c_cpp LZ4的例子

Posted 2021-05-14

#include "lz4.h"

using namespace std;

int main()
{
char szSource[] = "2013-01-07 00:00:04,0.98644,0.98676 2013-01-07 00:01:19,0.98654,0.98676 2013-01-07 00:01:38,0.98644,0.98696";
int nInputSize = sizeof(szSource);

// compress szSource into pchCompressed
char* pchCompressed = new char[nInputSize];
int nCompressedSize = LZ4_compress((const char *)(&szSource), pchCompressed, nInputSize);

// write pachCompressed to binary lz4.dat
ofstream outBinaryFile("lz4.dat",ofstream::binary);
outBinaryFile.write(pchCompressed, nCompressedSize);
outBinaryFile.close();
delete[] pchCompressed;
pchCompressed = 0;

//read compressed binary file (assume we pass/encode nInputSize but don't know nCompressedSize)
ifstream infCompressedBinaryFile( "lz4.dat", ifstream::binary );

//Get compressed file size for buffer
infCompressedBinaryFile.seekg (0,infCompressedBinaryFile.end);
int nCompressedInputSize = infCompressedBinaryFile.tellg();
infCompressedBinaryFile.clear();
infCompressedBinaryFile.seekg(0,ios::beg);

//Read file into buffer
char* pchCompressedInput = new char[nCompressedInputSize];
infCompressedBinaryFile.read(pchCompressedInput,nCompressedSize);
infCompressedBinaryFile.close();

// Decompress buffer
char* pchDeCompressed = new char[nInputSize]; //(nCompressedInputSize *2) +8
LZ4_uncompress(pchCompressedInput, pchDeCompressed, nInputSize);
delete[] pchCompressedInput;
pchCompressedInput = 0;

// write decompressed pachUnCompressed to
ofstream outFile("lz4.txt");
outFile.write(pchDeCompressed, nInputSize);
outFile.close();

delete[] pchDeCompressed;
pchDeCompressed = 0;

return 0;
}