Install native hook iff needed (#496)

* iff: https://en.wikipedia.org/wiki/If_and_only_if

core/src/main/cpp/main/src/context.cpp

@@ -68,7 +68,7 @@ namespace lspd {
         fseek(f, 0, SEEK_END);
         dex.resize(ftell(f));
         rewind(f);
-        if (dex.size() != fread(dex.data(), 1, dex.size(), f)) {
+        if (dex.size() != fread(dex.data(), sizeof(decltype(dex)::value_type), dex.size(), f)) {
             LOGE("Read dex failed");
             dex.resize(0);
         }
@@ -90,8 +90,7 @@ namespace lspd {
         auto initMid = JNI_GetMethodID(env, in_memory_classloader, "<init>",
                                        "(Ljava/nio/ByteBuffer;Ljava/lang/ClassLoader;)V");
         auto byte_buffer_class = JNI_FindClass(env, "java/nio/ByteBuffer");
-        auto dex_buffer = env->NewDirectByteBuffer(reinterpret_cast<void *>(dex.data()),
+        auto dex_buffer = env->NewDirectByteBuffer(dex.data(), dex.size());
-                                                   dex.size());
         if (auto my_cl = JNI_NewObject(env, in_memory_classloader, initMid,
                                        dex_buffer, sys_classloader)) {
             inject_class_loader_ = JNI_NewGlobalRef(env, my_cl);

core/src/main/cpp/main/src/context.h

@@ -69,7 +69,7 @@ namespace lspd {
         jclass class_linker_class_ = nullptr;
         jmethodID post_fixup_static_mid_ = nullptr;
         bool skip_ = false;
-        std::vector<char> dex{};
+        std::vector<std::byte> dex{};
 
         Context() {}
 

core/src/main/cpp/main/src/native_api.cpp

@@ -58,6 +58,11 @@ namespace lspd {
     }
 
     void RegisterNativeLib(const std::string &library_name) {
+        static bool initialized = []() {
+            InstallNativeAPI();
+            return true;
+        }();
+        if (UNLIKELY(!initialized)) return;
         LOGD("native_api: Registered %s", library_name.c_str());
         moduleNativeLibs.push_back(library_name);
     }

core/src/main/cpp/main/src/native_hook.cpp

@@ -64,7 +64,7 @@ namespace lspd {
         InstallRiruHooks();
         // install ART hooks
         InstallArtHooks(handle_libart);
-        InstallNativeAPI();
+//        InstallNativeAPI();
     }
 
     void InstallArtHooks(void *art_handle) {