Program Listing for File endpoint.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2022-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* 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 HOLOSCAN_CORE_ENDPOINT_HPP
#define HOLOSCAN_CORE_ENDPOINT_HPP

#include <iostream>
#include <memory>
#include <string>
#include <utility>

#include "./errors.hpp"
#include "./expected.hpp"
#include "./resource.hpp"
#include "gxf/serialization/endpoint.hpp"

namespace nvidia {
namespace gxf {
enum struct MemoryStorageType;
}
}  // namespace nvidia

namespace holoscan {

class Endpoint : public Resource {
 public:
  Endpoint() = default;
  Endpoint(Endpoint&&) = default;
  ~Endpoint() override = default;

  explicit Endpoint(nvidia::gxf::Endpoint* gxf_endpoint) : gxf_endpoint_(gxf_endpoint) {}

  using MemoryStorageType = nvidia::gxf::MemoryStorageType;

  // C++ API wrappers
  virtual bool is_write_available() {
    if (!gxf_endpoint_) { throw std::runtime_error("GXF endpoint has not been set"); }
    return gxf_endpoint_->isWriteAvailable();
  }
  virtual bool is_read_available() {
    if (!gxf_endpoint_) { throw std::runtime_error("GXF endpoint has not been set"); }
    return gxf_endpoint_->isReadAvailable();
  }

  virtual expected<size_t, RuntimeError> write(const void* data, size_t size) {
    if (!gxf_endpoint_) {
      return make_unexpected<RuntimeError>(
          RuntimeError(ErrorCode::kCodecError, "GXF endpoint has not been set"));
    }
    auto maybe_size = gxf_endpoint_->write(data, size);
    if (!maybe_size) {
      // converted nvidia::gxf::Unexpected to holoscan::unexpected
      auto err_msg = fmt::format("GXF endpoint read failure: {}", GxfResultStr(maybe_size.error()));
      return make_unexpected<RuntimeError>(RuntimeError(ErrorCode::kCodecError, err_msg));
    }
    return maybe_size.value();
  }
  virtual expected<size_t, RuntimeError> read(void* data, size_t size) {
    if (!gxf_endpoint_) {
      return make_unexpected<RuntimeError>(
          RuntimeError(ErrorCode::kCodecError, "GXF endpoint has not been set"));
    }
    auto maybe_size = gxf_endpoint_->read(data, size);
    if (!maybe_size) {
      // converted nvidia::gxf::Unexpected to holoscan::unexpected
      auto err_msg = fmt::format("GXF endpoint read failure: {}", GxfResultStr(maybe_size.error()));
      return make_unexpected<RuntimeError>(RuntimeError(ErrorCode::kCodecError, err_msg));
    }
    return maybe_size.value();
  }
  virtual expected<void, RuntimeError> write_ptr(const void* pointer, size_t size,
                                                 MemoryStorageType type) {
    if (!gxf_endpoint_) {
      return make_unexpected<RuntimeError>(
          RuntimeError(ErrorCode::kCodecError, "GXF endpoint has not been set"));
    }
    auto maybe_void = gxf_endpoint_->write_ptr(pointer, size, type);
    if (!maybe_void) {
      // converted nvidia::gxf::Unexpected to holoscan::unexpected
      auto err_msg = fmt::format("GXF endpoint read failure: {}", GxfResultStr(maybe_void.error()));
      return make_unexpected<RuntimeError>(RuntimeError(ErrorCode::kCodecError, err_msg));
    }
    return expected<void, RuntimeError>();
  }

  // Note: in GXF, writeTrivialType and readTrivialType below are not on Endpoint itself, but on
  // SerializationBuffer and UcxSerializationBuffer

  // Writes an object of type T to the endpoint
  template <typename T>
  expected<size_t, RuntimeError> write_trivial_type(const T* object) {
    return write(object, sizeof(T));
  }

  // Reads an object of type T from the endpoint
  template <typename T>
  expected<size_t, RuntimeError> read_trivial_type(T* object) {
    return read(object, sizeof(T));
  }

 private:
  nvidia::gxf::Endpoint* gxf_endpoint_ = nullptr;
};
}  // namespace holoscan

#endif/* HOLOSCAN_CORE_ENDPOINT_HPP */