/// <summary>
/// Extract a file to byte array using the path
/// </summary>
/// <param name="fullPath">Internal full path for the file to extract</param>
/// <returns>Uncompressed data and no error string on success, null data and an error string otherwise</returns>
public (byte[] data, string err) Extract(string fullPath)
{
// If the file isn't in the archive, we can't extract it
if (!Exists(fullPath))
{
return(null, $"Path '{fullPath}' does not exist in the archive");
}
// Get a local reference to the file we care about
CompressedFile file = Files[fullPath];
// Attempt to read the compressed data
inputStream.Seek(DataStart + file.Offset, SeekOrigin.Begin);
byte[] compressedData = new byte[file.CompressedSize];
int read = inputStream.Read(compressedData, 0, (int)file.CompressedSize);
if (read != (int)file.CompressedSize)
{
return(null, "Could not read all required data");
}
// Decompress the data
List <byte> output = new List <byte>();
int ret = BlastDecoder.Blast(compressedData, output);
if (ret != 0)
{
return(null, $"Blast error: {ret}");
}
// Return the decompressed data
return(output.ToArray(), null);
}
/// <summary>
/// Load the file set as the current path
/// </summary>
/// <returns>Success and error strings, if applicable</returns>
private (bool success, string err) LoadFile()
{
// If the file doesn't exist, we can't do anything
if (!File.Exists(FilePath))
{
return(false, $"File '{FilePath}' does not exist");
}
// Attempt to open the file for reading
try
{
inputStream = File.OpenRead(FilePath);
}
catch
{
return(false, "Cannot open file");
}
// Create the header from the input file
Header = Header.Create(inputStream);
if (Header == null)
{
return(false, "Header could not be read");
}
// Validate the file signature
if (Header.Signature != 0x8C655D13)
{
return(false, "Invalid signature");
}
// Validate the TOC
long fileSize = inputStream.Length;
if (Header.TocAddress >= fileSize)
{
return(false, $"Invalid TOC address: {Header.TocAddress}");
}
// Move to the TOC
inputStream.Seek(Header.TocAddress, SeekOrigin.Begin);
// Read all directory info
for (int i = 0; i < Header.DirCount; i++)
{
ushort fileCount = inputStream.ReadUInt16();
ushort chunkSize = inputStream.ReadUInt16();
string name = inputStream.ReadUInt16HeaderedString();
inputStream.Seek(chunkSize - name.Length - 6, SeekOrigin.Current);
Directories.Add(new ArchiveDirectory {
Name = name, FileCount = fileCount
});
}
// For each directory, read all file info
uint accumOffset = 0;
foreach (ArchiveDirectory directory in Directories)
{
for (int i = 0; i < directory.FileCount; i++)
{
// Read in the file information
inputStream.Seek(7, SeekOrigin.Current); // 00-06
uint compressedSize = inputStream.ReadUInt32(); // 07-10
inputStream.Seek(12, SeekOrigin.Current); // 11-22
ushort chunkSize = inputStream.ReadUInt16(); // 23-24
inputStream.Seek(4, SeekOrigin.Current); // 25-28
string filename = inputStream.ReadUInt8HeaderedString(); // 29-XX
inputStream.Seek(chunkSize - filename.Length - 30, SeekOrigin.Current);
// Determine the full path of the internal file
string fullpath;
if (!string.IsNullOrWhiteSpace(directory.Name) && directory.Name.Length > 0)
{
fullpath = Path.Combine(directory.Name, filename);
}
else
{
fullpath = filename;
}
// Add the file to the list
Files[fullpath] = new CompressedFile
{
Name = filename,
FullPath = fullpath,
CompressedSize = compressedSize,
Offset = accumOffset,
};
// Accumulate the new offset
accumOffset += compressedSize;
}
}
return(true, null);
}
