docs: consolidate mw/log design diagrams into docs/components/

docs/components/datarouter/detailed_design/index.rst

@@ -0,0 +1,59 @@
+..
+   # *******************************************************************************
+   # Copyright (c) 2026 Contributors to the Eclipse Foundation
+   #
+   # See the NOTICE file(s) distributed with this work for additional
+   # information regarding copyright ownership.
+   #
+   # This program and the accompanying materials are made available under the
+   # terms of the Apache License Version 2.0 which is available at
+   # https://www.apache.org/licenses/LICENSE-2.0
+   #
+   # SPDX-License-Identifier: Apache-2.0
+   # *******************************************************************************
+
+Detailed Design
+###############
+
+.. document:: Data Router Detailed Design
+   :id: doc__data_router_detailed_design
+   :status: valid
+   :safety: ASIL_B
+   :security: YES
+   :realizes: wp__sw_implementation
+
+
+Static View
+-----------
+
+.. comp_arc_sta:: Data Router Static View
+   :id: comp_arc_sta__data_router__static_view
+   :security: YES
+   :safety: ASIL_B
+   :status: valid
+   :fulfils: comp_req__data_router__dlt_server
+   :belongs_to: comp__data_router
+
+   .. uml:: datarouter_class_diagram.puml
+
+   .. uml:: inter_process_communication.puml
+
+   .. uml:: mw_log_shared_memory_reader.puml
+
+
+Dynamic View
+------------
+
+.. comp_arc_dyn:: Data Router Dynamic View
+   :id: comp_arc_dyn__data_router__dynamic_view
+   :security: YES
+   :safety: ASIL_B
+   :status: valid
+   :fulfils: comp_req__data_router__dlt_server
+   :belongs_to: comp__data_router
+
+   .. uml:: datarouter_backend_datarouterbackend.puml
+
+   .. uml:: shared_memory_reader_read.puml
+
+   .. uml:: datarouter_message_client_impl_connecttodatarouter.puml

docs/components/datarouter/index.rst

@@ -34,3 +34,4 @@ This section is reserved for data router-specific documentation.
    :glob:
 
    *
+   detailed_design/index

docs/components/mw/log/detailed_design/backend_registration_component_diagram.puml

