/// <summary>
/// Removes a file from <see cref="Files"/>
/// </summary>
/// <param name="file">The file to remove</param>
public void RemoveFile(ArFile file)
{
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
if (file.Parent != this)
{
throw new InvalidOperationException($"Cannot remove this file as it is not part of this {nameof(ArArchiveFile)} instance");
}
// If we are removing the SymbolTable
if (file == SymbolTable)
{
SymbolTable = null;
}
var i = (int)file.Index;
_files.RemoveAt(i);
file.Index = 0;
// Update indices for other sections
for (int j = i + 1; j < _files.Count; j++)
{
var nextEntry = _files[j];
nextEntry.Index--;
}
file.Parent = null;
}
/// <summary>
/// Adds a file to <see cref="Files"/>.
/// </summary>
/// <param name="file">A file</param>
public void AddFile(ArFile file)
{
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
if (file.Parent != null)
{
if (file.Parent == this)
{
throw new InvalidOperationException("Cannot add the file as it is already added");
}
if (file.Parent != this)
{
throw new InvalidOperationException($"Cannot add the file as it is already added to another {nameof(ArArchiveFile)} instance");
}
}
if (file is ArSymbolTable symbolTable)
{
InsertFileAt(0, file);
return;
}
file.Parent = this;
file.Index = (uint)_files.Count;
_files.Add(file);
}
/// <summary>
/// Inserts a file into <see cref="Files"/> at the specified index.
/// </summary>
/// <param name="index">Index into <see cref="Files"/> to insert the specified file</param>
/// <param name="file">The file to insert</param>
public void InsertFileAt(int index, ArFile file)
{
if (index < 0 || index > _files.Count)
{
throw new ArgumentOutOfRangeException(nameof(index), $"Invalid index {index}, Must be >= 0 && <= {_files.Count}");
}
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
if (file.Parent != null)
{
if (file.Parent == this)
{
throw new InvalidOperationException("Cannot add the file as it is already added");
}
if (file.Parent != this)
{
throw new InvalidOperationException($"Cannot add the file as it is already added to another {nameof(ArArchiveFile)} instance");
}
}
if (file is ArSymbolTable symbolTable)
{
if (SymbolTable == null)
{
if (index != 0)
{
throw new ArgumentException($"Cannot only add a symbol table at index 0", nameof(file));
}
SymbolTable = symbolTable;
}
else
{
throw new ArgumentException($"Cannot add this symbol table as an existing symbol table is already present in the file entries of {this}", nameof(file));
}
}
else
{
if (SymbolTable != null && index == 0)
{
throw new ArgumentException($"Cannot add the entry {file} at index 0 because a symbol table is already set and must be the first entry in the list of files", nameof(file));
}
}
file.Index = (uint)index;
_files.Insert(index, file);
file.Parent = this;
// Update the index of following files
for (int i = index + 1; i < _files.Count; i++)
{
var nextFile = _files[i];
nextFile.Index++;
}
}
private void WriteFileEntry(Span <byte> buffer, ArFile file)
{
Debug.Assert((ulong)(Stream.Position - _startStreamOffset) == file.Offset);
buffer.Fill((byte)' ');
var name = file.InternalName;
bool postFixSlash = false;
if (name == null)
{
name = file.Name;
if (ArArchiveFile.Kind != ArArchiveKind.Common && !name.EndsWith("/"))
{
postFixSlash = true;
}
}
uint?bsdNameLength = null;
if (ArArchiveFile.Kind == ArArchiveKind.BSD)
{
var nameLength = Encoding.UTF8.GetByteCount(name);
if (nameLength > ArFile.FieldNameLength)
{
name = $"#1/{nameLength}";
bsdNameLength = (uint)nameLength;
postFixSlash = false;
}
}
// Encode Length
