filterlzo.cpp

#include "filterlzo.h"

namespace n2nc {

FilterLZO::FilterLZO() : Filter("LZO_FILTER","lzo compression module"){
  if (lzo_init() != LZO_E_OK){
    fprintf(stderr,"internal error - lzo_init() failed !!!\n");
    fprintf(stderr,"(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable `-DLZO_DEBUG' for diagnostics)\n");
    exit( 3 );
  }
  this->m_tmpbuf = malloc (65535);
  this->m_maxoverhead = sizeof(lzoheader_t);
}


FilterLZO::~FilterLZO(){

}

Filter::status_t n2nc::FilterLZO::egress(void * inbuf, void * outbuf, size_t inlen, size_t * outlen){
  lzo_uint in_len = inlen ;
  lzo_uint out_len;
  lzo_uint new_len;
  lzoheader_t *phdr ;
  
  lzo1x_1_compress((u_char*)inbuf,in_len,(u_char*)outbuf + sizeof(lzoheader_t),&out_len,this->m_wrkmem);
  phdr = (lzoheader_t*)outbuf ;
  if (out_len >= inlen){
    /* uncomprimible data */
//   injecting my uncompressed header
    phdr->p_size = 65535 ;
    memcpy((u_char*)outbuf + sizeof(lzoheader_t),inbuf,inlen);  /* re-copy original data */
    *outlen = inlen + sizeof(lzoheader_t);
    std::cerr << "UNCOMPRESSABLE data, outlen: " << out_len << " inlen: " << inlen << std::endl ;
    return Filter::FILTER_CONTINUE ;
  }
  phdr->p_size = out_len ;
//   memcpy(outbuf,&phdr,sizeof(lzoheader_t)) ;
  *outlen = out_len + sizeof(lzoheader_t);
  std::cerr << "COMPRESS data, out_len: " << out_len << " inlen: " << inlen << " ratio: " << (float)out_len / (float)inlen  << std::endl ;
  return Filter::FILTER_CONTINUE ;
}

Filter::status_t n2nc::FilterLZO::ingress(void * inbuf, void * outbuf, size_t inlen, size_t * outlen){
  lzoheader_t *phdr ;
  lzo_uint new_len;
  phdr = (lzoheader_t*)inbuf ;
  /* check wether the data is compressed or not */
  if( phdr->p_size == 65535u ){
    /*stripping out the header */
// std::cerr << "ingress uncompresse data, inlen: " << inlen << std::endl ;
    memcpy(outbuf,(u_char*)inbuf + sizeof(lzoheader_t),inlen - sizeof(lzoheader_t));
    *outlen = inlen - sizeof(lzoheader_t);
    return Filter::FILTER_CONTINUE ;
  }
  
// std::cerr << "ingress compressed data, inlen: " << inlen << " hdr.psize: "<< phdr->p_size  << std::endl ;
  
  lzo_memcpy(this->m_in, (u_char*)inbuf + sizeof(lzoheader_t),inlen - sizeof(lzoheader_t)) ;
//   lzo1x_decompress((u_char*)inbuf + sizeof(lzoheader_t),phdr->p_size,(u_char*)outbuf,&new_len,NULL);
  lzo1x_decompress(m_in,inlen - sizeof(lzoheader_t),(u_char*)outbuf,&new_len,NULL);
  *outlen = new_len;
  return Filter::FILTER_CONTINUE ;
}


extern "C"
Filter* get_istance(){
  return new FilterLZO();
}

extern "C"
int free_istance(Filter *filter){
  delete filter ;
}



}

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