struct ara::diag::HttpRedirect

The structure ara::diag::HttpRedirect enables an SOVD server to inform an SOVD client of the new address of an SOVD resource that has been moved or is available under another path [SWS_DM_01828]. For this purpose, it provides the public attribute url, which defines the target URL of the redirection as a character string [SWS_DM_01829]. As a pure value object, the structure is instantiated on demand and encapsulates address information for the higher-level HTTP response protocol.

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Context

The structure ara::diag::HttpRedirect is part of the diagnostics module (diag) of the AUTOSAR Adaptive Platform and is declared via header file ara/diag/sovd_http_redirect.h AUTOSAR_AP_SWS_Diagnostics §8.55 “Header: ara/diag/sovd_http_redirect.h”. It serves for the standardized representation of an HTTP redirect in the context of SOVD (Service-Oriented Vehicle Diagnostics) according to [SWS_DM_01828]. If a diagnostic resource within the vehicle has been relocated or is reachable temporarily or permanently under another address, the SOVD server signals the new location to the requesting SOVD client via this type.

The structure represents an elementary data carrier whose only public member is variable url of type ara::core::String [SWS_DM_01829]. This field specifies the complete or relative target address to which the client is to redirect its original request AUTOSAR_AP_SWS_Diagnostics §8.55.1.1 “Public Member Variables”. ara::diag::HttpRedirect thus acts as a standardized link between internal resource management of the diagnostic server and external protocol handling toward the client.

Lifecycle

As a purely passive data structure (struct), ara::diag::HttpRedirect has a transient lifecycle bound to the execution context according to [SWS_DM_01828]. Interpretation: Instantiation takes place on demand by the SOVD server or a connected diagnostic application at the moment redirecting a request becomes necessary. Question (open) Here, the target URL is stored in field url directly during construction or immediately thereafter [SWS_DM_01829].

The structure has regular C++ value semantics; memory allocation and deallocation depend entirely on the lifetime of the encapsulating instance as well as embedded ara::core::String. Interpretation: Creating, assigning, and destroying the structure is side-effect-free and does not require registration or deregistration with central instances of the diagnostic service. Question (open) Regarding concurrency, an individual instance of ara::diag::HttpRedirect is not thread-safe for write access; however, since instances are usually created in isolation per client request and transported as a return value, no synchronization conflicts occur.

Usage Path

Typical use of ara::diag::HttpRedirect takes place in a three-stage interaction between SOVD client, SOVD server, and the relocated target resource. First, the SOVD client sends an HTTP call to a known resource URI. If the server cannot service the request directly because the resource was moved to a new endpoint, it creates an instance of ara::diag::HttpRedirect according to [SWS_DM_01828] and assigns the new target address to member url [SWS_DM_01829].

Interpretation: Transferring the structure contents into the HTTP response stream (for example in connection with an HTTP redirect status code and the corresponding Location header) is carried out by the underlying SOVD communication stack. Question Q-e68bb7696aa291c0 (open) As soon as the SOVD client receives the redirection, it transparently directs its diagnostic request to the transmitted target URL to execute the actual diagnostic operation.

Sequence diagram: Redirection of an SOVD client by the SOVD server using HttpRedirect. Sources: [SWS_DM_01828], [SWS_DM_01829]