VS.NET讀取純真IP數(shù)據(jù)庫(kù)(VB)

'參考文檔:http://lumaqq.linuxsir.org/article/qqwry_format_detail.html
'作者: gounliey
'Email:4473117@qq.com

'第一次寫(xiě)東西出來(lái)大家分享，還有很多不足之處，請(qǐng)大家指點(diǎn)。

'輔助類，用于保存IP索引信息
Public Class CZ_INDEX_INFO

�，�Public IpSet As UInt32
�，�Public IpEnd As UInt32
�，�Public Offset As UInt32

�，�Sub New()
�，，，�IpSet = 0
�，，，�IpEnd = 0
�，，，�Offset = 0
�，�End Sub

End Class

'讀取純真IP數(shù)據(jù)庫(kù)類
Public Class PHCZIP

�，�Protected bFilePathInitialized As Boolean
�，�Protected FilePath As String
�，�Protected FileStrm As FileStream

�，�Protected Index_Set As UInt32
�，�Protected Index_End As UInt32
�，�Protected Index_Count As UInt32

�，�Protected Search_Index_Set As UInt32
�，�Protected Search_Index_End As UInt32
�，�Protected Search_Set As CZ_INDEX_INFO
�，�Protected Search_Mid As CZ_INDEX_INFO
�，�Protected Search_End As CZ_INDEX_INFO

�，�Public Sub New()
�，，，�bFilePathInitialized = False
�，�End Sub

�，�Public Sub New(ByVal dbFilePath As String)
�，，，�bFilePathInitialized = False
�，，，�SetDbFilePath(dbFilePath)
�，�End Sub


�，�'使用二分法查找索引區(qū)，初始化查找區(qū)間
�，�Protected Sub Initialize()
�，，，�Search_Index_Set = 0
�，，，�Search_Index_End = Index_Count - 1
�，�End Sub

�，�'關(guān)閉文件
�，�Public Sub Dispose()
�，，，�If (bFilePathInitialized) Then
�，，，，，�bFilePathInitialized = False
�，，，，，�FileStrm.Close()
�，，，，，�FileStrm.Dispose()
�，，，�End If
�，�End Sub

�，�'設(shè)置純真IP數(shù)據(jù)庫(kù)的文件路徑
�，�Public Function SetDbFilePath(ByVal dbFilePath As String) As Boolean

�，，，�If (dbFilePath = "") Then
�，，，，，�Return False
�，，，�End If

�，，，�'Try
�，，，�'打開(kāi)數(shù)據(jù)文件

�，，，�FileStrm = New FileStream(dbFilePath, FileMode.Open, FileAccess.Read)
�，，，�'Catch
�，，，�'Return False
�，，，�'End Try

�，，，�'檢查文件長(zhǎng)度
�，，，�If (FileStrm.Length < 8) Then
�，，，，，�FileStrm.Close()
�，，，，，�FileStrm.Dispose()
�，，，，，�Return False
�，，，�End If

�，，，�'得到第一條索引的絕對(duì)偏移和最后一條索引的絕對(duì)偏移
�，，，�FileStrm.Seek(0, SeekOrigin.Begin)

�，，，�Index_Set = GetUInt32()
�，，，�Index_End = GetUInt32()

�，，，�'得到總索引條數(shù)
�，，，�Index_Count = (Index_End - Index_Set) / 7 + 1
�，，，�bFilePathInitialized = True

�，，，�Return True

�，�End Function

�，�'主接口函數(shù)，根據(jù)傳入的IP返回該IP的地址信息
�，�Public Function GetAddressWithIP(ByVal IPvalue As String) As String

�，，，�If Not bFilePathInitialized Then
�，，，，，�Return ""
�，，，�End If

�，，，�Initialize()

�，，，�'將IP轉(zhuǎn)化為數(shù)字
�，，，�Dim ip As UInt32 = IPToUInt32(IPvalue)

�，，，�While (True)

�，，，，，�'首先初始化本輪查找的區(qū)間

�，，，，，�'區(qū)間頭
�，，，，，�Search_Set = IndexInfoAtPos(Search_Index_Set)
�，，，，，�'區(qū)間尾
�，，，，，�Search_End = IndexInfoAtPos(Search_Index_End)

�，，，，，�'判斷IP是否在區(qū)間頭內(nèi)
�，，，，，�If (ip >= Search_Set.IpSet And ip <= Search_Set.IpEnd) Then
�，，，，，，，�Return ReadAddressInfoAtOffset(Search_Set.Offset)
�，，，，，�End If

�，，，，，�'判斷IP是否在區(qū)間尾內(nèi)
�，，，，，�If (ip >= Search_End.IpSet And ip <= Search_End.IpEnd) Then
�，，，，，，，�Return ReadAddressInfoAtOffset(Search_End.Offset)
�，，，，，�End If

