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Clean up some CAB decompressor code

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This commit is contained in:
Matt Nadareski
2022-05-23 15:05:03 -07:00
parent 98a7149cc9
commit 9e49703bc5
2 changed files with 242 additions and 232 deletions
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4
BurnOutSharp/External/libmspack/CAB/Compressor.cs vendored
View File

@@ -16,9 +16,7 @@
namespace LibMSPackSharp.CAB
{
/// <summary>
/// TODO
/// </summary>
// TODO
public class Compressor
{
public SystemImpl System { get; set; }

470
BurnOutSharp/External/libmspack/CAB/Decompressor.cs vendored
View File

@@ -54,14 +54,14 @@ namespace LibMSPackSharp.CAB
/// and a Cabinet structure will be returned, with a full list of
/// folders and files.
///
/// In the case of an error occuring, NULL is returned and the error code
/// In the case of an error occuring, null is returned and the error code
/// is available from last_error().
///
/// The filename pointer should be considered "in use" until close() is
/// called on the cabinet.
/// </summary>
/// <param name="filename">The filename of the cabinet file. This is passed directly to SystemImpl::open().</param>
/// <returns>A pointer to a Cabinet structure, or NULL on failure</returns>
/// <returns>A pointer to a Cabinet structure, or null on failure</returns>
/// <see cref="Close(Cabinet)"/>
/// <see cref="Search(string)"/>
/// <see cref="Error"/>
@@ -118,26 +118,12 @@ namespace LibMSPackSharp.CAB
/// <see cref="Prepend(Cabinet, Cabinet)"/>
public void Close(Cabinet cabinet)
{
FolderData dat, ndat;
Cabinet cab;
Folder fol, nfol;
InternalFile fi, nfi;
Error = Error.MSPACK_ERR_OK;
while (cabinet != null)
{
// Free files
for (fi = cabinet.Files; fi != null; fi = nfi)
{
nfi = fi.Next;
}
// Free folders
for (fol = cabinet.Folders; fol != null; fol = nfol)
for (Folder fol = cabinet.Folders; fol != null; fol = fol.Next)
{
nfol = fol.Next;
// Free folder decompression state if it has been decompressed
if (State != null && (State.Folder == fol))
{
@@ -147,19 +133,10 @@ namespace LibMSPackSharp.CAB
FreeDecompressionState();
State = null;
}
// Free folder data segments
for (dat = fol.Data.Next; dat != null; dat = ndat)
{
ndat = dat.Next;
}
}
// Free actual cabinet structure
cab = cabinet.Next;
// Repeat full procedure again with the cab.Next pointer (if set)
cabinet = cab;
cabinet = cabinet.Next;
}
}
@@ -178,10 +155,10 @@ namespace LibMSPackSharp.CAB
/// using the Cabinet::next field.
///
/// In the case of an error occuring anywhere other than the simulated
/// open(), NULL is returned and the error code is available from
/// open(), null is returned and the error code is available from
/// last_error().
///
/// If no error occurs, but no cabinets can be found in the file, NULL is
/// If no error occurs, but no cabinets can be found in the file, null is
/// returned and last_error() returns MSPACK_ERR_OK.
///
/// The filename pointer should be considered in use until close() is
@@ -190,45 +167,42 @@ namespace LibMSPackSharp.CAB
/// close() should only be called on the result of search(), not on any
/// subsequent cabinets in the Cabinet::next chain.
