保持固定大小的符号共享内存 [英] Keeping fixed size symbols in shared memory

问题描述

我一直在努力一些东西，我需要存储符号列表和相应的数量，这些被存储为一个字符串，整数的映射。问题是输入的大小约为32 MB但是当我试图将其存储在内存中的大小来腌支持速度高达1.4Gb，我通过几个环节去了，发现的std ::字符串占用的内存相当数量的记账和很容易造成臃肿，所以我看起来有点进一步发现，人们可以使用升压::数组大小等于符号的最大尺寸，并且由于升压阵列没有做任何的书保持它doesn' ŧ导致内存膨胀。
不过，我希望把这个升压数组中像共享内存中，以便地图＆LT;升压::数组＆LT;焦炭，15＆GT; ，int>的。我看了看升压::阵列文档，发现它不支持分配器，目前我使用的分配器和段经理从boost如下：

I have been working on something which requires me store the list of symbols and the corresponding count, these are being stored as a string,int mapping. The problem is the input size is around 32 MB however when I try to store it in memory the size bloats to 1.4Gb, I went through a few links and found that std::string takes up a fair amount of memory for book keeping and is likely to cause the bloat, so I looked a little further and found that one could use the boost::array with a size equal to the max size of the symbol and since the boost array doesn't do any book keeping it doesn't cause memory bloat. However, I wish to place this boost array in the shared memory like so map<boost::array<char, 15>, int>.I took a look at the boost::array documentation and found that it doesn't support allocators, currently I am using allocators and segment managers from boost as follows:

typedef bip::allocator<char, bip::managed_shared_memory::segment_manager> CharAllocator;
typedef bip::basic_string<char, std::char_traits<char>, CharAllocator> SharedString;  

我也遇到了这个环节，这似乎解释了很多：
    http://jovislab.com/blog/?p=89

有没有办法做到这一点，有什么，我有其他选择。我不是在寻找完整的解决方案，但提示。
   谢谢，
   德布！

Is there a way to do this, what are the other choices that I have. I am not looking for complete solutions, but hints. Thanks, Deb!

推荐答案

适当的提示是：

• 使用连续分配


• 储备达阵

这答案包含升压managed_shared_memory不同的分配技术好的一面并排比较：

This answer contains a good side-by-side comparison of different allocation techniques with Boost managed_shared_memory:

• How做我衡量共享内存升压进程间向量的大小？

在您的特定情况下，你可以通过扁平化的分配

In your particular case you could flatten the allocation by using

• flat_map 和


• 对于字符串使用池分配（或者使用的boost :: string_ref 指从大型分配的字符串的std ::矢量＆lt;字符＆GT ; ）

• flat_map and
• use pool allocator for the strings (or perhaps use boost::string_ref to refer to strings allocated from on large std::vector<char>)

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