Experimentally delete iterations after closing

franzpoeschel · Nov 21, 2023 · b1b8875 · b1b8875
1 parent 47da1e9
commit b1b8875
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Showing 4 changed files with 40 additions and 3 deletions.
diff --git a/include/openPMD/Series.hpp b/include/openPMD/Series.hpp
@@ -179,6 +179,8 @@ namespace internal
          */
         bool m_wroteAtLeastOneIOStep = false;
 
+        bool m_containedAtLeastOneIteration = false;
+
         /**
          * Remember the preference that the backend specified for parsing.
          * Not used in file-based iteration encoding, empty then.
@@ -750,6 +752,10 @@ OPENPMD_private
      * (We could also add this to the public API some time)
      */
     std::optional<std::vector<IterationIndex_t> > currentSnapshot() const;
+
+    Iteration resetIteration(IterationIndex_t);
+    std::pair<decltype(iterations)::iterator, Iteration>
+    resetIteration(decltype(iterations)::iterator);
 }; // Series
 } // namespace openPMD
 

diff --git a/src/ReadIterations.cpp b/src/ReadIterations.cpp
@@ -444,9 +444,12 @@ std::optional<SeriesIterator *> SeriesIterator::loopBody()
         }
     }
 
+    auto oldIterationIndex = data.currentIteration;
+
     auto guardReturn =
-        [&series, &iterations](
+        [&series, &iterations, oldIterationIndex](
             auto const &option) -> std::optional<openPMD::SeriesIterator *> {
+        series.resetIteration(oldIterationIndex);
         if (!option.has_value() || *option.value() == end())
         {
             return option;
@@ -489,13 +492,15 @@ std::optional<SeriesIterator *> SeriesIterator::loopBody()
             {
                 // we had this iteration already, skip it
                 iteration.endStep();
+                series.resetIteration(index);
                 return std::nullopt; // empty, go into next iteration
             }
         }
         else
         {
             // we had this iteration already, skip it
             series.advance(AdvanceMode::ENDSTEP);
+            series.resetIteration(index);
             return std::nullopt;
         }
     };
@@ -514,6 +519,7 @@ std::optional<SeriesIterator *> SeriesIterator::loopBody()
     if (series.iterationEncoding() == IterationEncoding::fileBased)
     {
         // this one is handled above, stream is over once it proceeds to here
+        series.resetIteration(oldIterationIndex);
         this->close();
         return {this};
     }
@@ -529,7 +535,7 @@ void SeriesIterator::deactivateDeadIteration(iteration_index_t index)
     {
     case IterationEncoding::fileBased: {
         Parameter<Operation::CLOSE_FILE> param;
-        Iteration resetted = data.series->iterations[index].resetIteration();
+        Iteration resetted = data.series->resetIteration(index);
         auto writable = &resetted.writable();
         param.keep_this_data_alive = std::move(resetted);
         data.series->IOHandler()->enqueue(IOTask(writable, std::move(param)));

diff --git a/src/Series.cpp b/src/Series.cpp
@@ -749,7 +749,7 @@ void Series::flushFileBased(
     bool flushIOHandler)
 {
     auto &series = get();
-    if (end == begin)
+    if (end == begin && !series.m_containedAtLeastOneIteration)
         throw std::runtime_error(
             "fileBased output can not be written with no iterations.");
 
@@ -2469,6 +2469,25 @@ auto Series::currentSnapshot() const
     }
 }
 
+Iteration Series::resetIteration(IterationIndex_t idx)
+{
+    auto it = iterations.find(idx);
+    if (it == iterations.end())
+    {
+        return {};
+    }
+    return resetIteration(it).second;
+}
+
+auto Series::resetIteration(decltype(iterations)::iterator it)
+    -> std::pair<decltype(iterations)::iterator, Iteration>
+{
+    auto res = it->second;
+    it = iterations.container().erase(it);
+    get().m_containedAtLeastOneIteration = true;
+    return {it, res};
+}
+
 namespace
 {
     CleanedFilename cleanFilename(

diff --git a/test/SerialIOTest.cpp b/test/SerialIOTest.cpp
@@ -187,6 +187,8 @@ void write_and_read_many_iterations(
 
         Series read(
             filename, Access::READ_ONLY, "{\"defer_iteration_parsing\": true}");
+        std::cout << "BEFORE: " << read.iterations.size() << " ITERATIONS"
+                  << std::endl;
         for (auto iteration : read.iterations)
         {
             iteration.second.open();
@@ -206,10 +208,14 @@ void write_and_read_many_iterations(
                 REQUIRE(array[i] == float(i));
             }
         }
+        std::cout << "AFTER: " << read.iterations.size() << " ITERATIONS"
+                  << std::endl;
+        REQUIRE(read.iterations.size() == 10);
     }
 
     Series list(filename, Access::READ_ONLY);
     helper::listSeries(list);
+    REQUIRE(list.iterations.size() == 0);
 }
 
 TEST_CASE("write_and_read_many_iterations", "[serial]")