stardard vs zLib

[melquaides]

Hi<br>
<br>
Can anyone explain why the below results are soooo similar in terms of
size, time, etc??<br>
<br>
<span style="font-weight: bold;">Method one:</span><br>
<br>
Comprees:<br>
  aZip := TVCLZip.Create(nil);<br>
  try<br>
    aMemStrm.LoadFromFile(ZipFN.FileName);<br>
    aMemStrm.Position := 0;<br>
<br>
    aZip.DoProcessMessages := False;<br>
    aZip.ArchiveStream := TMemoryStream.Create;<br>
<br>
    aZip.PackLevel := RxSpinEdit1.AsInteger; // 6 or 9
...<br>
<br>
    aDTStart := cdTickCount;<br>
    aZip.ZipFromStream(aMemStrm, 'jon');<br>
    aTotSecs := cdTickTime(aDTStart, cdTickCount);<br>
<br>
DeCompress:<br>
  aMemS4trm := TMemoryStream.Create;<br>
  aZip := TVCLZip.Create(nil);<br>
  try<br>
    aZip.DoProcessMessages := False;<br>
<br>
    aMemS4trm.LoadFromFile(UnZipFN.FileName);<br>
    aMemS4trm.Position := 0;<br>
<br>
    aZip.ArchiveStream := TMemoryStream.Create;<br>
    aZip.ArchiveStream.CopyFrom(aMemS4trm,
aMemS4trm.Size);<br>
<br>
    aMemS4trm.Position := 0;<br>
    aDTStart := cdTickCount;<br>
    aZip.UnZipToStream(aMemS4trm, 'jon');<br>
    aTotSecs := cdTickTime(aDTStart, cdTickCount);<br>
<br>
<span style="font-weight: bold;">Method 2:</span><br>
Compress:<br>
<br>
  aMemStrm := TMemoryStream.Create;<br>
  aStrmMem := TMemoryStream.Create;<br>
  aZip := TVCLZip.Create(nil);<br>
  try<br>
    aMemStrm.LoadFromFile(ZipFN.FileName);<br>
    aMemStrm.Position := 0;<br>
<br>
    aZip.DoProcessMessages := False;<br>
<br>
    aZip.PackLevel := RxSpinEdit1.AsInteger;<br>
<br>
    aDTStart := cdTickCount;<br>
    aZip.ZLibCompressStream(aMemStrm, aStrmMem);<br>
    aTotSecs := cdTickTime(aDTStart, cdTickCount);<br>
<br>
DeCompress::<br>
  aStrmMem := TMemoryStream.Create;<br>
  aMemS4trm := TMemoryStream.Create;<br>
  aZip := TVCLZip.Create(nil);<br>
  try<br>
    aZip.DoProcessMessages := False;<br>
<br>
    aMemS4trm.LoadFromFile(UnZipFN.FileName);<br>
    aMemS4trm.Position := 0;<br>
<br>
    aDTStart := cdTickCount;<br>
    aZip.ZLibDecompressStream(aMemS4trm, aStrmMem);<br>
    aTotSecs := cdTickTime(aDTStart, cdTickCount);<br>
<br>
<span style="font-weight: bold;">Results:</span><br>
<table x:str="" style="border-collapse: collapse; width: 598pt;"
border="0" cellpadding="0" cellspacing="0" width="795">
<col style="width: 107pt;" width="142"> <col style="width: 70pt;"
width="93"> <col style="width: 83pt;" width="111"> <col
style="width: 86pt;" width="115"> <col style="width: 86pt;"
width="114"> <col style="width: 80pt;" width="106"> <col
style="width: 86pt;" width="114"> <tbody>
<tr style="height: 51pt;" height="68">
<td class="xl26" style="height: 51pt; width: 107pt;" height="68"
width="142">File Type</td>
<td class="xl26" style="width: 70pt;" width="93">Compression
Method</td>
<td class="xl28" style="width: 83pt;" width="111">Orig File size
(kb)</td>
<td class="xl26" style="width: 86pt;" width="115">PackLevel<br>
</td>
<td class="xl31" style="width: 86pt;" width="114">Time to
Compress [secs]</td>
<td class="xl29" style="width: 80pt;" width="106">Compressed File
Size [kb]</td>
<td class="xl31" style="width: 86pt;" width="114">Time to
Uncompress [secs]</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142">10Mb Txt File</td>
<td class="xl25" style="width: 70pt;" width="93">Method 1</td>
<td class="xl29" style="width: 83pt;" x:num="10597" width="111">10,597</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">6</td>
<td class="xl32" style="width: 86pt;" x:num="" width="114">0.750</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">205</td>
<td class="xl32" style="width: 86pt;" x:num="3.109" width="114">3.109</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl26" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl24" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">9</td>
<td class="xl32" style="width: 86pt;" x:num="0.84299999999999997"
width="114">0.843</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">192</td>
<td class="xl32" style="width: 86pt;" x:num="3.234" width="114">3.234</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl30" style="width: 70pt;" width="93">Method 2</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">6</td>
