Querying an instance of an IP address by ipip.net implementing a database

The last time we introduced the method of querying IP address details using pure database.
However, the pure database is provided by the user feedback, a lot of data description is not accurate, so I went online to find some other IP database, finally found ipip.net this site provides IP database.

IPIP offers a free version of the database available for both paid and free two versions, which we can use directly.
Download address https://www.ipip.net/download.html (need to register an account first)
There is a PHP parsing class in the package, there is a 17monipdb.dat file is the database, we just need to use it.

Copy the 17monipdb.dat to the program's home directory, using the following code:

Imports system.ioimports system.textpublic Class ipip Shared offset as Integer shared index as UInteger () = New UInt Eger (255) {} shared DataBuffer as Byte () shared IndexBuffer as Byte () shared lastmodifytime as Long = 0L Share    D ipfile as String shared rwlock as New threading.readerwriterlock Shared Sub New () Load ("17monipdb.dat") End Sub Shared Sub Load (ByVal filename as String) ipfile = New FileInfo (filename). FullName load () End Sub Shared Sub Load () rwlock. AcquireWriterLock ( -1) Dim fi as New FileInfo (ipfile) LastModifyTime = fi. Lastwritetime.ticks Try DataBuffer = File.readallbytes (fi.            FullName) Dim indexlength = Bytestolong (DataBuffer (0), DataBuffer (1), DataBuffer (2), DataBuffer (3)) IndexBuffer = New Byte (indexLength-1) {} array.copy (DataBuffer, 4, indexbuffer, 0, Indexlength) of Fset = CType (Indexlength, Integer) for LP As Integer = 0 to 255 index (LP) = Bytestolong (_ IndexBuffer (LP * 4 + 3), _                 INDEXBUFFER (LP * 4 + 2), _ IndexBuffer (LP * 4 + 1), _ IndexBuffer (LP * 4) _ ) Next Catch ex as Exception Throw ex End Try rwlock. Releasewriterlock () End Sub Private Shared Function Bytestolong (ByVal A as Byte, ByVal B as Byte, ByVal C as Byte, b Yval D as Byte) as UInteger Return (CType (A, UInteger) <<) or (CType (b, UInteger) << +) or (CType (c , UInteger) << 8) Or d End Function Shared function Find (ByVal IP As String) as String () Rwlock. AcquireReaderLock ( -1) Dim ips = IP.        Split (".") Dim Ip_prefix_value = Integer.parse (IPs (0)) Dim ip2long_value As Long = Bytestolong (byte.parse (IPs (0)), Byte.parse ( IPs (1)), Byte.parse (IPs (2)), Byte.parse (IPs (3))) Dim start = Index (ip_prefix_value) Dim Max_comp_len =offset-1028 Dim index_offset As Long = -1l Dim index_length As Integer =-1 Dim b As Byte = 0 Start = start * 8 + 1024x768 While start < Max_comp_len If Bytestolong (indexbuffer (start + 0), Indexbuf Fer (start + 1), IndexBuffer (start + 2), IndexBuffer (start + 3)) >= Ip2long_value then Index_offset = Byt  Estolong (b, indexbuffer (start + 6), IndexBuffer (start + 5), IndexBuffer (start + 4)) Index_length = &hff and IndexBuffer (start + 7) Exit while end If start + = 8 End while Dim Areabytes = New Byte (index_length-1) {} array.copy (DataBuffer, offset + index_offset-1024, areabytes, 0, Index_ Length) Dim ret as String () = Encoding.UTF8.GetString (areabytes). Split (VbTab) rwlock. Releasereaderlock () Return ret end Function End Class

This code I translated from the official C # version, and removed some redundant code, leaving only the core functionality.
Without the complete test, there is a bug please feedback to me.

The way to use it is simple:

DIM ret = Ipip. Find ("127.0.0.1" separates all information with newline Dim Ipdesc = String.Join (vbCrLf, ret)