Convert the lfs module to using the ffi

automation/include/aegisub/ffi.moon

@@ -0,0 +1,48 @@
+-- Copyright (c) 2014, Thomas Goyne <plorkyeran@aegisub.org>
+--
+-- Permission to use, copy, modify, and distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+-- Aegisub Project http://www.aegisub.org/
+
+ffi = require 'ffi'
+ffi.cdef[[
+  void free(void *ptr);
+]]
+
+char_ptr = ffi.typeof 'char *'
+
+-- Convert a const char * to a lua string, returning nil rather than crashing
+-- if it's NULL and freeing the input if it's non-const
+string = (cdata) ->
+  return nil if cdata == nil
+  str = ffi.string cdata
+  if type(cdata) == char_ptr
+    ffi.C.free cdata
+  str
+
+err_buff = ffi.new 'char *[1]'
+
+-- Convert a function which has an error out parameter to one which returns
+-- the original return value and the error as a string
+err_arg_to_multiple_return = (f) -> (arg) ->
+  err_buff[0] = nil
+  result = if arg != nil
+    f arg, err_buff
+  else
+    f err_buff
+  errmsg = string err_buff[0]
+  if errmsg
+    return nil, errmsg
+  return result
+
+{:string, :err_arg_to_multiple_return}

automation/include/aegisub/lfs.moon

@@ -0,0 +1,80 @@
+-- Copyright (c) 2014, Thomas Goyne <plorkyeran@aegisub.org>
+--
+-- Permission to use, copy, modify, and distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+-- Aegisub Project http://www.aegisub.org/
+
+impl = require 'aegisub.__lfs_impl'
+ffi = require 'ffi'
+ffi_util = require 'aegisub.ffi'
+
+for k, v in pairs impl
+  impl[k] = ffi_util.err_arg_to_multiple_return v
+
+string_ret = (f) -> (...) ->
+  res, err = f ...
+  ffi_util.string(res), err
+
+number_ret = (f) -> (...) ->
+  res, err = f ...
+  tonumber(res), err
+
+attributes = (path, field) ->
+  switch field
+    when 'mode'
+      res, err = impl.get_mode path
+      ffi_util.string(res), err
+    when 'modification'
+      res, err = impl.get_mtime path
+      tonumber(res), err
+    when 'size'
+      res, err = impl.get_size path
+      tonumber(res), err
+    else
+      mode, err = impl.get_mode path
+      if err or mode == nil then return nil, err
+
+      mod, err = impl.get_mtime path
+      if err then return nil, err
+
+      size, err = impl.get_size path
+      if err then return nil, err
+
+      mode: ffi_util.string(mode), modification: tonumber(mod), size: tonumber(size)
+
+class dir_iter
+  new: (iter) =>
+    @iter = ffi.gc iter, -> impl.dir_free iter
+  close: =>
+    impl.dir_close @iter
+  next: =>
+    str, err = impl.dir_next @iter
+    if err then error err, 2
+    ffi_util.string str
+
+dir = (path) ->
+  obj, err = impl.dir_new path
+  if err
+    error 2, err
+  iter = dir_iter obj
+  iter.next, iter
+
+return {
+  :attributes
+  chdir: number_ret impl.chdir
+  currentdir: string_ret impl.currentdir
+  :dir
+  mkdir: number_ret impl.mkdir
+  rmdir: number_ret impl.rmdir
+  touch: number_ret impl.touch
+}

automation/include/aegisub/unicode.moon

@@ -30,25 +30,16 @@
 
 impl = require 'aegisub.__unicode_impl'
 ffi = require 'ffi'
-ffi.cdef[[
-  void free(void *ptr);
-]]
+ffi_util = require 'aegisub.ffi'
 
