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/* $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);
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