Test rapidjson parsing speed, like in http://computers-are-fast.github.io/

testrapidjson.cpp

// this is hacky and assumes messages.json is <64k bytes. that's the case for
// https://github.com/kamalmarhubi/one-second/blob/master/setup/protobuf/message.json

#include "rapidjson/document.h"
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char** argv)
{
        size_t numIterations = 1;
        if(argc > 1)
                numIterations = atoi(argv[1]);
                
        char buf[64*1024];

        FILE* f = fopen("message.json", "r");
        size_t size = fread(buf, 1, sizeof(buf), f);
        fclose(f);

        buf[size++] = '\0';
        
        char jbuf[sizeof(buf)];
        
        for(size_t i=0; i<numIterations; ++i)
        {
                rapidjson::Document document;
                
#if 1 // test insitu, change to "#if 0" for nondestructive parsing (which takes ~20-25% longer)

                // as the buffer will be modified by ParseInsitu(),
                // copy it from orig json string
                memcpy(jbuf, buf, size);
                bool hasError = document.ParseInsitu(jbuf).HasParseError();
#else
                bool hasError = document.Parse(buf).HasParseError();
#endif
                // make sure the code above (=> this loop) is not
                // optimized away by telling the compiler hasError
                // is important in a away it doesn't understand
                asm volatile("" : "+r" (hasError));
        }

        return 0;
}