http_stream.h

#ifndef SOURCEMETA_HYDRA_HTTP_STREAM_H
#define SOURCEMETA_HYDRA_HTTP_STREAM_H
 
#ifndef SOURCEMETA_HYDRA_HTTP_EXPORT
#include <sourcemeta/hydra/http_export.h>
#endif
 
#include <cstdint>     // std::uint8_t
#include <functional>  // std::function
#include <memory>      // std::unique_ptr
#include <span>        // std::span
#include <string>      // std::string
#include <string_view> // std::string_view
#include <vector>      // std::vector
 
namespace sourcemeta::hydra::http {
 
class SOURCEMETA_HYDRA_HTTP_EXPORT ClientStream {
public:
  ClientStream(std::string url);
 
  ClientStream(ClientStream &&other) noexcept;
 
  auto operator=(ClientStream &&other) noexcept -> ClientStream &;
 
  // While technically possible, copy semantics are not very useful here
  // Also, not worth documenting these.
#if !defined(DOXYGEN)
  ClientStream(const ClientStream &other) = delete;
  auto operator=(const ClientStream &other) -> ClientStream & = delete;
#endif
 
  ~ClientStream();
 
  auto method(const Method method) noexcept -> void;
 
  auto method() const noexcept -> Method;
 
  auto header(std::string_view key, std::string_view value) -> void;
 
  auto header(std::string_view key, int value) -> void;
 
  auto url() const -> std::string_view;
 
  auto send() -> Status;
 
  using DataCallback =
      std::function<void(const Status, std::span<const std::uint8_t>)>;
  using HeaderCallback =
      std::function<void(const Status, std::string_view, std::string_view)>;
  using BodyCallback =
      std::function<std::vector<std::uint8_t>(const std::size_t)>;
 
  auto on_data(DataCallback callback) noexcept -> void;
 
  auto on_header(HeaderCallback callback) noexcept -> void;
 
  auto on_body(BodyCallback callback) noexcept -> void;
 
private:
  struct Internal;
 
  // No need to make this private, as the contents of `Internal`
  // are already hidden with the PIMPL idiom.
public:
// Exporting symbols that depends on the standard C++ library is considered
// safe.
// https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-2-c4275?view=msvc-170&redirectedfrom=MSDN
#if defined(_MSC_VER)
#pragma warning(disable : 4251)
#endif
  std::unique_ptr<Internal> internal;
#if defined(_MSC_VER)
#pragma warning(default : 4251)
#endif
};
 
} // namespace sourcemeta::hydra::http
 
#endif