-transfer_string = (cdata) ->
-  return nil if cdata == nil
-  str = ffi.string cdata
-  ffi.C.free cdata
-  str
-
-conv_func = (f) ->
-  err = ffi.new 'char *[1]'
-  (str) ->
-    err[0] = nil
-    result = f str, err
-    errmsg = transfer_string err[0]
-    if errmsg
-      error errmsg, 2
-    transfer_string result
+err_buff = ffi.new 'char *[1]'
+conv_func = (f) -> (str) ->
+  err_buff[0] = nil
+  result = f str, err_buff
+  errmsg = ffi_util.string err_buff[0]
+  if errmsg
+    error errmsg, 2
+  ffi_util.string result
 
 local unicode
 unicode =

automation/include/lfs.lua

@@ -0,0 +1,2 @@
+lfs = require 'aegisub.lfs'
+return lfs

automation/tests/modules/lfs.moon

@@ -12,7 +12,7 @@
 -- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 -- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-lfs = require 'lfs'
+lfs = require 'aegisub.lfs'
 uuid = require 'uuid'
 
 uuid.randomseed os.time()

libaegisub/include/libaegisub/type_name.h

@@ -21,15 +21,19 @@ namespace agi {
 // Currently supports primitives, pointers, references, const, and function pointers
 template<typename T> struct type_name;
 
-#define AGI_TYPE_NAME_PRIMITIVE(type) \
+#define AGI_DEFINE_TYPE_NAME(type) \
 	template<> struct type_name<type> { static const char *name() { return #type; }}
 
-AGI_TYPE_NAME_PRIMITIVE(bool);
-AGI_TYPE_NAME_PRIMITIVE(char);
-AGI_TYPE_NAME_PRIMITIVE(double);
-AGI_TYPE_NAME_PRIMITIVE(float);
-AGI_TYPE_NAME_PRIMITIVE(int);
-AGI_TYPE_NAME_PRIMITIVE(void);
+AGI_DEFINE_TYPE_NAME(bool);
+AGI_DEFINE_TYPE_NAME(char);
+AGI_DEFINE_TYPE_NAME(double);
+AGI_DEFINE_TYPE_NAME(float);
+AGI_DEFINE_TYPE_NAME(int);
+AGI_DEFINE_TYPE_NAME(long long);
+AGI_DEFINE_TYPE_NAME(long);
+AGI_DEFINE_TYPE_NAME(size_t);
+AGI_DEFINE_TYPE_NAME(unsigned long long);
+AGI_DEFINE_TYPE_NAME(void);
 
 #undef AGI_TYPE_NAME_PRIMITIVE
 

libaegisub/lua/modules.cpp

@@ -21,7 +21,7 @@
 extern "C" int luaopen_luabins(lua_State *L);
 extern "C" int luaopen_re_impl(lua_State *L);
 extern "C" int luaopen_unicode_impl(lua_State *L);
-extern "C" int luaopen_lfs(lua_State *L);
+extern "C" int luaopen_lfs_impl(lua_State *L);
 extern "C" int luaopen_lpeg(lua_State *L);
 
 namespace agi { namespace lua {
@@ -35,7 +35,7 @@ void preload_modules(lua_State *L) {
 
 	set_field(L, "aegisub.__re_impl", luaopen_re_impl);
 	set_field(L, "aegisub.__unicode_impl", luaopen_unicode_impl);
-	set_field(L, "lfs", luaopen_lfs);
+	set_field(L, "aegisub.__lfs_impl", luaopen_lfs_impl);
 	set_field(L, "lpeg", luaopen_lpeg);
 	set_field(L, "luabins", luaopen_luabins);
 

libaegisub/lua/modules/lfs.cpp

@@ -14,150 +14,152 @@
 //
 // Aegisub Project http://www.aegisub.org/
 
-#include "libaegisub/lua/utils.h"
+#include "libaegisub/fs.h"
+#include "libaegisub/type_name.h"
 
 #include <boost/filesystem/operations.hpp>
 #include <boost/filesystem/path.hpp>
-#include <boost/range/size.hpp>
+#include <lua.hpp>
 
-namespace {
-using namespace agi::lua;
 using namespace agi::fs;
 namespace bfs = boost::filesystem;
 
-template<void (*func)(lua_State *L)>
-int wrap(lua_State *L) {
+namespace agi {
+AGI_DEFINE_TYPE_NAME(DirectoryIterator);
+}
+
+namespace {
+template<typename Func>
+auto wrap(char **err, Func f) -> decltype(f()) {
 	try {
-		func(L);
-		return 1;
+		return f();
 	}
 	catch (bfs::filesystem_error const& e) {
-		lua_pushnil(L);
-		push_value(L, e.what());
-		return 2;
+		*err = strdup(e.what());
+		return 0;
 	}
 	catch (agi::Exception const& e) {
-		lua_pushnil(L);
-		push_value(L, e.GetMessage());
-		return 2;
-	}
-	catch (error_tag) {
-		return lua_error(L);
+		*err = strdup(e.GetMessage().c_str());
+		return 0;
 	}
 }
 
