Exemplo n.º 1
0
		/// <summary>
		/// Get the next entry in this tar archive. This will skip
		/// over any remaining data in the current entry, if there
		/// is one, and place the input stream at the header of the
		/// next entry, and read the header and instantiate a new
		/// TarEntry from the header bytes and return that entry.
		/// If there are no more entries in the archive, null will
		/// be returned to indicate that the end of the archive has
		/// been reached.
		/// </summary>
		/// <returns>
		/// The next TarEntry in the archive, or null.
		/// </returns>
		public TarEntry GetNextEntry()
		{
			if (hasHitEOF) {
				return null;
			}
			
			if (currentEntry != null) {
				SkipToNextEntry();
			}
			
			byte[] headerBuf = tarBuffer.ReadBlock();
			
			if (headerBuf == null) {
				hasHitEOF = true;
			} else if (TarBuffer.IsEndOfArchiveBlock(headerBuf)) {
				hasHitEOF = true;
			}
			
			if (hasHitEOF) {
				currentEntry = null;
			} else {
				try {
					TarHeader header = new TarHeader();
					header.ParseBuffer(headerBuf);
					if ( !header.IsChecksumValid )
					{
						throw new TarException("Header checksum is invalid");
					}
					this.entryOffset = 0;
					this.entrySize = header.Size;
					
					StringBuilder longName = null;
					
					if (header.TypeFlag == TarHeader.LF_GNU_LONGNAME) {
						
						byte[] nameBuffer = new byte[TarBuffer.BlockSize];
						long numToRead = this.entrySize;
						
						longName = new StringBuilder();
						
						while (numToRead > 0) {
							int numRead = this.Read(nameBuffer, 0, (numToRead > nameBuffer.Length ? nameBuffer.Length : (int)numToRead));
							
							if (numRead == -1) {
								throw new InvalidHeaderException("Failed to read long name entry");
							}
							
							longName.Append(TarHeader.ParseName(nameBuffer, 0, numRead).ToString());
							numToRead -= numRead;
						}
						
						SkipToNextEntry();
						headerBuf = this.tarBuffer.ReadBlock();
					} else if (header.TypeFlag == TarHeader.LF_GHDR) {  // POSIX global extended header 
						// Ignore things we dont understand completely for now
						SkipToNextEntry();
						headerBuf = this.tarBuffer.ReadBlock();
					} else if (header.TypeFlag == TarHeader.LF_XHDR) {  // POSIX extended header
						// Ignore things we dont understand completely for now
						SkipToNextEntry();
						headerBuf = this.tarBuffer.ReadBlock();
					} else if (header.TypeFlag == TarHeader.LF_GNU_VOLHDR) {
						// TODO: could show volume name when verbose
						SkipToNextEntry();
						headerBuf = this.tarBuffer.ReadBlock();
					} else if (header.TypeFlag != TarHeader.LF_NORMAL && 
							   header.TypeFlag != TarHeader.LF_OLDNORM &&
							   header.TypeFlag != TarHeader.LF_DIR) {
						// Ignore things we dont understand completely for now
						SkipToNextEntry();
						headerBuf = tarBuffer.ReadBlock();
					}
					
					if (entryFactory == null) {
						currentEntry = new TarEntry(headerBuf);
						if (longName != null) {
							currentEntry.Name = longName.ToString();
						}
					} else {
						currentEntry = entryFactory.CreateEntry(headerBuf);
					}
					
					// Magic was checked here for 'ustar' but there are multiple valid possibilities
					// so this is not done anymore.
					
					entryOffset = 0;
					
					// TODO: Review How do we resolve this discrepancy?!
					entrySize = this.currentEntry.Size;
				} catch (InvalidHeaderException ex) {
					entrySize = 0;
					entryOffset = 0;
					currentEntry = null;
					string errorText = string.Format("Bad header in record {0} block {1} {2}",
						tarBuffer.CurrentRecord, tarBuffer.CurrentBlock, ex.Message);
					throw new InvalidHeaderException(errorText);
				}
			}
			return currentEntry;
		}
Exemplo n.º 2
0
		/// <summary>
		/// Construct an entry from an archive's header bytes. File is set
		/// to null.
		/// </summary>
		/// <param name = "headerBuffer">
		/// The header bytes from a tar archive entry.
		/// </param>
		public TarEntry(byte[] headerBuffer)
		{
			header = new TarHeader();
			header.ParseBuffer(headerBuffer);
		}