ceph/src/boost/libs/beast/test/extern/zlib-1.2.11/old/visual-basic.txt

   1 See below some functions declarations for Visual Basic.
   2
   3 Frequently Asked Question:
   4
   5 Q: Each time I use the compress function I get the -5 error (not enough
   6    room in the output buffer).
   7
   8 A: Make sure that the length of the compressed buffer is passed by
   9    reference ("as any"), not by value ("as long"). Also check that
  10    before the call of compress this length is equal to the total size of
  11    the compressed buffer and not zero.
  12
  13
  14 From: "Jon Caruana" <jon-net@usa.net>
  15 Subject: Re: How to port zlib declares to vb?
  16 Date: Mon, 28 Oct 1996 18:33:03 -0600
  17
  18 Got the answer! (I haven't had time to check this but it's what I got, and
  19 looks correct):
  20
  21 He has the following routines working:
  22         compress
  23         uncompress
  24         gzopen
  25         gzwrite
  26         gzread
  27         gzclose
  28
  29 Declares follow: (Quoted from Carlos Rios <c_rios@sonda.cl>, in Vb4 form)
  30
  31 #If Win16 Then   'Use Win16 calls.
  32 Declare Function compress Lib "ZLIB.DLL" (ByVal compr As
  33         String, comprLen As Any, ByVal buf As String, ByVal buflen
  34         As Long) As Integer
  35 Declare Function uncompress Lib "ZLIB.DLL" (ByVal uncompr
  36         As String, uncomprLen As Any, ByVal compr As String, ByVal
  37         lcompr As Long) As Integer
  38 Declare Function gzopen Lib "ZLIB.DLL" (ByVal filePath As
  39         String, ByVal mode As String) As Long
  40 Declare Function gzread Lib "ZLIB.DLL" (ByVal file As
  41         Long, ByVal uncompr As String, ByVal uncomprLen As Integer)
  42         As Integer
  43 Declare Function gzwrite Lib "ZLIB.DLL" (ByVal file As
  44         Long, ByVal uncompr As String, ByVal uncomprLen As Integer)
  45         As Integer
  46 Declare Function gzclose Lib "ZLIB.DLL" (ByVal file As
  47         Long) As Integer
  48 #Else
  49 Declare Function compress Lib "ZLIB32.DLL"
  50         (ByVal compr As String, comprLen As Any, ByVal buf As
  51         String, ByVal buflen As Long) As Integer
  52 Declare Function uncompress Lib "ZLIB32.DLL"
  53         (ByVal uncompr As String, uncomprLen As Any, ByVal compr As
  54         String, ByVal lcompr As Long) As Long
  55 Declare Function gzopen Lib "ZLIB32.DLL"
  56         (ByVal file As String, ByVal mode As String) As Long
  57 Declare Function gzread Lib "ZLIB32.DLL"
  58         (ByVal file As Long, ByVal uncompr As String, ByVal
  59         uncomprLen As Long) As Long
  60 Declare Function gzwrite Lib "ZLIB32.DLL"
  61         (ByVal file As Long, ByVal uncompr As String, ByVal
  62         uncomprLen As Long) As Long
  63 Declare Function gzclose Lib "ZLIB32.DLL"
  64         (ByVal file As Long) As Long
  65 #End If
  66
  67 -Jon Caruana
  68 jon-net@usa.net
  69 Microsoft Sitebuilder Network Level 1 Member - HTML Writer's Guild Member
  70
  71
  72 Here is another example from Michael <michael_borgsys@hotmail.com> that he
  73 says conforms to the VB guidelines, and that solves the problem of not
  74 knowing the uncompressed size by storing it at the end of the file:
  75
  76 'Calling the functions:
  77 'bracket meaning: <parameter> [optional] {Range of possible values}
  78 'Call subCompressFile(<path with filename to compress> [, <path with
  79 filename to write to>, [level of compression {1..9}]])
