/* $Id: RTDirCreateUniqueNumbered-generic.cpp 63146 2016-08-08 10:30:07Z vboxsync $ */ /** @file * IPRT - RTDirCreateUniqueNumbered, generic implementation. */ /* * Copyright (C) 2011-2016 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include #include "internal/iprt.h" #include #include #include #include #include RTDECL(int) RTDirCreateUniqueNumbered(char *pszPath, size_t cbSize, RTFMODE fMode, size_t cchDigits, char chSep) { /* * Validate input. */ AssertPtrReturn(pszPath, VERR_INVALID_POINTER); AssertReturn(cbSize, VERR_BUFFER_OVERFLOW); AssertReturn(cchDigits > 0, VERR_INVALID_PARAMETER); AssertReturn(cchDigits < 64, VERR_INVALID_PARAMETER); /* Check that there is sufficient space. */ char *pszEnd = RTStrEnd(pszPath, cbSize); AssertReturn(pszEnd, VERR_BUFFER_OVERFLOW); size_t cbLeft = cbSize - (pszEnd - pszPath); AssertReturn(cbLeft > (chSep ? 1U : 0U) + cchDigits, VERR_BUFFER_OVERFLOW); /* * First try the pretty name without any numbers appended. */ int rc = RTDirCreate(pszPath, fMode, 0); if (RT_SUCCESS(rc)) return rc; if (rc == VERR_ALREADY_EXISTS) { /* * Already exist, apply template specification. */ /* Max 10000 tries (like RTDirCreateTemp), but stop earlier if we haven't got enough digits to work with. */ uint32_t cMaxTries; switch (cchDigits) { case 1: cMaxTries = 40; break; case 2: cMaxTries = 400; break; case 3: cMaxTries = 4000; break; default: cMaxTries = 10000; break; } static uint64_t const s_aEndSeqs[] = { UINT64_C(0), UINT64_C(9), UINT64_C(99), UINT64_C(999), UINT64_C(9999), UINT64_C(99999), UINT64_C(999999), UINT64_C(9999999), UINT64_C(99999999), UINT64_C(999999999), UINT64_C(9999999999), UINT64_C(99999999999), UINT64_C(999999999999), UINT64_C(9999999999999), UINT64_C(99999999999999), UINT64_C(999999999999999), UINT64_C(9999999999999999), UINT64_C(99999999999999999), UINT64_C(999999999999999999), UINT64_C(9999999999999999999), }; uint64_t const uEndSeq = cchDigits < RT_ELEMENTS(s_aEndSeqs) ? s_aEndSeqs[cchDigits] : UINT64_MAX; /* Add separator if requested. */ if (chSep != '\0') { *pszEnd++ = chSep; *pszEnd = '\0'; cbLeft--; } Assert(cbLeft > cchDigits); for (uint32_t iTry = 0; iTry <= cMaxTries; iTry++) { /* Try sequentially first for a little bit, then switch to random numbers. */ uint64_t iSeq; if (iTry > 20) iSeq = RTRandU64Ex(0, uEndSeq); else { iSeq = iTry; if (uEndSeq < UINT64_MAX) iSeq %= uEndSeq + 1; } ssize_t cchRet = RTStrFormatU64(pszEnd, cbLeft, iSeq, 10 /*uiBase*/, (int)cchDigits /*cchWidth*/, 0 /*cchPrecision*/, RTSTR_F_WIDTH | RTSTR_F_ZEROPAD); Assert((size_t)cchRet == cchDigits); NOREF(cchRet); rc = RTDirCreate(pszPath, fMode, 0); if (RT_SUCCESS(rc)) return rc; if (rc != VERR_ALREADY_EXISTS) break; } } /* We've given up or failed. */ *pszPath = '\0'; return rc; } RT_EXPORT_SYMBOL(RTDirCreateUniqueNumbered);