--- /dev/null
+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
git.samba.org / samba.git / blobdiff