win-capture: Cache data to reduce load time

Caches the D3D graphics offsets to file for the sake of improving module
load time.  If the D3D/DXGI DLL versions change, the data will be
refreshed.

plugins/win-capture/load-graphics-offsets.c

 #define _CRT_SECURE_NO_WARNINGS
 #include <obs-module.h>
+#include <util/windows/win-version.h>
 #include <util/platform.h>
 #include <util/dstr.h>
 #include <util/config-file.h>
 #include <util/pipe.h>
 
 #include <windows.h>
+#include <shlobj.h>
 #include "graphics-hook-info.h"
 
 extern struct graphics_offsets offsets32;
@@ -45,10 +47,115 @@ static inline bool load_offsets_from_string(struct graphics_offsets *offsets,
 	return true;
 }
 
+static inline bool load_offsets_from_file(struct graphics_offsets *offsets,
+		const char *file)
+{
+	char *str = os_quick_read_utf8_file(file);
+	bool success = false;
+	if (str && *str)
+		success = load_offsets_from_string(offsets, str);
+	bfree(str);
+	return success;
+}
+
+static inline bool config_ver_mismatch(
+		config_t *ver_config,
+		const char *section,
+		struct win_version_info *ver)
+{
+	struct win_version_info config_ver;
+	bool mismatch = false;
+
+#define get_sub_ver(subver) \
+	config_ver.subver = (int)config_get_int(ver_config, section, #subver); \
+	mismatch |= config_ver.subver != ver->subver;
+
+	get_sub_ver(major);
+	get_sub_ver(minor);
+	get_sub_ver(build);
+	get_sub_ver(revis);
+
+#undef get_sub_ver
+
+	return mismatch;
+}
+
+static inline void write_config_ver(config_t *ver_config, const char *section,
+		struct win_version_info *ver)
+{
+#define set_sub_ver(subver) \
+	config_set_int(ver_config, section, #subver, ver->subver);
+
+	set_sub_ver(major);
+	set_sub_ver(minor);
+	set_sub_ver(build);
+	set_sub_ver(revis);
+
+#undef set_sub_ver
+}
+
+static bool get_32bit_system_dll_ver(const wchar_t *system_lib,
+		struct win_version_info *ver)
+{
+	wchar_t path[MAX_PATH];
+
+	HRESULT hr = SHGetFolderPathW(NULL, CSIDL_SYSTEMX86, NULL,
+			SHGFP_TYPE_CURRENT, path);
+	if (hr != S_OK) {
+		blog(LOG_ERROR, "Failed to get windows 32bit system path: "
+		                "%08lX", hr);
+		return false;
+	}
+
+	wcscat(path, L"\\");
+	wcscat(path, system_lib);
+	return get_dll_ver(path, ver);
+}
+
+bool cached_versions_match(void)
+{
+	struct win_version_info d3d8_ver  = {0};
+	struct win_version_info d3d9_ver  = {0};
+	struct win_version_info dxgi_ver = {0};
+	bool ver_mismatch = false;
+	config_t *config;
+	char *ver_file;
+	int ret;
+
+	ver_mismatch |= !get_32bit_system_dll_ver(L"d3d8.dll", &d3d8_ver);
+	ver_mismatch |= !get_32bit_system_dll_ver(L"d3d9.dll", &d3d9_ver);
+	ver_mismatch |= !get_32bit_system_dll_ver(L"dxgi.dll", &dxgi_ver);
+
+	ver_file = obs_module_config_path("version.ini");
+	if (!ver_file)
+		return false;
+
+	ret = config_open(&config, ver_file, CONFIG_OPEN_ALWAYS);
+	if (ret != CONFIG_SUCCESS)
+		goto failed;
+
+	ver_mismatch |= config_ver_mismatch(config, "d3d8", &d3d8_ver);
+	ver_mismatch |= config_ver_mismatch(config, "d3d9", &d3d9_ver);
+	ver_mismatch |= config_ver_mismatch(config, "dxgi", &dxgi_ver);
+
+	if (ver_mismatch) {
+		write_config_ver(config, "d3d8", &d3d8_ver);
+		write_config_ver(config, "d3d9", &d3d9_ver);
+		write_config_ver(config, "dxgi", &dxgi_ver);
+		config_save_safe(config, "tmp", NULL);
+	}
+
+failed:
+	bfree(ver_file);
+	config_close(config);
+	return !ver_mismatch;
+}
+
 bool load_graphics_offsets(bool is32bit)
 {
 	char *offset_exe_path = NULL;
 	struct dstr offset_exe = {0};
+	char *config_ini = NULL;
 	struct dstr str = {0};
 	os_process_pipe_t *pp;
 	bool success = false;
@@ -73,6 +180,11 @@ bool load_graphics_offsets(bool is32bit)
 		dstr_ncat(&str, data, len);
 	}
 
+	config_ini = obs_module_config_path(is32bit ? "32.ini" : "64.ini");
+	os_quick_write_utf8_file_safe(config_ini, str.array, str.len, false,
+			"tmp", NULL);
+	bfree(config_ini);
+
 	success = load_offsets_from_string(is32bit ? &offsets32 : &offsets64,
 			str.array);
 	if (!success) {
@@ -87,3 +199,18 @@ error:
 	dstr_free(&str);
 	return success;
 }
+
+bool load_cached_graphics_offsets(bool is32bit)
+{
+	char *config_ini = NULL;
+	bool success;
+
+	config_ini = obs_module_config_path(is32bit ? "32.ini" : "64.ini");
+	success = load_offsets_from_file(is32bit ? &offsets32 : &offsets64,
+			config_ini);
+	if (!success)
+		success = load_graphics_offsets(is32bit);
+
+	bfree(config_ini);
+	return success;
+}

plugins/win-capture/plugin-main.c

 #include <windows.h>
 #include <obs-module.h>
 #include <util/windows/win-version.h>
+#include <util/platform.h>
 
 OBS_DECLARE_MODULE()
 OBS_MODULE_USE_DEFAULT_LOCALE("win-capture", "en-US")
@@ -10,6 +11,8 @@ extern struct obs_source_info monitor_capture_info;
 extern struct obs_source_info window_capture_info;
 extern struct obs_source_info game_capture_info;
 
+extern bool cached_versions_match(void);
+extern bool load_cached_graphics_offsets(bool is32bit);
 extern bool load_graphics_offsets(bool is32bit);
 
 /* temporary, will eventually be erased once we figure out how to create both
@@ -24,6 +27,13 @@ bool obs_module_load(void)
 {
 	struct win_version_info ver;
 	bool win8_or_above = false;
+	char *config_dir;
+
+	config_dir = obs_module_config_path(NULL);
+	if (config_dir) {
+		os_mkdirs(config_dir);
+		bfree(config_dir);
+	}
 
 	get_win_ver(&ver);
 
@@ -40,7 +50,11 @@ bool obs_module_load(void)
 
 	obs_register_source(&window_capture_info);
 
-	if (load_graphics_offsets(IS32BIT)) {
+	if (cached_versions_match() && load_cached_graphics_offsets(IS32BIT)) {
+		load_cached_graphics_offsets(!IS32BIT);
+		obs_register_source(&game_capture_info);
+
+	} else if (load_graphics_offsets(IS32BIT)) {
 		load_graphics_offsets(!IS32BIT);
 		obs_register_source(&game_capture_info);
 	}