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Diffstat (limited to 'src/VBox/Runtime/common/sort/shellsort.cpp')
-rw-r--r-- | src/VBox/Runtime/common/sort/shellsort.cpp | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/sort/shellsort.cpp b/src/VBox/Runtime/common/sort/shellsort.cpp new file mode 100644 index 00000000..f0b067de --- /dev/null +++ b/src/VBox/Runtime/common/sort/shellsort.cpp @@ -0,0 +1,111 @@ +/* $Id: shellsort.cpp $ */ +/** @file + * IPRT - RTSortShell and RTSortApvShell. + */ + +/* + * Copyright (C) 2010-2023 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/sort.h> + +#include <iprt/alloca.h> +#include <iprt/assert.h> +#include <iprt/string.h> + + + +RTDECL(void) RTSortShell(void *pvArray, size_t cElements, size_t cbElement, PFNRTSORTCMP pfnCmp, void *pvUser) +{ + Assert(cbElement <= 128); + + /* Anything worth sorting? */ + if (cElements < 2) + return; + + uint8_t *pbArray = (uint8_t *)pvArray; + void *pvTmp = alloca(cbElement); + size_t cGap = (cElements + 1) / 2; + while (cGap > 0) + { + size_t i; + for (i = cGap; i < cElements; i++) + { + memcpy(pvTmp, &pbArray[i * cbElement], cbElement); + size_t j = i; + while ( j >= cGap + && pfnCmp(&pbArray[(j - cGap) * cbElement], pvTmp, pvUser) > 0) + { + memmove(&pbArray[j * cbElement], &pbArray[(j - cGap) * cbElement], cbElement); + j -= cGap; + } + memcpy(&pbArray[j * cbElement], pvTmp, cbElement); + } + + /* This does not generate the most optimal gap sequence, but it has the + advantage of being simple and avoid floating point. */ + cGap /= 2; + } +} + + +RTDECL(void) RTSortApvShell(void **papvArray, size_t cElements, PFNRTSORTCMP pfnCmp, void *pvUser) +{ + /* Anything worth sorting? */ + if (cElements < 2) + return; + + size_t cGap = (cElements + 1) / 2; + while (cGap > 0) + { + size_t i; + for (i = cGap; i < cElements; i++) + { + void *pvTmp = papvArray[i]; + size_t j = i; + while ( j >= cGap + && pfnCmp(papvArray[j - cGap], pvTmp, pvUser) > 0) + { + papvArray[j] = papvArray[j - cGap]; + j -= cGap; + } + papvArray[j] = pvTmp; + } + + /* This does not generate the most optimal gap sequence, but it has the + advantage of being simple and avoid floating point. */ + cGap /= 2; + } +} + |