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Diffstat (limited to 'include/iprt/strcache.h')
| -rw-r--r-- | include/iprt/strcache.h | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/include/iprt/strcache.h b/include/iprt/strcache.h new file mode 100644 index 00000000..a94fa616 --- /dev/null +++ b/include/iprt/strcache.h @@ -0,0 +1,201 @@ +/* $Id: strcache.h $ */ +/** @file + * IPRT - String Cache, stub implementation. + */ + +/* + * Copyright (C) 2009-2022 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 + */ + +#ifndef IPRT_INCLUDED_strcache_h +#define IPRT_INCLUDED_strcache_h +#ifndef RT_WITHOUT_PRAGMA_ONCE +# pragma once +#endif + +#include <iprt/types.h> + +RT_C_DECLS_BEGIN + + +/** + * Create a new string cache. + * + * @returns IPRT status code + * + * @param phStrCache Where to return the string cache handle. + * @param pszName The name of the cache (for debug purposes). + */ +RTDECL(int) RTStrCacheCreate(PRTSTRCACHE phStrCache, const char *pszName); + + +/** + * Destroys a string cache. + * + * This will cause all strings in the cache to be released and thus become + * invalid. + * + * @returns IPRT status. + * + * @param hStrCache Handle to the string cache. The nil and default + * handles are ignored quietly (VINF_SUCCESS). + */ +RTDECL(int) RTStrCacheDestroy(RTSTRCACHE hStrCache); + + +/** + * Enters a string into the cache. + * + * @returns Pointer to a read-only copy of the string. + * + * @param hStrCache Handle to the string cache. + * @param pchString Pointer to a string. This does not need to be + * zero terminated, but must not contain any zero + * characters. + * @param cchString The number of characters (bytes) to enter. + * + * @remarks It is implementation dependent whether the returned string pointer + * differs when entering the same string twice. + */ +RTDECL(const char *) RTStrCacheEnterN(RTSTRCACHE hStrCache, const char *pchString, size_t cchString); + +/** + * Enters a string into the cache. + * + * @returns Pointer to a read-only copy of the string. + * + * @param hStrCache Handle to the string cache. + * @param psz Pointer to a zero terminated string. + * + * @remarks See RTStrCacheEnterN. + */ +RTDECL(const char *) RTStrCacheEnter(RTSTRCACHE hStrCache, const char *psz); + + +/** + * Enters a string into the cache in lower cased form. + * + * @returns Pointer to a read-only lower cased copy of the string. + * + * @param hStrCache Handle to the string cache. + * @param pchString Pointer to a string. This does not need to be + * zero terminated, but must not contain any zero + * characters. + * @param cchString The number of characters (bytes) to enter. + * + * @remarks It is implementation dependent whether the returned string pointer + * differs when entering the same string twice. + */ +RTDECL(const char *) RTStrCacheEnterLowerN(RTSTRCACHE hStrCache, const char *pchString, size_t cchString); + +/** + * Enters a string into the cache in lower cased form. + * + * @returns Pointer to a read-only lower cased copy of the string. + * + * @param hStrCache Handle to the string cache. + * @param psz Pointer to a zero terminated string. + * + * @remarks See RTStrCacheEnterN. + */ +RTDECL(const char *) RTStrCacheEnterLower(RTSTRCACHE hStrCache, const char *psz); + + +/** + * Retains a reference to a string. + * + * @returns The new reference count. UINT32_MAX is returned if the string + * pointer is invalid. + */ +RTDECL(uint32_t) RTStrCacheRetain(const char *psz); + +/** + * Releases a reference to a string. + * + * @returns The new reference count. + * UINT32_MAX is returned if the string pointer is invalid. + * + * @param hStrCache Handle to the string cache. NIL is NOT allowed. + * @param psz Pointer to a cached string. + */ +RTDECL(uint32_t) RTStrCacheRelease(RTSTRCACHE hStrCache, const char *psz); + +/** + * Gets the string length of a cache entry. + * + * @returns The string length. 0 if the string is invalid (asserted). + * + * @param psz Pointer to a cached string. + */ +RTDECL(size_t) RTStrCacheLength(const char *psz); + + +/** + * Gets cache statistics. + * + * All parameters, except @a hStrCache, are optional and can be NULL. + * + * @returns Number of strings, UINT32_MAX on failure (or not supported). + * @param hStrCache Handle to the string cache. + * @param pcbStrings The number of string bytes (including + * terminators) . + * @param pcbChunks Amount of memory we've allocated for the + * internal allocator. + * @param pcbBigEntries Amount of memory we've allocated off the heap + * for really long strings that doesn't fit in the + * internal allocator. + * @param pcHashCollisions Number of hash table insert collisions. + * @param pcHashCollisions2 Number of hash table secondary insert + * collisions. + * @param pcHashInserts Number of hash table inserts. + * @param pcRehashes The number of rehashes. + * + * @remarks This is not a stable interface as it needs to reflect the cache + * implementation. + */ +RTDECL(uint32_t) RTStrCacheGetStats(RTSTRCACHE hStrCache, size_t *pcbStrings, size_t *pcbChunks, size_t *pcbBigEntries, + uint32_t *pcHashCollisions, uint32_t *pcHashCollisions2, uint32_t *pcHashInserts, + uint32_t *pcRehashes); + +/** + * Indicates whether this a real string cache or a cheap place holder. + * + * A real string cache will return the same address when a string is added + * multiple times. + * + * @returns true / false. + */ +RTDECL(bool) RTStrCacheIsRealImpl(void); + + +RT_C_DECLS_END + +#endif /* !IPRT_INCLUDED_strcache_h */ + |