Devirtualization + internal linkage: mark leaf impl classes final and TU-local helpers static

[bmehta001]

Devirtualization: mark concrete leaf impl classes final

Marks the leaf concrete implementations of the hot IHttpClient / IOfflineStorage
interfaces final, so the compiler can devirtualize (and frequently inline)
virtual calls made through a known-final type ? smaller, faster code on every
HTTP upload and offline-storage operation.

Marked final (9):

• HttpClient_Curl, HttpClient_WinInet, HttpClient_WinRt, HttpClient_Apple, HttpClient_Android, HttpClient_CAPI
• OfflineStorage_Room, MemoryStorage, OfflineStorageHandler

Verification: each was confirmed to have no subclass anywhere in the tree (lib + tests + wrappers).

Deliberately NOT marked:

• OfflineStorage_SQLite ? tests/unittests/OfflineStorageTests_SQLite.cpp subclasses it (OfflineStorage_SQLiteNoAutoCommit).
• TelemetrySystemBase ? it's the base of TelemetrySystem / AITelemetrySystem.

Validation: NDK aarch64 -fsyntax-only clean on OfflineStorage_Room, OfflineStorageHandler, MemoryStorage. The platform-specific HTTP impls (WinInet/WinRt/Apple) rely on the no-subclass verification + per-platform CI.

Note on static/anonymous-namespace

The companion static/anon-namespace cleanup for file-local helpers is a planned follow-up. Its primary benefit (keeping internals out of the exported symbol set) is largely already delivered by the -fvisibility=hidden change in the vcpkg PR (#1475), so it's lower priority; static adds the incremental win of stronger inlining/DCE and no symbol entry at all, which can be a focused follow-up.

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Internal linkage (static) — added in d0c0afb

Companion micro-optimization in the same spirit: give internal linkage to translation-unit-local symbols so the compiler can inline/drop them and keep them out of the symbol table. This specifically helps the static-library consumption path (e.g. vcpkg), which -fvisibility=hidden does not fully cover — hidden visibility only trims a shared object's dynamic export table, whereas these symbols otherwise keep external linkage across TUs.

• lib/api/capi.cpp — marked the 10 file-local C-API dispatch helpers static (remove_client, mat_open_core, mat_open, mat_open_with_params, mat_log, mat_close, mat_pause, mat_resume, mat_upload, mat_flushAndTeardown). Each is called only from the single exported entry point evt_api_call_default (and from one another) within capi.cpp, and appears in no header and no other TU. MAT::capi_get_client stays external (header-declared, used by the CAPI HTTP client).
• lib/shared/dllmain.cpp — marked thread_count static (file-scope global mutated only inside DllMain).

Deliberately not touched: get_platform_uuid (sysinfo_sources.cpp) has no in-tree caller, so static would trip -Wunused-function under -Werror.

Verified: NDK clang aarch64 -fsyntax-only on capi.cpp is clean; whole-tree cross-reference confirmed none of the internalized symbols are referenced from any header or other translation unit.

[Copilot]

Pull request overview

This PR optimizes hot-path virtual dispatch by marking leaf concrete implementations of the IHttpClient and IOfflineStorage interfaces as final, enabling better compiler devirtualization/inlining in the SDK’s HTTP upload and offline-storage code paths.

Changes:

• Mark concrete HTTP client implementations (HttpClient_*) as final.
• Mark concrete offline storage implementations/handler (OfflineStorage_*, MemoryStorage, OfflineStorageHandler) as final.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lib/offline/OfflineStorageHandler.hpp	Marks OfflineStorageHandler as final to enable devirtualization through known concrete type usage.
lib/offline/OfflineStorage_Room.hpp	Marks OfflineStorage_Room as final to allow devirtualization in Android Room-backed storage path.
lib/offline/MemoryStorage.hpp	Marks MemoryStorage as final to enable devirtualization for in-memory storage operations.
lib/http/HttpClient_WinRt.hpp	Marks HttpClient_WinRt as final to improve call-site optimization on WinRT HTTP path.
lib/http/HttpClient_WinInet.hpp	Marks HttpClient_WinInet as final to improve call-site optimization on WinInet HTTP path.
lib/http/HttpClient_Curl.hpp	Marks HttpClient_Curl as final to improve call-site optimization on Curl HTTP path.
lib/http/HttpClient_CAPI.hpp	Marks HttpClient_CAPI as final to improve call-site optimization for C API-backed HTTP client.
lib/http/HttpClient_Apple.hpp	Marks HttpClient_Apple as final to improve call-site optimization on Apple HTTP path.
lib/http/HttpClient_Android.hpp	Marks HttpClient_Android as final to improve call-site optimization on Android HTTP path.

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[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 1 comment.

[lalitb]

I believe most of our storage/upload calls go through IHttpClient / IOfflineStorage references after construction. Do we have compiler output, size data, or a concrete call path showing where this actually devirtualizes without LTO?

My only concern is the tradeoff here: if this does not actually devirtualize the main hot paths, we may be restricting downstream/internal users from subclassing these concrete types without much benefit.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated no new comments.