Made copying rosbag::Bag a compiler error to prevent crashes and added a swap function instead

test/test_rosbag_storage/CMakeLists.txt

@@ -15,4 +15,8 @@ if(CATKIN_ENABLE_TESTING)
   if(TARGET create_and_iterate_bag)
     target_link_libraries(create_and_iterate_bag ${catkin_LIBRARIES})
   endif()
+  catkin_add_gtest(swap_bags src/swap_bags.cpp)
+  if(TARGET swap_bags)
+    target_link_libraries(swap_bags ${catkin_LIBRARIES})
+  endif()
 endif()

test/test_rosbag_storage/src/swap_bags.cpp

@@ -0,0 +1,101 @@
+#include "ros/time.h"
+#include "rosbag/bag.h"
+#include "rosbag/view.h"
+#include "std_msgs/Int32.h"
+
+#include "boost/foreach.hpp"
+#include <gtest/gtest.h>
+
+void writeBags(rosbag::CompressionType a, rosbag::CompressionType b) {
+    using std::swap;
+    rosbag::Bag bag1("/tmp/swap1.bag", rosbag::bagmode::Write);
+    rosbag::Bag bag2("/tmp/swap2.bag", rosbag::bagmode::Write);
+
+    // In the end "/tmp/swap1.bag" should have CompressionType a and contain two messages of value a.
+    // "/tmp/swap2.bag" should have CompressionType b and contain two messages of value b.
+    // We use these pointers to track the bags accordingly.
+
+    rosbag::Bag* a_bag = &bag1;
+    rosbag::Bag* b_bag = &bag2;
+
+    std_msgs::Int32 a_msg, b_msg;
+    a_msg.data = a;
+    b_msg.data = b;
+
+    swap(bag1, bag2);
+    swap(a_bag, b_bag);
+
+    a_bag->setCompression(a);
+    b_bag->setCompression(b);
+
+    swap(bag1, bag2);
+    swap(a_bag, b_bag);
+
+    a_bag->write("/data", ros::Time::now(), a_msg);
+    b_bag->write("/data", ros::Time::now(), b_msg);
+
+    swap(bag1, bag2);
+    swap(a_bag, b_bag);
+
+    a_bag->write("/data", ros::Time::now(), a_msg);
+    b_bag->write("/data", ros::Time::now(), b_msg);
+
+    swap(bag1, bag2);
+
+    bag1.close();
+    bag2.close();
+
+    swap(bag1, bag2);
+}
+
+void readBags(rosbag::CompressionType a, rosbag::CompressionType b) {
+    using std::swap;
+    rosbag::Bag bag1("/tmp/swap1.bag", rosbag::bagmode::Read);
+    rosbag::Bag bag2("/tmp/swap2.bag", rosbag::bagmode::Read);
+
+    rosbag::Bag* a_bag = &bag1;
+    rosbag::Bag* b_bag = &bag2;
+
+    swap(bag1, bag2);
+    swap(a_bag, b_bag);
+
+    // only valid when writing
+    //EXPECT_EQ(a_bag->getCompression(), a);
+    //EXPECT_EQ(b_bag->getCompression(), b);
+
+    std::vector<std::string> topics;
+    topics.push_back("data");
+
+    rosbag::View a_view(*a_bag, rosbag::TopicQuery(topics));
+    rosbag::View b_view(*b_bag, rosbag::TopicQuery(topics));
+
+    BOOST_FOREACH(rosbag::MessageInstance const m, a_view)
+    {
+        std_msgs::Int32::ConstPtr i = m.instantiate<std_msgs::Int32>();
+        ASSERT_TRUE(i);
+        EXPECT_EQ(i->data, a);
+    }
+    BOOST_FOREACH(rosbag::MessageInstance const m, b_view)
+    {
+        std_msgs::Int32::ConstPtr i = m.instantiate<std_msgs::Int32>();
+        ASSERT_TRUE(i);
+        EXPECT_EQ(i->data, b);
+    }
+}
+
+TEST(rosbag_storage, swap_bags)
+{
+    for (int i = 0; i < 3; ++i) {
+        for (int j = 0; j < 3; ++j) {
+            writeBags(rosbag::CompressionType(i), rosbag::CompressionType(j));
+            readBags(rosbag::CompressionType(i), rosbag::CompressionType(j));
+        }
+    }
+}
+
+int main(int argc, char **argv) {
+    ros::Time::init();
+
+    testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}

