MaxMind DB Reader

Description

This is the .NET API for reading MaxMind DB files. MaxMind DB is a binary file format that stores data indexed by IP address subnets (IPv4 or IPv6).

Installation

NuGet

We recommend installing this library with NuGet. To do this, type the following into the Visual Studio Package Manager Console:

install-package MaxMind.Db

Usage

Note: For accessing MaxMind GeoIP2 databases, we generally recommend using the GeoIP2 .NET API rather than using this package directly.

To use the API, you must first create a Reader object. The constructor for the reader object takes a string with the path to the MaxMind DB file. Optionally you may pass a second parameter with a FileAccessMode enum with the value MemoryMapped or Memory. The default mode is MemoryMapped, which maps the file to virtual memory. This often provides performance comparable to loading the file into real memory with the Memory mode while using significantly less memory.

To look up an IP address, pass a System.Net.IPAddress object to the Find<T> method on Reader. This method will return the result as type T. T may either be a generic collection or a class using the [MaxMind.Db.Constructor] attribute to declare which constructor to use during deserialization and the [MaxMind.Db.Parameter("name")] to map the database key name to a particular constructor parameter.

We recommend reusing the object rather than creating a new one for each lookup. The creation of this object is relatively expensive as it must read in metadata for the file.