Here it is again... It only needs 20 loops to get 99% compression.
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Declare Function compress_loop( chrs as string ) as string
Declare Function decompress_loop( chrs as string ) as string
Namespace Zlibrary
#inclib "zlib"
Extern "C"
Declare Function compressBound(Byval sourceLen As Ulong) As Ulong
Declare Function uncompress(Byval dest As Ubyte Ptr, Byval destLen As Uinteger Ptr, Byval source As Ubyte Ptr, Byval sourceLen As Ulong) As Long
Declare Function compress(Byval dest As Ubyte Ptr, Byval destLen As Uinteger Ptr, Byval source As Ubyte Ptr, Byval sourceLen As Ulong) As Long
End Extern
Function getpassedinfo(text As String,Byref passed_length As Integer) As String
Dim As String var1,var2
Dim As Integer pst
#macro splice(stri,char,var1,var2)
pst=Instr(stri,char)
var1="":var2=""
If pst<>0 Then
var1=Mid(stri,1,pst-1)
var2=Mid(stri,pst+1)
Else
var1=stri
End If
#endmacro
splice(text,"|",var1,var2)
text=var2
passed_length=Valint(var1)
Return text
End Function
'================= UNPACK ===============
Function unpack(file As String) As String
Dim As Integer passed_length
Dim As String text=getpassedinfo(file,passed_length)
Dim As Integer stringlength,destinationlength
stringlength=Len(text)
destinationlength =passed_length
Dim As Ubyte Ptr source
Dim As Ubyte Ptr destination =Callocate(destinationlength,1)
source=@text[0]
Var mistake=uncompress(destination,@destinationlength, source, stringlength)
If mistake<>0 Then Print "There was an error":Sleep:End
Dim As String uncompressed
uncompressed=String(destinationlength,0)
For i As Integer = 0 To destinationlength- 1
uncompressed[i]=(destination[i])
Next
Deallocate destination
Return uncompressed
End Function
'=================== PACK ============
Function pack(file As String) As String
Dim As String text=file
Dim As Integer stringlength,destinationlength
stringlength=Len(text)
destinationlength = compressBound(stringlength)
Dim As Ubyte Ptr source
Dim As Ubyte Ptr destination =Callocate(destinationlength,1)
source=@text[0]
Var mistake=compress(destination, @destinationlength, source, stringlength)
If mistake <>0 Then Print "There was an error"
Dim As String compressed
compressed=String(destinationlength,0)
For n As Integer=0 To destinationlength-1
compressed[n]=destination[n]
Next n
compressed=stringlength &"|"+compressed
Deallocate destination
Return compressed
End Function
End Namespace
'==================================================================
'==================================================================
'test zipper
'==================================================================
'==================================================================
screen 19
Dim Shared As String s
Randomize
s=""
dim as string check=""
dim as string compare=""
dim as longint length = 0
dim as double compression = 0
dim as longint loops = 0
dim as double time1 , time2
time1 = timer
do
loops+=1
'one time run , create initial string
if loops = 1 then
For n As Long = 1 To 100000
s+=chr(Int(Rnd*256))'+48
Next
compare = s
length = len(s)
else
'modify compression to make further compression possible
s = compress_loop(s)
end if
check = s
compression = (100 - ( 100 / ( length / len(check) ) ))
Print "original string"
Print Len(s)
Print
Dim As String compressed=Zlibrary.pack(s)
s = compressed
Print "packed string "
Print Len(compressed)
Print
Dim As String uncompressed=Zlibrary.unpack(compressed)
Print "Retrieve"
Print Len(uncompressed)
Print
'Print "compression ratio "; 100 - ( 100 / ( Len(s) / len(compressed) ) ) ; "%"
Print "compression ratio "; 100 - ( 100 / ( length / len(s) ) ) ; "%"
Print Iif(uncompressed=check,"OK","ERROR")
Print "-------------------------------"
'sleep 1000
'if loops > 2 and (100 - ( 100 / ( length / len(s) ) )) < compression then exit do
print "press a key for next compression." ; " loops = " ; loops ; " out of 20."
print
print "press esc to exit."
'sleep
if inkey = chr(27) then exit do
loop until loops = 20
time2 = timer
print
print "Compress time = " ; time2 - time1
print
print "Press a key to decompress."
sleep
s = str(loops) + "_" + s ' save as an output file...
'==================================================================
'decompress
'==================================================================
dim as longint dec = instr(1,s,"_")
dim as longint count = val(left(s,dec-1))
dim as string comp = mid(s,dec+1)
dim as string val1
dim as string outs
for a as longint = count to 2 step -1
s = Zlibrary.unpack(comp)
outs = decompress_loop(s)
comp = outs
next
comp = Zlibrary.unpack(comp)
print
print "input = "; length , "output = " ; len(comp) , "compression ratio "; 100 - ( 100 / ( length / len(s) ) ) ; "%"
print
if comp = compare then print "Decompression successful." else print "ERROR"
print
print
Print "!!~~Done~~!!"
Sleep
end
'===============================================================================
'============================,===================================================
'begin functions
'===============================================================================
'================='==============================================================
Function compress_loop( chrs as string ) as string
print "c inp = " ; len(chrs)
'CONVERT INPUT TO 8 BIT BINARY
dim as string bits = ""
dim as string zeros = string( 8 , "0" )
dim as string n1
dim as ubyte ptr ubp = cptr( ubyte ptr , strptr( chrs ) )
for a as longint = 1 to len( chrs ) step 1
n1 = zeros + bin( *ubp ) : ubp+= 1
n1 = right( n1 , 8 )
bits+=n1
next
print "c bin = " ; len( bits ) ', bits
'STEP THROUGH BINARY BY 6'S AND BUILD OUTPUT
'FOR SOME REASON STEPPING BY 6'S , COMPRESSES MORE THAN STEPPING BY 8'S
dim as string outs = ""
dim as longint sum0
dim as longint sum1
for a as longint = 1 to len( bits ) step 2
n1 = mid( bits , a , 2 )
'SUM 1'S AND 0'S
sum0 = 0
sum1 = 0
for b as longint = 1 to len( n1 ) step 1
if n1[ b - 1 ] = 48 then sum0+= ( 1 shl ( len( n1 ) - b ) )
if n1[ b - 1 ] = 49 then sum1+= ( 1 shl ( len( n1 ) - b ) )
next
sum1+=1
'DECIDE WHICH SUM IS LOWER AND PUT THAT CHR() INTO THE OUTPUT
if sum0 < sum1 then outs+= chr( sum0 )
if sum1 < sum0 then outs+= chr( 3 + sum1 )
'UN COMMENT TO SEE IF VALUES EQUAL OKAY.
'print n1 , val( "&B" + n1 ) , sum0 , sum1
'sleep
'if inkey = " " then end
next
print "c out = " ; len( outs ) ', outs
'CREATE OUTPUT
dim as string final = outs
'for a as longint = 1 to len( outs ) step 8
' final+= chr( val( "&B" + mid( outs , a , 8 ) ) )
'next
print "c fin = " ; len(final)
return final
end function
'===============================================================================
'============================================================================
Function decompress_loop( chrs as string ) as string
print "d inp = " ; len(chrs)
return chrs
end function