get_file_metadata

get_file_metadata(std::string filename) returns blaze::file_metadata for a stored application file.

Function variants

blaze::file_metadata get_file_metadata(std::string filename);
blaze::file_metadata get_file_metadata(std::string filename, std::error_code& ec) noexcept;
void async_get_file_metadata(std::string filename, std::function<void(std::error_code, blaze::file_metadata)> callback);
blaze::coro::awaitable_result<blaze::file_metadata> co_get_file_metadata(std::string filename);

Status vs error

file_metadata.status is the API result. std::error_code and std::system_error are used for transport/runtime failures only.

Parameters

Prop

Type

Result

struct file_metadata {
  std::string checksum;
  uint64_t size;
  uint32_t transfer_count;
  std::chrono::seconds last_transferred_at;
  blaze::status status;

  bool good() const noexcept;
};

Prop

Type

file_metadata.good() is equivalent to status == blaze::status::ok.

Checking returned fields

Missing fields are returned as default values. If result.status != blaze::status::ok, treat metadata fields as optional in practice and check them explicitly.

Field	Practical check
`result.checksum`	`result.checksum.empty()`
`result.size`	Check `result.status == blaze::status::ok` before relying on it. `0` is valid on success for an empty file.
`result.transfer_count`	Check `result.status == blaze::status::ok` before relying on it. `0` is also valid on success.
`result.last_transferred_at`	`result.last_transferred_at.count() == 0` means no transfer timestamp was provided.

Behavior notes

Call get_file_metadata only after successful connect and initialize.
This operation does not require an authorized license or account context.
checksum describes the whole stored file, not a transfer range.
last_transferred_at is populated only when the server has a successful transfer timestamp for this file.

Example

Compilation note

Synchronous and Asynchronous examples compile in the same form from C++14 to C++26.

#include "blazeauth/api/api.hpp"

#include <iostream>
#include <string>
#include <system_error>

void print_error_code(const std::string& context, const std::error_code& ec) {
  std::cout << context << ": " << ec.message() << " ("
            << ec.value() << " : " << ec.category().name() << ")\n";
}

std::string read_line(const std::string& label) {
  std::string value;
  std::cout << label << ": ";
  std::getline(std::cin, value);
  return value;
}

void print_status(const std::string& context, blaze::status status) {
  std::cout << context << ": "
            << static_cast<unsigned int>(status)
            << " (" << blaze::to_string(status) << ")\n";
}

int main() {
  const std::string websocket_api_key = read_line("Websocket API key");
  const std::string client_id = read_line("Client ID");
  const std::string filename = read_line("Filename");

  blaze::session session;

  try {
    const blaze::api_server server = session.connect();
    std::cout << "Connected to server location: " << server.location << '\n';

    const blaze::application app = session.initialize(websocket_api_key, client_id);
    if (!app.good()) {
      print_status("Initialize returned status", app.status);
      return 1;
    }

    const blaze::file_metadata result = session.get_file_metadata(filename);
    if (!result.good()) {
      print_status("Get-file-metadata returned status", result.status);
      return 1;
    }

    std::cout << "Checksum: " << result.checksum << '\n';
    std::cout << "Size: " << result.size << " bytes\n";
    std::cout << "Transfer count: " << result.transfer_count << '\n';
    if (result.last_transferred_at.count() != 0) {
      std::cout << "Last transferred at (unix): " << result.last_transferred_at.count() << '\n';
    } else {
      std::cout << "Last transferred at: never\n";
    }

    session.shutdown();
  } catch (const std::system_error& e) {
    print_error_code("Get-file-metadata failed", e.code());
    return 1;
  }

  return 0;
}

#include "blazeauth/api/api.hpp"

#include <future>
#include <iostream>
#include <string>
#include <system_error>

void print_error_code(const std::string& context, const std::error_code& ec) {
  std::cout << context << ": " << ec.message() << " ("
            << ec.value() << " : " << ec.category().name() << ")\n";
}

std::string read_line(const std::string& label) {
  std::string value;
  std::cout << label << ": ";
  std::getline(std::cin, value);
  return value;
}

void print_status(const std::string& context, blaze::status status) {
  std::cout << context << ": "
            << static_cast<unsigned int>(status)
            << " (" << blaze::to_string(status) << ")\n";
}

int main() {
  const std::string websocket_api_key = read_line("Websocket API key");
  const std::string client_id = read_line("Client ID");
  const std::string filename = read_line("Filename");

  blaze::session session;

  std::promise<int> completion;
  std::future<int> result = completion.get_future();

  session.async_connect(
    [&session, &completion, websocket_api_key, client_id, filename](std::error_code connect_ec, blaze::api_server server) {
      if (connect_ec) {
        print_error_code("Connect failed", connect_ec);
        completion.set_value(1);
        return;
      }

      std::cout << "Connected to server location: " << server.location << '\n';

