/*
* end of central dir signature 4 bytes (0x06054b50)
* number of this disk 2 bytes
* number of the disk with the start of the central directory 2 bytes
* total number of entries in the central directory on this disk 2 bytes
* total number of entries in the central directory 2 bytes
* size of the central directory 4 bytes
* offset of start of central directory
* with respect to the starting disk number 4 bytes
* .ZIP file comment length 2 bytes
* .ZIP file comment (variable size)
*/
/// <summary>
/// TODO: case when the whole file is smaller than 64K
/// TODO: handle non HTTP case
/// </summary>
/// <param name="url"></param>
/// <returns></returns>
public bool Load()
{
int CentralOffset, CentralSize;
int TotalEntries;
if (!FindCentralDirectory(out CentralOffset, out CentralSize, out TotalEntries))
{
return(false);
}
MaxFileOffset = CentralOffset;
// now retrieve the Central Directory
entries = new ZipEntry[TotalEntries];
//HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
//req.AddRange(CentralOffset, CentralOffset+CentralSize);
//HttpWebResponse res = (HttpWebResponse)req.GetResponse();
using (Stream s = protocolProvider.CreateStream(this.url,
CentralOffset, CentralOffset + CentralSize))
{
// code taken from SharpZipLib with modification for not seekable stream
// and adjustement for Central Directory entry
for (int i = 0; i < TotalEntries; i++)
{
if (ReadLeInt(s) != ZipConstants.CentralHeaderSignature)
{
throw new ZipException("Wrong Central Directory signature");
}
// skip 6 bytes: version made (W), version ext (W), flags (W)
ReadLeInt(s);
ReadLeShort(s);
int method = ReadLeShort(s);
int dostime = ReadLeInt(s);
int crc = ReadLeInt(s);
int csize = ReadLeInt(s);
int size = ReadLeInt(s);
int nameLen = ReadLeShort(s);
int extraLen = ReadLeShort(s);
int commentLen = ReadLeShort(s);
// skip 8 bytes: disk number start, internal file attribs, external file attribs (DW)
ReadLeInt(s);
ReadLeInt(s);
int offset = ReadLeInt(s);
byte[] buffer = new byte[Math.Max(nameLen, commentLen)];
StreamHelper.ReadAll(buffer, 0, nameLen, s);
string name = ZipConstants.ConvertToString(buffer);
ZipEntry entry = new ZipEntry(name);
entry.CompressionMethod = (CompressionMethod)method;
entry.Crc = crc & 0xffffffffL;
entry.Size = size & 0xffffffffL;
entry.CompressedSize = csize & 0xffffffffL;
entry.DosTime = (uint)dostime;
if (extraLen > 0)
{
byte[] extra = new byte[extraLen];
StreamHelper.ReadAll(extra, 0, extraLen, s);
entry.ExtraData = extra;
}
if (commentLen > 0)
{
StreamHelper.ReadAll(buffer, 0, commentLen, s);
entry.Comment = ZipConstants.ConvertToString(buffer);
}
entry.ZipFileIndex = i;
entry.Offset = offset;
entries[i] = entry;
OnProgress((i * 100) / TotalEntries);
}
}
OnProgress(100);
return(true);
}
