Datatid 1999 #6/Datatid_1999-06.iso/internet/Tango352Promo/P.SQL/PTKPKG.1/BTR32VBFieldMap.bas

BASIC Source File | 1998-09-15 | 11.0 KB | 391 lines

Attribute VB_Name = "BTR32VBFieldMap"
'{*************************************************************************
'**
'**  Copyright 1998 Pervasive Software Inc. All Rights Reserved
'**
'*************************************************************************}
'{*************************************************************************
'**
'**  BTR32VBFieldMap.bas
'**
'**  This software is part of the Pervasive Software Developer Kit.
'**
'**  This source code is only intended as a supplement to the
'**  Pervasive.SQL documentation; see that documentation for detailed
'**  information regarding the use of Pervasive.SQL.
'**
'*************************************************************************}

Option Explicit

Declare Sub CopyMemory Lib "KERNEL32" Alias "RtlMoveMemory" (hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)

'**************************************************************************
'When compiling a 32-bit application, Visual Basic aligns members of a
'user-defined data type (UDT) on 8-, 16-, or 32-bit boundaries, depending
'on the size of that particular member. Unlike structures, database rows
'are packed, meaning there is no unused space between fields. Because there
'is no way to turn alignment off, there must be some method to pack and
'unpack structures so that Visual Basic applications can access a database.
'The Pervasive Btrieve Alignment DLL, or PAln32.DLL, is designed to handle
'this structure alignment issue.
'***************************************************************************

'**************************************************************************
'The Pervasive Btrieve Alignment library (PAln32.DLL) is provided in the
'Pervasive Software Developer's Kit. This library is used for packing aligned
'structures and unpacking database rows.
'**************************************************************************

'First, before the database can be accessed, there first must exist the
'required data structures needed to manipulate the data.
'Here we create structures to hold the data.

'**************************************************************************
'Person Position Block
'**************************************************************************

Public Type PosBlock
  buf(0 To 127) As Byte
End Type

'***************************************************************************
' Record type definitions for Version operation
'****************************************************************************

Public Type Version_BaseStruct
    version    As Integer
    revision   As Integer
    MKDEId     As String * 1
End Type

Public Type Version_Struct
    ver(0 To 2) As Version_BaseStruct
End Type


Public Type Client_ID
    networkandnode(0 To 11) As Byte
    applicationID(0 To 2)   As Byte
    threadID                As Integer
End Type

'***************************************************************************
'  Record type definitions for Stat and Create operations
'****************************************************************************

Public Type BtrFileSpec
    length     As Integer
    PageSize   As Integer
    NumIndexes As Integer
    Reserved   As Long
    FileFlags  As Integer
    NumDupPtr  As Byte
    NotUsed    As Byte
    Allocation As Integer
End Type

'***************************************************************************
'  Definition of record from 'sample.btr'
'****************************************************************************

Public Type PersonRecType
    ID          As Long
    FirstName   As String * 16
    LastName    As String * 26
    Street      As String * 31
    City        As String * 31
    State       As String * 3
    Zip         As String * 11
    Country     As String * 21
    Phone       As String * 14
 End Type

'***************************************************************************
'  Record type definitions for Get Next Extended operation
'****************************************************************************

Public Type GNE_HEADER
    descriptionLen  As Integer
    currencyConst   As String * 2
    rejectCount     As Integer
    numberTerms     As Integer
End Type

Public Type TERM_HEADER
    fieldType       As Byte
    fieldLen        As Integer
    fieldOffset     As Integer
    comparisonCode  As Byte
    connector       As Byte
    value           As String * 3
End Type

Public Type RETRIEVAL_HEADER
    maxRecsToRetrieve   As Integer
    noFieldsToRetrieve  As Integer
End Type

Public Type FIELD_RETRIEVAL_HEADER
    fieldLen    As Integer
    fieldOffset As Integer
End Type

Public Type PRE_GNE_BUFFER
    gneHeader As GNE_HEADER
    term1     As TERM_HEADER
    term2     As TERM_HEADER
    retrieval As RETRIEVAL_HEADER
    recordRet As FIELD_RETRIEVAL_HEADER
End Type

