diff options
Diffstat (limited to 'src/VBox/Main/glue/xpcom/helpers.cpp')
| -rw-r--r-- | src/VBox/Main/glue/xpcom/helpers.cpp | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/src/VBox/Main/glue/xpcom/helpers.cpp b/src/VBox/Main/glue/xpcom/helpers.cpp new file mode 100644 index 00000000..de185186 --- /dev/null +++ b/src/VBox/Main/glue/xpcom/helpers.cpp @@ -0,0 +1,204 @@ +/* $Id: helpers.cpp $ */ +/** @file + * COM helper functions for XPCOM + */ + +/* + * Copyright (C) 2006-2022 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>. + * + * SPDX-License-Identifier: GPL-3.0-only + */ + +#include "VBox/com/defs.h" +#include <nsMemory.h> +#include <iprt/assertcompile.h> +#include <iprt/utf16.h> + + +// +// OLE Automation string APIs +// + +// Note: on Windows, every BSTR stores its length in the +// byte just before the pointer you get. If we do it like this, +// the caller cannot just use nsMemory::Free() on our strings. +// Therefore we'll try to implement it differently and hope that +// we don't run into problems. + +/** + * Copies a string into a new memory block including the terminating UCS2 NULL. + * + * @param pwsz Source string to duplicate. + * @returns New BSTR string buffer. + */ +BSTR SysAllocString(const OLECHAR *pwszSrc) +{ + AssertCompile(sizeof(*pwszSrc) == sizeof(PRUnichar)); + if (pwszSrc) + return SysAllocStringLen(pwszSrc, RTUtf16Len((PCRTUTF16)pwszSrc)); + return NULL; +} + +/** + * Duplicates an ANSI string into a BSTR / allocates a BSTR with a size given in + * bytes. + * + * No conversion is done. + * + * @param pszSrc Source string to copy, optional. + * @param cbSrcReq Length of the source string / memory request in bytes. + * @returns new BSTR string buffer, NULL on failure. + */ +BSTR SysAllocStringByteLen(char const *pszSrc, unsigned int cbSrcReq) +{ + BSTR pBstrNew = (BSTR)nsMemory::Alloc(RT_ALIGN_Z(cbSrcReq + sizeof(OLECHAR), sizeof(OLECHAR))); + AssertCompile(sizeof(*pBstrNew) == sizeof(OLECHAR)); + if (pBstrNew) + { + if (!pszSrc) + memset(pBstrNew, 0, cbSrcReq + sizeof(OLECHAR)); + else + { + // Copy the string and make sure it is terminated. + memcpy(pBstrNew, pszSrc, cbSrcReq); + char *pchTerminator = (char *)pBstrNew; + pchTerminator[cbSrcReq] = '\0'; + pchTerminator[cbSrcReq + 1] = '\0'; + } + } + return pBstrNew; +} + +/** + * Duplicates a UTF-16 string into a BSTR / Allocates a BSTR with a size given + * in UTF-16 characters. + * + * @param pwszSrc Pointer to the source string, optional. + * @param cwcSrcReq Length of the source string / memory request in UTF-16 + * characters. + * @returns new BSTR string buffer, NULL on failure. + */ +BSTR SysAllocStringLen(const OLECHAR *pwszSrc, unsigned int cwcSrcReq) +{ + size_t const cbReq = (cwcSrcReq + 1) * sizeof(OLECHAR); + BSTR pBstrNew = (BSTR)nsMemory::Alloc(cbReq); + AssertCompile(sizeof(*pBstrNew) == sizeof(OLECHAR)); + if (pBstrNew) + { + if (!pwszSrc) + memset(pBstrNew, 0, cbReq); + else + { + // Copy the string and make sure it is terminated. + memcpy(pBstrNew, pwszSrc, cbReq - sizeof(OLECHAR)); + pBstrNew[cwcSrcReq] = L'\0'; + } + } + return pBstrNew; +} + +/** + * Frees the memory associated with the given BSTR. + * + * @param pBstr The string to free. NULL is ignored. + */ +void SysFreeString(BSTR pBstr) +{ + if (pBstr) + nsMemory::Free(pBstr); +} + +/** + * Duplicates @a pwszSrc into an exsting BSTR, adjust its size to make it fit. + * + * @param ppBstr The existing BSTR buffer pointer. + * @param pwszSrc Source string to copy. If NULL, the existing BSTR is freed. + * @returns success indicator (TRUE/FALSE) + */ +int SysReAllocString(BSTR *ppBstr, const OLECHAR *pwszSrc) +{ + if (pwszSrc) + return SysReAllocStringLen(ppBstr, pwszSrc, RTUtf16Len((PCRTUTF16)pwszSrc)); + SysFreeString(*ppBstr); + *ppBstr = NULL; + return 1; +} + +/** + * Duplicates @a pwszSrc into an exsting BSTR / resizing an existing BSTR buffer + * into the given size (@a cwcSrcReq). + * + * @param ppBstr The existing BSTR buffer pointer. + * @param pwszSrc Source string to copy into the adjusted pbstr, optional. + * @param cwcSrcReq Length of the source string / request in UCS2 + * characters, a zero terminator is always added. + * @returns success indicator (TRUE/FALSE) + */ +int SysReAllocStringLen(BSTR *ppBstr, const OLECHAR *pwszSrc, unsigned int cwcSrcReq) +{ + BSTR pBstrOld = *ppBstr; + AssertCompile(sizeof(*pBstrOld) == sizeof(OLECHAR)); + if (pBstrOld) + { + if ((BSTR)pwszSrc == pBstrOld) + pwszSrc = NULL; + + size_t cbReq = (cwcSrcReq + 1) * sizeof(OLECHAR); + BSTR pBstrNew = (BSTR)nsMemory::Realloc(pBstrOld, cbReq); + if (pBstrNew) + { + if (pwszSrc) + memcpy(pBstrNew, pwszSrc, cbReq - sizeof(OLECHAR)); + pBstrNew[cwcSrcReq] = L'\0'; + *ppBstr = pBstrNew; + return 1; + } + } + else + { + // allocate a new string + *ppBstr = SysAllocStringLen(pwszSrc, cwcSrcReq); + if (*ppBstr) + return 1; + } + return 0; +} + +/** + * Returns the string length in bytes without the terminator. + * + * @param pBstr The BSTR to get the byte length of. + * @returns String length in bytes. + */ +unsigned int SysStringByteLen(BSTR pBstr) +{ + AssertCompile(sizeof(OLECHAR) == sizeof(*pBstr)); + return RTUtf16Len(pBstr) * sizeof(OLECHAR); +} + +/** + * Returns the string length in OLECHARs without the terminator. + * + * @param pBstr The BSTR to get the length of. + * @returns String length in OLECHARs. + */ +unsigned int SysStringLen(BSTR pBstr) +{ + return RTUtf16Len(pBstr); +} |