int length = Encoding.UTF8.GetBytes(name, buffer.Slice(0, ArFile.FieldNameLength));
if (postFixSlash)
{
buffer[length] = (byte)'/';
}
if (!(file is ArLongNamesTable))
{
// 16 12 File modification timestamp Decimal
EncodeDecimal(buffer, ArFile.FieldTimestampOffset, ArFile.FieldTimestampLength, (ulong)file.Timestamp.ToUnixTimeSeconds());
// 28 6 Owner ID Decimal
EncodeDecimal(buffer, ArFile.FieldOwnerIdOffset, ArFile.FieldOwnerIdLength, file.OwnerId);
// 34 6 Group ID Decimal
EncodeDecimal(buffer, ArFile.FieldGroupIdOffset, ArFile.FieldGroupIdLength, file.GroupId);
// 40 8 File mode Octal
EncodeOctal(buffer, ArFile.FieldFileModeOffset, ArFile.FieldFileModeLength, file.FileMode);
}
// 48 10 File size in bytes Decimal
EncodeDecimal(buffer, ArFile.FieldFileSizeOffset, ArFile.FieldFileSizeLength, file.Size);
buffer[ArFile.FieldEndCharactersOffset] = 0x60;
buffer[ArFile.FieldEndCharactersOffset + 1] = (byte)'\n';
// Write the entry
Stream.Write(buffer);
// Handle BSD file name by serializing the name before the data if it is required
if (bsdNameLength.HasValue)
{
uint nameLength = bsdNameLength.Value;
var bufferName = ArrayPool <byte> .Shared.Rent((int)nameLength);
Encoding.UTF8.GetBytes(file.Name, 0, file.Name.Length, bufferName, 0);
try
{
Stream.Write(bufferName, 0, (int)nameLength);
}
finally
{
ArrayPool <byte> .Shared.Return(bufferName);
}
}
// Write the content following the entry
file.WriteInternal(this);
// Align to even byte
if ((Stream.Position & 1) != 0)
{
Stream.WriteByte((byte)'\n');
}
}
private bool TryReadFileEntry(Span <byte> buffer, out ArFile entry)
{
entry = null;
Debug.Assert((Stream.Position & 1) == 0);
long entryOffset = Stream.Position;
int length = Stream.Read(buffer);
if (length == 0)
{
return(false);
}
if (length < buffer.Length)
{
Diagnostics.Error(DiagnosticId.AR_ERR_InvalidFileEntryLength, $"Invalid length {length} while trying to read a file entry from stream at offset {entryOffset}. Expecting {buffer.Length} bytes");
return(false);
}
// 0 16 File identifier ASCII
// discard right padding characters
int idLength = 16;
while (idLength > 0)
{
if (buffer[idLength - 1] != ' ')
{
break;
}
idLength--;
}
string name = null;
ulong? bsdNameLength = null;
if (idLength > 3 && ArArchiveFile.Kind == ArArchiveKind.BSD)
{
if (buffer[0] == '#' && buffer[1] == '1' && buffer[2] == '/')
{
// If we have a future header table, we are using it and expecting only numbers
if (!TryDecodeDecimal(entryOffset, buffer, 3, ArFile.FieldNameLength - 3, $"BSD Name length following #1/ at offset {entryOffset}", out ulong bsdNameLengthDecoded))
{
// Don't try to process more entries, the archive might be corrupted
return(false);
}
bsdNameLength = bsdNameLengthDecoded;
}
}
// If the last char is `/`
// Keep file names with / or //
// But remove trailing `/`for regular file names
if (!bsdNameLength.HasValue && ArArchiveFile.Kind != ArArchiveKind.Common && idLength > 0 && buffer[idLength - 1] == '/')
{
if (!(idLength == 1 || idLength == 2 && buffer[idLength - 2] == '/'))
{
idLength--;
}
}
if (_futureHeaders != null && buffer[0] == (byte)'/')
{
// If we have a future header table, we are using it and expecting only numbers
if (!TryDecodeDecimal(entryOffset, buffer, 1, ArFile.FieldNameLength - 1, $"Name with offset to Future Headers Table at file offset {entryOffset}", out ulong offsetInFutureHeaders))
{
// Don't try to process more entries, the archive might be corrupted
return(false);
}
// If the number is ok, check that we have actually a string for this offset
