C ++ std :: container（vector）如何存储其内部（元素地址，通过索引访问）？ [英] How does a C++ std::container (vector) store its internals (element address, access by index)?

问题描述

我试图攻击一个游戏（红色警报3），我尝试做一个程序，显示我的选手的单位列表。至于我首先需要找到一个（静态）指针到我自己的列表，我可以在单人游戏。

I am trying to "hack" a game (Red Alert 3), I try to make a program which shows the unit list of my oponents. As for that I first need to find a (static) pointer to my own list which I can do on singleplayer.

我注意到这种行为：地址由add_unit代码更改）：

I have noticed this behaviour: (by looking at which addresses are changed by the add_unit code):

• 如果单位尚未构建，请为其创建一个新地址），并将该值设置为1（该类型的单位数量）


• 当游戏中已经构建单位时，将单位类型的原始地址增加1
• 
  

• if a units hasn't been build yet, create a new adress for it (random?) and set the value to 1 (amount of units of that type)
• when the unit has been already build once in the game, increment the original adress of the unit type by 1

这看起来像std :: vector行为。现在我有麻烦找到矢量的基地地址，和一个更大的问题：我将如何通过索引访问？

This looks to me like std::vector behaviour. Now I am having trouble to find the "base" adress of the vector, and a bigger problem: How would I access by index? Where does a std::vector store it's adresses it has for elements?

额外信息：

代码是用MS Visual C ++ 2005（需要播放MSVCR80 dll）编译的（从我从程序集中读取的）

The code is (from what I have read from the assembly) compiled with MS Visual C++ 2005 (MSVCR80 dll's are required to play)

这是矢量中的地址看起来像：

This is what the addresses in the vector look like:

>

（突出显示的地址是显示为第一个元素 - 第一个单元构建的地址）

(The highlighted address is the one which appeared as the first element - first unit build)

这看起来不像我可以通过添加一个常量值来迭代？

This doesn't look like I could iterate by adding a constant value?

每当添加一个新地址时，所有其他地址都是完全有效的，不会改变。

Whenever a new address is added, all the other addresses are perfectly valid and don't change.

推荐答案

向量的一个典型的（虽然不是强制性的） ：

A typical (though by no means mandatory) implementation of vector is to have three consecutive words:

struct TypicalVector
{
    T * start;
    T * end;
    T * capacity;
};

元素访问通过 start [i] （这是为什么在前面有开始指针很重要，以避免不必要的偏移计算），大小是 end-start ，容量为 capacity-start 。内存分配获得 c * sizeof（T）字节，并将 start 设置为已分配内存的地址， capacity 到 start + c 。元素构造递增结束。

Element access is done via start[i] (which is why it's important to have the start pointer at the front, to avoid unnecessary offset computations), size is end - start, and capacity is capacity - start. Memory allocation obtains c * sizeof(T) bytes and sets start to the address of the allocated memory and capacity to start + c. Element construction increments end.

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