Add FrameIdFilteringPointsProcessor (#566)

* Add FrameIdFilteringPointsProcessor

Implements a PointProcessor that filters PointBatches (either by
whitelisting or blacklisting) the frame_id.

cartographer/io/frame_id_filtering_points_processor.cc

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2017 The Cartographer Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "cartographer/io/frame_id_filtering_points_processor.h"
+
+#include "cartographer/common/lua_parameter_dictionary.h"
+#include "cartographer/common/make_unique.h"
+#include "cartographer/io/points_batch.h"
+#include "glog/logging.h"
+
+namespace cartographer {
+namespace io {
+
+std::unique_ptr<FrameIdFilteringPointsProcessor>
+FrameIdFilteringPointsProcessor::FromDictionary(
+    common::LuaParameterDictionary* dictionary,
+    PointsProcessor* next) {
+  std::vector<string> keep_frames, drop_frames;
+  if (dictionary->HasKey("keep_frames")) {
+    keep_frames =
+        dictionary->GetDictionary("keep_frames")->GetArrayValuesAsStrings();
+  }
+  if (dictionary->HasKey("drop_frames")) {
+    drop_frames =
+        dictionary->GetDictionary("drop_frames")->GetArrayValuesAsStrings();
+  }
+  return common::make_unique<FrameIdFilteringPointsProcessor>(
+      std::unordered_set<string>(keep_frames.begin(), keep_frames.end()),
+      std::unordered_set<string>(drop_frames.begin(), drop_frames.end()), next);
+}
+
+FrameIdFilteringPointsProcessor::FrameIdFilteringPointsProcessor(
+    const std::unordered_set<string>& keep_frame_ids,
+    const std::unordered_set<string>& drop_frame_ids,
+    PointsProcessor* next)
+    : keep_frame_ids_(keep_frame_ids),
+      drop_frame_ids_(drop_frame_ids),
+      next_(next) {
+  CHECK_NE(keep_frame_ids.empty(), drop_frame_ids.empty())
+      << "You have to specify exactly one of the `keep_frames` property or the "
+      << "`drop_frames` property, but not both at the same time.";
+}
+
+void FrameIdFilteringPointsProcessor::Process(
+    std::unique_ptr<PointsBatch> batch) {
+  if ((!keep_frame_ids_.empty() && keep_frame_ids_.count(batch->frame_id)) ||
+      (!drop_frame_ids_.empty() && !drop_frame_ids_.count(batch->frame_id))) {
+    next_->Process(std::move(batch));
+  }
+}
+
+PointsProcessor::FlushResult FrameIdFilteringPointsProcessor::Flush() {
+  return next_->Flush();
+}
+
+}  // namespace io
+}  // namespace cartographer

cartographer/io/frame_id_filtering_points_processor.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2017 The Cartographer Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CARTOGRAPHER_IO_FRAME_ID_FILTERING_POINTS_PROCESSOR_H_
+#define CARTOGRAPHER_IO_FRAME_ID_FILTERING_POINTS_PROCESSOR_H_
+
+#include <unordered_set>
+
+#include "cartographer/common/lua_parameter_dictionary.h"
+#include "cartographer/io/points_processor.h"
+
+namespace cartographer {
+namespace io {
+
+// Filters all points with blacklisted frame id or a non-whitelisted frame id.
+// Note that you can either specify the whitelist or the blacklist, but not both
+// at the same time.
+class FrameIdFilteringPointsProcessor : public PointsProcessor {
+ public:
+  constexpr static const char* kConfigurationFileActionName = "frame_id_filter";
+  FrameIdFilteringPointsProcessor(
+      const std::unordered_set<string>& keep_frame_ids,
+      const std::unordered_set<string>& drop_frame_ids,
+      PointsProcessor* next);
+  static std::unique_ptr<FrameIdFilteringPointsProcessor> FromDictionary(
+      common::LuaParameterDictionary* dictionary,
+      PointsProcessor* next);
+  ~FrameIdFilteringPointsProcessor() override {}
+
+  FrameIdFilteringPointsProcessor(const FrameIdFilteringPointsProcessor&) =
+      delete;
+  FrameIdFilteringPointsProcessor& operator=(
+      const FrameIdFilteringPointsProcessor&) = delete;
+
+  void Process(std::unique_ptr<PointsBatch> batch) override;
+  FlushResult Flush() override;
+
+ private:
+  const std::unordered_set<string> keep_frame_ids_;
+  const std::unordered_set<string> drop_frame_ids_;
+  PointsProcessor* const next_;
+};
+
+}  // namespace io
+}  // namespace cartographer
+
+#endif  // CARTOGRAPHER_IO_FRAME_ID_FILTERING_POINTS_PROCESSOR_H_

cartographer/io/points_processor_pipeline_builder.cc

@@ -19,6 +19,7 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/io/coloring_points_processor.h"
 #include "cartographer/io/counting_points_processor.h"
+#include "cartographer/io/frame_id_filtering_points_processor.h"
 #include "cartographer/io/fixed_ratio_sampling_points_processor.h"
 #include "cartographer/io/hybrid_grid_points_processor.h"
 #include "cartographer/io/intensity_to_color_points_processor.h"
@@ -81,6 +82,7 @@ void RegisterBuiltInPointsProcessors(
     PointsProcessorPipelineBuilder* builder) {
   RegisterPlainPointsProcessor<CountingPointsProcessor>(builder);
   RegisterPlainPointsProcessor<FixedRatioSamplingPointsProcessor>(builder);
+  RegisterPlainPointsProcessor<FrameIdFilteringPointsProcessor>(builder);
   RegisterPlainPointsProcessor<MinMaxRangeFiteringPointsProcessor>(builder);
   RegisterPlainPointsProcessor<OutlierRemovingPointsProcessor>(builder);
   RegisterPlainPointsProcessor<ColoringPointsProcessor>(builder);