/// <summary>
/// Treats this file as a zip file and extracts it to the specified target directory. This file and
/// the target directory do NOT need to be in the same file system.
/// If this file is not a valid zip archive, or any error occurs, then false is returned.
/// </summary>
public static bool ExtractZip(this FSFile zipFile, FSDir targetDir,
ZipExtractionOptions options)
{
// First open the FSFile for reading
Stream fsFileStream = zipFile.OpenReadOnly();
// Create a zip archive (for reading) from the stream
ZipArchive zipA = null;
try
{
zipA = new ZipArchive(fsFileStream, ZipArchiveMode.Read);
}
catch (Exception)
{
fsFileStream.Dispose();
return(false);
}
// Call the utility function to do the actual extraction
ExtractZip(zipA, targetDir, options);
// Clean up and return
zipA.Dispose();
fsFileStream.Dispose();
return(true);
}
private static ZipExtractionStats ExtractZip(ZipArchive zipA, FSDir targetDirectory, ZipExtractionOptions options)
{
// Keep track of the number of entries encountered and extracted
ZipExtractionStats stats = new ZipExtractionStats();
// Loop through entries and extract
foreach (ZipArchiveEntry entry in zipA.Entries)
{
stats.NumEntriesSeen++;
bool skipThisEntry = false;
FSDir targetDir = targetDirectory;
// Split the full name on '/'
string[] pieces = entry.FullName.Split('/');
int i;
for (i = 0; i < pieces.Length - 1; i++)
{
targetDir = targetDir.CreateDir(pieces[i]);
if (null == targetDir)
{
skipThisEntry = true;
break;
}
}
// Skip this entry if need be
if (skipThisEntry)
{
continue;
}
// At this point pieces[i] is the file we need to create in targetDir
if (targetDir.GetFile(pieces[i]) != null && !options.Overwrite)
{
// We can't overwrite the file
continue;
}
FSFile fileForEntry = targetDir.CreateFile(pieces[i]);
if (null == fileForEntry)
{
continue;
}
// Open the zip entry stream for reading and the FSFile for writing. Notice that despite
// the possibility of failure to open the source stream from the zip file entry, we've
// already created the FSFile in the target directory. This is intentional. If we fail
// to extract a file, then a 0-byte placeholder is desired (for now, may change later).
Stream src = entry.Open();
if (src == null)
{
continue;
}
Stream dst = fileForEntry.OpenReadWrite();
if (dst == null)
{
src.Dispose();
continue;
}
// Copy the contents
byte[] buf = new byte[8192];
while (true)
{
int bytesRead = src.Read(buf, 0, buf.Length);
if (bytesRead <= 0)
{
break;
}
dst.Write(buf, 0, bytesRead);
}
// Clean up and increment number of files extracted
src.Dispose();
dst.Dispose();
stats.NumEntriesExtracted++;
}
return(stats);
}