tools/rosbag_storage/include/rosbag/bag.h

@@ -171,7 +171,12 @@ class ROSBAG_DECL Bag
     void write(std::string const& topic, ros::Time const& time, boost::shared_ptr<T> const& msg,
                boost::shared_ptr<ros::M_string> connection_header = boost::shared_ptr<ros::M_string>());
 
+    void swap(Bag&);
+
 private:
+    Bag(const Bag&);
+    Bag& operator=(const Bag&);
+
     // This helper function actually does the write with an arbitrary serializable message
     template<class T>
     void doWrite(std::string const& topic, ros::Time const& time, T const& msg, boost::shared_ptr<ros::M_string> const& connection_header);
@@ -621,6 +626,10 @@ void Bag::writeMessageDataRecord(uint32_t conn_id, ros::Time const& time, T cons
         curr_chunk_info_.start_time = time;
 }
 
+inline void swap(Bag& a, Bag& b) {
+    a.swap(b);
+}
+
 } // namespace rosbag
 
 #endif

tools/rosbag_storage/include/rosbag/buffer.h

@@ -51,8 +51,11 @@ class ROSBAG_DECL Buffer
     uint32_t getSize()     const;
 
     void setSize(uint32_t size);
+    void swap(Buffer& other);
 
 private:
+    Buffer(const Buffer&);
+    Buffer& operator=(const Buffer&);
     void ensureCapacity(uint32_t capacity);
 
 private:
@@ -61,6 +64,10 @@ class ROSBAG_DECL Buffer
     uint32_t size_;
 };
 
+inline void swap(Buffer& a, Buffer& b) {
+    a.swap(b);
+}
+
 } // namespace rosbag
 
 #endif

tools/rosbag_storage/include/rosbag/chunked_file.h

@@ -79,8 +79,12 @@ class ROSBAG_DECL ChunkedFile
     bool        truncate(uint64_t length);
     void        seek(uint64_t offset, int origin = std::ios_base::beg); //!< seek to given offset from origin
     void        decompress(CompressionType compression, uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len);
+    void        swap(ChunkedFile& other);
 
 private:
+    ChunkedFile(const ChunkedFile&);
+    ChunkedFile& operator=(const ChunkedFile&);
+
     void open(std::string const& filename, std::string const& mode);
     void clearUnused();
 
@@ -98,6 +102,10 @@ class ROSBAG_DECL ChunkedFile
     boost::shared_ptr<Stream> write_stream_;
 };
 
+inline void swap(ChunkedFile& a, ChunkedFile& b) {
+    a.swap(b);
+}
+
 } // namespace rosbag
 
 #endif

tools/rosbag_storage/include/rosbag/stream.h

@@ -63,8 +63,11 @@ typedef compression::CompressionType CompressionType;
 
 class ChunkedFile;
 
+class FileAccessor;
+
 class ROSBAG_DECL Stream
 {
+    friend class FileAccessor;
 public:
     Stream(ChunkedFile* file);
     virtual ~Stream();
@@ -110,6 +113,13 @@ class ROSBAG_DECL StreamFactory
     boost::shared_ptr<Stream> lz4_stream_;
 };
 
+class FileAccessor {
+    friend class ChunkedFile;
+    static void setFile(Stream& a, ChunkedFile* file) {
+        a.file_ = file;
+    }
+};
+
 class ROSBAG_DECL UncompressedStream : public Stream
 {
 public:
@@ -173,6 +183,8 @@ class ROSBAG_DECL LZ4Stream : public Stream
     void decompress(uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len);
 
 private:
+    LZ4Stream(const LZ4Stream&);
+    LZ4Stream operator=(const LZ4Stream&);
     void writeStream(int action);
 
     char *buff_;

tools/rosbag_storage/src/bag.cpp

@@ -1117,4 +1117,35 @@ void Bag::write(char const* s, std::streamsize n) { file_.write((char*) s, n);
 void Bag::read(char* b, std::streamsize n) const  { file_.read(b, n);             }
 void Bag::seek(uint64_t pos, int origin) const    { file_.seek(pos, origin);      }
 
