使用Boost内存Uncom preSS数据gzip_decom pressor [英] Uncompress data in memory using Boost gzip_decompressor

问题描述

我使用升压试图DECOM preSS二进制数据在内存中 gzip_decom pressor ​​。从这个答案，我适应以下code：

I'm trying to decompress binary data in memory using Boost gzip_decompressor. From this answer, I adapted the following code:

vector<char> unzip(const vector<char> compressed)
{
    vector<char> decompressed = vector<char>();

    boost::iostreams::filtering_ostream os;

    os.push(boost::iostreams::gzip_decompressor());
    os.push(boost::iostreams::back_inserter(decompressed));

    boost::iostreams::write(os, &compressed[0], compressed.size());

    return decompressed;
}

但是，返回的向量长度为​​零。我究竟做错了什么？我试着打电话刷新（）上的操作系统流，但它并没有区别

However, the returned vector has zero length. What am I doing wrong? I tried calling flush() on the os stream, but it did not make a difference

推荐答案

您code适用于我这个简单的测试程序：

Your code works for me with this simple test program:

#include <iostream>
#include <vector>
#include <boost/iostreams/filtering_stream.hpp>
#include <boost/iostreams/filter/gzip.hpp>

std::vector<char> unzip(const std::vector<char> compressed)
{
   std::vector<char> decompressed = std::vector<char>();

   boost::iostreams::filtering_ostream os;

   os.push(boost::iostreams::gzip_decompressor());
   os.push(boost::iostreams::back_inserter(decompressed));

   boost::iostreams::write(os, &compressed[0], compressed.size());

   return decompressed;
}

int main() {
   std::vector<char> compressed;
   {
      boost::iostreams::filtering_ostream os;
      os.push(boost::iostreams::gzip_compressor());
      os.push(boost::iostreams::back_inserter(compressed));
      os << "hello\n";
      os.reset();
   }
   std::cout << "Compressed size: " << compressed.size() << '\n';

   const std::vector<char> decompressed = unzip(compressed);
   std::cout << std::string(decompressed.begin(), decompressed.end());

   return 0;
}

您确认您输入的是COM pressed用gzip而不是一些其他的方法（例如原放气）？用gzip的字节COM pressed数据开始 1F 8B 。

Are you sure your input was compressed with gzip and not some other method (e.g. raw deflate)? gzip compressed data begins with bytes 1f 8b.

我一般使用 复位（） 或放流和过滤器在自己的块，以确保输出完成。我做既为COM pression之上，只是作为一个例子。

I generally use reset() or put the stream and filters in their own block to make sure that output is complete. I did both for compression above, just as an example.

这篇关于使用Boost内存Uncom preSS数据gzip_decom pressor的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！