/// </summary>
/// <param name="filename">The filename of the file to search for cabinets. This is passed directly to SystemImpl::open().</param>
/// <returns>a pointer to a Cabinet structure, or NULL</returns>
/// <param name="filename">The filename of the file to search for cabinets. This is passed directly to SystemImpl.Open().</param>
/// <returns>A pointer to a Cabinet structure, or null</returns>
/// <see cref="Close(Cabinet)"/>
/// <see cref="Open(string)"/>
/// <see cref="Error"/>
public Cabinet Search(string filename)
{
// Allocate a search buffer
byte[] search_buf = new byte[SearchBufferSize];
if (search_buf == null)
byte[] searchBuffer = new byte[SearchBufferSize];
// Attempt to open the file
FileStream fh = System.Open(filename, OpenMode.MSPACK_SYS_OPEN_READ);
if (fh == null)
{
Error = Error.MSPACK_ERR_NOMEMORY;
Error = Error.MSPACK_ERR_OPEN;
return null;
}
// Open file and get its full file length
FileStream fh; Cabinet cab = null;
if ((fh = System.Open(filename, OpenMode.MSPACK_SYS_OPEN_READ)) != null)
{
long firstlen = 0;
if ((Error = System.GetFileLength(fh, out long filelen)) == Error.MSPACK_ERR_OK)
Error = Find(search_buf, fh, filename, filelen, ref firstlen, out cab);
// Get its full file length
long firstlen = 0;
if ((Error = System.GetFileLength(fh, out long filelen)) != Error.MSPACK_ERR_OK)
return null;
// Truncated / extraneous data warning:
if (firstlen != 0 && (firstlen != filelen) && (cab == null || cab.BaseOffset == 0))
{
if (firstlen < filelen)
System.Message(fh, $"WARNING; possible {filelen - firstlen} extra bytes at end of file.");
else
System.Message(fh, $"WARNING; file possibly truncated by {firstlen - filelen} bytes.");
}
// Attempt to to find the cabinet
Error = Find(searchBuffer, fh, filename, filelen, ref firstlen, out Cabinet cab);
System.Close(fh);
}
else
// Truncated / extraneous data warning:
if (firstlen != 0 && (firstlen != filelen) && (cab == null || cab.BaseOffset == 0))
{
Error = Error.MSPACK_ERR_OPEN;
if (firstlen < filelen)
System.Message(fh, $"WARNING; possible {filelen - firstlen} extra bytes at end of file.");
else
System.Message(fh, $"WARNING; file possibly truncated by {firstlen - filelen} bytes.");
}
System.Close(fh);
return cab;
}
@@ -313,8 +287,6 @@ namespace LibMSPackSharp.CAB
if (file == null)
return Error = Error.MSPACK_ERR_ARGS;
Folder fol = file.Folder;
// If offset is beyond 2GB, nothing can be extracted
if (file.Header.FolderOffset > CAB_LENGTHMAX)
return Error = Error.MSPACK_ERR_DATAFORMAT;
@@ -331,7 +303,7 @@ namespace LibMSPackSharp.CAB
}
// Extraction impossible if no folder, or folder needs predecessor
if (fol == null || fol.MergePrev != null)
if (file.Folder == null || file.Folder.MergePrev != null)
{
System.Message(null, $"ERROR; file \"{file.Filename}\" cannot be extracted, cabinet set is incomplete");
return Error = Error.MSPACK_ERR_DECRUNCH;
@@ -341,7 +313,7 @@ namespace LibMSPackSharp.CAB
// In salvage mode, don't assume block sizes, just try decoding
if (!Salvage)
{
long maxlen = fol.Header.NumBlocks * CAB_BLOCKMAX;
long maxlen = file.Folder.Header.NumBlocks * CAB_BLOCKMAX;
if ((file.Header.FolderOffset + filelen) > maxlen)
{
System.Message(null, $"ERROR; file \"{file.Filename}\" cannot be extracted, cabinet set is incomplete");
@@ -356,16 +328,16 @@ namespace LibMSPackSharp.CAB
// Allocate generic decompression state
State = new DecompressState()
{
Folder = fol,
Data = fol.Data,
Folder = file.Folder,
Data = file.Folder.Data,
Offset = 0,
Block = 0,
Outlen = 0,
System = System,
InputCabinet = fol.Data.Cab,
InputFileHandle = System.Open(fol.Data.Cab.Filename, OpenMode.MSPACK_SYS_OPEN_READ),
InputCabinet = file.Folder.Data.Cab,
InputFileHandle = System.Open(file.Folder.Data.Cab.Filename, OpenMode.MSPACK_SYS_OPEN_READ),
OutputFileHandle = null, // Required for skipping existing data
InputPointer = 0,
InputEnd = 0,
@@ -378,11 +350,11 @@ namespace LibMSPackSharp.CAB
return Error = Error.MSPACK_ERR_OPEN;
// Seek to start of data blocks
if (!System.Seek(State.InputFileHandle, fol.Data.Offset, SeekMode.MSPACK_SYS_SEEK_START))
if (!System.Seek(State.InputFileHandle, file.Folder.Data.Offset, SeekMode.MSPACK_SYS_SEEK_START))
return Error = Error.MSPACK_ERR_SEEK;
// Set up decompressor
if (InitDecompressionState(fol.Header.CompType) != Error.MSPACK_ERR_OK)
if (InitDecompressionState(file.Folder.Header.CompType) != Error.MSPACK_ERR_OK)
return Error;
// ReadError lasts for the lifetime of a decompressor
@@ -392,16 +364,14 @@ namespace LibMSPackSharp.CAB
// If file has more than 0 bytes
if (filelen != 0)
{
long bytes;
Error error;
// Get to correct offset.
