DISCONTINUATION OF PROJECT.

This project will no longer be maintained by Intel.

Intel has ceased development and contributions including, but not limited to, maintenance, bug fixes, new releases, or updates, to this project.

Intel no longer accepts patches to this project.

If you have an ongoing need to use this project, are interested in independently developing it, or would like to maintain patches for the open source software community, please create your own fork of this project.

ROS2 Message Filters

ros2_message_filters blends various messages based on the conditions that filter needs to met and derives from ROS2 porting of ROS message_filters. It collects commonly used message "filtering" algorithms into a common space. A message filter is defined as something which a message arrives into and may or may not be spit back out of at a later point in time.

The API is a combination of parts:

• Filter Pattern
  • registerCallback(cb)
  • connectInput(filter)
• Subscriber
  • subscribe(nodep, topic, 1, myCallback)
• Time Synchronizer
  • Input :
    • C++: Up to 9 separate filters, each of which is of the form void callback(const std::shared_ptr<M const>&). The number of filters supported is determined by the number of template arguments the class was created with.
    • Python: N separate filters, each of which has signature callback(msg).
  • Output :
    • C++: For message types M0..M8, void callback(const std::shared_ptr<M0 const>&, ..., const std::shared_ptr<M8 const>&). The number of parameters is determined by the number of template arguments the class was created with.
    • Python: callback(msg0.. msgN). The number of parameters is determined by the number of template arguments the class was created with.

  #include <message_filters/subscriber.h>
  #include <message_filters/time_synchronizer.h>
  #include <sensor_msgs/Image.h>
  #include <sensor_msgs/CameraInfo.h>

  using namespace sensor_msgs;
  using namespace message_filters;
    
  void callback(const ImageConstPtr& image, const CameraInfoConstPtr& cam_info)
  {
     // Solve all of perception here...
  }
  
  int main(int argc, char** argv)
  {
    rclcpp::init(argc, argv);
    auto nh = std::make_shared<rclcpp::Node>("test_node");
    Subscriber<Image> image_sub(nh.get(), "image");
    Subscriber<CameraInfo> info_sub(nh.get(), "camera");
    TimeSynchronizer<Image, CameraInfo> sync(image_sub, info_sub, 10);
    sync.registerCallback(std::bind(&callback, _1, _2));
    rclcpp::spin(nh);
    return 0;
   }

Environment

• Hardware: Compliant to ROS2 HW requirements
• Software: ROS2 + Supported OS(Linux, Win, Mac)

How to build and test ROS2 message filters

• Clone and build ROS2 source code under ros2 workspace, please refer to ROS2 Installation for more details and the following is the example in Ubuntu 16.04 LTS.

$cd ~/<ros2_workspace>
$src/ament/ament_tools/scripts/ament.py build --build-tests --symlink-install

• Build message filters

$cd src/ros2
$git clone https://github.com/intel/ros2_message_filters.git
$source <ros2_workspace>/install/local_setup.bash
$ament build src/ros2/ros2_message_filters

• Run unit tests

$ament test src/ros2/ros2_message_filters

1: Test timeout computed to be: 60
1: -- run_test.py: invoking following command in '/home/jwang-robot/ros2_ws/src/ros2/message_filters':
1:  - /home/jwang-robot/ros2_ws/build/message_filters/message_filters-test_simple --gtest_output=xml:/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-test_simple.gtest.xml
1: [==========] Running 2 tests from 1 test case.
1: [----------] Global test environment set-up.
1: [----------] 2 tests from SimpleFilter
1: [ RUN      ] SimpleFilter.callbackTypes
1: [       OK ] SimpleFilter.callbackTypes (0 ms)
1: [ RUN      ] SimpleFilter.oldRegisterWithNewFilter
1: [       OK ] SimpleFilter.oldRegisterWithNewFilter (0 ms)
1: [----------] 2 tests from SimpleFilter (0 ms total)
1: 
1: [----------] Global test environment tear-down
1: [==========] 2 tests from 1 test case ran. (0 ms total)
1: [  PASSED  ] 2 tests.
1: -- run_test.py: return code 0
1: -- run_test.py: inject classname prefix into gtest result file '/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-test_simple.gtest.xml'
1: -- run_test.py: verify result file '/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-test_simple.gtest.xml'
 1/10 Test  #1: message_filters-test_simple ....................   Passed    0.09 sec
test 2
      Start  2: message_filters-msg_cache_unittest