�，，，，，�'計(jì)算出區(qū)間中點(diǎn)
�，，，，，�Search_Mid = IndexInfoAtPos((Search_Index_End + Search_Index_Set) / 2)

�，，，，，�'判斷IP是否在中點(diǎn)
�，，，，，�If (ip >= Search_Mid.IpSet And ip <= Search_Mid.IpEnd) Then
�，，，，，，，�Return ReadAddressInfoAtOffset(Search_Mid.Offset)
�，，，，，�End If

�，，，，，�'本輪沒(méi)有找到，準(zhǔn)備下一輪
�，，，，，�If (ip < Search_Mid.IpSet) Then
�，，，，，，，�'IP比區(qū)間中點(diǎn)要小，將區(qū)間尾設(shè)為現(xiàn)在的中點(diǎn)，將區(qū)間縮小1倍。
�，，，，，，，�Search_Index_End = (Search_Index_End + Search_Index_Set) / 2
�，，，，，�Else
�，，，，，，，�'IP比區(qū)間中點(diǎn)要大，將區(qū)間頭設(shè)為現(xiàn)在的中點(diǎn)，將區(qū)間縮小1倍。
�，，，，，，，�Search_Index_Set = (Search_Index_End + Search_Index_Set) / 2
�，，，，，�End If

�，，，�End While

�，，，�Return ""

�，�End Function

'讀取指定文件偏移位置的國(guó)家和地區(qū)信息
�，�Protected Function ReadAddressInfoAtOffset(ByVal Offset As UInt32) As String

�，，，�Dim country As String = ""
�，，，�Dim area As String = ""
�，，，�Dim country_Offset As UInt32 = 0
�，，，�Dim Tag As Byte = 0
�，，，�'跳過(guò)4字節(jié)，因這4個(gè)字節(jié)是該索引的IP區(qū)間上限。
�，，，�FileStrm.Seek(Offset + 4, SeekOrigin.Begin)

�，，，�'讀取一個(gè)字節(jié)，得到描述國(guó)家信息的“尋址方式”
�，，，�Tag = GetTag()

�，，，�If (Tag = &H1) Then

�，，，，，�'模式0x01，表示接下來(lái)的3個(gè)字節(jié)是表示偏移位置
�，，，，，�FileStrm.Seek(GetOffset(), SeekOrigin.Begin)

�，，，，，�'繼續(xù)檢查“尋址方式”
�，，，，，�Tag = GetTag()
�，，，，，�If (Tag = &H2) Then
�，，，，，，，�'模式0x02，表示接下來(lái)的3個(gè)字節(jié)代表國(guó)家信息的偏移位置
�，，，，，，，�'先將這個(gè)偏移位置保存起來(lái)，因?yàn)槲覀円�讀取它后面的地區(qū)信息。
�，，，，，，，�country_Offset = GetOffset()
�，，，，，，，�'讀取地區(qū)信息（注：按照Luma的說(shuō)明，好像沒(méi)有這么多種可能性，但在測(cè)試過(guò)程中好像有些情況沒(méi)有考慮到，
�，，，，，，，�'所以寫(xiě)了個(gè)ReadArea()來(lái)讀取。
�，，，，，，，�area = ReadArea()
�，，，，，，，�'讀取國(guó)家信息
�，，，，，，，�FileStrm.Seek(country_Offset, SeekOrigin.Begin)
�，，，，，，，�country = ReadString()

�，，，，，�Else
�，，，，，，，�'這種模式說(shuō)明接下來(lái)就是保存的國(guó)家和地區(qū)信息了，以'\0'代表結(jié)束。
�，，，，，，，�FileStrm.Seek(-1, SeekOrigin.Current)
�，，，，，，，�country = ReadString()
�，，，，，，，�area = ReadArea()

�，，，，，�End If

�，，，�ElseIf (Tag = &H2) Then
�，，，，，�'模式0x02，說(shuō)明國(guó)家信息是一個(gè)偏移位置
�，，，，，�country_Offset = GetOffset()
�，，，，，�'先讀取地區(qū)信息
�，，，，，�area = ReadArea()
�，，，，，�'讀取國(guó)家信息
�，，，，，�FileStrm.Seek(country_Offset, SeekOrigin.Begin)
�，，，，，�country = ReadString()

�，，，�Else
�，，，，，�'這種模式最簡(jiǎn)單了，直接讀取國(guó)家和地區(qū)就OK了
�，，，，，�FileStrm.Seek(-1, SeekOrigin.Current)
�，，，，，�country = ReadString()
�，，，，，�area = ReadArea()

