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author | Lars Knoll <lars.knoll@nokia.com> | 2009-03-23 09:18:55 (GMT) |
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committer | Simon Hausmann <simon.hausmann@nokia.com> | 2009-03-23 09:18:55 (GMT) |
commit | e5fcad302d86d316390c6b0f62759a067313e8a9 (patch) | |
tree | c2afbf6f1066b6ce261f14341cf6d310e5595bc1 /tools/porting/src/smallobject.h | |
download | Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.zip Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.gz Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.bz2 |
Long live Qt 4.5!
Diffstat (limited to 'tools/porting/src/smallobject.h')
-rw-r--r-- | tools/porting/src/smallobject.h | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/tools/porting/src/smallobject.h b/tools/porting/src/smallobject.h new file mode 100644 index 0000000..f086b70 --- /dev/null +++ b/tools/porting/src/smallobject.h @@ -0,0 +1,182 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** Copyright (C) 2001-2004 Roberto Raggi +** +** This file is part of the qt3to4 porting application of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef SMALLOBJECT_H +#define SMALLOBJECT_H + +#include <QList> + +#include <assert.h> +#include <stdlib.h> +#include <string.h> + +QT_BEGIN_NAMESPACE + +struct block_t +{ + static int N; + + block_t *chain; + char *data; + char *ptr; + char *end; + + inline void init(int block_size = 256) + { + ++N; + chain = 0; + data = (char*) malloc(block_size); + ptr = data; + end = data + block_size; + } + + inline void init0(int block_size) + { + init(); + memset(data, '0', block_size); + } + + inline void destroy() + { + --N; + if (chain) { + chain->destroy(); + free(chain); + } + + free(data); + } + + inline void *allocate(size_t size, block_t **right_most) + { + const unsigned int block_size = 1 << 16; + if (end < ptr + size) { + assert( size < block_size ); + + if (!chain) { + chain = (block_t*) malloc(sizeof(block_t)); + Q_ASSERT(chain); + chain->init(block_size); + } + + return chain->allocate(size, right_most); + } + + char *r = ptr; + ptr += size; + + if (right_most) + *right_most = this; + + return r; + } + +}; + +// a stupid memory pool +struct pool +{ + block_t blk; + block_t *right_most; + + inline pool() { blk.init(); right_most = &blk; } + inline ~pool() { blk.destroy(); } + + inline void *allocate(size_t size) + { + void *ptr = right_most->allocate(size, &right_most); + Q_ASSERT(ptr); + return ptr; + + } + inline void *reallocate(void *old, size_t old_size, size_t size) + { + void *alloc = right_most->allocate(size, &right_most); + memcpy(alloc, old, old_size); + return alloc; + } +private: + Q_DISABLE_COPY(pool) +}; + +/* + A memory pool that calls the destructor for each stored item when memory is + freed, at the expence storing one BaseType* per item. + + Note that allocations for types that does not inherit BaseType + is not allowed and will result in a crash when the memory is freed. +*/ +template <typename BaseType> +class TypedPool +{ +public: + inline TypedPool() { blk.init(); right_most = &blk; } + inline ~TypedPool() + { + foreach(BaseType *item, allocated) + item->~BaseType(); + blk.destroy(); + } + + inline void *allocate(size_t size) + { + void *memory = right_most->allocate(size, &right_most); + allocated.append(reinterpret_cast<BaseType *>(memory)); + Q_ASSERT(memory); + return memory; + } +private: + Q_DISABLE_COPY(TypedPool) + block_t blk; + block_t *right_most; + QList<BaseType *> allocated; +}; + +struct SmallObject +{ + static void *operator new(size_t size); + static void operator delete(void *p); +}; + +QT_END_NAMESPACE + +#endif |