class ara::diag::DiagnosticSovdRecordContentElementDataConstView

The class provides an immutable view onto structured SOVD record content elements for efficient and read-only evaluation in diagnostic applications ([SWS_DM_02295]). Users can check the error status via result objects, address record elements selectively by key, or traverse the entire content sequentially using constant iterators ([SWS_DM_02300]). All interfaces are fully thread-safe and declared exception-safe, but require that the referenced content element corresponds to the expected record type.

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Context

The class ara::diag::DiagnosticSovdRecordContentElementDataConstView defines an immutable view (Const View) onto diagnostic SOVD content elements of data record type Record ([SWS_DM_02295], AUTOSAR_AP_SWS_Diagnostics §8.60.9 “Class: DiagnosticSovdRecordContentElementDataConstView”). The interface is provided via the header #include "ara/diag/diagnostic_sovd_content_element_data.h" ([SWS_DM_02298]). It allows diagnostic applications to selectively and structurally read out hierarchically organized data fields of an SOVD content element without having to create copies of payload data or perform modifying operations.

The primary interaction partners include the calling diagnostic component, the underlying object of type DiagnosticSovdContentElementData, and the individual elements addressed through it, which are provided as a constant reference wrapper std::reference_wrapper<DiagnosticSovdContentElementData const> or via constant iterators ([SWS_DM_02300], [SWS_DM_02301]).

Lifecycle

As a view type, ara::diag::DiagnosticSovdRecordContentElementDataConstView presumably does not possess its own ownership of the underlying payload data; the validity of the view is likely bound to the lifetime of the referenced DiagnosticSovdContentElementData object. Question Q-4aca4f6f723cd3f5 (open) Destruction of the view instance merely releases the view descriptor, but leaves the underlying data structure untouched.

Regarding concurrency, all member functions of the class are explicitly specified as thread-safe and exception-safe (noexcept) ([SWS_DM_02296], [SWS_DM_02298]). Multiple threads can thus access the interface for reading in parallel without synchronization, provided that the referenced data structure is not modified concurrently during the access.

Usage Path

A typical sequence for evaluating a record element is divided into error checking, dimension checking, and element access:

1. Checking error state: Before processing, HasError() is used to validate whether the content is free of errors ([SWS_DM_02296]).
2. Querying occupancy: Using Empty(), it can be checked whether the data record is empty ([SWS_DM_02299], AUTOSAR_AP_SWS_Diagnostics §8.60.9.1.1.5 “Empty”). The methods Size() and Capacity() return the number of elements and the capacity of the data record ([SWS_DM_02297], [SWS_DM_02298], AUTOSAR_AP_SWS_Diagnostics §8.60.9.1.1.4 “Capacity”).
3. Targeted element access: Prior to accessing a named field, the presence of a key can be checked using HasContentElement() ([SWS_DM_02305]). Random access is then performed via operator[] by passing a ara::core::StringView, which returns a reference to the sub-element ([SWS_DM_02300]). Alternatively, Find() returns an iterator to the element found ([SWS_DM_02306]).
4. Sequential iteration: For full traversal of all sub-elements, the iterator methods Begin() / End() and CBegin() / CEnd() are available, returning instances of DiagnosticSovdRecordContentElementDataConstIterator ([SWS_DM_02301], [SWS_DM_02302], [SWS_DM_02303], [SWS_DM_02304], AUTOSAR_AP_SWS_Diagnostics §8.60.9.1.1.1 “Begin”, AUTOSAR_AP_SWS_Diagnostics §8.60.9.1.1.2 “CBegin”, AUTOSAR_AP_SWS_Diagnostics §8.60.9.1.1.3 “CEnd”).

Sequence diagram: Call order for error checking and key-based element querying. Sources: [SWS_DM_02296], [SWS_DM_02300], [SWS_DM_02305].

Error Scenarios

The class uses the return type ara::core::Result for error handling instead of C++ exceptions:

• Internal error state: If the underlying SOVD content element exhibits an error, HasError() returns a ara::core::Result<void> containing the error code ara::diag::DiagSovdErrc ([SWS_DM_02296]).
• Missing key or type mismatch: When accessing via operator[] or checking with HasContentElement(), the return value yields an error result if the DiagnosticSovdContentElementData is not of type RecordContentElementData or ContentData, or if the specified key does not exist ([SWS_DM_02300], [SWS_DM_02305]).
• Violation of preconditions: For methods Begin(), End(), CBegin(), CEnd(), Size(), Capacity(), Empty(), and Find(), the precondition is that the referenced content element must be of type RecordContentElementData or ContentData ([SWS_DM_02297], [SWS_DM_02298], [SWS_DM_02299], [SWS_DM_02301], [SWS_DM_02302], [SWS_DM_02303], [SWS_DM_02304], [SWS_DM_02306]).