�，，，�End If

�，，，�Return country + " " + area

�，�End Function

�，�'從當(dāng)前位置讀取一個(gè)字符串（國(guó)家或者地區(qū)信息）
�，�Protected Function ReadString() As String

�，，，�Dim Offset As UInt32 = 0
�，，，�Dim TempByteArray(256) As Byte
�，，，�TempByteArray(Offset) = FileStrm.ReadByte()
�，，，�While (TempByteArray(Offset) <> &H0)
�，，，，，�Offset += 1
�，，，，，�TempByteArray(Offset) = FileStrm.ReadByte()
�，，，�End While

�，，，�Return System.Text.Encoding.Default.GetString(TempByteArray)

�，�End Function

�，�'從當(dāng)前文件位置讀取地區(qū)信息
�，�Protected Function ReadArea() As String

�，，，�Dim Tag As Byte = GetTag()

�，，，�If (Tag = &H1 Or Tag = &H2) Then
�，，，，，�FileStrm.Seek(GetOffset(), SeekOrigin.Begin)
�，，，，，�Return ReadString()
�，，，�Else
�，，，，，�FileStrm.Seek(-1, SeekOrigin.Current)
�，，，，，�Return ReadString()
�，，，�End If

�，�End Function

�，�'從當(dāng)前文件位置讀取一個(gè)字節(jié)的標(biāo)識(shí)
�，�Protected Function GetTag() As Byte
�，，，�Return FileStrm.ReadByte()
�，�End Function

�，�'得到指定索引位置的信息（IP起始范圍）
�，�Protected Function IndexInfoAtPos(ByVal Index_Pos As Int32) As CZ_INDEX_INFO

�，，，�Dim Index_Info As New CZ_INDEX_INFO
�，，，�'根據(jù)索引編號(hào)計(jì)算出在文件中在偏移位置
�，，，�FileStrm.Seek(Index_Set + 7 * Index_Pos, SeekOrigin.Begin)
�，，，�Index_Info.IpSet = GetUInt32()
�，，，�Index_Info.Offset = GetOffset()
�，，，�FileStrm.Seek(Index_Info.Offset, SeekOrigin.Begin)
�，，，�Index_Info.IpEnd = GetUInt32()

�，，，�Return Index_Info

�，�End Function

�，�'讀取3個(gè)字節(jié)，得到偏移位置
�，�Protected Function GetOffset() As UInt32

�，，，�Dim TempByte4(4) As Byte
�，，，�TempByte4(0) = FileStrm.ReadByte()
�，，，�TempByte4(1) = FileStrm.ReadByte()
�，，，�TempByte4(2) = FileStrm.ReadByte()
�，，，�TempByte4(3) = 0
�，，，�Return BitConverter.ToUInt32(TempByte4, 0)

�，�End Function

�，�Protected Function GetUInt32() As UInt32

�，，，�Dim TempByte4(4) As Byte
�，，，�FileStrm.Read(TempByte4, 0, 4)
�，，，�Return BitConverter.ToUInt32(TempByte4, 0)

�，�End Function


�，�'將字符串的IP轉(zhuǎn)換成Int32
�，�Public Shared Function IPToUInt32(ByVal Ipvalue As String) As UInt32

�，，，�Dim IpByte() As String = Ipvalue.Split(".")
�，，，�Dim nUpperBound As Int32 = IpByte.GetUpperBound(0)
�，，，�If nUpperBound <> 3 Then
�，，，，，�ReDim Preserve IpByte(4)
�，，，，，�For i As Int32 = 1 To 3 - nUpperBound
�，，，，，，，�IpByte(nUpperBound + i) = "0"
�，，，，，�Next
�，，，�End If

�，，，�Dim TempByte4(4) As Byte
�，，，�For i As Int32 = 0 To 3
�，，，，，�'如果是.Net 2.0可以支持TryParse。
�，，，，，�'If Not (Byte.TryParse(IpByte(i), TempByte4(3 - i))) Then
�，，，，，�'�，�TempByte4(3 - i) = &H0
�，，，，，�'End If
�，，，，，�If (IsNumeric(IpByte(i))) Then
�，，，，，，，�TempByte4(3 - i) = CInt(IpByte(i)) And &HFF
�，，，，，�End If
�，，，�Next

�，，，�Return BitConverter.ToUInt32(TempByte4, 0)
�，，，�'System.Net.IPAddress.NetworkToHostOrder

�，�End Function

�，�'將Int32型的IP轉(zhuǎn)換成字符串
�，�Public Shared Function UInt32ToIP(ByVal UInt32value As UInt32) As String
�，，，�Return New System.Net.IPAddress(System.Net.IPAddress.HostToNetworkOrder(UInt32value)).ToString()
�，�End Function

End Class