@@ -0,0 +1,119 @@
+@startuml component_diagram
+
+skinparam componentStyle rectangle
+skinparam backgroundColor #FEFEFE
+skinparam component {
+    BackgroundColor<<always>> #D5E8D4
+    BorderColor<<always>> #82B366
+    BackgroundColor<<additive>> #DAE8FC
+    BorderColor<<additive>> #6C8EBF
+    BackgroundColor<<core>> #FFF2CC
+    BorderColor<<core>> #D6B656
+    BackgroundColor<<recorder>> #E1D5E7
+    BorderColor<<recorder>> #9673A6
+    BackgroundColor<<app>> #F8CECC
+    BorderColor<<app>> #B85450
+}
+skinparam note {
+    BackgroundColor #FFFFCC
+    BorderColor #999999
+}
+
+title **mw::log — Lightweight Selectable Backend Architecture**\nComponent Overview
+
+' === Application Layer ===
+package "Application Binary" <<app>> {
+    component "Application Code" as app <<app>> {
+        note right of app
+            #include "score/mw/log/logging.h"
+            LOG_INFO() << "message";
+        end note
+    }
+}
+
+' === Frontend Layer (public API) ===
+package "mw/log:frontend" <<always>> {
+    component "Logger" as logger <<always>>
+    component "LoggerContainer" as container <<always>>
+    component "LogStream" as stream <<always>>
+    component "Runtime\n(Meyers' Singleton)" as runtime <<always>>
+    component "IRecorderFactory\n(pure virtual)" as irecorder_factory <<core>>
+}
+
+' === Backend Infrastructure (always linked) ===
+package "mw/log:console  [alwayslink=True]" <<always>> {
+    component "gBackendCreators\n(std::array<FnPtr, 6>)\n---\nConstant-initialized\nZero-init at load time\nNo constructor / No destructor" as backend_table <<core>>
+    component "RegistryAwareRecorderFactory\n: IRecorderFactory" as registry_factory <<always>>
+    component "ConsoleRegistrant\n(static const)" as console_reg <<always>>
+    component "CreateRecorderFactory()\n[link-time injection]" as create_factory <<always>>
+}
+
+' === Additive Backend Plugins (optional, each alwayslink=True) ===
+package "Additive Backend Plugins" <<additive>> {
+    component "backend:file\nFileRegistrant" as file_reg <<additive>>
+    component "backend:remote\nRemoteRegistrant" as remote_reg <<additive>>
+    component "backend:slog\nSlogRegistrant\n(QNX only)" as slog_reg <<additive>>
+    component "backend:custom\nCustomRegistrant" as custom_reg <<additive>>
+}
+
+' === Recorder Implementations ===
+package "Recorder Implementations" <<recorder>> {
+    component "TextRecorder\n(Console)" as text_recorder <<always>>
+    component "FileRecorder\n(DLT File)" as file_recorder <<recorder>>
+    component "DataRouterRecorder\n(Remote DLT)" as dr_recorder <<recorder>>
+    component "SlogRecorder\n(QNX slog2)" as slog_recorder <<recorder>>
+    component "EmptyRecorder\n(No-op stub)" as empty_recorder <<recorder>>
+    component "CompositeRecorder\n(Multiplexer)" as composite <<recorder>>
+}
+
+' === Configuration ===
+package "Configuration" <<core>> {
+    component "TargetConfigReader" as config_reader <<core>>
+    component "Configuration" as config <<core>>
+}
+
+' === Relationships ===
+
+' App -> Frontend
+app --> logger : "LOG_xxx()"
+app --> stream
+logger --> runtime : "GetRecorder()"
+
+' Frontend -> Factory
+runtime --> create_factory : "CreateRecorderFactory()\n(link-time injection)"
+create_factory --> registry_factory : "returns"
+registry_factory --|> irecorder_factory : "implements"
+
+' Factory -> Backend Table
+registry_factory --> backend_table : "queries\ngBackendCreators[mode]"
+registry_factory --> config_reader : "reads config files"
+config_reader --> config : "produces"
+
+' Registrants -> Backend Table
+console_reg --> backend_table : "writes slot[0]\n(kConsole)"
+file_reg --> backend_table : "writes slot[1]\n(kFile)"
+remote_reg --> backend_table : "writes slot[2]\n(kRemote)"
+slog_reg --> backend_table : "writes slot[3]\n(kSystem)"
+custom_reg --> backend_table : "writes slot[4]\n(kCustom)"
+
+' Registrants -> Recorder Factories -> Recorders
+console_reg ..> text_recorder : "creates via\nConsoleRecorderFactory"
+file_reg ..> file_recorder : "creates via\nFileRecorderFactory"
+remote_reg ..> dr_recorder : "creates via\nRemoteDltRecorderFactory"
+slog_reg ..> slog_recorder : "creates via\nSlogRecorderFactory"
+
+' Factory -> Recorders
+registry_factory ..> composite : "wraps multiple\nrecorders"
+registry_factory ..> empty_recorder : "last resort\nfallback"
+
+' Legend
+legend bottom
+    |= Color |= Meaning |
+    | <back:#D5E8D4>  green  </back> | **Always linked** — part of mw/log:console |
+    | <back:#DAE8FC>  blue   </back> | **Additive plugin** — opt-in via Bazel deps |
+    | <back:#FFF2CC>  yellow </back> | **Core infrastructure** — backend table, config, interfaces |
+    | <back:#E1D5E7>  purple </back> | **Recorder implementations** — linked only when needed |
+    | <back:#F8CECC>  red    </back> | **Application code** — user binary |
+end legend
+
+@enduml

docs/components/mw/log/detailed_design/backend_registration_sequence_diagram.puml