      session.async_initialize(websocket_api_key, client_id,
        [&session, &completion, filename](std::error_code init_ec, blaze::application app) {
          if (init_ec) {
            print_error_code("Initialize failed", init_ec);
            completion.set_value(1);
            return;
          }

          if (!app.good()) {
            print_status("Initialize returned status", app.status);
            completion.set_value(1);
            return;
          }

          session.async_get_file_metadata(
            filename,
            [&session, &completion](std::error_code metadata_ec, blaze::file_metadata result) {
              if (metadata_ec) {
                print_error_code("Get-file-metadata failed", metadata_ec);
                completion.set_value(1);
                return;
              }

              if (!result.good()) {
                print_status("Get-file-metadata returned status", result.status);
                completion.set_value(1);
                return;
              }

              std::cout << "Checksum: " << result.checksum << '\n';
              std::cout << "Size: " << result.size << " bytes\n";
              std::cout << "Transfer count: " << result.transfer_count << '\n';
              if (result.last_transferred_at.count() != 0) {
                std::cout << "Last transferred at (unix): " << result.last_transferred_at.count() << '\n';
              } else {
                std::cout << "Last transferred at: never\n";
              }

              session.async_shutdown([&completion](std::error_code shutdown_ec) {
                if (shutdown_ec) {
                  print_error_code("Shutdown failed", shutdown_ec);
                  completion.set_value(1);
                  return;
                }

                completion.set_value(0);
              });
            });
        });
    });

  return result.get();
}

Project must be built with C++20 support and with coroutine support available both in the language mode and in the standard library implementation for this example to compile correctly.

#include "blazeauth/api/api.hpp"

#include <future>
#include <iostream>
#include <string>
#include <system_error>

void print_error_code(const std::string& context, const std::error_code& ec) {
  std::cout << context << ": " << ec.message() << " ("
            << ec.value() << " : " << ec.category().name() << ")\n";
}

std::string read_line(const std::string& label) {
  std::string value;
  std::cout << label << ": ";
  std::getline(std::cin, value);
  return value;
}

#if BLAZEAUTH_HAS_COROUTINES

blaze::coro::task<std::error_code> run_example(
  blaze::session& session,
  const std::string& websocket_api_key,
  const std::string& client_id,
  const std::string& filename
) {
  const auto [connect_ec, server] = co_await session.co_connect();
  if (connect_ec) {
    co_return connect_ec;
  }

  std::cout << "Connected to server location: " << server.location << '\n';

  const auto [init_ec, app] = co_await session.co_initialize(websocket_api_key, client_id);
  if (init_ec) {
    co_return init_ec;
  }

  if (!app.good()) {
    co_return blaze::make_error_code(app.status);
  }

  const auto [metadata_ec, result] = co_await session.co_get_file_metadata(filename);
  if (metadata_ec) {
    co_return metadata_ec;
  }

  if (!result.good()) {
    co_return blaze::make_error_code(result.status);
  }

  std::cout << "Checksum: " << result.checksum << '\n';
  std::cout << "Size: " << result.size << " bytes\n";
  std::cout << "Transfer count: " << result.transfer_count << '\n';
  if (result.last_transferred_at.count() != 0) {
    std::cout << "Last transferred at (unix): " << result.last_transferred_at.count() << '\n';
  } else {
    std::cout << "Last transferred at: never\n";
  }

  const auto [shutdown_ec] = co_await session.co_shutdown();
  co_return shutdown_ec;
}

int main() {
  const std::string websocket_api_key = read_line("Websocket API key");
  const std::string client_id = read_line("Client ID");
  const std::string filename = read_line("Filename");

  blaze::session session;

  std::promise<std::error_code> completion;
  std::future<std::error_code> result = completion.get_future();

  blaze::coro::co_spawn([&session, &completion, websocket_api_key, client_id, filename]() -> blaze::coro::task<void> {
    const std::error_code ec = co_await run_example(session, websocket_api_key, client_id, filename);
    completion.set_value(ec);
    co_return;
  }());

  const std::error_code ec = result.get();
  if (ec) {
    print_error_code("Get-file-metadata failed", ec);
    return 1;
  }

  return 0;
}

#else

int main() {
  std::cout << "This example requires coroutine support in the Blazeauth library build.\n";
  return 0;
}

#endif

Get-file-metadata statuses

Value	Status	Returned when
`1`	`ok`	Metadata was returned successfully.
`6`	`internal_server_error`	Server failed while reading file metadata.
`300`	`file_not_found`	File with the provided `filename` does not exist in the current application.
`301`	`file_invalid_name`	`filename` is shorter than 4 characters.

Connection-level shutdowns

Normal get-file-metadata results are returned in result.status. The websocket may still be closed by session-level guards:

Close code	Meaning	When it can happen
`4200`	`not_initialized`	`get_file_metadata` was called before a successful `initialize`.
`4201`	`rate_limited`	Session or IP rate limiting closed the websocket around this operation.

get_file_metadata

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