New set of member functions h5pp::File::vlen???(...) to control tra…

…cking of variable-length data allocations made by HDF5. Users can enable/disable tracking and call `h5pp::File::vlenReclaim()` to free all allocated memory in one go if tracking is enabled.
DavidAce · Oct 1, 2022 · 9d25d58 · 9d25d58
1 parent 6f91fb8
commit 9d25d58
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Showing 3 changed files with 23 additions and 11 deletions.
diff --git a/examples/example-04d-tables-vlen-arrays.cpp b/examples/example-04d-tables-vlen-arrays.cpp
@@ -62,7 +62,7 @@ int main() {
         scienceReadEntry.emplace_back(ScienceEntry{helper.index, std::vector<double>(data_begin, data_end)});
     }
     // Free hvl_t data! h5pp stores metadata when it detects H5T_VLEN data being read, so that we can reclaim (free) it later.
-    file.reclaim(); // Note that you can also reclaim from TableInfo objects
+    file.vlenReclaim(); // Note that you can also reclaim from TableInfo objects
 
     // Print data
     h5pp::print("Wrote and read entry:\n");

diff --git a/include/h5pp/details/h5ppFile.h b/include/h5pp/details/h5ppFile.h
@@ -93,11 +93,20 @@ namespace h5pp {
             H5Eprint(H5E_DEFAULT, stderr);
         }
         /*! Calls H5Treclaim(...) on any data that HDF5 may have allocated for variable-length data during the last reads */
-        void reclaim() const {
+        void vlenReclaim() const {
             for(auto &item : reclaimStack) { item.reclaim(); }
             reclaimStack.clear();
         }
 
+        /*!  Drop all tracked claims to allocated variable-length data (users should call H5Treclaim or free manually)  */
+        void vlenDropReclaims() const { reclaimStack.clear(); }
+
+        /*! Enable tracking of variable-length data allocations (e.g. when reading tables containgin H5T_VLEN members) */
+        void vlenEnableReclaimsTracking() { plists.vlenTrackReclaims = true; }
+
+        /*! Disable tracking of variable-length data allocations (users should call H5Treclaim or free manually) */
+        void vlenDisableReclaimsTracking() { plists.vlenTrackReclaims = false; }
+
         /*! Returns an HDF5 file handle
          *
          * - The file permission is set when initializing h5pp::File.

diff --git a/include/h5pp/details/h5ppInfo.h b/include/h5pp/details/h5ppInfo.h
@@ -138,6 +138,14 @@ namespace h5pp {
             std::string  tag;    /*!< The name of the object that was read */
             mutable long counter = 0; // Counts how many instances of this object there are
             public:
+            void drop() {
+                type    = std::nullopt;
+                space   = std::nullopt;
+                plist   = std::nullopt;
+                buf     = nullptr;
+                tag     = "";
+                counter = 0;
+            }
             void reclaim() {
                 if(buf != nullptr and type and space and plist) {
                     h5pp::logger::log->trace("Reclaiming vlen buffer from reading [{}]", tag);
@@ -147,12 +155,7 @@ namespace h5pp {
                     H5Dvlen_reclaim(type.value(), space.value(), plist.value(), buf);
 #endif
                 }
-                type    = std::nullopt;
-                space   = std::nullopt;
-                plist   = std::nullopt;
-                buf     = nullptr;
-                tag     = "";
-                counter = 0;
+                drop();
             }
             Reclaim() = default;
             Reclaim(const hid::h5t &type, const hid::h5s &space, const hid::h5p &plist, void *buf, const std::string &tag)
@@ -184,13 +187,13 @@ namespace h5pp {
                 counter--;
                 if(buf != nullptr and counter == 0)
                     h5pp::logger::log->warn("~Reclaim: buffer for variable-length array likely remains after reading [{}]. "
-                                             "Call h5pp::File::reclaim() or <Dset|Attr|Table>Info::reclaim() to avoid a memory leak.",
-                                             tag);
+                                            "Call h5pp::File::reclaim() or <Dset|Attr|Table>Info::vlenReclaim() to avoid a memory leak.",
+                                            tag);
             }
         };
 
         public:
-        mutable std::optional<Reclaim> reclaimInfo = /*!< Used to reclaim any memory allocated for variable-length arrays */
+        mutable std::optional<Reclaim> reclaimInfo = /*!< Used to vlenReclaim any memory allocated for variable-length arrays */
             std::nullopt;
 
         /*! Calls H5Treclaim(...) on memory that HDF5 allocates when reading variable-length arrays */