Add command line override to setting definition

Summary: Add ability to control if settings can be overridden by a command line argument to setting definitions Reviewed By: yfeldblum Differential Revision: D63698031 fbshipit-source-id: f7c8ee29f0fbed280deee65c609d5f0e702ade8c
DenisYaroshevskiy · Oct 2, 2024 · 4a4a803 · 4a4a803
1 parent 19095b7
commit 4a4a803
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Showing 6 changed files with 58 additions and 28 deletions.
diff --git a/folly/settings/Settings.h b/folly/settings/Settings.h
@@ -189,36 +189,44 @@ class SettingWrapper {
  * @param _Type  setting value type
  * @param _def   default value for the setting
  * @param _mut   mutability of the setting
+ * @param _cli   determines if a setting can be set through the command line
  * @param _desc  setting documentation
  */
-#define FOLLY_SETTING_DEFINE(_project, _name, _Type, _def, _mut, _desc)        \
-  /* Fastpath optimization, see notes in FOLLY_SETTINGS_DEFINE_LOCAL_FUNC__.   \
-     Aggregate all off these together in a single section for better TLB       \
-     and cache locality. */                                                    \
-  __attribute__((__section__(".folly.settings.cache"))) ::std::atomic<         \
-      ::folly::settings::detail::SettingCore<_Type>*>                          \
-      FOLLY_SETTINGS_CACHE__##_project##_##_name;                              \
-  /* Location for the small value cache (if _Type is small and trivial).       \
-     Intentionally located right after the pointer cache above to take         \
-     advantage of the prefetching */                                           \
-  __attribute__((                                                              \
-      __section__(".folly.settings.cache"))) ::std::atomic<uint64_t>           \
-      FOLLY_SETTINGS_TRIVIAL__##_project##_##_name;                            \
-  /* Meyers singleton to avoid SIOF */                                         \
-  FOLLY_NOINLINE ::folly::settings::detail::SettingCore<_Type>&                \
-      FOLLY_SETTINGS_FUNC__##_project##_##_name() {                            \
-    static ::folly::Indestructible<                                            \
-        ::folly::settings::detail::SettingCore<_Type>>                         \
-        setting(                                                               \
-            ::folly::settings::SettingMetadata{                                \
-                #_project, #_name, #_Type, typeid(_Type), #_def, _mut, _desc}, \
-            ::folly::type_t<_Type>{_def},                                      \
-            FOLLY_SETTINGS_TRIVIAL__##_project##_##_name);                     \
-    return *setting;                                                           \
-  }                                                                            \
-  /* Ensure the setting is registered even if not used in program */           \
-  auto& FOLLY_SETTINGS_INIT__##_project##_##_name =                            \
-      FOLLY_SETTINGS_FUNC__##_project##_##_name();                             \
+#define FOLLY_SETTING_DEFINE(_project, _name, _Type, _def, _mut, _cli, _desc) \
+  /* Fastpath optimization, see notes in FOLLY_SETTINGS_DEFINE_LOCAL_FUNC__.  \
+     Aggregate all off these together in a single section for better TLB      \
+     and cache locality. */                                                   \
+  __attribute__((__section__(".folly.settings.cache"))) ::std::atomic<        \
+      ::folly::settings::detail::SettingCore<_Type>*>                         \
+      FOLLY_SETTINGS_CACHE__##_project##_##_name;                             \
+  /* Location for the small value cache (if _Type is small and trivial).      \
+     Intentionally located right after the pointer cache above to take        \
+     advantage of the prefetching */                                          \
+  __attribute__((                                                             \
+      __section__(".folly.settings.cache"))) ::std::atomic<uint64_t>          \
+      FOLLY_SETTINGS_TRIVIAL__##_project##_##_name;                           \
+  /* Meyers singleton to avoid SIOF */                                        \
+  FOLLY_NOINLINE ::folly::settings::detail::SettingCore<_Type>&               \
+      FOLLY_SETTINGS_FUNC__##_project##_##_name() {                           \
+    static ::folly::Indestructible<                                           \
+        ::folly::settings::detail::SettingCore<_Type>>                        \
+        setting(                                                              \
+            ::folly::settings::SettingMetadata{                               \
+                #_project,                                                    \
+                #_name,                                                       \
+                #_Type,                                                       \
+                typeid(_Type),                                                \
+                #_def,                                                        \
+                _mut,                                                         \
+                _cli,                                                         \
+                _desc},                                                       \
+            ::folly::type_t<_Type>{_def},                                     \
+            FOLLY_SETTINGS_TRIVIAL__##_project##_##_name);                    \
+    return *setting;                                                          \
+  }                                                                           \
+  /* Ensure the setting is registered even if not used in program */          \
+  auto& FOLLY_SETTINGS_INIT__##_project##_##_name =                           \
+      FOLLY_SETTINGS_FUNC__##_project##_##_name();                            \
   FOLLY_DETAIL_SETTINGS_DEFINE_LOCAL_FUNC__(_project, _name, _Type, char)
 
