diff options
Diffstat (limited to 'src/VBox/Runtime/generic/RTDirCreateUniqueNumbered-generic.cpp')
| -rw-r--r-- | src/VBox/Runtime/generic/RTDirCreateUniqueNumbered-generic.cpp | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/VBox/Runtime/generic/RTDirCreateUniqueNumbered-generic.cpp b/src/VBox/Runtime/generic/RTDirCreateUniqueNumbered-generic.cpp new file mode 100644 index 00000000..3eae486c --- /dev/null +++ b/src/VBox/Runtime/generic/RTDirCreateUniqueNumbered-generic.cpp @@ -0,0 +1,142 @@ +/* $Id: RTDirCreateUniqueNumbered-generic.cpp $ */ +/** @file + * IPRT - RTDirCreateUniqueNumbered, generic implementation. + */ + +/* + * Copyright (C) 2011-2019 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 <iprt/dir.h> +#include "internal/iprt.h" + +#include <iprt/assert.h> +#include <iprt/err.h> +#include <iprt/path.h> +#include <iprt/rand.h> +#include <iprt/string.h> + + +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); + |