if (!_futureHeaders.FileNames.TryGetValue((int)offsetInFutureHeaders, out name))
{
Diagnostics.Error(DiagnosticId.AR_ERR_InvalidReferenceToFutureHeadersTable, $"Invalid reference {offsetInFutureHeaders} found at file offset {entryOffset}. This file is invalid.");
}
}
if (!bsdNameLength.HasValue && name == null)
{
name = idLength == 0 ? string.Empty : Encoding.UTF8.GetString(buffer.Slice(0, idLength));
}
// 16 12 File modification timestamp Decimal
if (!TryDecodeDecimal(entryOffset, buffer, ArFile.FieldTimestampOffset, ArFile.FieldTimestampLength, "File modification timestamp Decimal", out ulong timestamp))
{
return(false);
}
// 28 6 Owner ID Decimal
if (!TryDecodeDecimal(entryOffset, buffer, ArFile.FieldOwnerIdOffset, ArFile.FieldOwnerIdLength, "Owner ID", out ulong ownerId))
{
return(false);
}
// 34 6 Group ID Decimal
if (!TryDecodeDecimal(entryOffset, buffer, ArFile.FieldGroupIdOffset, ArFile.FieldGroupIdLength, "Group ID", out ulong groupId))
{
return(false);
}
// 40 8 File mode Octal
if (!TryDecodeOctal(entryOffset, buffer, ArFile.FieldFileModeOffset, ArFile.FieldFileModeLength, "File mode", out uint fileMode))
{
return(false);
}
// 48 10 File size in bytes Decimal
if (!TryDecodeDecimal(entryOffset, buffer, ArFile.FieldFileSizeOffset, ArFile.FieldFileSizeLength, "File size in bytes", out ulong fileSize))
{
return(false);
}
// 58 2 Ending characters 0x60 0x0A
if (buffer[ArFile.FieldEndCharactersOffset] != 0x60 || buffer[ArFile.FieldEndCharactersOffset + 1] != '\n')
{
Diagnostics.Error(DiagnosticId.AR_ERR_InvalidCharacterFoundInFileEntry, $"Invalid ASCII characters found 0x{buffer[ArFile.FieldEndCharactersOffset]:x} 0x{buffer[ArFile.FieldEndCharactersOffset+1]:x} instead of `\\n at the end of file entry at offset {entryOffset + ArFile.FieldEndCharactersOffset}");
return(false);
}
entry = CreateFileEntryFromName(name);
entry.Timestamp = DateTimeOffset.FromUnixTimeSeconds((long)timestamp);
entry.OwnerId = (uint)ownerId;
entry.GroupId = (uint)groupId;
entry.FileMode = fileMode;
entry.Offset = (ulong)entryOffset;
entry.Size = fileSize;
// Read the BSD name if necessary
if (bsdNameLength.HasValue)
{
var nameLength = (int)bsdNameLength.Value;
var bufferForName = ArrayPool <byte> .Shared.Rent(nameLength);
var streamPosition = Stream.Position;
var dataReadCount = Stream.Read(bufferForName, 0, nameLength);
if (dataReadCount != nameLength)
{
Diagnostics.Error(DiagnosticId.AR_ERR_UnexpectedEndOfFile, $"Unexpected end of file while trying to read the filename from the data section of the file entry at offset of {streamPosition}. Expecting {nameLength} bytes while only {dataReadCount} bytes were read from the stream.");
return(false);
}
name = Encoding.UTF8.GetString(bufferForName, 0, nameLength);
}
if (!entry.IsSystem)
{
if (name.Contains('/'))
{
Diagnostics.Error(DiagnosticId.AR_ERR_InvalidCharacterInFileEntryName, $"The character `/` was found in the entry `{name}` while it is invalid.");
return(false);
}
entry.Name = name;
}
entry.ReadInternal(this);
// The end of an entry is always aligned
if ((Stream.Position & 1) != 0)
{
long padOffset = Stream.Position;
int pad = Stream.ReadByte();
if (pad < 0)
{
Diagnostics.Error(DiagnosticId.AR_ERR_UnexpectedEndOfFile, $"Unexpected end of file while trying to Invalid character 0x{pad:x} found at offset {padOffset} while expecting \\n 0xa");
return(false);
}
if (pad != '\n')
{
Diagnostics.Error(DiagnosticId.AR_ERR_ExpectingNewLineCharacter, $"Invalid character 0x{pad:x} found at offset {padOffset} while expecting \\n 0xa");
return(false);
}
}
return(true);
}
