diff options
Diffstat (limited to 'cpukit/zlib/old/visual-basic.txt')
| -rw-r--r-- | cpukit/zlib/old/visual-basic.txt | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/cpukit/zlib/old/visual-basic.txt b/cpukit/zlib/old/visual-basic.txt new file mode 100644 index 0000000000..57efe58124 --- /dev/null +++ b/cpukit/zlib/old/visual-basic.txt @@ -0,0 +1,160 @@ +See below some functions declarations for Visual Basic. + +Frequently Asked Question: + +Q: Each time I use the compress function I get the -5 error (not enough + room in the output buffer). + +A: Make sure that the length of the compressed buffer is passed by + reference ("as any"), not by value ("as long"). Also check that + before the call of compress this length is equal to the total size of + the compressed buffer and not zero. + + +From: "Jon Caruana" <jon-net@usa.net> +Subject: Re: How to port zlib declares to vb? +Date: Mon, 28 Oct 1996 18:33:03 -0600 + +Got the answer! (I haven't had time to check this but it's what I got, and +looks correct): + +He has the following routines working: + compress + uncompress + gzopen + gzwrite + gzread + gzclose + +Declares follow: (Quoted from Carlos Rios <c_rios@sonda.cl>, in Vb4 form) + +#If Win16 Then 'Use Win16 calls. +Declare Function compress Lib "ZLIB.DLL" (ByVal compr As + String, comprLen As Any, ByVal buf As String, ByVal buflen + As Long) As Integer +Declare Function uncompress Lib "ZLIB.DLL" (ByVal uncompr + As String, uncomprLen As Any, ByVal compr As String, ByVal + lcompr As Long) As Integer +Declare Function gzopen Lib "ZLIB.DLL" (ByVal filePath As + String, ByVal mode As String) As Long +Declare Function gzread Lib "ZLIB.DLL" (ByVal file As + Long, ByVal uncompr As String, ByVal uncomprLen As Integer) + As Integer +Declare Function gzwrite Lib "ZLIB.DLL" (ByVal file As + Long, ByVal uncompr As String, ByVal uncomprLen As Integer) + As Integer +Declare Function gzclose Lib "ZLIB.DLL" (ByVal file As + Long) As Integer +#Else +Declare Function compress Lib "ZLIB32.DLL" + (ByVal compr As String, comprLen As Any, ByVal buf As + String, ByVal buflen As Long) As Integer +Declare Function uncompress Lib "ZLIB32.DLL" + (ByVal uncompr As String, uncomprLen As Any, ByVal compr As + String, ByVal lcompr As Long) As Long +Declare Function gzopen Lib "ZLIB32.DLL" + (ByVal file As String, ByVal mode As String) As Long +Declare Function gzread Lib "ZLIB32.DLL" + (ByVal file As Long, ByVal uncompr As String, ByVal + uncomprLen As Long) As Long +Declare Function gzwrite Lib "ZLIB32.DLL" + (ByVal file As Long, ByVal uncompr As String, ByVal + uncomprLen As Long) As Long +Declare Function gzclose Lib "ZLIB32.DLL" + (ByVal file As Long) As Long +#End If + +-Jon Caruana +jon-net@usa.net +Microsoft Sitebuilder Network Level 1 Member - HTML Writer's Guild Member + + +Here is another example from Michael <michael_borgsys@hotmail.com> that he +says conforms to the VB guidelines, and that solves the problem of not +knowing the uncompressed size by storing it at the end of the file: + +'Calling the functions: +'bracket meaning: <parameter> [optional] {Range of possible values} +'Call subCompressFile(<path with filename to compress> [, <path with +filename to write to>, [level of compression {1..9}]]) +'Call subUncompressFile(<path with filename to compress>) + +Option Explicit +Private lngpvtPcnSml As Long 'Stores value for 'lngPercentSmaller' +Private Const SUCCESS As Long = 0 +Private Const strFilExt As String = ".cpr" +Private Declare Function lngfncCpr Lib "zlib.dll" Alias "compress2" (ByRef +dest As Any, ByRef destLen As Any, ByRef src As Any, ByVal srcLen As Long, +ByVal level As Integer) As Long +Private Declare Function lngfncUcp Lib "zlib.dll" Alias "uncompress" (ByRef +dest As Any, ByRef destLen As Any, ByRef src As Any, ByVal srcLen As Long) +As Long + +Public Sub subCompressFile(ByVal strargOriFilPth As String, Optional ByVal +strargCprFilPth As String, Optional ByVal intLvl As Integer = 9) + Dim strCprPth As String + Dim lngOriSiz As Long + Dim lngCprSiz As Long + Dim bytaryOri() As Byte + Dim bytaryCpr() As Byte + lngOriSiz = FileLen(strargOriFilPth) + ReDim bytaryOri(lngOriSiz - 1) + Open strargOriFilPth For Binary Access Read As #1 + Get #1, , bytaryOri() + Close #1 + strCprPth = IIf(strargCprFilPth = "", strargOriFilPth, strargCprFilPth) +'Select file path and name + strCprPth = strCprPth & IIf(Right(strCprPth, Len(strFilExt)) = +strFilExt, "", strFilExt) 'Add file extension if not exists + lngCprSiz = (lngOriSiz * 1.01) + 12 'Compression needs temporary a bit +more space then original file size + ReDim bytaryCpr(lngCprSiz - 1) + If lngfncCpr(bytaryCpr(0), lngCprSiz, bytaryOri(0), lngOriSiz, intLvl) = +SUCCESS Then + lngpvtPcnSml = (1# - (lngCprSiz / lngOriSiz)) * 100 + ReDim Preserve bytaryCpr(lngCprSiz - 1) + Open strCprPth For Binary Access Write As #1 + Put #1, , bytaryCpr() + Put #1, , lngOriSiz 'Add the the original size value to the end +(last 4 bytes) + Close #1 + Else + MsgBox "Compression error" + End If + Erase bytaryCpr + Erase bytaryOri +End Sub + +Public Sub subUncompressFile(ByVal strargFilPth As String) + Dim bytaryCpr() As Byte + Dim bytaryOri() As Byte + Dim lngOriSiz As Long + Dim lngCprSiz As Long + Dim strOriPth As String + lngCprSiz = FileLen(strargFilPth) + ReDim bytaryCpr(lngCprSiz - 1) + Open strargFilPth For Binary Access Read As #1 + Get #1, , bytaryCpr() + Close #1 + 'Read the original file size value: + lngOriSiz = bytaryCpr(lngCprSiz - 1) * (2 ^ 24) _ + + bytaryCpr(lngCprSiz - 2) * (2 ^ 16) _ + + bytaryCpr(lngCprSiz - 3) * (2 ^ 8) _ + + bytaryCpr(lngCprSiz - 4) + ReDim Preserve bytaryCpr(lngCprSiz - 5) 'Cut of the original size value + ReDim bytaryOri(lngOriSiz - 1) + If lngfncUcp(bytaryOri(0), lngOriSiz, bytaryCpr(0), lngCprSiz) = SUCCESS +Then + strOriPth = Left(strargFilPth, Len(strargFilPth) - Len(strFilExt)) + Open strOriPth For Binary Access Write As #1 + Put #1, , bytaryOri() + Close #1 + Else + MsgBox "Uncompression error" + End If + Erase bytaryCpr + Erase bytaryOri +End Sub +Public Property Get lngPercentSmaller() As Long + lngPercentSmaller = lngpvtPcnSml +End Property |