40 lines
866 B
Markdown
40 lines
866 B
Markdown
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# LinearAllocator::GetUsedSize
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```cpp
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size_t GetUsedSize() const;
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```
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返回当前已使用的字节数，即内部偏移量的值。此值在 `Allocate` 后增加，在 `Clear` 或 `SetMarker` 后可能减少（取决于设置的目标位置）。
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**参数：** 无
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**返回：** 已使用的字节数
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**复杂度：** O(1)
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**示例：**
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```cpp
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#include <XCEngine/Memory/LinearAllocator.h>
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LinearAllocator allocator(1024);
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size_t before = allocator.GetUsedSize(); // 0
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allocator.Allocate(128);
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allocator.Allocate(256);
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size_t after = allocator.GetUsedSize(); // 384
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void* marker = allocator.GetMarker();
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allocator.Allocate(64);
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size_t with_temp = allocator.GetUsedSize(); // 448
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allocator.SetMarker(marker);
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size_t after_rollback = allocator.GetUsedSize(); // 384
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```
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## 相关文档
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- [LinearAllocator 总览](linear-allocator.md) - 返回类总览
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