Public Type RETURNED_REC
    recLen        As Integer
    recPos        As Long
    personRecord  As PersonRecType
End Type

Public Type POST_GNE_BUFFER
    numReturned    As Integer
    recs(0 To 19)  As RETURNED_REC
End Type

'***************************************************************
' Define FieldMaps.  Create structure for holding file structure.
'***************************************************************

Global Version_StructMap(0 To 8) As FieldMap
Const Versionsize = 15

Global ClientIDFldMap(0 To 16) As FieldMap
Const ClientIDsize = 17

Global PersonFldMap(0 To 8) As FieldMap
Const PersonRowSize = 157

Global gneheaderMap(0 To 3) As FieldMap
Const gneheadersize = 8

Global termheaderMap(0 To 5) As FieldMap
Const termheadersize = 10

Global retrievalheaderMap(0 To 1) As FieldMap
Const retrievalheadersize = 4

Global fieldretrievalMap(0 To 1) As FieldMap
Const fieldretrievalsize = 4

Global pregnebufferMap(0 To 23) As FieldMap
Const pregnebuffersize = 36

Global returnrecMap(0 To 12) As FieldMap
Const returnrecsize = 163

Global Post_GNE_BUFFERFieldMap(0 To 281) As FieldMap
Const postgnebuffersize = 3262


'**************************************************************
'  Define FldMapTypes.  Create structures needed to store a packed
'  database row.
'**************************************************************

Public Type PersonRowType
    buf(1 To PersonRowSize) As Byte
End Type

Public Type VersionType
  buf(1 To Versionsize) As Byte
End Type

Public Type ClientIDType
  buf(1 To ClientIDsize) As Byte
End Type

Public Type gneheaderType
  buf(1 To gneheadersize) As Byte
End Type

Public Type termheaderType
   buf(1 To termheadersize) As Byte
End Type

Public Type retrievalheadertype
  buf(1 To retrievalheadersize) As Byte
End Type

Public Type fieldretrievaltype
  buf(1 To fieldretrievalsize) As Byte
End Type

Public Type pregnebuffertype
  buf(1 To pregnebuffersize) As Byte
End Type

Public Type returnrectype
  buf(1 To returnrecsize) As Byte
End Type

Public Type postgnebuffertype
  buf(1 To postgnebuffersize) As Byte
End Type

Public Const FLD_PAD32 = 42




'*******************************************************************
'Build FieldMaps.  Load the file structure into memory.
'*******************************************************************

Sub AddField(map() As FieldMap, ByRef ctr As Integer, dataType As Long, _
            length As Long)

  SetField map(ctr), dataType, length
  ctr = ctr + 1

End Sub


Sub AddgneHeaderFldMap(map() As FieldMap, ByRef ctr As Integer)

  AddField map, ctr, FLD_INTEGER, 2 ' descriptionLen
  AddField map, ctr, FLD_STRING, 2   ' currencyConst
  AddField map, ctr, FLD_INTEGER, 2 ' rejectCount
  AddField map, ctr, FLD_INTEGER, 2 ' numberTerms

End Sub


Sub AddTERM_HEADERFldMap(map() As FieldMap, ByRef ctr As Integer)

  AddField map, ctr, FLD_BYTE, 1    ' fieldType
  AddField map, ctr, FLD_INTEGER, 2 ' fieldLen
  AddField map, ctr, FLD_INTEGER, 2 ' fieldOffset
  AddField map, ctr, FLD_BYTE, 1    ' comparisonCode
  AddField map, ctr, FLD_BYTE, 1    ' connector
  AddField map, ctr, FLD_STRING, 3  ' value

End Sub


Sub AddPersonFieldMap(map() As FieldMap, ByRef ctr As Integer)