 /**

diff --git a/folly/settings/Types.h b/folly/settings/Types.h
@@ -42,6 +42,10 @@ enum class Mutability {
   Mutable,
   Immutable,
 };
+enum class CommandLine {
+  AcceptOverrides,
+  RejectOverrides,
+};
 
 /**
  * Static information about the setting definition
@@ -78,6 +82,11 @@ struct SettingMetadata {
    */
   Mutability mutability;
 
+  /**
+   * Determines if the setting can be set from the command line.
+   */
+  CommandLine commandLine;
+
   /**
    * Setting description field.
    */

diff --git a/folly/settings/test/SettingsBenchmarks.cpp b/folly/settings/test/SettingsBenchmarks.cpp
@@ -33,6 +33,7 @@ FOLLY_SETTING_DEFINE(
     int,
     100,
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "desc");
 
 BENCHMARK(settings_get_bench, iters) {

diff --git a/folly/settings/test/SettingsTest.cpp b/folly/settings/test/SettingsTest.cpp
@@ -31,20 +31,23 @@ FOLLY_SETTING_DEFINE(
     std::string,
     "default",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Description");
 FOLLY_SETTING_DEFINE(
     follytest,
     unused,
     std::string,
     "unused_default",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Not used, but should still be in the list");
 FOLLY_SETTING_DEFINE(
     follytest,
     multi_token_type,
     unsigned int,
     123,
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Test that multi-token type names can be used");
 // Enable to test runtime collision checking logic
 #if 0
@@ -54,6 +57,7 @@ FOLLY_SETTING_DEFINE(
     std::string,
     "collision_with_a",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Collision_with_a");
 #endif
 
@@ -119,27 +123,31 @@ FOLLY_SETTING_DEFINE(
     UserDefinedType,
     "b",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "User defined type constructed from string");
 FOLLY_SETTING_DEFINE(
     follytest,
     user_defined_with_meta,
     UserDefinedWithMeta,
     {"default"},
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "User defined type constructed from string and metadata");
 FOLLY_SETTING_DEFINE(
     follytest,
     immutable_setting,
     UserDefinedType,
     "b",
     folly::settings::Mutability::Immutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "User defined type constructed from string");
 FOLLY_SETTING_DEFINE(
     otherproj,
     some_flag,
     std::string,
     "default",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Description");
 
 } // namespace some_ns

diff --git a/folly/settings/test/a.cpp b/folly/settings/test/a.cpp
@@ -25,6 +25,7 @@ FOLLY_SETTING_DEFINE(
     int,
     456,
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Public flag to a");
 namespace {
 FOLLY_SETTING_DEFINE(
@@ -33,6 +34,7 @@ FOLLY_SETTING_DEFINE(
     int,
     789,
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Desc of int");
 }
 

diff --git a/folly/settings/test/b.cpp b/folly/settings/test/b.cpp
@@ -26,6 +26,7 @@ FOLLY_SETTING_DEFINE(
     std::string,
     "basdf",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Public flag to b");
 
 namespace {
@@ -35,6 +36,7 @@ FOLLY_SETTING_DEFINE(
     std::string,
     "test",
     folly::settings::Mutability::Mutable,
+    folly::settings::CommandLine::AcceptOverrides,
     "Desc of str");
 }