-void chdir(lua_State *L) {
-	bfs::current_path(check_string(L, 1));
-	push_value(L, true);
+template<typename Ret>
+bool setter(const char *path, char **err, Ret (*f)(bfs::path const&)) {
+	return wrap(err, [=]{
+		f(path);
+		return true;
+	});
 }
 
-void currentdir(lua_State *L) {
-	push_value(L, bfs::current_path());
+bool lfs_chdir(const char *dir, char **err) {
+	return setter(dir, err, &bfs::current_path);
 }
 
-void mkdir(lua_State *L) {
-	CreateDirectory(check_string(L, 1));
-	push_value(L, true);
+char *currentdir(char **err) {
+	return wrap(err, []{
+		return strdup(bfs::current_path().string().c_str());
+	});
 }
 
-void rmdir(lua_State *L) {
-	Remove(check_string(L, 1));
-	push_value(L, true);
+bool mkdir(const char *dir, char **err) {
+	return setter(dir, err, &CreateDirectory);
 }
 
-void touch(lua_State *L) {
-	Touch(check_string(L, 1));
-	push_value(L, true);
+bool lfs_rmdir(const char *dir, char **err) {
+	return setter(dir, err, &Remove);
 }
 
-int dir_next(lua_State *L) {
-	auto& it = get<agi::fs::DirectoryIterator>(L, 1, "aegisub.lfs.dir");
-	if (it == end(it)) return 0;
-	push_value(L, *it);
-	++it;
-	return 1;
+bool touch(const char *path, char **err) {
+	return setter(path, err, &Touch);
 }
 
-int dir_close(lua_State *L) {
-	auto& it = get<agi::fs::DirectoryIterator>(L, 1, "aegisub.lfs.dir");
-	// Convert to end iterator rather than destroying to avoid crashes if this
-	// is called multiple times
+char *dir_next(DirectoryIterator &it, char **err) {
+	if (it == end(it)) return nullptr;
+	return wrap(err, [&]{
+		auto str = strdup((*it).c_str());
+		++it;
+		return str;
+	});
+}
+
+void dir_close(DirectoryIterator &it) {
 	it = DirectoryIterator();
-	return 0;
 }
 
-int dir(lua_State *L) {
-	const path p = check_string(L, 1);
-	push_value(L, dir_next);
-	make<agi::fs::DirectoryIterator>(L, "aegisub.lfs.dir", check_string(L, 1), "");
-	return 2;
+void dir_free(DirectoryIterator *it) {
+	delete it;
 }
 
-void attributes(lua_State *L) {
-	static std::pair<const char *, void (*)(lua_State *, path const&)> fields[] = {
-		{"mode", [](lua_State *L, path const& p) {
-			switch (status(p).type()) {
-			case bfs::file_not_found: lua_pushnil(L);                 break;
-			case bfs::regular_file:   push_value(L, "file");          break;
-			case bfs::directory_file: push_value(L, "directory");     break;
-			case bfs::symlink_file:   push_value(L, "link");          break;
-			case bfs::block_file:     push_value(L, "block device");  break;
-			case bfs::character_file: push_value(L, "char device");   break;
-			case bfs::fifo_file:      push_value(L, "fifo");          break;
-			case bfs::socket_file:    push_value(L, "socket");        break;
-			case bfs::reparse_file:   push_value(L, "reparse point"); break;
-			default:                  push_value(L, "other");         break;
-			}
-		}},
-		{"modification", [](lua_State *L, path const& p) { push_value(L, ModifiedTime(p)); }},
-		{"size",         [](lua_State *L, path const& p) { push_value(L, Size(p)); }}
-	};
+DirectoryIterator *dir_new(const char *path, char **err) {
+	return wrap(err, [=]{
+		return new DirectoryIterator(path, "");
+	});
+}
 
