static BOOL register_monitoring_entry(WDM_PEntry entry) { BOOL success; DWORD bytes; bytes = 0; // Not used because the process callback gets passed the written bytes success = ReadDirectoryChangesW( entry->dir_handle, // handle to directory entry->buffer, // read results buffer WDM_BUFFER_SIZE, // length of buffer entry->user_data->watch_childeren, // monitoring option entry->user_data->flags, // filter conditions &bytes, // bytes returned &entry->event_container, // overlapped buffer &handle_entry_change // process callback ); if ( ! success ) { WDM_DEBUG("ReadDirectoryChangesW failed with error (%d): %s", GetLastError(), rb_w32_strerror(GetLastError())); return FALSE; } return TRUE; }
// TODO: // 1. this function uses a lot of 'alloca' calls, which AFAIK is not recommeneded! Can this be avoided? // 2. all wcscat calls can be done faster with memcpy, but is it worth sacrificing the readability? static VALUE extract_absolute_path_from_notification(const LPWSTR base_dir, const PFILE_NOTIFY_INFORMATION info) { LPWSTR buffer, absolute_filepath; WCHAR file[_MAX_FNAME], ext[_MAX_EXT], filename[WDM_MAX_FILENAME]; DWORD filename_len, absolute_filepath_len; LPSTR multibyte_filepath; int multibyte_filepath_buffer_size; VALUE path; filename_len = info->FileNameLength/sizeof(WCHAR); // The file in the 'info' struct is NOT null-terminated, so add 1 extra char to the allocation buffer = ALLOCA_N(WCHAR, filename_len + 1); memcpy(buffer, info->FileName, info->FileNameLength); // Null-terminate the string buffer[filename_len] = L'\0'; WDM_WDEBUG("change in: '%s'", buffer); absolute_filepath_len = wcslen(base_dir) + filename_len; absolute_filepath = ALLOCA_N(WCHAR, absolute_filepath_len + 1); // 1 for NULL absolute_filepath[0] = L'\0'; wcscat(absolute_filepath, base_dir); wcscat(absolute_filepath, buffer); WDM_WDEBUG("absolute path is: '%s'", absolute_filepath); _wsplitpath(buffer, NULL, NULL, file, ext); // TODO: Extracting the file name from 'buffer' is only needed when watching sub-dirs filename[0] = L'\0'; if ( file[0] != L'\0' ) wcscat(filename, file); if ( ext[0] != L'\0' ) wcscat(filename, ext); WDM_WDEBUG("filename: '%s'", filename); filename_len = wcslen(filename); // The maximum length of an 8.3 filename is twelve, including the dot. if (filename_len <= 12 && wcschr(filename, L'~')) { LPWSTR unicode_absolute_filepath; WCHAR absolute_long_filepath[WDM_MAX_WCHAR_LONG_PATH]; BOOL is_unc_path; is_unc_path = wdm_utils_is_unc_path(absolute_filepath); unicode_absolute_filepath = ALLOCA_N(WCHAR, absolute_filepath_len + (is_unc_path ? 8 : 4) + 1); // 8 for "\\?\UNC\" or 4 for "\\?\", and 1 for \0 unicode_absolute_filepath[0] = L'\0'; wcscat(unicode_absolute_filepath, L"\\\\?\\"); if ( is_unc_path ) { wcscat(unicode_absolute_filepath, L"UNC\\"); wcscat(unicode_absolute_filepath, absolute_filepath + 2); // +2 to skip the begin of a UNC path } else { wcscat(unicode_absolute_filepath, absolute_filepath); } // Convert to the long filename form. Unfortunately, this // does not work for deletions, so it's an imperfect fix. if (GetLongPathNameW(unicode_absolute_filepath, absolute_long_filepath, WDM_MAX_WCHAR_LONG_PATH) != 0) { absolute_filepath = absolute_long_filepath + 4; // Skip first 4 pointers of "\\?\" absolute_filepath_len = wcslen(absolute_filepath); WDM_WDEBUG("Short path converted to long: '%s'", absolute_filepath); } else { WDM_DEBUG("Can't convert short path to long: '%s'", rb_w32_strerror(GetLastError())); } } // The convention in Ruby is to use forward-slashes to seprarate dirs on all platforms. wdm_utils_convert_back_to_forward_slashes(absolute_filepath, absolute_filepath_len + 1); // Convert the path from WCHAR to multibyte CHAR to use it in a ruby string multibyte_filepath_buffer_size = WideCharToMultiByte(CP_UTF8, 0, absolute_filepath, absolute_filepath_len + 1, NULL, 0, NULL, NULL); multibyte_filepath = ALLOCA_N(CHAR, multibyte_filepath_buffer_size); if ( 0 == WideCharToMultiByte(CP_UTF8, 0, absolute_filepath, absolute_filepath_len + 1, multibyte_filepath, multibyte_filepath_buffer_size, NULL, NULL) ) { rb_raise(eWDM_Error, "Failed to add the change file path to the event!"); } WDM_DEBUG("will report change in: '%s'", multibyte_filepath); path = rb_enc_str_new(multibyte_filepath, multibyte_filepath_buffer_size - 1, // -1 because this func takes the chars count, not bytes count wdm_rb_enc_utf8); OBJ_TAINT(path); return path; }