Fix constantly increasing memory in std::list (#636)

* Fix constantly increasing memory in std::list

When someone is constantly publishing with the same tf2 timestamp
(application error, I know), the storage_ of the tf2::TimeCache grows
unbounded causing system-wide memory leaks. In a ROS system, each tf2
Listener will spawn one of these TimeCache objects and thus, all ROS
nodes that have any sort of tf2 listener will slowly start allocating
more and more memory

And also fixed the situation where two different tf2 needs to be
introduced at the same timestamp.

Since the tests were failing I realized that I had to dive a bit deeper
into the simple solution. And extend a bit the TransformStorage clase to
be comparable, now instead of just looking to the timestamps, the
implementation avoids inserting duplicates in the buffer.

If for some reason, someone is publishing a different Transfrom
(xyz,rpy) at the same timestamp. Well, that case is not being captured
now, but I'd say that's another problem

Signed-off-by: Ignacio Vizzo <ignaciovizzo@gmail.com>

tf2/CMakeLists.txt

@@ -105,6 +105,11 @@ if(BUILD_TESTING)
   if(TARGET test_time)
     target_link_libraries(test_time tf2)
   endif()
+
+  ament_add_gtest(test_storage test/test_storage.cpp)
+  if(TARGET test_storage)
+    target_link_libraries(test_storage tf2)
+  endif()
 endif()
 
 ament_export_dependencies(console_bridge geometry_msgs rcutils rosidl_runtime_cpp)

tf2/include/tf2/transform_storage.h

@@ -67,6 +67,22 @@ class TransformStorage
     return *this;
   }
 
+  TF2_PUBLIC
+  bool operator==(const TransformStorage & rhs) const
+  {
+    return (this->rotation_ == rhs.rotation_) &&
+           (this->translation_ == rhs.translation_) &&
+           (this->stamp_ == rhs.stamp_) &&
+           (this->frame_id_ == rhs.frame_id_) &&
+           (this->child_frame_id_ == rhs.child_frame_id_);
+  }
+
+  TF2_PUBLIC
+  bool operator!=(const TransformStorage & rhs) const
+  {
+    return !(*this == rhs);
+  }
+
   tf2::Quaternion rotation_;
   tf2::Vector3 translation_;
   TimePoint stamp_;

tf2/src/cache.cpp

@@ -28,6 +28,7 @@
 
 /** \author Tully Foote */
 
+#include <algorithm>
 #include <cassert>
 #include <sstream>
 #include <string>
@@ -260,7 +261,10 @@ bool TimeCache::insertData(const TransformStorage & new_data)
     }
     storage_it++;
   }
-  storage_.insert(storage_it, new_data);
+  // Insert elements only if not already present
+  if (std::find(storage_.begin(), storage_.end(), new_data) == storage_.end()) {
+    storage_.insert(storage_it, new_data);
+  }
 
   pruneList();
   return true;

tf2/test/cache_unittest.cpp

@@ -112,6 +112,27 @@ TEST(TimeCache, RepeatabilityReverseInsertOrder)
   }
 }
 
+TEST(TimeCache, RepeatedElements)
+{
+  constexpr uint64_t runs = 100;
+
+  tf2::TimeCache cache;
+  EXPECT_EQ(cache.getListLength(), 0);
+
+  tf2::TransformStorage stor;
+  setIdentity(stor);
+  stor.frame_id_ = tf2::CompactFrameID(0);
+  stor.stamp_ = tf2::TimePoint(std::chrono::nanoseconds(0));
+
+  // Attempt to insert the same element 100 times
+  for (uint64_t i = 1; i < runs; ++i) {
+    cache.insertData(stor);
+  }
+
+  // Even after 100 insertions, there should be one unique element in the internal list
+  EXPECT_EQ(cache.getListLength(), 1);
+}
+
 TEST(TimeCache, ZeroAtFront)
 {
   uint64_t runs = 100;

tf2/test/test_storage.cpp

@@ -0,0 +1,130 @@
+// Copyright (c) 2024 Dexory. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the Willow Garage nor the names of its
+//      contributors may be used to endorse or promote products derived from
+//      this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#include <gtest/gtest.h>
+
+#include "tf2/LinearMath/Quaternion.h"
+#include "tf2/LinearMath/Vector3.h"
+#include "tf2/time.h"
+#include "tf2/transform_storage.h"
+
+class TransformStorageTest : public ::testing::Test
+{
+protected:
+  tf2::TransformStorage createTransformStorage()
+  {
+    const tf2::CompactFrameID frame_id(0);
+    const tf2::CompactFrameID child_frame_id(1);
+    const tf2::TimePoint stamp(tf2::TimePointZero);
+    const tf2::Quaternion rotation(0.0, 0.0, 0.0, 1.0);
+    const tf2::Vector3 translation(0.0, 0.0, 0.0);
+    return tf2::TransformStorage(stamp, rotation, translation, frame_id, child_frame_id);
+  }
+};
+
+TEST_F(TransformStorageTest, EqualityOperator) {
+  // Create a dummy storage, set to identity
+  tf2::TransformStorage transformStorage1 = createTransformStorage();
+
+  // tf2::Quaternion rotation_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.rotation_.setValue(1.0, 0.0, 0.0, 0.0);
+    ASSERT_FALSE(transformStorage1 == transformStorage2);
+  }
+  // tf2::Vector3 translation_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.translation_.setValue(1.0, 0.0, 0.0);
+    ASSERT_FALSE(transformStorage1 == transformStorage2);
+  }
+  // TimePoint stamp_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.stamp_ = tf2::TimePoint(tf2::durationFromSec(1.0));
+    ASSERT_FALSE(transformStorage1 == transformStorage2);
+  }
+  // CompactFrameID frame_id_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.frame_id_ = 55;
+    ASSERT_FALSE(transformStorage1 == transformStorage2);
+  }
+  // CompactFrameID child_frame_id_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.translation_.setValue(1.0, 0.0, 0.0);
+    ASSERT_FALSE(transformStorage1 == transformStorage2);
+  }
+}
+
+TEST_F(TransformStorageTest, InequalityOperator) {
+  // Create a dummy storage, set to identity
+  tf2::TransformStorage transformStorage1 = createTransformStorage();
+
+  // tf2::Quaternion rotation_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.rotation_.setValue(1.0, 0.0, 0.0, 0.0);
+    ASSERT_TRUE(transformStorage1 != transformStorage2);
+  }
+  // tf2::Vector3 translation_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.translation_.setValue(1.0, 0.0, 0.0);
+    ASSERT_TRUE(transformStorage1 != transformStorage2);
+  }
+  // TimePoint stamp_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.stamp_ = tf2::TimePoint(tf2::durationFromSec(1.0));
+    ASSERT_TRUE(transformStorage1 != transformStorage2);
+  }
+  // CompactFrameID frame_id_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.frame_id_ = 55;
+    ASSERT_TRUE(transformStorage1 != transformStorage2);
+  }
+  // CompactFrameID child_frame_id_;
+  {
+    tf2::TransformStorage transformStorage2 = createTransformStorage();
+    ASSERT_TRUE(transformStorage1 == transformStorage2);
+    transformStorage2.translation_.setValue(1.0, 0.0, 0.0);
+    ASSERT_TRUE(transformStorage1 != transformStorage2);
+  }
+}