+void Bag::swap(Bag& other) {
+    using std::swap;
+    swap(mode_, other.mode_);
+    swap(file_, other.file_);
+    swap(version_, other.version_);
+    swap(compression_, other.compression_);
+    swap(chunk_threshold_, other.chunk_threshold_);
+    swap(bag_revision_, other.bag_revision_);
+    swap(file_size_, other.file_size_);
+    swap(file_header_pos_, other.file_header_pos_);
+    swap(index_data_pos_, other.index_data_pos_);
+    swap(connection_count_, other.connection_count_);
+    swap(chunk_count_, other.chunk_count_);
+    swap(chunk_open_, other.chunk_open_);
+    swap(curr_chunk_info_, other.curr_chunk_info_);
+    swap(curr_chunk_data_pos_, other.curr_chunk_data_pos_);
+    swap(topic_connection_ids_, other.topic_connection_ids_);
+    swap(header_connection_ids_, other.header_connection_ids_);
+    swap(connections_, other.connections_);
+    swap(chunks_, other.chunks_);
+    swap(connection_indexes_, other.connection_indexes_);
+    swap(curr_chunk_connection_indexes_, other.curr_chunk_connection_indexes_);
+    swap(header_buffer_, other.header_buffer_);
+    swap(record_buffer_, other.record_buffer_);
+    swap(chunk_buffer_, other.chunk_buffer_);
+    swap(decompress_buffer_, other.decompress_buffer_);
+    swap(outgoing_chunk_buffer_, other.outgoing_chunk_buffer_);
+    swap(current_buffer_, other.current_buffer_);
+    swap(decompressed_chunk_, other.decompressed_chunk_);
+}
+
 } // namespace rosbag

tools/rosbag_storage/src/buffer.cpp

@@ -34,6 +34,7 @@
 
 #include <stdlib.h>
 #include <assert.h>
+#include <utility>
 
 #include "rosbag/buffer.h"
 
@@ -71,4 +72,11 @@ void Buffer::ensureCapacity(uint32_t capacity) {
     assert(buffer_);
 }
 
+void Buffer::swap(Buffer& other) {
+    using std::swap;
+    swap(buffer_, other.buffer_);
+    swap(capacity_, other.capacity_);
+    swap(size_, other.size_);
+}
+
 } // namespace rosbag

tools/rosbag_storage/src/chunked_file.cpp

@@ -221,4 +221,33 @@ void ChunkedFile::clearUnused() {
     nUnused_ = 0;
 }
 
+void ChunkedFile::swap(ChunkedFile& other) {
+    using std::swap;
+    using boost::swap;
+    swap(filename_, other.filename_);
+    swap(file_, other.file_);
+    swap(offset_, other.offset_);
+    swap(compressed_in_, other.compressed_in_);
+    swap(unused_, other.unused_);
+    swap(nUnused_, other.nUnused_);
+
+    swap(stream_factory_, other.stream_factory_);
+
+    FileAccessor::setFile(*stream_factory_->getStream(compression::Uncompressed), this);
+    FileAccessor::setFile(*stream_factory_->getStream(compression::BZ2), this);
+    FileAccessor::setFile(*stream_factory_->getStream(compression::LZ4), this);
+
+    FileAccessor::setFile(*other.stream_factory_->getStream(compression::Uncompressed), &other);
+    FileAccessor::setFile(*other.stream_factory_->getStream(compression::BZ2), &other);
+    FileAccessor::setFile(*other.stream_factory_->getStream(compression::LZ4), &other);
+
+    swap(read_stream_, other.read_stream_);
+    FileAccessor::setFile(*read_stream_, this);
+    FileAccessor::setFile(*other.read_stream_, &other);
+
+    swap(write_stream_, other.write_stream_);
+    FileAccessor::setFile(*write_stream_, this);
+    FileAccessor::setFile(*other.write_stream_, &other);
+}
+
 } // namespace rosbag