// - use null fh to say 'no writing' to cabd_sys_write()
// - if SysRead() has an error, it will set self.ReadError
// - Use null fh to say 'no writing' to cabd_sys_write()
// - If SysRead() has an error, it will set self.ReadError
// and pass back MSPACK_ERR_READ
if ((bytes = file.Header.FolderOffset - State.Offset) != 0)
long bytes = file.Header.FolderOffset - State.Offset;
if (bytes != 0)
{
error = State.Decompress(State.DecompressorState, bytes);
Error error = State.Decompress(State.DecompressorState, bytes);
Error = (error == Error.MSPACK_ERR_READ) ? ReadError : error;
}
@@ -414,7 +384,7 @@ namespace LibMSPackSharp.CAB
if (Error == Error.MSPACK_ERR_OK)
{
UpdateDecompressionState();
error = State.Decompress(State.DecompressorState, filelen);
Error error = State.Decompress(State.DecompressorState, filelen);
Error = (error == Error.MSPACK_ERR_READ) ? ReadError : error;
}
}
@@ -814,26 +784,30 @@ namespace LibMSPackSharp.CAB
/// </summary>
private bool CanMergeFolders(Folder lfol, Folder rfol)
{
InternalFile lfi, rfi, l, r;
bool matching = true;
// Check that both folders use the same compression method/settings
if (lfol.Header.CompType != rfol.Header.CompType)
{
Console.WriteLine("folder merge: compression type mismatch");
Console.WriteLine("Folder merge: compression type mismatch");
return false;
}
// Check there are not too many data blocks after merging
if ((lfol.Header.NumBlocks + rfol.Header.NumBlocks) > CAB_FOLDERMAX)
{
Console.WriteLine("folder merge: too many data blocks in merged folders");
Console.WriteLine("Folder merge: too many data blocks in merged folders");
return false;
}
if ((lfi = lfol.MergeNext) == null || (rfi = rfol.MergePrev) == null)
// Assign the merge next and previous values
InternalFile lfi = lfol.MergeNext;
InternalFile rfi = rfol.MergePrev;
// Check that we can merge the two cabinets
if (lfi == null || rfi == null)
{
Console.WriteLine("folder merge: one cabinet has no files to merge");
Console.WriteLine("Folder merge: one cabinet has no files to merge");
return false;
}
@@ -841,7 +815,7 @@ namespace LibMSPackSharp.CAB
// only has files to merge), compare them to the files from rfol. They
// should be identical in number and order. to verify this, check the
// offset and length of each file.
for (l = lfi, r = rfi; l != null; l = l.Next, r = r.Next)
for (InternalFile l = lfi, r = rfi; l != null; l = l.Next, r = r.Next)
{
if (r == null || (l.Header.FolderOffset != r.Header.FolderOffset) || (l.Header.UncompressedSize != r.Header.UncompressedSize))
{
@@ -857,12 +831,13 @@ namespace LibMSPackSharp.CAB
// make a judgement call; if at least ONE file from lfol is in rfol, allow
// the merge with a warning about missing files.
