/// <summary>
/// Advances the enumerator to the next element of the collection
/// </summary>
/// <summary>Sets <see cref="_currentZipEntry"/> to the next zip entry</summary>
/// <returns>true if the next entry is not null, otherwise false</returns>
private bool MoveNext()
{
int result;
if (_currentZipEntry == null)
{
result = ZlibWrapper.ZlibUnzGoToFirstFile(_zipFileHandle);
}
else
{
CloseCurrentEntry();
result = ZlibWrapper.ZlibUnzGoToNextFile(_zipFileHandle);
}
if (result == ZipReturnCode.EndOfListOfFile)
{
// No more entries
_currentZipEntry = null;
}
else if (result < 0)
{
throw new ZipException("MoveNext failed.", result);
}
else
{
// Entry found,m open it
OpenCurrentEntry();
}
return(_currentZipEntry != null);
}
/// <summary>
/// Creates a new Zip file entry reading values from a zip file
/// </summary>
internal ZipEntry(IntPtr handle)
{
var entryInfo = new ZipEntryInfo64();
int result = ZlibWrapper.ZlibUnzGetCurrentFileInfo64(handle, out entryInfo, null, 0, null, 0, null, 0);
if (result != 0)
{
throw new ZipException($"Could not read entry from zip file \"{Name}\"", result);
}
byte[] extraField = new byte[entryInfo.ExtraFieldLength];
byte[] entryNameBuffer = new byte[entryInfo.FileNameLength];
byte[] commentBuffer = new byte[entryInfo.CommentLength];
result = ZlibWrapper.ZlibUnzGetCurrentFileInfo64(handle, out entryInfo,
entryNameBuffer, (uint)entryNameBuffer.Length,
extraField, (uint)extraField.Length,
commentBuffer, (uint)commentBuffer.Length);
if (result != 0)
{
throw new ZipException($"Could not read entry from zip file \"{Name}\"", result);
}
_utf8Encoding = (entryInfo.Flag & ZipEntryFlag.UTF8) == ZipEntryFlag.UTF8;
Encoding encoding = _utf8Encoding ? Encoding.UTF8 : ZlibWrapper.OEMEncoding;
Name = encoding.GetString(entryNameBuffer);
UncompressedLength = (long)entryInfo.UncompressedSize;
_fileAttributes = (FileAttributes)entryInfo.ExternalFileAttributes;
IsDirectory = (_fileAttributes & FileAttributes.Directory) != 0;
}
/// <summary>
/// Reads the current entry into the specified memory stream
/// </summary>
/// <remarks>
/// The data is put directly into the memory stream buffer
/// No write operations are performed on the memory stream
/// </remarks>
/// <param name="memoryStream">memory stream</param>
public void ReadCurrentEntry(MemoryStream memoryStream)
{
// Make sure the memory stream has enough capacity to hold the data
memoryStream.SetLength(_currentZipEntry.UncompressedLength);
byte[] memBuffer = memoryStream.GetBuffer();
int bytesRead = 0;
int offset = 0;
unsafe
{
fixed(byte *p = memBuffer)
{
for (; ;)
{
bytesRead = ZlibWrapper.ZlibUnzReadCurrentFile(_zipFileHandle, (IntPtr)p + offset, 4096);
offset += bytesRead;
if (bytesRead <= 0)
{
break;
}
}
}
}
}
/// <summary>
/// Initializes a instance of the <see cref="ZipReader"/> class for reading the zip file with the given name
/// </summary>
/// <param name="fileName">The path to the zip file that will be read</param>
public ZipReader(string fileName)
{
FileName = fileName;
_zipFileHandle = ZlibWrapper.ZlibUnzOpen(fileName);
if (_zipFileHandle == IntPtr.Zero)
{
throw new ZipException(string.Format("Could not open zip file '{0}'", fileName));
}
}
/// <summary>
/// Opens the current selected Zip entry
/// </summary>
private void OpenCurrentEntry()
{
_currentZipEntry = new ZipEntry(_zipFileHandle);
int result = ZlibWrapper.ZlibUnzOpenCurrentFile(_zipFileHandle);
if (result < 0)
{
_currentZipEntry = null;
throw new ZipException("Could not open entry for reading.", result);
}
}
/// <summary>
/// Closes the current Zip entry
/// </summary>
private void CloseCurrentEntry()
{
if (_currentZipEntry == null)
{
return;
}
int result = ZlibWrapper.ZlibUnzCloseCurrentFile(_zipFileHandle);
if (result < 0)
{
throw new ZipException("Could not close zip entry.", result);
}
_currentZipEntry = null;
}
/// <summary>
/// Closes the Zip file and releases the unmanaged resources
/// </summary>
private void CloseFile()
{
if (_zipFileHandle == IntPtr.Zero)
{
return;
}
try
{
CloseCurrentEntry();
}
finally
{
int result = ZlibWrapper.ZlibUnzClose(_zipFileHandle);
if (result < 0)
{
throw new ZipException("Could not close zip file.", result);
}
_zipFileHandle = IntPtr.Zero;
}
}
