set.mitm: much more aggressively cache locale (#1160)

stratosphere/ams_mitm/source/set_mitm/set_mitm_service.cpp

@@ -15,37 +15,94 @@
  */
 #include <stratosphere.hpp>
 #include "set_mitm_service.hpp"
+#include "set_shim.h"
 
 namespace ams::mitm::settings {
 
     using namespace ams::settings;
 
+    namespace {
+
+        constinit os::ProcessId g_application_process_id = os::InvalidProcessId;
+        constinit cfg::OverrideLocale g_application_locale;
+        constinit bool g_valid_language;
+        constinit bool g_valid_region;
+    }
+
+    SetMitmService::SetMitmService(std::shared_ptr<::Service> &&s, const sm::MitmProcessInfo &c) : sf::MitmServiceImplBase(std::forward<std::shared_ptr<::Service>>(s), c) {
+        if (this->client_info.program_id == ncm::SystemProgramId::Ns) {
+            os::ProcessId application_process_id;
+            if (R_SUCCEEDED(pm::dmnt::GetApplicationProcessId(std::addressof(application_process_id))) && g_application_process_id == application_process_id) {
+                this->locale = g_application_locale;
+                this->is_valid_language = g_valid_language;
+                this->is_valid_region   = g_valid_region;
+                this->got_locale = true;
+            } else {
+                this->InvalidateLocale();
+            }
+        } else {
+            this->InvalidateLocale();
+        }
+    }
+
     Result SetMitmService::EnsureLocale() {
+        /* Optimization: if locale has already been gotten, we can stop. */
+        if (AMS_LIKELY(this->got_locale)) {
+            return ResultSuccess();
+        }
+
         std::scoped_lock lk(this->lock);
 
         const bool is_ns = this->client_info.program_id == ncm::SystemProgramId::Ns;
 
         if (!this->got_locale) {
-            std::memset(&this->locale, 0xCC, sizeof(this->locale));
             ncm::ProgramId program_id = this->client_info.program_id;
+            os::ProcessId application_process_id = os::InvalidProcessId;
+
             if (is_ns) {
                 /* When NS asks for a locale, refresh to get the current application locale. */
-                os::ProcessId application_process_id;
+                R_TRY(pm::dmnt::GetApplicationProcessId(std::addressof(application_process_id)));
-                R_TRY(pm::dmnt::GetApplicationProcessId(&application_process_id));
+                R_TRY(pm::info::GetProgramId(std::addressof(program_id), application_process_id));
-                R_TRY(pm::info::GetProgramId(&program_id, application_process_id));
+            }
+            this->locale            = cfg::GetOverrideLocale(program_id);
+            this->is_valid_language = settings::IsValidLanguageCode(this->locale.language_code);
+            this->is_valid_region   = settings::IsValidRegionCode(this->locale.region_code);
+            this->got_locale        = true;
+
+            if (is_ns) {
+                g_application_locale     = this->locale;
+                g_valid_language         = this->is_valid_language;
+                g_valid_region           = this->is_valid_region;
+                g_application_process_id = application_process_id;
             }
-            this->locale = cfg::GetOverrideLocale(program_id);
-            this->got_locale = !is_ns;
         }
 
         return ResultSuccess();
     }
 
+    void SetMitmService::InvalidateLocale() {
+        std::scoped_lock lk(this->lock);
+
+        std::memset(std::addressof(this->locale), 0xCC, sizeof(this->locale));
+        this->is_valid_language = false;
+        this->is_valid_region   = false;
+        this->got_locale        = false;
+    }
+
     Result SetMitmService::GetLanguageCode(sf::Out<settings::LanguageCode> out) {
         this->EnsureLocale();
 