matching = false;
for (l = lfi; l != null; l = l.Next)
for (InternalFile l = lfi; l != null; l = l.Next)
{
for (r = rfi; r != null; r = r.Next)
InternalFile r = rfi;
for (; r != null; r = r.Next)
{
if (l.Header.FolderOffset == r.Header.FolderOffset && l.Header.UncompressedSize == r.Header.UncompressedSize)
break;
break;
}
if (r != null)
@@ -1056,9 +1031,7 @@ namespace LibMSPackSharp.CAB
/// </summary>
private Error Merge(Cabinet lcab, Cabinet rcab)
{
FolderData data, ndata;
Folder lfol, rfol;
InternalFile fi, rfi, lfi;
InternalFile rfi, lfi;
// Basic args check
if (lcab == null || rcab == null || (lcab == rcab))
@@ -1075,8 +1048,7 @@ namespace LibMSPackSharp.CAB
}
// Do not create circular cabinet chains
Cabinet cab;
for (cab = lcab.PreviousCabinet; cab != null; cab = cab.PreviousCabinet)
for (Cabinet cab = lcab.PreviousCabinet; cab != null; cab = cab.PreviousCabinet)
{
if (cab == rcab)
{
@@ -1084,7 +1056,8 @@ namespace LibMSPackSharp.CAB
return Error = Error.MSPACK_ERR_ARGS;
}
}
for (cab = rcab.NextCabinet; cab != null; cab = cab.NextCabinet)
for (Cabinet cab = rcab.NextCabinet; cab != null; cab = cab.NextCabinet)
{
if (cab == lcab)
{
@@ -1101,8 +1074,8 @@ namespace LibMSPackSharp.CAB
System.Message(null, "WARNING; merged cabinets with odd order.");
// Merging the last folder in lcab with the first folder in rcab
lfol = lcab.Folders;
rfol = rcab.Folders;
Folder lfol = lcab.Folders;
Folder rfol = rcab.Folders;
while (lfol.Next != null)
{
lfol = lfol.Next;
@@ -1121,7 +1094,7 @@ namespace LibMSPackSharp.CAB
lfol.Next = rfol;
// Attach files
fi = lcab.Files;
InternalFile fi = lcab.Files;
while (fi.Next != null)
{
fi = fi.Next;
@@ -1136,14 +1109,14 @@ namespace LibMSPackSharp.CAB
return Error = Error.MSPACK_ERR_DATAFORMAT;
// Allocate a new folder data structure
data = new FolderData();
FolderData data = new FolderData();
// Attach cabs
lcab.NextCabinet = rcab;
rcab.PreviousCabinet = lcab;
// Append rfol's data to lfol
ndata = lfol.Data;
FolderData ndata = lfol.Data;
while (ndata.Next != null)
{
ndata = ndata.Next;
@@ -1170,7 +1143,7 @@ namespace LibMSPackSharp.CAB
lfol.Next = rfol.Next;
// Attach rfol's files
fi = lcab.Files;
InternalFile fi = lcab.Files;
while (fi.Next != null)
{
fi = fi.Next;
@@ -1201,13 +1174,13 @@ namespace LibMSPackSharp.CAB
// All done! fix files and folders pointers in alsl cabs so they all
// point to the same list
for (cab = lcab.PreviousCabinet; cab != null; cab = cab.PreviousCabinet)
for (Cabinet cab = lcab.PreviousCabinet; cab != null; cab = cab.PreviousCabinet)
{
cab.Files = lcab.Files;
cab.Folders = lcab.Folders;
}
for (cab = lcab.NextCabinet; cab != null; cab = cab.NextCabinet)
for (Cabinet cab = lcab.NextCabinet; cab != null; cab = cab.NextCabinet)
{
cab.Files = lcab.Files;
cab.Folders = lcab.Folders;
@@ -1224,9 +1197,8 @@ namespace LibMSPackSharp.CAB
private Error ReadHeaders(FileStream fh, Cabinet cab, long offset, bool salvage, bool quiet)
{
Error err = Error.MSPACK_ERR_OK;
Folder fol, linkfol = null;
Folder linkfol = null;
InternalFile linkfile = null;
byte[] buf = new byte[64];
// Initialise pointers
if (cab == null)
@@ -1241,18 +1213,21 @@ namespace LibMSPackSharp.CAB
cab.BaseOffset = offset;
#region Cabinet Header
// Seek to CFHEADER
if (!System.Seek(fh, offset, SeekMode.MSPACK_SYS_SEEK_START))
return Error.MSPACK_ERR_SEEK;
return Error = Error.MSPACK_ERR_SEEK;
// Read in the CFHEADER
byte[] buf = new byte[_CabinetHeader.Size];
if (System.Read(fh, buf, 0, _CabinetHeader.Size) != _CabinetHeader.Size)
return Error.MSPACK_ERR_READ;
return Error = Error.MSPACK_ERR_READ;
// Create a new header based on that
err = _CabinetHeader.Create(buf, out _CabinetHeader cabinetHeader);
