http: prefer reference rather than shared pointer for route()

[wbpcode]

Commit Message: stream info: prefer reference rather than shared pointer for route()
Additional Description:

See new style #44025 for more detail

Risk Level: n/a.
Testing: n/a.
Docs Changes: n/a.
Release Notes: n/a.
Platform Specific Features: n/a.

[wbpcode]

Wait #43938 to be merged first.

[wbpcode]

/retest

[wbpcode]

/retest

[wbpcode]

/gemini review

[gemini-code-assist]

Code Review

This pull request refactors the route() method across the HTTP filter stack to return an OptRef<const Router::Route> instead of a SharedPtr, introducing routeSharedPtr() for cases where ownership management is required. The changes span the core connection manager, filter manager, and numerous extensions, with corresponding updates to the test suite. Feedback focuses on reducing code duplication in ConnectionManagerImpl and optimizing performance and readability in the CORS and Lua filters by caching the result of route() calls in local variables.

[Copilot]

Pull request overview

Refactors the HTTP filter callback route() API to return an OptRef<const Router::Route> (non-owning optional reference) instead of a shared_ptr, while adding routeSharedPtr() for callers that need ownership extension/transfer.

Changes:

• Updates StreamFilterCallbacks::route() / DownstreamStreamFilterCallbacks::route(...) to return OptRef<const Router::Route>.
• Introduces routeSharedPtr() variants and updates core implementations (HCM, filter manager, async client, tcp proxy).
• Migrates call sites and tests to the new API patterns (!route, route.has_value(), route().ptr(), or routeSharedPtr() where ownership is needed).

Reviewed changes

Copilot reviewed 54 out of 54 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/mocks/http/mocks.h	Update mock route APIs + add routeSharedPtr
test/mocks/http/mocks.cc	Default mock behavior for route/routeSharedPtr
test/integration/filters/set_route_filter.cc	Use routeSharedPtr for delegating route
test/integration/filters/async_upstream_filter.cc	Adapt route assertions to OptRef
test/extensions/filters/http/on_demand/on_demand_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/lua/lua_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/jwt_authn/jwt_authn_fuzz_test.cc	Set mock route via callback state
test/extensions/filters/http/jwt_authn/filter_test.cc	Update test expectations to OptRef
test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/grpc_json_reverse_transcoder/filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/grpc_http1_reverse_bridge/reverse_bridge_test.cc	Return empty OptRef in tests
test/extensions/filters/http/grpc_http1_bridge/http1_bridge_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/gcp_authn/gcp_authn_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/file_system_buffer/filter_test.cc	Update route mocking to OptRef
test/extensions/filters/http/ext_proc/ordering_test.cc	Return route as OptRef
test/extensions/filters/http/ext_proc/filter_test_common.cc	Return route as OptRef
test/extensions/filters/http/ext_proc/filter_test.cc	Return route as OptRef
test/extensions/filters/http/ext_authz/ext_authz_test.cc	Return empty OptRef in tests
test/extensions/filters/http/dynamic_forward_proxy/proxy_filter_test.cc	Remove/adjust route default mocks
test/extensions/filters/http/csrf/csrf_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/cors/cors_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/cache_v2/cache_filter_test.cc	Return empty OptRef in tests
test/extensions/filters/http/cache/cache_filter_test.cc	Return empty OptRef in tests
test/common/router/upstream_request_test.cc	Update route comparison for new API
test/common/router/router_test.cc	Expect routeSharedPtr() behavior in router test
test/common/http/filter_manager_test.cc	Update downstream callback route returns to OptRef
test/common/http/conn_manager_impl_test_3.cc	Compare routes via .ptr() / .has_value()
test/common/http/conn_manager_impl_test_2.cc	Compare routes via .ptr() / .has_value()
test/common/http/conn_manager_impl_test.cc	Update routing tests to new callbacks
test/common/http/async_client_impl_test.cc	Update route assertions to OptRef
source/extensions/filters/http/ratelimit/ratelimit.cc	Persist route via routeSharedPtr()
source/extensions/filters/http/on_demand/on_demand_update.cc	Switch nullptr checks to OptRef
source/extensions/filters/http/lua/lua_filter.cc	Switch nullptr checks to OptRef
source/extensions/filters/http/local_ratelimit/local_ratelimit.h	Update helper signature to OptRef
source/extensions/filters/http/local_ratelimit/local_ratelimit.cc	Adapt route usage to OptRef
source/extensions/filters/http/grpc_http1_reverse_bridge/filter.cc	Switch nullptr checks to OptRef
source/extensions/filters/http/gcp_authn/gcp_authn_filter.cc	Switch nullptr checks to OptRef
source/extensions/filters/http/fault/fault_filter.cc	Switch route local to OptRef
source/extensions/filters/http/ext_authz/ext_authz.h	Update helper signature to OptRef
source/extensions/filters/http/ext_authz/ext_authz.cc	Use OptRef in routing/metadata handling
source/extensions/filters/http/dynamic_forward_proxy/proxy_filter.cc	Switch route local to OptRef
source/extensions/filters/http/cors/cors_filter.cc	Switch route checks to OptRef
source/extensions/filters/http/cache_v2/cache_filter.cc	Switch route local to OptRef
source/extensions/filters/http/cache/cache_filter.cc	Switch route local to OptRef
source/common/tcp_proxy/tcp_proxy.h	Implement route() + add routeSharedPtr()
source/common/router/upstream_request.cc	Store route via routeSharedPtr()
source/common/router/router.cc	Store route via routeSharedPtr()
source/common/http/filter_manager.h	Add routeSharedPtr() and OptRef route plumbing
source/common/http/filter_manager.cc	Implement new route getters
source/common/http/conn_manager_impl.h	Add downstream routeSharedPtr() API
source/common/http/conn_manager_impl.cc	Implement downstream route() as OptRef and shared variant
source/common/http/async_client_impl.h	Implement route() as OptRef + shared variant
envoy/http/filter.h	Update public filter callback interfaces
contrib/istio/filters/http/alpn/source/alpn_filter.cc	Switch route local to OptRef

[wbpcode]

This refactoring have discussed at slack channel and no any logic change. Let's merge it because other 5 PRs have been merged.