codefile.cpp

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//---------------------------------------------
//              File: codefile.cpp             
//---------------------------------------------

using namespace std;

#include<cstdlib>
#include<cstring>
#include<string>
#include<vector>
#include<unistd.h>

#ifndef PARAMETERSINCLUDED
#include "parameters.cpp"
#endif

#define CODEFILEINCLUDED

class codefile
{
private:
      string emailid;//uniquely identifies repository and also name of the repository directory.
        string path;  //system path of the directory under which all the repositories are stored. 
        vector<unsigned int> codestream;  //buffer to be emptied into the codefile
        unsigned long int curloc;        // current location inside the codestream

public:
      //constructor to be called by the encoder module
      codefile(string cf_path ,string email_id,unsigned long int size)
      {
        path=cf_path;
        emailid=email_id;
        curloc=0;
        for(unsigned long int i=0;i<size;i++)
          codestream.push_back(0);
        FILE* fptr=fopen(path.c_str(),"w+");
        fprintf(fptr,"%s",emailid.c_str());
        fprintf(fptr,"%c",'\0');
        curloc=ftell(fptr);
        fclose(fptr);
      }

       //constructor to be called by the decoder module
      codefile(string cf_path)
      {
        curloc=0;
        path=cf_path;
        FILE* fptr=fopen(path.c_str(),"r+");
        char c='a';
        while((c=fgetc(fptr))!='\0')
        {
          curloc++;
        }
        curloc++;
        fclose(fptr);
        reademailid();
        read(); 
      }

      int append(unsigned int code)
      {
        FILE* fptr=fopen(path.c_str(),"a+");
        int bytes=fwrite((unsigned int*)&code,sizeof(unsigned int),1,fptr);
        curloc=ftell(fptr);
        fclose(fptr);
      }

      unsigned int read(void)
      {
        unsigned long int size;
        FILE* fptr=fopen(path.c_str(),"r+"); 
        if(fptr==NULL)
        {
          cout<<"Problem with opening the file"<<endl;
          exit(1);
        }
        size=ftell(fptr);
        fseek(fptr,0L,SEEK_END);
        size=ftell(fptr);
        for(unsigned long int i=0;i<(size-emailid.length()-1)/sizeof(unsigned int);i++)
          codestream.push_back(0);
        fseek(fptr,curloc,SEEK_SET);
        int i=0;
        unsigned int tempo;
        while(fread((unsigned int*)&tempo,sizeof(unsigned int),1,fptr))  
        {
          codestream[i]=tempo;
          i++;
        }
        fclose(fptr);
        curloc=0;
        return SUCCESS;
      }
      
      unsigned int getcode() 
      {
        if(curloc>codestream.size())
          return END_OF_CODESTREAM;// -1 signifies an error condition: end of code file...
        return codestream[curloc++];
      }

      string reademailid(void)
      {
        char id[257];
        FILE* fptr=fopen(path.c_str(),"r+");
        fscanf(fptr,"%s",id);
        fclose(fptr);
        emailid=(string)id;
        return emailid;
      }

      ~codefile() {
      }
};  

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