2: Test timeout computed to be: 60
2: -- run_test.py: invoking following command in '/home/jwang-robot/ros2_ws/src/ros2/message_filters':
2:  - /home/jwang-robot/ros2_ws/build/message_filters/message_filters-msg_cache_unittest --gtest_output=xml:/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-msg_cache_unittest.gtest.xml
2: [==========] Running 5 tests from 1 test case.
2: [----------] Global test environment set-up.
2: [----------] 5 tests from Cache
2: [ RUN      ] Cache.easyInterval
2: [       OK ] Cache.easyInterval (0 ms)
2: [ RUN      ] Cache.easySurroundingInterval
2: [       OK ] Cache.easySurroundingInterval (0 ms)
2: [ RUN      ] Cache.easyUnsorted
2: [       OK ] Cache.easyUnsorted (0 ms)
2: [ RUN      ] Cache.easyElemBeforeAfter
2: [       OK ] Cache.easyElemBeforeAfter (0 ms)
2: [ RUN      ] Cache.eventInEventOut
2: [       OK ] Cache.eventInEventOut (0 ms)
2: [----------] 5 tests from Cache (0 ms total)
2: 
2: [----------] Global test environment tear-down
2: [==========] 5 tests from 1 test case ran. (0 ms total)
2: [  PASSED  ] 5 tests.
2: -- run_test.py: return code 0
2: -- run_test.py: inject classname prefix into gtest result file '/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-msg_cache_unittest.gtest.xml'
2: -- run_test.py: verify result file '/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-msg_cache_unittest.gtest.xml'
 2/10 Test  #2: message_filters-msg_cache_unittest .............   Passed    0.09 sec
test 3
      Start  3: message_filters-test_chain

3: Test timeout computed to be: 60
3: -- run_test.py: invoking following command in '/home/jwang-robot/ros2_ws/src/ros2/message_filters':
3:  - /home/jwang-robot/ros2_ws/build/message_filters/message_filters-test_chain --gtest_output=xml:/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-test_chain.gtest.xml
3: [==========] Running 8 tests from 1 test case.
3: [----------] Global test environment set-up.
3: [----------] 8 tests from Chain
3: [ RUN      ] Chain.simple
3: [       OK ] Chain.simple (0 ms)
3: [ RUN      ] Chain.multipleFilters
3: [       OK ] Chain.multipleFilters (0 ms)
3: [ RUN      ] Chain.addingFilters
3: [       OK ] Chain.addingFilters (1 ms)
3: [ RUN      ] Chain.inputFilter
3: [       OK ] Chain.inputFilter (0 ms)
3: [ RUN      ] Chain.nonSharedPtrFilter
3: [       OK ] Chain.nonSharedPtrFilter (0 ms)
3: [ RUN      ] Chain.retrieveFilter
3: [       OK ] Chain.retrieveFilter (0 ms)
3: [ RUN      ] Chain.retrieveFilterThroughBaseClass
3: [       OK ] Chain.retrieveFilterThroughBaseClass (0 ms)
3: [ RUN      ] Chain.retrieveBaseClass
3: [       OK ] Chain.retrieveBaseClass (0 ms)
3: [----------] 8 tests from Chain (1 ms total)
3: 
3: [----------] Global test environment tear-down
3: [==========] 8 tests from 1 test case ran. (1 ms total)
3: [  PASSED  ] 8 tests.
3: -- run_test.py: return code 0
3: -- run_test.py: inject classname prefix into gtest result file '/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-test_chain.gtest.xml'
3: -- run_test.py: verify result file '/home/jwang-robot/ros2_ws/build/message_filters/test_results/message_filters/message_filters-test_chain.gtest.xml'
 3/10 Test  #3: message_filters-test_chain .....................   Passed    0.09 sec
test 4
...
...
...
100% tests passed, 0 tests failed out of 10

Label Time Summary:
gtest     =  16.15 sec (9 tests)
pytest    =   0.54 sec (1 test)

Total Test time (real) =  16.69 sec

• Run fuzz tests (disabled by default)

$./build/message_filters/message_filters-test_fuzz

[==========] Running 3 tests from 3 test cases.
[----------] Global test environment set-up.
[----------] 1 test from TimeSequencer
[ RUN      ] TimeSequencer.fuzz_sequencer
[       OK ] TimeSequencer.fuzz_sequencer (5118 ms)
[----------] 1 test from TimeSequencer (5118 ms total)

[----------] 1 test from TimeSynchronizer
[ RUN      ] TimeSynchronizer.fuzz_synchronizer
[       OK ] TimeSynchronizer.fuzz_synchronizer (5013 ms)
[----------] 1 test from TimeSynchronizer (5013 ms total)

[----------] 1 test from Subscriber
[ RUN      ] Subscriber.fuzz_subscriber
[       OK ] Subscriber.fuzz_subscriber (5010 ms)
[----------] 1 test from Subscriber (5010 ms total)

[----------] Global test environment tear-down
[==========] 3 tests from 3 test cases ran. (15142 ms total)
[  PASSED  ] 3 tests.

Known issue

• python not support headless message
• Not verify with Windows and OS X environment and there may be some errors

Security check

If there is any security issue, it should be reported using process at https://01.org/security.