How to speed up the unzip action on windows phone 7? - windows-phone-7

Question

When I used the SharpZipLib to unzip a zip file which has 5000 files on the windows phone 7. It took more than 5 minutes to finish it.
Here is the code:
using (StreamReader httpwebStreamReader = new StreamReader(ea.Result))
{
//open isolated storage to save files
using (IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication())
{
using (ZipInputStream s = new ZipInputStream(httpwebStreamReader.BaseStream))
{
//s.Password = "123456";//if archive is encrypted
ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string directoryName = Path.GetDirectoryName(theEntry.Name);
string fileName = Path.GetFileName(theEntry.Name);
// create directory
if (directoryName.Length > 0)
{
isoStore.CreateDirectory(directoryName);
}
if (fileName != String.Empty)
{
//save file to isolated storage
using (BinaryWriter streamWriter =
new BinaryWriter(new IsolatedStorageFileStream(theEntry.Name,
FileMode.OpenOrCreate, FileAccess.Write, FileShare.Write, isoStore)))
{
int size = 2048;
byte[] data = new byte[2048];
while (true)
{
size = s.Read(data, 0, data.Length);
if (size > 0)
{
streamWriter.Write(data, 0, size);
}
else
{
break;
}
}
}
}
}
}
}
}
Why it's so slow?
How can I speed up the unzip action?
Anyone knows?

Answer 1

I think you need to increase your buffer size. Change the lines
int size = 2048;
byte[] data = new byte[2048];
And change the 2048 to something like 32768 (32*1024).
A 2KB block size is making a lot of individual writes to the flash storage. In my experience that's a somewhat slow thing and can vary from device to device. A 32KB block size should do 16 times fewer but I don't know if that will result in a direct 16x speedup. I'm interested to hear back.