f0
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Showing 2 changed files with 21 additions and 4 deletions.
diff --git a/src/4D_api.cpp b/src/4D_api.cpp
@@ -307,8 +307,7 @@ int pj_get_suggested_operation(PJ_CONTEXT *,
                                 !opList[iBest].isPriorityOp)) &&
                               !alt.isOffshore)) {
 
-                if (skipNonInstantiable &&
-                    !proj_coordoperation_is_instantiable(alt.pj->ctx, alt.pj)) {
+                if (skipNonInstantiable && !alt.isInstantiable()) {
                     continue;
                 }
                 iBest = i;
@@ -320,6 +319,16 @@ int pj_get_suggested_operation(PJ_CONTEXT *,
     return iBest;
 }
 
+//! @cond Doxygen_Suppress
+/**************************************************************************************/
+bool PJCoordOperation::isInstantiable() const {
+    /**************************************************************************************/
+    if (isInstantiableCached == INSTANTIABLE_STATUS_UNKNOWN)
+        isInstantiableCached = proj_coordoperation_is_instantiable(pj->ctx, pj);
+    return bool(isInstantiableCached);
+}
+//! @endcond
+
 /**************************************************************************************/
 static void warnAboutMissingGrid(PJ *P)
 /**************************************************************************************/
@@ -2100,7 +2109,7 @@ PJ *proj_create_crs_to_crs_from_pj(PJ_CONTEXT *ctx, const PJ *source_crs,
             !foundInstanciableAndNonBallpark) {
             if (!proj_coordoperation_has_ballpark_transformation(op.pj->ctx,
                                                                  op.pj) &&
-                proj_coordoperation_is_instantiable(op.pj->ctx, op.pj)) {
+                op.isInstantiable()) {
                 foundInstanciableAndNonBallpark = true;
             }
         }
@@ -2432,7 +2441,7 @@ PJ_PROJ_INFO proj_pj_info(PJ *P) {
             // If there's just a single coordinate operation which is
             // instanciable, use it.
             for (const auto &op : P->alternativeCoordinateOperations) {
-                if (proj_coordoperation_is_instantiable(op.pj->ctx, op.pj)) {
+                if (op.isInstantiable()) {
                     if (candidateOp == nullptr) {
                         candidateOp = op.pj;
                     } else {

diff --git a/src/proj_internal.h b/src/proj_internal.h
@@ -316,6 +316,7 @@ typedef void (*PJ_OPERATOR)(PJ_COORD &, PJ *);
 #define PJD_WGS84 4 /* WGS84 (or anything considered equivalent) */
 
 struct PJCoordOperation {
+  public:
     int idxInOriginalList;
     double minxSrc = 0.0;
     double minySrc = 0.0;
@@ -390,6 +391,13 @@ struct PJCoordOperation {
     }
 
     ~PJCoordOperation() { proj_destroy(pj); }
+
+    bool isInstantiable() const;
+
+  private:
+    static constexpr int INSTANTIABLE_STATUS_UNKNOWN =
+        -1; // must be different from 0(=false) and 1(=true)
+    mutable int isInstantiableCached = INSTANTIABLE_STATUS_UNKNOWN;
 };
 
 enum class TMercAlgo {