-	const path p = check_string(L, 1);
-
-	const auto field = get_string(L, 2);
-	if (!field.empty()) {
-		for (const auto getter : fields) {
-			if (field == getter.first) {
-				getter.second(L, p);
-				return;
-			}
+const char *get_mode(const char *path, char **err) {
+	return wrap(err, [=]() -> const char * {
+		switch (bfs::status(path).type()) {
+			case bfs::file_not_found: return nullptr;         break;
+			case bfs::regular_file:   return "file";          break;
+			case bfs::directory_file: return "directory";     break;
+			case bfs::symlink_file:   return "link";          break;
+			case bfs::block_file:     return "block device";  break;
+			case bfs::character_file: return "char device";   break;
+			case bfs::fifo_file:      return "fifo";          break;
+			case bfs::socket_file:    return "socket";        break;
+			case bfs::reparse_file:   return "reparse point"; break;
+			default:                  return "other";         break;
 		}
-		error(L, "Invalid attribute name: %s", field.c_str());
-	}
+	});
+}
 
-	lua_createtable(L, 0, boost::size(fields));
-	for (const auto getter : fields) {
-		getter.second(L, p);
-		lua_setfield(L, -2, getter.first);
-	}
+time_t get_mtime(const char *path, char **err) {
+	return wrap(err, [=] { return ModifiedTime(path); });
+}
+
+uintmax_t get_size(const char *path, char **err) {
+	return wrap(err, [=] { return Size(path); });
+}
+
+template<typename T>
+void push_ffi_function(lua_State *L, const char *name, T *func) {
+	lua_pushvalue(L, -2); // push cast function
+	lua_pushstring(L, agi::type_name<T*>::name().c_str());
+	// This cast isn't legal, but LuaJIT internally requires that it work
+	lua_pushlightuserdata(L, (void *)func);
+	lua_call(L, 2, 1);
+	lua_setfield(L, -2, name);
 }
 }
 
-extern "C" int luaopen_lfs(lua_State *L) {
-	if (luaL_newmetatable(L, "aegisub.lfs.dir")) {
-		set_field<dir_close>(L, "__gc");
+extern "C" int luaopen_lfs_impl(lua_State *L) {
+	lua_getglobal(L, "require");
+	lua_pushstring(L, "ffi");
+	lua_call(L, 1, 1);
 
-		lua_createtable(L, 0, 2);
-		set_field<dir_next>(L, "next");
-		set_field<dir_close>(L, "close");
-		lua_setfield(L, -2, "__index");
-		lua_pop(L, 1);
-	}
+	lua_getfield(L, -1, "cdef");
+	lua_pushstring(L, "typedef struct DirectoryIterator DirectoryIterator;");
+	lua_call(L, 1, 0);
 
-	const struct luaL_Reg lib[] = {
-		{"attributes", wrap<attributes>},
-		{"chdir", wrap<chdir>},
-		{"currentdir", wrap<currentdir>},
-		{"dir", exception_wrapper<dir>},
-		{"mkdir", wrap<mkdir>},
-		{"rmdir", wrap<rmdir>},
-		{"touch", wrap<touch>},
-		{nullptr, nullptr},
-	};
-	lua_createtable(L, 0, boost::size(lib) - 1);
-	luaL_register(L, nullptr, lib);
-	lua_pushvalue(L, -1);
-	lua_setglobal(L, "lfs");
+	lua_getfield(L, -1, "cast");
+	lua_remove(L, -2); // ffi table
+
+	lua_createtable(L, 0, 12);
+	push_ffi_function(L, "chdir", lfs_chdir);
+	push_ffi_function(L, "currentdir", currentdir);
+	push_ffi_function(L, "mkdir", mkdir);
+	push_ffi_function(L, "rmdir", lfs_rmdir);
+	push_ffi_function(L, "touch", touch);
+	push_ffi_function(L, "get_mtime", get_mtime);
+	push_ffi_function(L, "get_mode", get_mode);
+	push_ffi_function(L, "get_size", get_size);
+
+	push_ffi_function(L, "dir_new", dir_new);
+	push_ffi_function(L, "dir_free", dir_free);
+	push_ffi_function(L, "dir_next", dir_next);
+	push_ffi_function(L, "dir_close", dir_close);
+
+	lua_remove(L, -2); // ffi.cast function
 	return 1;
 }