  80 'Call subUncompressFile(<path with filename to compress>)
  81
  82 Option Explicit
  83 Private lngpvtPcnSml As Long 'Stores value for 'lngPercentSmaller'
  84 Private Const SUCCESS As Long = 0
  85 Private Const strFilExt As String = ".cpr"
  86 Private Declare Function lngfncCpr Lib "zlib.dll" Alias "compress2" (ByRef
  87 dest As Any, ByRef destLen As Any, ByRef src As Any, ByVal srcLen As Long,
  88 ByVal level As Integer) As Long
  89 Private Declare Function lngfncUcp Lib "zlib.dll" Alias "uncompress" (ByRef
  90 dest As Any, ByRef destLen As Any, ByRef src As Any, ByVal srcLen As Long)
  91 As Long
  92
  93 Public Sub subCompressFile(ByVal strargOriFilPth As String, Optional ByVal
  94 strargCprFilPth As String, Optional ByVal intLvl As Integer = 9)
  95     Dim strCprPth As String
  96     Dim lngOriSiz As Long
  97     Dim lngCprSiz As Long
  98     Dim bytaryOri() As Byte
  99     Dim bytaryCpr() As Byte
 100     lngOriSiz = FileLen(strargOriFilPth)
 101     ReDim bytaryOri(lngOriSiz - 1)
 102     Open strargOriFilPth For Binary Access Read As #1
 103         Get #1, , bytaryOri()
 104     Close #1
 105     strCprPth = IIf(strargCprFilPth = "", strargOriFilPth, strargCprFilPth)
 106 'Select file path and name
 107     strCprPth = strCprPth & IIf(Right(strCprPth, Len(strFilExt)) =
 108 strFilExt, "", strFilExt) 'Add file extension if not exists
 109     lngCprSiz = (lngOriSiz * 1.01) + 12 'Compression needs temporary a bit
 110 more space then original file size
 111     ReDim bytaryCpr(lngCprSiz - 1)
 112     If lngfncCpr(bytaryCpr(0), lngCprSiz, bytaryOri(0), lngOriSiz, intLvl) =
 113 SUCCESS Then
 114         lngpvtPcnSml = (1# - (lngCprSiz / lngOriSiz)) * 100
 115         ReDim Preserve bytaryCpr(lngCprSiz - 1)
 116         Open strCprPth For Binary Access Write As #1
 117             Put #1, , bytaryCpr()
 118             Put #1, , lngOriSiz 'Add the the original size value to the end
 119 (last 4 bytes)
 120         Close #1
 121     Else
 122         MsgBox "Compression error"
 123     End If
 124     Erase bytaryCpr
 125     Erase bytaryOri
 126 End Sub
 127
 128 Public Sub subUncompressFile(ByVal strargFilPth As String)
 129     Dim bytaryCpr() As Byte
 130     Dim bytaryOri() As Byte
 131     Dim lngOriSiz As Long
 132     Dim lngCprSiz As Long
 133     Dim strOriPth As String
 134     lngCprSiz = FileLen(strargFilPth)
 135     ReDim bytaryCpr(lngCprSiz - 1)
 136     Open strargFilPth For Binary Access Read As #1
 137         Get #1, , bytaryCpr()
 138     Close #1
 139     'Read the original file size value:
 140     lngOriSiz = bytaryCpr(lngCprSiz - 1) * (2 ^ 24) _
 141               + bytaryCpr(lngCprSiz - 2) * (2 ^ 16) _
 142               + bytaryCpr(lngCprSiz - 3) * (2 ^ 8) _
 143               + bytaryCpr(lngCprSiz - 4)
 144     ReDim Preserve bytaryCpr(lngCprSiz - 5) 'Cut of the original size value
 145     ReDim bytaryOri(lngOriSiz - 1)
 146     If lngfncUcp(bytaryOri(0), lngOriSiz, bytaryCpr(0), lngCprSiz) = SUCCESS
 147 Then
 148         strOriPth = Left(strargFilPth, Len(strargFilPth) - Len(strFilExt))
 149         Open strOriPth For Binary Access Write As #1
 150             Put #1, , bytaryOri()
 151         Close #1
 152     Else
 153         MsgBox "Uncompression error"
 154     End If
 155     Erase bytaryCpr
 156     Erase bytaryOri
 157 End Sub
 158 Public Property Get lngPercentSmaller() As Long
 159     lngPercentSmaller = lngpvtPcnSml
 160 End Property