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106 lines
3.6 KiB
C++
106 lines
3.6 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/*
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* The contents of this file are subject to the Mozilla Public
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* License Version 1.1 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy of
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* the License at http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
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* implied. See the License for the specific language governing
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* rights and limitations under the License.
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*
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* The Original Code is Mozilla strings.
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*
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* The Initial Developer of the Original Code is Netscape
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* Communications Corporation. Portions created by Netscape are
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* Copyright (C) 2000 Netscape Communications Corporation. All
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* Rights Reserved.
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*
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* Contributor(s):
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* Scott Collins <scc@mozilla.org> (original author)
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*
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*/
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#ifndef nsBufferHandleUtils_h___
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#define nsBufferHandleUtils_h___
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#ifndef nsAReadableString_h___
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#include "nsAReadableString.h"
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// for |basic_nsAReadableString|...
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#endif
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#include <new.h>
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// for placement |new|
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template <class HandleT, class CharT>
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inline
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size_t
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NS_AlignedHandleSize( const HandleT*, const CharT* )
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{
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// figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
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return ((sizeof(HandleT) + sizeof(CharT) - 1) / sizeof(CharT)) * sizeof(CharT);
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}
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template <class HandleT, class CharT>
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inline
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const CharT*
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NS_DataAfterHandle( const HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
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{
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typedef const CharT* CharT_ptr;
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return CharT_ptr(NS_STATIC_CAST(const unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
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}
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template <class HandleT, class CharT>
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inline
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CharT*
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NS_DataAfterHandle( HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
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{
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typedef CharT* CharT_ptr;
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return CharT_ptr(NS_STATIC_CAST(unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
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}
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template <class HandleT, class CharT>
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HandleT*
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NS_AllocateContiguousHandleWithData( const HandleT* aDummyHandlePtr, const basic_nsAReadableString<CharT>& aDataSource, PRUint32 aAdditionalCapacity=1 )
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{
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typedef CharT* CharT_ptr;
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// figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
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size_t handle_size = NS_AlignedHandleSize(aDummyHandlePtr, CharT_ptr(0));
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// figure out how many |CharT|s wee need to fit in the data part
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size_t data_length = aDataSource.Length();
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size_t buffer_length = data_length + aAdditionalCapacity;
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// how many bytes is that (including a zero-terminator so we can claim to be flat)?
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size_t buffer_size = buffer_length * sizeof(CharT);
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HandleT* result = 0;
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void* handle_ptr = ::operator new(handle_size + buffer_size);
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if ( handle_ptr )
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{
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CharT* data_start_ptr = CharT_ptr(NS_STATIC_CAST(unsigned char*, handle_ptr) + handle_size);
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CharT* data_end_ptr = data_start_ptr + data_length;
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CharT* buffer_end_ptr = data_start_ptr + buffer_length;
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nsReadingIterator<CharT> fromBegin, fromEnd;
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CharT* toBegin = data_start_ptr;
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copy_string(aDataSource.BeginReading(fromBegin), aDataSource.EndReading(fromEnd), toBegin);
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// and if the caller bothered asking for a buffer bigger than their string, we'll zero-terminate
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if ( aAdditionalCapacity > 0 )
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*toBegin = CharT(0);
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result = new (handle_ptr) HandleT(data_start_ptr, data_end_ptr, data_start_ptr, buffer_end_ptr, PR_TRUE);
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}
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return result;
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}
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#endif // !defined(nsBufferHandleUtils_h___)
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