epee.string_tools: add conversion between UTF-8 and UTF-16

2 files changed, 45 insertions, 15 deletions

diff --git a/contrib/epee/include/file_io_utils.h b/contrib/epee/include/file_io_utils.h
index 4434f7383..25f8c648b 100644
--- a/contrib/epee/include/file_io_utils.h
+++ b/contrib/epee/include/file_io_utils.h
@@ -33,6 +33,7 @@
 #include <boost/filesystem/operations.hpp>
 #ifdef WIN32
 #include <windows.h>
+#include "string_tools.h"
 #endif
 
 // On Windows there is a problem with non-ASCII characters in path and file names
@@ -72,11 +73,9 @@ namespace file_io_utils
 		bool save_string_to_file(const std::string& path_to_file, const std::string& str)
 	{
 #ifdef WIN32
-                WCHAR wide_path[1000];
-                int chars = MultiByteToWideChar(CP_UTF8, 0, path_to_file.c_str(), path_to_file.size() + 1, wide_path, 1000);
-                if (chars == 0)
-                    return false;
-                HANDLE file_handle = CreateFileW(wide_path, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
+                std::wstring wide_path;
+                try { wide_path = string_tools::utf8_to_utf16(path_to_file); } catch (...) { return false; }
+                HANDLE file_handle = CreateFileW(wide_path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
                 if (file_handle == INVALID_HANDLE_VALUE)
                     return false;
                 DWORD bytes_written;
@@ -131,11 +130,9 @@ namespace file_io_utils
 		bool load_file_to_string(const std::string& path_to_file, std::string& target_str, size_t max_size = 1000000000)
 	{
 #ifdef WIN32
-                WCHAR wide_path[1000];
-                int chars = MultiByteToWideChar(CP_UTF8, 0, path_to_file.c_str(), path_to_file.size() + 1, wide_path, 1000);
-                if (chars == 0)
-                    return false;
-                HANDLE file_handle = CreateFileW(wide_path, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+                std::wstring wide_path;
+                try { wide_path = string_tools::utf8_to_utf16(path_to_file); } catch (...) { return false; }
+                HANDLE file_handle = CreateFileW(wide_path.c_str(), GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
                 if (file_handle == INVALID_HANDLE_VALUE)
                     return false;
                 DWORD file_size = GetFileSize(file_handle, NULL);
@@ -202,11 +199,9 @@ namespace file_io_utils
 		bool get_file_size(const std::string& path_to_file, uint64_t &size)
 	{
 #ifdef WIN32
-                WCHAR wide_path[1000];
-                int chars = MultiByteToWideChar(CP_UTF8, 0, path_to_file.c_str(), path_to_file.size() + 1, wide_path, 1000);
-                if (chars == 0)
-                    return false;
-                HANDLE file_handle = CreateFileW(wide_path, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+                std::wstring wide_path;
+                try { wide_path = string_tools::utf8_to_utf16(path_to_file); } catch (...) { return false; }
+                HANDLE file_handle = CreateFileW(wide_path.c_str(), GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
                 if (file_handle == INVALID_HANDLE_VALUE)
                     return false;
                 LARGE_INTEGER file_size;
diff --git a/contrib/epee/include/string_tools.h b/contrib/epee/include/string_tools.h
index 63705e401..8d8603076 100644
--- a/contrib/epee/include/string_tools.h
+++ b/contrib/epee/include/string_tools.h
@@ -381,6 +381,41 @@ POP_WARNINGS
 		res = str.substr(0, pos);
 		return res;
 	}
+  //----------------------------------------------------------------------------
+#ifdef _WIN32
+  inline std::wstring utf8_to_utf16(const std::string& str)
+  {
+    if (str.empty())
+      return {};
+    int wstr_size = MultiByteToWideChar(CP_UTF8, 0, &str[0], str.size(), NULL, 0);
+    if (wstr_size == 0)
+    {
+      throw std::runtime_error(std::error_code(GetLastError(), std::system_category()).message());
+    }
+    std::wstring wstr(wstr_size, wchar_t{});
+    if (!MultiByteToWideChar(CP_UTF8, 0, &str[0], str.size(), &wstr[0], wstr_size))
+    {
+      throw std::runtime_error(std::error_code(GetLastError(), std::system_category()).message());
+    }
+    return wstr;
+  }
+  inline std::string utf16_to_utf8(const std::wstring& wstr)
+  {
+    if (wstr.empty())
+      return {};
+    int str_size = WideCharToMultiByte(CP_UTF8, 0, &wstr[0], wstr.size(), NULL, 0, NULL, NULL);
+    if (str_size == 0)
+    {
+      throw std::runtime_error(std::error_code(GetLastError(), std::system_category()).message());
+    }
+    std::string str(str_size, char{});
+    if (!WideCharToMultiByte(CP_UTF8, 0, &wstr[0], wstr.size(), &str[0], str_size, NULL, NULL))
+    {
+      throw std::runtime_error(std::error_code(GetLastError(), std::system_category()).message());
+    }
+    return str;
+  }
+#endif
 }
 }
 #endif //_STRING_TOOLS_H_