Move Payload into zenoh_utils

rmw_zenoh_cpp/src/detail/rmw_subscription_data.hpp

@@ -35,7 +35,6 @@
 #include "attachment_helpers.hpp"
 #include "type_support_common.hpp"
 #include "zenoh_utils.hpp"
-#include "payload.hpp"
 
 #include "rcutils/allocator.h"
 

rmw_zenoh_cpp/src/detail/zenoh_utils.cpp

@@ -96,4 +96,48 @@ std::chrono::nanoseconds::rep ZenohReply::get_received_timestamp() const
 {
   return received_timestamp_;
 }
+
+///=============================================================================
+Payload::Payload(const zenoh::Bytes & bytes)
+{
+  zenoh::Bytes::SliceIterator slices = bytes.slice_iter();
+  std::optional<zenoh::Slice> slice = slices.next();
+  if (!slice.has_value()) {
+    bytes_ = nullptr;
+  } else {
+    if (!slices.next().has_value()) {
+      bytes_ = Contiguous {slice.value(), bytes.clone()};
+    } else {
+      bytes_ = bytes.as_vector();
+    }
+  }
+}
+
+const uint8_t * Payload::data()
+{
+  if (std::holds_alternative<Empty>(bytes_)) {
+    return nullptr;
+  } else if (std::holds_alternative<NonContiguous>(bytes_)) {
+    return std::get<NonContiguous>(bytes_).data();
+  } else {
+    return std::get<Contiguous>(bytes_).slice.data;
+  }
+}
+
+size_t Payload::size()
+{
+  if (std::holds_alternative<Empty>(bytes_)) {
+    return 0;
+  } else if (std::holds_alternative<NonContiguous>(bytes_)) {
+    return std::get<NonContiguous>(bytes_).size();
+  } else {
+    return std::get<Contiguous>(bytes_).slice.len;
+  }
+}
+
+bool Payload::empty()
+{
+  return std::holds_alternative<Empty>(bytes_);
+}
+
 }  // namespace rmw_zenoh_cpp

rmw_zenoh_cpp/src/detail/zenoh_utils.hpp

@@ -21,6 +21,9 @@
 #include <chrono>
 #include <functional>
 #include <optional>
+#include <utility>
+#include <variant>
+#include <vector>
 
 #include "rmw/types.h"
 
@@ -80,6 +83,32 @@ class ZenohQuery final
   zenoh::Query query_;
   std::chrono::nanoseconds::rep received_timestamp_;
 };
+
+class Payload
+{
+public:
+  explicit Payload(const zenoh::Bytes & bytes);
+
+  ~Payload() = default;
+
+  const uint8_t * data() const;
+
+  size_t size() const;
+
+  bool empty() const;
+
+private:
+  struct Contiguous
+  {
+    zenoh::Slice slice;
+    zenoh::Bytes bytes;
+  };
+  using NonContiguous = std::vector<uint8_t>;
+  using Empty = std::nullptr_t;
+  // Is `std::vector<uint8_t>` in case of a non-contiguous payload
+  // and `zenoh::Slice` plus a `zenoh::Bytes` otherwise.
+  std::variant<NonContiguous, Contiguous, Empty> bytes_;
+}
 }  // namespace rmw_zenoh_cpp
 
 #endif  // DETAIL__ZENOH_UTILS_HPP_