1 files changed, 152 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..c2317836
--- /dev/null
+++ b/src/VBox/Runtime/generic/RTDirCreateUniqueNumbered-generic.cpp
@@ -0,0 +1,152 @@
+/* $Id: RTDirCreateUniqueNumbered-generic.cpp $ */
+/** @file
+ * IPRT - RTDirCreateUniqueNumbered, generic implementation.
+ */
+
+/*
+ * Copyright (C) 2011-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox 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.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+
+/*********************************************************************************************************************************
+*   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);
+