<td class="xl32" style="width: 86pt;" x:num="0.64100000000000001"
width="114">0.641</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">204</td>
<td class="xl32" style="width: 86pt;" x:num="3.1869999999999998"
width="114">3.187</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">9</td>
<td class="xl32" style="width: 86pt;" x:num="0.73399999999999999"
width="114">0.734</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">192</td>
<td class="xl32" style="width: 86pt;" x:num="3.0310000000000001"
width="114">3.031</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142">MetaFile image</td>
<td class="xl25" style="width: 70pt;" width="93">Method 1</td>
<td class="xl29" style="width: 83pt;" x:num="1795" width="111">1,795</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">6</td>
<td class="xl32" style="width: 86pt;" x:num="" width="114">0.360</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">918</td>
<td class="xl32" style="width: 86pt;" x:num="0.125" width="114">0.125</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl25" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">9</td>
<td class="xl32" style="width: 86pt;" x:num="" width="114">0.680</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">917</td>
<td class="xl32" style="width: 86pt;" x:num="0.125" width="114">0.125</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl27" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl30" style="width: 70pt;" width="93">Method 2</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">6</td>
<td class="xl32" style="width: 86pt;" x:num="0.375" width="114">0.375</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">918</td>
<td class="xl32" style="width: 86pt;" x:num="0.125" width="114">0.125</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">9</td>
<td class="xl32" style="width: 86pt;" x:num="0.70399999999999996"
width="114">0.704</td>
<td class="xl29" style="width: 80pt;" x:num="" width="106">917</td>
<td class="xl32" style="width: 86pt;" x:num="0.125" width="114">0.125</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142">685K row CSV</td>
<td class="xl25" style="width: 70pt;" width="93">Method 1</td>
<td class="xl29" style="width: 83pt;" x:num="21815" width="111">21,815</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">6</td>
<td class="xl32" style="width: 86pt;" x:num="4.2190000000000003"
width="114">4.219</td>
<td class="xl29" style="width: 80pt;" x:num="6803" width="106">6,803</td>
<td class="xl32" style="width: 86pt;" x:num="12.297000000000001"
width="114">12.297</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">9</td>
<td class="xl32" style="width: 86pt;" x:num="16.625" width="114">16.625</td>
<td class="xl29" style="width: 80pt;" x:num="6749" width="106">6,749</td>
<td class="xl32" style="width: 86pt;" x:num="12.343" width="114">12.343</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 12.75pt;" height="17">
<td class="xl27" style="height: 12.75pt; width: 107pt;"
height="17" width="142"><br>
</td>
<td class="xl30" style="width: 70pt;" width="93">Method 2</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" width="115"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
<td class="xl29" style="width: 80pt;" width="106"><br>
</td>
<td class="xl32" style="width: 86pt;" width="114"><br>
</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">6</td>
<td class="xl32" style="width: 86pt;" x:num="4.8129999999999997"
width="114">4.813</td>
<td class="xl29" style="width: 80pt;" x:num="6803" width="106">6,803</td>
<td class="xl32" style="width: 86pt;" x:num="16.109000000000002"
width="114">16.109</td>
</tr>
<tr style="height: 13.5pt;" height="18">
<td class="xl27" style="height: 13.5pt; width: 107pt;" height="18"
width="142"><br>
</td>
<td class="xl25" style="width: 70pt;" width="93"><br>
</td>
<td class="xl29" style="width: 83pt;" width="111"><br>
</td>
<td class="xl24" style="width: 86pt;" x:num="" width="115">9</td>
<td class="xl32" style="width: 86pt;" x:num="17.515999999999998"
width="114">17.516</td>
<td class="xl29" style="width: 80pt;" x:num="6749" width="106">6,749</td>
<td class="xl32" style="width: 86pt;" x:num="16.295999999999999"
width="114">16.296</td>
</tr>
</tbody>
</table>
<br>
Cheers<br>
<br>
Jon<br>