README

The Abivia geocoding library provides a caching interface to IP address lookup APIs from these sources:

• ipinfo.io
• ipstack.com
• ipapi.co

The library supports both IPv4 and IPv6 addresses and is designed to seamlessly support other IP address geocoding services.

Requirements

Geocoding requires:

• PHP 8.2 or higher
• ext-curl to perform API calls
• abivia/cogs for address support
• mlocati/ip-lib for IP address support

PHP does not need to be built with IPv6 support.

Installation

Via composer:

composer require abivia/geocoding

Caching

Geocoding comes with two cache handlers designed for light use and a database cache for heavier use. The array cache will retain lookup results for the lifetime of the current request (or session if stored in a session variable). The file cache stores cached data in a text file. Neither offers support for concurrent requests.

The PDO Cache takes a connection to a database, optionally with table names to override the default tables geocoder_cache_ip, geocoder_cache_subnet and geocoder_cache_options. The cache handler will create these tables if they do not already exist.

Applications can create persistent caches by conforming to the CacheHandler interface. Caches support different retention times for lookup hits and lookup misses. In a file cache, the default retention time for a successful lookup is seven days, the default retention time for a failed lookup is one hour. The PDO cache defaults to 30 days for a successful lookup and one hour for a failed lookup.

Cache Purging

Array caches are expected to be transient, so there is no purge logic. The file cache runs a purge at the time the cache is loaded. The PDO cache runs at the interval set by the purgeCacheTime() method, which defaults to 24 hours. On the first object creation, the last purge time is loaded from the database and cached in the session to reduce overhead.

Proxy headers

The static getAddressFromHttp() method now accepts an optional $proxyHeaders parameter. If the parameter is null or not provided, and allowHeaders is true, GeoCoder looks for HTTP_CF_CONNECTING_IP, HTTP_CLIENT_IP, and HTTP_X_FORWARDED_FOR headers, in that order (more proxies may be added as they are discovered). A GeoCoder instance can maintain an independent proxy list.

By default, and address lookup via Geocoder::lookupHttp() checks for the HTTP_X_FORWARDED_FOR header. However, other services such as CloudFlare use non-standard headers. A call to Geocoder::addKnownProxyHeaders() adds all known proxy headers, which are checked for an IP address in order until a valid address is found.

Other proxies can be added or removed by calling Geocoder::addProxyHeader() and Geocoder::removeProxyHeader(). Header names are converted to uppercase. Headers are checked in the reverse order that they are added, so that the most recently added header is checked first.

Sample Usage

use Abivia\Geocode\Geocoder;
use Abivia\Geocode\LookupService\IpInfoApi;

$geocoder = new Geocoder(IpInfoApi::make());
$info = $geocoder->lookup('4.4.4.4');
echo $info->getLatitude() . ', ' . $info->getLongitude();

The geocoder normalizes results from different services using the GeocodeResult interface, but applications can retrieve the service's response through the GeocodeResult::data() method to access extended information.

Example using a file cache

use Abivia\Geocode\CacheHandler\FileCache;
use Abivia\Geocode\Geocoder;
use Abivia\Geocode\LookupService\IpInfoApi;

// Get a cache and set the cache time for a hit to six hours
$cache = new FileCache('mycache.json');
$cache->hitCacheTime(6 * 3600);
$geocoder = new Geocoder(IpInfoApi::make(), $cache);
$info = $geocoder->lookup('4.4.4.4');
echo $info->getLatitude() . ', ' . $info->getLongitude();

Subnet queries

For the most part from a geolocation perspective, only the first 24 bits of an IPv4 and the first 48 of an IPv6 address are significant. Geocoding provides a "subnet" query that will return the last queries result in the v4 or v6 range. This can reduce the number of queries on the lookup service, increasing performance and (in the case of paid services) reducing costs.

Subnet Example

use Abivia\Geocode\Geocoder;
use Abivia\Geocode\LookupService\IpInfoApi;

$geocoder = new Geocoder(IpInfoApi::make());

// Assume 4.4.4.4 is not currently cached. This will cause the service to be queried. 
$info = $geocoder->lookupSubnet('4.4.4.4');
echo $info->getLatitude() . ', ' . $info->getLongitude();

// This query will return the cached data for 4.4.4.4
$info2 = $geocoder->lookupSubnet('4.4.4.8');

Donations welcome

If you're getting something out of Geocoding, you can sponsor us in any amount you wish using Liberapay . Liberapay is itself run on donations and takes no fees beyond bank charges.