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/* $Id: strcache.h $ */
/** @file
* IPRT - String Cache, stub implementation.
*/
/*
* Copyright (C) 2009-2019 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.
*/
#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 */
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