index.js

var fs    = require('fs'),
path      = require('path'),
buf2long  = require('./lib/utils.js').buf2long,
matchFingerPrint = require('./lib/utils.js').matchFingerPrint,
DATA      = require('./include/models.js').DATA, 
CONST     = Object.freeze(require('./include/constants.js'));

/******************************************************************************
 * Inner Functions
 *****************************************************************************/
 function _setup_segments(data) {
   var seg, delim, i, j, 
   buf = data.buffer, offset = buf.length - 3;

   // Set data type and segments
   for (i = 0; i < CONST.STRUCTURE_INFO_MAX_SIZE; i++) {
     delim = buf2long(buf.slice(offset, offset + 3));
     offset += 3;
     if (delim === CONST.DELIMETER_NUMBER) {
       data.db_type = parseInt(buf[offset], 10);
       offset++;
       if (data.db_type === CONST.REGION_EDITION_REV0) {
         data.db_segments = CONST.STATE_BEGIN_REV0;
       } else if (data.db_type === CONST.REGION_EDITION_REV1) {
         data.db_segments = CONST.STATE_BEGIN_REV1;
       } else if (data.db_type === CONST.CITY_EDITION_REV0 ||
       data.db_type === CONST.CITY_EDITION_REV1 ||
       data.db_type === CONST.ORG_EDITION  ||
       data.db_type === CONST.DOMAIN_EDITION ||
       data.db_type === CONST.ISP_EDITION    ||
       data.db_type === CONST.LOCATIONA_EDITION   ||
       data.db_type === CONST.ACCURACYRADIUS_EDITION ||
       data.db_type === CONST.ASNUM_EDITION) {
         data.db_segments = 0;
         seg = buf.slice(offset, offset + CONST.SEGMENT_RECORD_LENGTH);
         for (j = 0; j < CONST.SEGMENT_RECORD_LENGTH; j++) {
           data.db_segments += (parseInt(seg[j], 10) << (j * 8));
         }
       } else if (data.db_type === CONST.PROXY_EDITION ||
       data.db_type === CONST.NETSPEED_EDITION) {
         data.db_segments = CONST.COUNTRY_BEGIN;
       }   
       break;
     } else {
       offset -= 4;
     }

     // Set default data type to country edition
     if (data.db_type === undefined) {
       if (matchFingerPrint(data)) {
         data.db_type = CONST.COUNTRY_EDITION;
         data.db_segments = CONST.COUNTRY_BEGIN;
       }
     }
   }

   // Set record length
   if (data.db_type === CONST.ORG_EDITION ||
   data.db_type === CONST.DOMAIN_EDITION ||
   data.db_type === CONST.ISP_EDITION) {
     data.record_length = CONST.ORG_RECORD_LENGTH;
   } else {
     data.record_length = CONST.STANDARD_RECORD_LENGTH; 
   }

   return data;
 }


 /******************************************************************************
  * Exprots Functions
  *****************************************************************************/
  exports.open = function(file) {
    var stats, bytesRead;
    var data = new DATA();
    data.file_descriptor = fs.openSync(file, 'r');
    stats = fs.fstatSync(data.file_descriptor);
    data.buffer = new Buffer(stats.size);
    bytesRead = fs.readSync(data.file_descriptor, data.buffer, 0, stats.size, 0);

    if (bytesRead >= 0) {
      return _setup_segments(data);
    } else {
      return false;
    }

  };

  exports.check = function(data) {
    var code, type;
    code = data.db_type;
    switch(code)
    {
      case CONST.COUNTRY_EDITION:
      type = 'country';
      break;

      case CONST.CITY_EDITION_REV0:
      type = 'city';
      break;

      case CONST.CITY_EDITION_REV1:
      type = 'city';
      break;

      case CONST.REGION_EDITION_REV0:
      type = 'region';
      break;

      case CONST.REGION_EDITION_REV1:
      type = 'region';
      break;

      case CONST.ORG_EDITION:
      type = 'org';
      break;

      case CONST.ASNUM_EDITION:
      type = 'asnumber';
      break;

      case CONST.NETSPEED_EDITION:
      type = 'netspeed';
      break;

      default:
      type = null;
      break;
    }  

    return type;
  };

  exports.filter = function(file, callback) {
    var error, code, type, data = new DATA();
    fs.open(file, 'r', function(err, fd) {
      if (err) {throw err;}
      data.file_descriptor = fd;
      fs.fstat(data.file_descriptor, function(err, stats) {
        if (err) {throw err;}
        data.buffer = new Buffer(stats.size);
        fs.read(data.file_descriptor, data.buffer, 0, stats.size, 0, function(err, bytesRead) {
          if (err) {throw err;}
          data = _setup_segments(data);
          code = data.db_type;
          switch(code)
          {
            case CONST.COUNTRY_EDITION:
            type = 'country';
            break;

            case CONST.CITY_EDITION_REV0:
            type = 'city';
            break;

            case CONST.CITY_EDITION_REV1:
            type = 'city';
            break;

            case CONST.REGION_EDITION_REV0:
            type = 'region';
            break;

            case CONST.REGION_EDITION_REV1:
            type = 'region';
            break;

            case CONST.ORG_EDITION:
            type = 'org';
            break;

            case CONST.ASNUM_EDITION:
            type = 'asnumber';
            break;

            case CONST.NETSPEED_EDITION:
            type = 'netspeed';
            break;

            default:
            error = new Error('Unkown data type');
            break;
          }
          callback(error, type, data);
        });
      });
    });
  };

  exports.close = function(data) {
    var keys;
    fs.closeSync(data.file_descriptor);
    keys = Object.keys(data);
    keys.forEach(function(k) {
      delete data[k];
    });
  };    

  exports.NetSpeed = require('./lib/netspeed.js');
  exports.Country  = require('./lib/country.js');
  exports.Region   = require('./lib/region.js');
  exports.City     = require('./lib/city.js');
  exports.Org      = require('./lib/org.js');