@@ -0,0 +1,123 @@
+@startuml sequence_diagram
+' Sequence Diagram: Backend Registration and Recorder Creation Flow
+
+skinparam backgroundColor #FEFEFE
+skinparam sequenceArrowThickness 2
+skinparam sequenceParticipantBorderColor #666666
+skinparam sequenceLifeLineBorderColor #999999
+skinparam noteBackgroundColor #FFFFCC
+skinparam noteBorderColor #999999
+skinparam sequenceGroupBackgroundColor #F5F5F5
+
+title **mw::log — Backend Registration & Recorder Creation Sequence**
+
+' === Participants ===
+participant "OS Loader" as loader #F8CECC
+participant "gBackendCreators\n[std::array<FnPtr,6>]" as table #FFF2CC
+participant "ConsoleRegistrant\n(static const)" as console_reg #D5E8D4
+participant "FileRegistrant\n(static const)" as file_reg #DAE8FC
+participant "RemoteRegistrant\n(static const)" as remote_reg #DAE8FC
+participant "Application\nmain()" as app #F8CECC
+participant "Runtime\n(Meyers' Singleton)" as runtime #D5E8D4
+participant "RegistryAware\nRecorderFactory" as factory #D5E8D4
+participant "TargetConfigReader" as config_reader #FFF2CC
+participant "CompositeRecorder" as composite #E1D5E7
+
+' === Phase 1: Constant Initialization (load time) ===
+autonumber
+group #E8F5E9 Phase 1: Constant Initialization (before main)
+    loader -> table : Zero-initialize gBackendCreators
+    note over table
+        gBackendCreators = {nullptr, nullptr, nullptr, nullptr, nullptr, nullptr}
+    end note
+end
+
+' === Phase 2: Dynamic Initialization (static constructors, before main) ===
+group #E3F2FD Phase 2: Dynamic Initialization (static constructors, TU order unspecified)
+    console_reg -> table : RegisterBackend(kConsole, &CreateConsoleRecorder)
+    note right : gBackendCreators[0] = &CreateConsoleRecorder
+    activate table
+    deactivate table
+
+    file_reg -> table : RegisterBackend(kFile, &CreateFileRecorder)
+    note right : gBackendCreators[1] = &CreateFileRecorder
+    activate table
+    deactivate table
+
+    note over table
+        Assuming the user has linked the respective backends (E.g.: mw/log/backend:file)*
+            - If a backend is not linked, its slot remains nullptr.
+        mw/log:console is always linked, so kConsole is guaranteed to be registered.
+    end note
+end
+
+' === Phase 3: main() starts ===
+group #FFF3E0 Phase 3: Application Runtime (after main)
+    app -> runtime : First LOG_INFO() call
+    activate runtime
+
+    runtime -> runtime : Instance() — Meyers' singleton created
+    note right of runtime
+        Single creation point.
+        All registrants have completed.
+    end note
+
+    runtime -> factory : CreateRecorderFactory()
+    activate factory
+
+    factory -> config_reader : ReadConfig()
+    activate config_reader
+    config_reader --> factory : Result<Configuration>\n{logMode: kConsole | kFile | kRemote}
+    deactivate config_reader
+
+    ' --- Iterate over configured log modes ---
+    loop for each mode in config.GetLogMode()
+        alt mode = kConsole
+            factory -> table : IsBackendAvailable(kConsole)
+            table --> factory : true
+            factory -> table : CreateRecorderForMode(kConsole, config, memory_resource)
+            table --> factory : unique_ptr<TextRecorder>
+        else mode = kFile
+            factory -> table : IsBackendAvailable(kFile)
+            table --> factory : true
+            factory -> table : CreateRecorderForMode(kFile, config, memory_resource)
+            table --> factory : unique_ptr<FileRecorder>
+        else mode = kRemote (not linked)
+            factory -> table : IsBackendAvailable(kRemote)
+            table --> factory : false (nullptr)
+            note right
+                **Fallback:** Backend not linked.
+                Create console recorder instead.
+            end note
+            factory -> table : CreateRecorderForMode(kConsole, config, memory_resource)
+            table --> factory : unique_ptr<TextRecorder> (fallback)
+        end
+    end
+
+    alt recorders.size() == 1
+        factory --> runtime : single Recorder
+    else recorders.size() > 1
+        factory -> composite : CompositeRecorder(move(recorders))
+        activate composite
+        composite --> factory : unique_ptr<CompositeRecorder>
+        deactivate composite
+        factory --> runtime : unique_ptr<CompositeRecorder>
+    end
+    deactivate factory
+
+    runtime --> app : Recorder& (ready for logging)
+    deactivate runtime
+end
+
+' === Phase 4: Shutdown ===
+group #FFEBEE Phase 4: Program Shutdown
+    app -> runtime : Process exit
+    note over runtime, table
+        - Runtime singleton destroyed releasing owned Recorder instances
+        - BackendRegistrant instances destroyed -> no-op (no destructor body)
+        - gBackendCreators "destroyed" -> trivially destructible, no dtor runs
+
+    end note
+end
+
+@enduml