ssdfasd
58a83f445a
- Fix link resolution with proper relative/absolute path handling - Improve link styling with underline decoration - Hide leaf nodes from tree, only show directories - Fix log file path for packaged app
56 lines
1.5 KiB
Markdown
56 lines
1.5 KiB
Markdown
# IAllocator::Reallocate
|
||
|
||
```cpp
|
||
virtual void* Reallocate(void* ptr, size_t newSize) = 0;
|
||
```
|
||
|
||
调整已分配内存块的大小。如果 `ptr` 为 `nullptr`，行为等同于 `Allocate(newSize)`。如果 `newSize` 为 0，行为等同于 `Free(ptr)` 并返回 `nullptr`。如果分配器不支持重新分配，应返回 `nullptr` 并保持原内存不变。
|
||
|
||
**参数：**
|
||
- `ptr` - 指向现有内存块的指针
|
||
- `newSize` - 新的字节大小
|
||
|
||
**返回：** 调整后的新内存块指针（可能与原指针不同）
|
||
|
||
**复杂度：** O(n)，需要分配新内存并复制数据
|
||
|
||
**示例：**
|
||
|
||
```cpp
|
||
#include <XCEngine/Memory/Allocator.h>
|
||
|
||
class MyAllocator : public IAllocator {
|
||
public:
|
||
void* Allocate(size_t size, size_t alignment = 0) override {
|
||
return ::operator new(size);
|
||
}
|
||
|
||
void Free(void* ptr) override {
|
||
if (ptr) ::operator delete(ptr);
|
||
}
|
||
|
||
void* Reallocate(void* ptr, size_t newSize) override {
|
||
if (newSize == 0) {
|
||
Free(ptr);
|
||
return nullptr;
|
||
}
|
||
if (!ptr) return Allocate(newSize);
|
||
|
||
size_t oldSize = /* 需要外部记录 */ 256; // 示例中硬编码
|
||
void* newPtr = Allocate(newSize);
|
||
memcpy(newPtr, ptr, oldSize < newSize ? oldSize : newSize);
|
||
Free(ptr);
|
||
return newPtr;
|
||
}
|
||
// ... 其他方法实现
|
||
};
|
||
|
||
MyAllocator alloc;
|
||
void* ptr = alloc.Allocate(128);
|
||
void* bigger = alloc.Reallocate(ptr, 256); // 扩展到 256 字节
|
||
```
|
||
|
||
## 相关文档
|
||
|
||
- [IAllocator 总览](allocator.md) - 返回类总览
|