create-platform-client-settings.md

Create platform client settings

The OlpClientSettings class pulls together all the settings for customization of the client library behavior. You need to create the OlpClientSettings object to get catalog and partition metadata, retrieve versioned, volatile, and stream layer data, and publish data to the HERE platform.

To create OlpClientSettings object:

1. To perform requests asynchronously, create the TaskScheduler object.

   std::shared_ptr<olp::thread::TaskScheduler> task_scheduler =
         olp::client::OlpClientSettingsFactory::CreateDefaultTaskScheduler(1u);

2. To internally operate with the HERE platform Services, create the Network client.

   std::shared_ptr<olp::http::Network> http_client = olp::client::
        OlpClientSettingsFactory::CreateDefaultNetworkRequestHandler();

   Note

   The Network client is designed and intended to be shared.

3. To configure handling of failed requests, create the RetrySettings object with the following parameters:

   • retry_condition – the HTTP status codes that you want to retry.
   • backdown_strategy – the delay between retries.
   • max_attempts – the number of attempts.
   • timeout – the connection timeout limit (in seconds).
   • initial_backdown_period – the period between the error and the first retry attempt (in milliseconds).

   Note

   We recommend that your application includes retry logic for handling HTTP 429 and 5xx errors. Use exponential backoff in the retry logic.

   olp::client::RetrySettings retry_settings;
   retry_settings.retry_condition = [](const olp::client::HttpResponse& response) {
     return olp::http::HttpStatusCode::TOO_MANY_REQUESTS == response.status;
   };
   retry_settings.backdown_strategy = olp::client::ExponentialBackdownStrategy();
   retry_settings.max_attempts = 3;
   retry_settings.timeout = 60;
   retry_settings.initial_backdown_period = 200;

4. Authenticate to the HERE platform.

5. (Optional) To configure a cache:

   1. Create the CacheSettings instance with the cache that you want to enable and, if needed, the maximum cache size in bytes.

      Note

      By default, the downloaded data is cached in memory, and the maximum size of it is 1 MB.

      olp::cache::CacheSettings cache_settings;
      // On iOS, the path is relative to the Application Data folder.
      cache_settings.disk_path_mutable = "path to mutable cache";
      cache_settings.disk_path_protected = "path to protected cache";
      cache_settings.max_disk_storage = 1024ull * 1024ull * 32ull;

   2. Add the CacheSettings instance to the DefaultCache constructor.

      olp::client::OlpClientSettingsFactory::CreateDefaultCache(cache_settings);

      To learn how to get or change cache size, see Work with a cache.

6. Set up the OlpClientSettings object, and if you want to add the expiration limit for the data that is stored in the cache, set the default_cache_expiration to the needed expiration time.

   By default, expiration is disabled.

   Note

   You can only disable expiration for the mutable and in-memory cache. This setting does not affect the protected cache as no entries are added to the protected cache in the read-only mode.

   olp::client::OlpClientSettings client_settings;
   client_settings.authentication_settings = auth_settings;
   client_settings.task_scheduler = task_scheduler;
   client_settings.network_request_handler = http_client;
   client_settings.retry_settings = retry_settings;
   client_settings.cache =
       olp::client::OlpClientSettingsFactory::CreateDefaultCache(cache_settings);
   client_settings.default_cache_expiration = std::chrono::seconds(200);