Geo::PostalCode::InstallDB - Create and install a new location database for Geo::PostalCode.

Geo-PostalCode documentation Contained in the Geo-PostalCode distribution.

Index

Code Index:

NAME

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Geo::PostalCode::InstallDB - Create and install a new location database for Geo::PostalCode.

SYNOPSIS

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  use Geo::PostalCode::InstallDB;

  Geo::PostalCode::InstallDB->install(zipdata => 'Geo-PostalCode_19991101.txt',
                                      db_dir  => '.')
    or die "Couldn't install DB!\n";

DESCRIPTION

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This class contains only one useful method: install. It takes a text file, the name of which should be given in the zipdata parameter, and converts it into three Berkeley database files (postalcode.db, latlon.db, and city.db) which will be installed in the directory given as the db_dir parameter.

The format of these files is a series of lines, the first of which is skipped. Each has five tab-seperated values:

  postal_code	lat	lon	city	state

SEE ALSO

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Geo::PostalCode, http://www.census.gov/geo/www/tiger/zip1999.html.

Geo-PostalCode documentation Contained in the Geo-PostalCode distribution. 
package Geo::PostalCode::InstallDB;


use strict;
use warnings;
use Geo::PostalCode; our $VERSION = $Geo::PostalCode::VERSION;
use DB_File;
use FileHandle;
use POSIX;
use File::Spec;

use constant ZIPCODEDB => 'postalcode.db';
use constant CELLDB    => 'latlon.db';
use constant CITYDB    => 'city.db';

sub install
{
  my $class = shift;
  my %o = @_;
  my(%zipcode, %cell, %city, %lat, %lon);
  my $dir;

  $o{zipdata}
      or die "Missing required parameter zipdata";
  my $zip = FileHandle->new($o{zipdata}, "r")
      or die "Couldn't open '$o{zipdata}': $!\n";
  if ($o{db_dir})
  {
    $dir = $o{db_dir};
    if (!mkdir($dir))
    {
      die "Couldn't mkdir($dir): $!\n"
	  unless ($! eq 'File exists')
    }
  }
  foreach my $db (ZIPCODEDB, CELLDB, CITYDB)
  {
    if (!unlink(File::Spec->catfile($dir,"$db.tmp")))
    {
      die "Couldn't unlink '$db.tmp': $!\n"
	  unless ($! eq 'No such file or directory')
    }
  }

  tie (%zipcode, 'DB_File', File::Spec->catfile($dir,ZIPCODEDB.".tmp"), O_RDWR|O_CREAT, 0666, $DB_BTREE)
      or die "cannot tie %zipcode to file";
  tie (%cell,    'DB_File', File::Spec->catfile($dir,CELLDB.".tmp"),    O_RDWR|O_CREAT, 0666, $DB_BTREE)
      or die "cannot tie %cell to file";
  tie (%city,    'DB_File', File::Spec->catfile($dir,CITYDB.".tmp"),    O_RDWR|O_CREAT, 0666, $DB_BTREE)
    or die "cannot tie %city to file";

  # Skip header line
  <$zip>;
  while (<$zip>)
  {
    chomp;
    my ($zipcode, $lat, $lon, $city, $state);

    if ($o{is_csv}) {
	# strip enclosing quotes from fields
	($zipcode, $city, $state, $lat, $lon) =
	    map { substr($_, 1, length($_) - 2) } 
	split(",");

	# the CSV format has mixed case cities
	$city = uc($city);
    } else {
	($zipcode, $lat, $lon, $city, $state) = split("\t");
    }

    $zipcode{$zipcode} = "$lat,$lon,$city,$state";
    $lat{$zipcode} = $lat;
    $lon{$zipcode} = $lon;
    
    my $int_lat = floor($lat);
    my $int_lon = floor($lon);
    
    $cell{"$int_lat-$int_lon"} .= $zipcode;
    $city{"$state$city"} .= $zipcode;
  }
  
  foreach my $k (keys %city) {
    my $v = $city{$k};
    my @postal_codes = ($v =~ m!(.{5})!g);
    next unless @postal_codes;
    my ($tot_lat, $tot_lon, $count) = (0,0,0,0);
    for (@postal_codes) {
      $tot_lat += $lat{$_};
      $tot_lon += $lon{$_};
      $count++;
    }
    my $avg_lat = sprintf("%.5f",$tot_lat/$count);
    my $avg_lon = sprintf("%.5f",$tot_lon/$count);
    $city{$k} = "$v|$avg_lat|$avg_lon";
  }

  untie %zipcode;
  untie %cell;
  untie %city;

  foreach my $db (ZIPCODEDB, CELLDB, CITYDB)
  {
    rename(File::Spec->catfile($dir,"$db.tmp"),File::Spec->catfile($dir,$db))
	or die "Couldn't rename '$db.tmp' to '$db': $!\n";
  }
  1;
}

1;