  AddField map, ctr, FLD_INTEGER, 4 'ID
  AddField map, ctr, FLD_STRING, 16 'FirstName
  AddField map, ctr, FLD_STRING, 26 'LastName
  AddField map, ctr, FLD_STRING, 31 'Street
  AddField map, ctr, FLD_STRING, 31 'City
  AddField map, ctr, FLD_STRING, 3  'State
  AddField map, ctr, FLD_STRING, 11 'Zip
  AddField map, ctr, FLD_STRING, 21 'Country
  AddField map, ctr, FLD_STRING, 14 'Phone

End Sub


Sub AddFieldMap(out() As FieldMap, ByRef ctr As Integer, nin() As FieldMap)
' Append a fieldmap to another
Dim fld As Integer

  For fld = LBound(nin) To UBound(nin)
    out(ctr) = nin(fld)
    ctr = ctr + 1
  Next fld

End Sub


Sub AddRETRIEVAL_HEADER(map() As FieldMap, ByRef ctr As Integer)

  AddField map, ctr, FLD_INTEGER, 2 ' maxRecsToRetrieve
  AddField map, ctr, FLD_INTEGER, 2 ' noFieldsToRetrieve

End Sub


Sub AddFIELD_RETRIEVAL_HEADER(map() As FieldMap, ByRef ctr As Integer)

  AddField map, ctr, FLD_INTEGER, 2 ' fieldLen
  AddField map, ctr, FLD_INTEGER, 2 ' fieldOffset

End Sub

Sub AddPreGNEBufferFldMap(map() As FieldMap, ByRef ctr As Integer)

  AddgneHeaderFldMap map, ctr         'gneHeader
  AddTERM_HEADERFldMap map, ctr       ' term1
  AddTERM_HEADERFldMap map, ctr       ' term2
  AddRETRIEVAL_HEADER map, ctr        ' retrieval
  AddFIELD_RETRIEVAL_HEADER map, ctr  ' recordRet

End Sub

Sub AddRETURNED_RECFldMap(map() As FieldMap, ByRef ctr As Integer)

  AddField map, ctr, FLD_INTEGER, 2  ' recLen
  AddField map, ctr, FLD_INTEGER, 4  ' recPos
  AddFieldMap map, ctr, PersonFldMap ' personRecord

End Sub


Sub AddPostGNEBufferFldMap(map() As FieldMap, ByRef ctr As Integer)

Dim fld As Integer

  AddField map, ctr, FLD_INTEGER, 2   ' numReturned

  For fld = 0 To 19
    AddField map, ctr, FLD_PAD32, 0
    AddRETURNED_RECFldMap map, ctr    ' recs
  Next fld

End Sub


Sub AddVersionBufferFldMap(map() As FieldMap, ByRef ctr As Integer)
Dim fld As Integer

  For fld = 0 To 2
    AddField map, ctr, FLD_INTEGER, 2 ' version
    AddField map, ctr, FLD_INTEGER, 2 ' revision
    AddField map, ctr, FLD_STRING, 1  'MKDEId
  Next fld

End Sub

Sub AddClientIDBufferFldMap(map() As FieldMap, ByRef ctr As Integer)
Dim fld As Integer

  For fld = 0 To 11
     AddField map, ctr, FLD_BYTE, 1 'networkandnode
  Next fld

  For fld = 0 To 2
    AddField map, ctr, FLD_BYTE, 1  'applicationID
  Next fld

  AddField map, ctr, FLD_INTEGER, 2 'threadID

End Sub


Sub InitFieldMaps()
'Initialize FieldMaps

  AddPersonFieldMap PersonFldMap, 0
  AddgneHeaderFldMap gneheaderMap, 0
  AddTERM_HEADERFldMap termheaderMap, 0
  AddFIELD_RETRIEVAL_HEADER fieldretrievalMap, 0
  AddRETRIEVAL_HEADER retrievalheaderMap, 0
  AddRETURNED_RECFldMap returnrecMap, 0
  AddPreGNEBufferFldMap pregnebufferMap, 0
  AddPostGNEBufferFldMap Post_GNE_BUFFERFieldMap, 0
  AddVersionBufferFldMap Version_StructMap, 0
  AddClientIDBufferFldMap ClientIDFldMap, 0

End Sub