         /* If there's no override locale, just use the actual one. */
-        R_UNLESS(settings::IsValidLanguageCode(this->locale.language_code), sm::mitm::ResultShouldForwardToSession());
+        if (AMS_UNLIKELY(!this->is_valid_language)) {
+            static_assert(sizeof(u64) == sizeof(settings::LanguageCode));
+            R_TRY(setGetLanguageCodeFwd(this->forward_service.get(), reinterpret_cast<u64 *>(std::addressof(this->locale.language_code))));
+
+            this->is_valid_language = true;
+            if (this->client_info.program_id == ncm::SystemProgramId::Ns) {
+                g_application_locale.language_code = this->locale.language_code;
+                g_valid_language                   = true;
+            }
+        }
 
         out.SetValue(this->locale.language_code);
         return ResultSuccess();
@@ -55,7 +112,16 @@ namespace ams::mitm::settings {
         this->EnsureLocale();
 
         /* If there's no override locale, just use the actual one. */
-        R_UNLESS(settings::IsValidRegionCode(this->locale.region_code), sm::mitm::ResultShouldForwardToSession());
+        if (AMS_UNLIKELY(!this->is_valid_region)) {
+            static_assert(sizeof(::SetRegion) == sizeof(settings::RegionCode));
+            R_TRY(setGetRegionCodeFwd(this->forward_service.get(), reinterpret_cast<::SetRegion *>(std::addressof(this->locale.region_code))));
+
+            this->is_valid_region = true;
+            if (this->client_info.program_id == ncm::SystemProgramId::Ns) {
+                g_application_locale.region_code = this->locale.region_code;
+                g_valid_region                   = true;
+            }
+        }
 
         out.SetValue(this->locale.region_code);
         return ResultSuccess();

stratosphere/ams_mitm/source/set_mitm/set_mitm_service.hpp

@@ -33,8 +33,10 @@ namespace ams::mitm::settings {
             os::Mutex lock{false};
             cfg::OverrideLocale locale;
             bool got_locale = false;
+            bool is_valid_language = false;
+            bool is_valid_region   = false;
         public:
-            using MitmServiceImplBase::MitmServiceImplBase;
+            SetMitmService(std::shared_ptr<::Service> &&s, const sm::MitmProcessInfo &c);
         public:
             static bool ShouldMitm(const sm::MitmProcessInfo &client_info) {
                 /* We will mitm:
@@ -44,6 +46,7 @@ namespace ams::mitm::settings {
                 return client_info.program_id == ncm::SystemProgramId::Ns || is_game;
             }
         private:
+            void InvalidateLocale();
             Result EnsureLocale();
         public:
             Result GetLanguageCode(sf::Out<ams::settings::LanguageCode> out);

stratosphere/ams_mitm/source/set_mitm/set_shim.c

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "set_shim.h"
+
+static Result _setCmdNoInOut64(Service* srv, u64 *out, u32 cmd_id) {
+    return serviceDispatchOut(srv, cmd_id, *out);
+}
+
+static Result _setCmdNoInOutU32(Service* srv, u32 *out, u32 cmd_id) {
+    return serviceDispatchOut(srv, cmd_id, *out);
+}
+
+/* Forwarding shims. */
+Result setGetLanguageCodeFwd(Service *s, u64* out) {
+    return _setCmdNoInOut64(s, out, 0);
+}
+
+Result setGetRegionCodeFwd(Service *s, SetRegion *out) {
+    s32 code=0;
+    Result rc = _setCmdNoInOutU32(s, (u32*)&code, 4);
+    if (R_SUCCEEDED(rc) && out) *out = code;
+    return rc;
+}

stratosphere/ams_mitm/source/set_mitm/set_shim.h

@@ -0,0 +1,20 @@
+/**
+ * @file set_shim.h
+ * @brief Settings Services (fs) IPC wrapper for set.mitm.
+ * @author SciresM
+ * @copyright libnx Authors
+ */
+#pragma once
+#include <switch.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Forwarding shims. */
+Result setGetLanguageCodeFwd(Service *s, u64* out);
+Result setGetRegionCodeFwd(Service *s, SetRegion *out);
+
+#ifdef __cplusplus
+}
+#endif