feat(ffe): PHP FFE implementation

.github/CODEOWNERS

@@ -14,6 +14,11 @@ compile_rust.sh @Datadog/libdatadog-apm
 # APM IDM Team
 /src/ @DataDog/apm-idm-php
 
+# FFE (Feature Flagging & Experimentation) SDK Team
+/src/DDTrace/FeatureFlags/ @DataDog/feature-flagging-and-experimentation-sdk
+/src/DDTrace/OpenFeature/ @DataDog/feature-flagging-and-experimentation-sdk
+/tests/FeatureFlags/ @DataDog/feature-flagging-and-experimentation-sdk
+
 # Release files
 Cargo.lock @DataDog/apm-php @DataDog/profiling-php @Datadog/libdatadog-apm
 package.xml @DataDog/apm-php @DataDog/profiling-php @Datadog/asm-php

components-rs/Cargo.toml

@@ -15,14 +15,15 @@ libdd-telemetry-ffi = { path = "../libdatadog/libdd-telemetry-ffi", default-feat
 datadog-live-debugger = { path = "../libdatadog/datadog-live-debugger" }
 datadog-live-debugger-ffi = { path = "../libdatadog/datadog-live-debugger-ffi", default-features = false }
 datadog-ipc = { path = "../libdatadog/datadog-ipc" }
-datadog-remote-config = { path = "../libdatadog/datadog-remote-config" }
+datadog-remote-config = { path = "../libdatadog/datadog-remote-config", features = ["ffe"] }
 datadog-sidecar = { path = "../libdatadog/datadog-sidecar" }
 datadog-sidecar-ffi = { path = "../libdatadog/datadog-sidecar-ffi" }
 libdd-tinybytes = { path = "../libdatadog/libdd-tinybytes" }
 libdd-trace-utils = { path = "../libdatadog/libdd-trace-utils" }
 libdd-crashtracker-ffi = { path = "../libdatadog/libdd-crashtracker-ffi", default-features = false, features = ["collector"] }
 libdd-library-config-ffi = { path = "../libdatadog/libdd-library-config-ffi", default-features = false }
 spawn_worker = { path = "../libdatadog/spawn_worker" }
+datadog-ffe = { path = "../libdatadog/datadog-ffe" }
 anyhow = { version = "1.0" }
 const-str = "0.5.6"
 itertools = "0.11.0"

components-rs/ddtrace.h

@@ -61,14 +61,46 @@ uint32_t ddog_get_logs_count(ddog_CharSlice level);
 
 void ddog_init_remote_config(bool live_debugging_enabled,
                              bool appsec_activation,
-                             bool appsec_config);
+                             bool appsec_config,
+                             bool ffe_enabled);
 
 struct ddog_RemoteConfigState *ddog_init_remote_config_state(const struct ddog_Endpoint *endpoint);
 
 const char *ddog_remote_config_get_path(const struct ddog_RemoteConfigState *remote_config);
 
 bool ddog_process_remote_configs(struct ddog_RemoteConfigState *remote_config);
 
+bool ddog_ffe_load_config(const char *json);
+
+bool ddog_ffe_has_config(void);
+
+bool ddog_ffe_config_changed(void);
+
+struct FfeResult;
+
+struct FfeAttribute {
+    const char *key;
+    int32_t value_type;       /* 0=string, 1=number, 2=bool */
+    const char *string_value;
+    double number_value;
+    bool bool_value;
+};
+
+struct FfeResult *ddog_ffe_evaluate(
+    const char *flag_key,
+    int32_t expected_type,
+    const char *targeting_key,
+    const struct FfeAttribute *attributes,
+    size_t attributes_count);
+
+const char *ddog_ffe_result_value(const struct FfeResult *r);
+const char *ddog_ffe_result_variant(const struct FfeResult *r);
+const char *ddog_ffe_result_allocation_key(const struct FfeResult *r);
+int32_t ddog_ffe_result_reason(const struct FfeResult *r);
+int32_t ddog_ffe_result_error_code(const struct FfeResult *r);
+bool ddog_ffe_result_do_log(const struct FfeResult *r);
+void ddog_ffe_free_result(struct FfeResult *r);
+
 bool ddog_type_can_be_instrumented(const struct ddog_RemoteConfigState *remote_config,
                                    ddog_CharSlice typename_);