/* $Id: strcache.h 82968 2020-02-04 10:35:17Z vboxsync $ */ /** @file * IPRT - String Cache, stub implementation. */ /* * Copyright (C) 2009-2020 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. */ #ifndef IPRT_INCLUDED_strcache_h #define IPRT_INCLUDED_strcache_h #ifndef RT_WITHOUT_PRAGMA_ONCE # pragma once #endif #include 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 */