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Add thread-local TypeSupport cache to rmw_serialize/deserialize #866

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Add thread-local TypeSupport cache to rmw_serialize/deserialize #866

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7c2a0f6
Add thread-local TypeSupport cache to rmw_serialize/deserialize
Mar 5, 2026
ef5c378
Revert "Add thread-local TypeSupport cache to rmw_serialize/deserialize"
Mar 5, 2026
9aeaacc
Add thread-local TypeSupport cache to rmw_serialize/deserialize
Mar 5, 2026
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76 changes: 51 additions & 25 deletions rmw_fastrtps_cpp/src/rmw_serialize.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,8 @@
// See the License for the specific language governing permissions and
// limitations under the License.

#include <memory>

#include "fastcdr/FastBuffer.h"

#include "rmw/error_handling.h"
Expand All @@ -20,6 +22,46 @@

#include "./type_support_common.hpp"

namespace
{

// Per-thread cache: resolves and constructs the MessageTypeSupport object once per unique
// type_support pointer, avoiding repeated get_message_typesupport_handle dispatch and
// MessageTypeSupport_cpp construction on every serialize/deserialize call.
struct TypeSupportCache
{
const rosidl_message_type_support_t * input_ts = nullptr;
const message_type_support_callbacks_t * callbacks = nullptr;
std::unique_ptr<MessageTypeSupport_cpp> tss;
};

// Returns nullptr and sets the RMW error on failure.
const TypeSupportCache * get_type_support_cache(
const rosidl_message_type_support_t * type_support)
{
thread_local TypeSupportCache cache;

if (cache.input_ts != type_support) {
const rosidl_message_type_support_t * ts = get_message_typesupport_handle(
type_support, RMW_FASTRTPS_CPP_TYPESUPPORT_C);
if (!ts) {
ts = get_message_typesupport_handle(
type_support, RMW_FASTRTPS_CPP_TYPESUPPORT_CPP);
if (!ts) {
RMW_SET_ERROR_MSG("type support not from this implementation");
return nullptr;
}
}
cache.input_ts = type_support;
cache.callbacks = static_cast<const message_type_support_callbacks_t *>(ts->data);
cache.tss = std::make_unique<MessageTypeSupport_cpp>(cache.callbacks, type_support);
}

return &cache;
}

} // namespace

extern "C"
{
rmw_ret_t
Expand All @@ -28,20 +70,12 @@ rmw_serialize(
const rosidl_message_type_support_t * type_support,
rmw_serialized_message_t * serialized_message)
{
const rosidl_message_type_support_t * ts = get_message_typesupport_handle(
type_support, RMW_FASTRTPS_CPP_TYPESUPPORT_C);
if (!ts) {
ts = get_message_typesupport_handle(
type_support, RMW_FASTRTPS_CPP_TYPESUPPORT_CPP);
if (!ts) {
RMW_SET_ERROR_MSG("type support not from this implementation");
return RMW_RET_ERROR;
}
const TypeSupportCache * cache = get_type_support_cache(type_support);
if (!cache) {
return RMW_RET_ERROR;
}

auto callbacks = static_cast<const message_type_support_callbacks_t *>(ts->data);
auto tss = MessageTypeSupport_cpp(callbacks, type_support);
auto data_length = tss.getEstimatedSerializedSize(ros_message, callbacks);
auto data_length = cache->tss->getEstimatedSerializedSize(ros_message, cache->callbacks);
if (serialized_message->buffer_capacity < data_length) {
if (rmw_serialized_message_resize(serialized_message, data_length) != RMW_RET_OK) {
rmw_reset_error();
Expand All @@ -56,7 +90,7 @@ rmw_serialize(
buffer, eprosima::fastcdr::Cdr::DEFAULT_ENDIAN, eprosima::fastcdr::CdrVersion::XCDRv1);
ser.set_encoding_flag(eprosima::fastcdr::EncodingAlgorithmFlag::PLAIN_CDR);

auto ret = tss.serializeROSmessage(ros_message, ser, callbacks);
auto ret = cache->tss->serializeROSmessage(ros_message, ser, cache->callbacks);
serialized_message->buffer_length = data_length;
serialized_message->buffer_capacity = data_length;
return ret == true ? RMW_RET_OK : RMW_RET_ERROR;
Expand All @@ -68,24 +102,16 @@ rmw_deserialize(
const rosidl_message_type_support_t * type_support,
void * ros_message)
{
const rosidl_message_type_support_t * ts = get_message_typesupport_handle(
type_support, RMW_FASTRTPS_CPP_TYPESUPPORT_C);
if (!ts) {
ts = get_message_typesupport_handle(
type_support, RMW_FASTRTPS_CPP_TYPESUPPORT_CPP);
if (!ts) {
RMW_SET_ERROR_MSG("type support not from this implementation");
return RMW_RET_ERROR;
}
const TypeSupportCache * cache = get_type_support_cache(type_support);
if (!cache) {
return RMW_RET_ERROR;
}

auto callbacks = static_cast<const message_type_support_callbacks_t *>(ts->data);
auto tss = MessageTypeSupport_cpp(callbacks, type_support);
eprosima::fastcdr::FastBuffer buffer(
reinterpret_cast<char *>(serialized_message->buffer), serialized_message->buffer_length);
eprosima::fastcdr::Cdr deser(buffer, eprosima::fastcdr::Cdr::DEFAULT_ENDIAN);

auto ret = tss.deserializeROSmessage(deser, ros_message, callbacks);
auto ret = cache->tss->deserializeROSmessage(deser, ros_message, cache->callbacks);
return ret == true ? RMW_RET_OK : RMW_RET_ERROR;
}

Expand Down