private ContinuationSystemUseEntry Parse(IsoContext context, byte[] data, int offset) { ContinuationSystemUseEntry contEntry = null; SuspExtension extension = null; if (context.SuspExtensions != null && context.SuspExtensions.Count > 0) { extension = context.SuspExtensions[0]; } int pos = offset; while (data.Length - pos > 4) { byte len; SystemUseEntry entry = SystemUseEntry.Parse(data, pos, context.VolumeDescriptor.CharacterEncoding, extension, out len); pos += len; if (entry == null) { // A null entry indicates SUSP parsing must terminate. // This will occur if a termination record is found, // or if there is a problem with the SUSP data. return(contEntry); } switch (entry.Name) { case "CE": contEntry = (ContinuationSystemUseEntry)entry; break; case "ES": ExtensionSelectSystemUseEntry esEntry = (ExtensionSelectSystemUseEntry)entry; extension = context.SuspExtensions[esEntry.SelectedExtension]; break; case "PD": break; case "SP": case "ER": StoreEntry(null, entry); break; default: StoreEntry(extension, entry); break; } } return(contEntry); }
private void StoreEntry(SuspExtension extension, SystemUseEntry entry) { string extensionId = extension == null ? string.Empty : extension.Identifier; Dictionary <string, List <SystemUseEntry> > extensionEntries; if (!_records.TryGetValue(extensionId, out extensionEntries)) { extensionEntries = new Dictionary <string, List <SystemUseEntry> >(); _records.Add(extensionId, extensionEntries); } List <SystemUseEntry> entries; if (!extensionEntries.TryGetValue(entry.Name, out entries)) { entries = new List <SystemUseEntry>(); extensionEntries.Add(entry.Name, entries); } entries.Add(entry); }
public static SystemUseEntry Parse(byte[] data, int offset, Encoding encoding, SuspExtension extension, out byte length) { if (data[offset] == 0) { // A zero-byte here is invalid and indicates an incorrectly written SUSP field. // Return null to indicate to the caller that SUSP parsing is terminated. length = 0; return(null); } string name = EndianUtilities.BytesToString(data, offset, 2); length = data[offset + 2]; byte version = data[offset + 3]; switch (name) { case "CE": return(new ContinuationSystemUseEntry(name, length, version, data, offset)); case "PD": return(new PaddingSystemUseEntry(name, length, version)); case "SP": return(new SharingProtocolSystemUseEntry(name, length, version, data, offset)); case "ST": // Termination entry. There's no point in storing or validating this one. // Return null to indicate to the caller that SUSP parsing is terminated. return(null); case "ER": return(new ExtensionSystemUseEntry(name, length, version, data, offset, encoding)); case "ES": return(new ExtensionSelectSystemUseEntry(name, length, version, data, offset)); case "AA": case "AB": case "AS": // Placeholder support for Apple and Amiga extension records. return(new GenericSystemUseEntry(name, length, version, data, offset)); default: if (extension == null) { return(new GenericSystemUseEntry(name, length, version, data, offset)); } return(extension.Parse(name, length, version, data, offset, encoding)); } }