if (err != Error.MSPACK_ERR_OK)
return err;
return Error = err;
// Assign the header
cab.Header = cabinetHeader;
@@ -1260,8 +1235,9 @@ namespace LibMSPackSharp.CAB
// Check for the extended header
if (cab.Header.Flags.HasFlag(HeaderFlags.MSCAB_HDR_RESV))
{
buf = new byte[_CabinetHeader.ExtendedSize];
if (System.Read(fh, buf, 0, _CabinetHeader.ExtendedSize) != _CabinetHeader.ExtendedSize)
return Error.MSPACK_ERR_READ;
return Error = Error.MSPACK_ERR_READ;
// Populate the extended header
cabinetHeader.PopulateExtendedHeader(buf);
@@ -1270,7 +1246,7 @@ namespace LibMSPackSharp.CAB
if (cab.Header.HeaderReserved != 0)
{
if (!System.Seek(fh, cab.Header.HeaderReserved, SeekMode.MSPACK_SYS_SEEK_CUR))
return Error.MSPACK_ERR_SEEK;
return Error = Error.MSPACK_ERR_SEEK;
}
}
@@ -1279,11 +1255,11 @@ namespace LibMSPackSharp.CAB
{
cab.PreviousName = ReadString(fh, false, ref err);
if (err != Error.MSPACK_ERR_OK)
return err;
return Error = err;
cab.PreviousInfo = ReadString(fh, true, ref err);
if (err != Error.MSPACK_ERR_OK)
return err;
return Error = err;
}
// Read name and info of next cabinet in set, if present
@@ -1291,159 +1267,195 @@ namespace LibMSPackSharp.CAB
{
cab.NextName = ReadString(fh, false, ref err);
if (err != Error.MSPACK_ERR_OK)
return err;
return Error = err;
cab.NextInfo = ReadString(fh, true, ref err);
if (err != Error.MSPACK_ERR_OK)
return err;
return Error = err;
}
#endregion
#region Folder and File Pointers
// Read folders
for (int i = 0; i < cab.Header.NumFolders; i++)
{
// Read in the FOHEADER
if (System.Read(fh, buf, 0, _FolderHeader.Size) != _FolderHeader.Size)
return Error.MSPACK_ERR_READ;
if (cab.Header.FolderReserved != 0)
{
if (!System.Seek(fh, cab.Header.FolderReserved, SeekMode.MSPACK_SYS_SEEK_CUR))
return Error.MSPACK_ERR_SEEK;
}
// Create an empty folder
fol = new Folder()
{
Next = null,
MergePrev = null,
MergeNext = null,
};
// Create a new header based on that
err = _FolderHeader.Create(buf, out _FolderHeader folderHeader);
err = ReadSingleFolder(fh, cab, offset, ref linkfol);
if (err != Error.MSPACK_ERR_OK)
return err;
// Assign the header
fol.Header = folderHeader;
// Set the folder data fields
fol.Data = new FolderData();
fol.Data.Next = null;
fol.Data.Cab = cab;
fol.Data.Offset = offset + fol.Header.DataOffset;
// Link folder into list of folders
if (linkfol == null)
cab.Folders = fol;
else
linkfol.Next = fol;
linkfol = fol;
return Error = err;
}
// Read files
for (int i = 0; i < cab.Header.NumFiles; i++)
{
// Read in the FIHEADER
if (System.Read(fh, buf, 0, _FileHeader.Size) != _FileHeader.Size)
return Error.MSPACK_ERR_READ;
InternalFile file = new InternalFile() { Next = null };
// Create a new header based on that
err = _FileHeader.Create(buf, out _FileHeader fileHeader);
err = ReadSingleFile(fh, cab, salvage, ref linkfile);
if (err != Error.MSPACK_ERR_OK)
return err;
// Assign the header
file.Header = fileHeader;
// Set folder pointer
if (file.Header.FolderIndex < FileFlags.CONTINUED_FROM_PREV)
{
// Normal folder index; count up to the correct folder
if ((int)file.Header.FolderIndex < cab.Header.NumFolders)
{
Folder ifol = cab.Folders;
while (file.Header.FolderIndex-- != 0)
{
if (ifol != null)
ifol = ifol.Next;
}
file.Folder = ifol;
}
else
{
Console.WriteLine("Invalid folder index");
file.Folder = null;
}
}
else
{
// Either CONTINUED_TO_NEXT, CONTINUED_FROM_PREV or CONTINUED_PREV_AND_NEXT
if (file.Header.FolderIndex == FileFlags.CONTINUED_TO_NEXT || file.Header.FolderIndex == FileFlags.CONTINUED_PREV_AND_NEXT)
{
// Get last folder
Folder ifol = cab.Folders;
while (ifol.Next != null)
{
ifol = ifol.Next;
}
file.Folder = ifol;
// Set "merge next" pointer
fol = ifol;
if (fol.MergeNext == null)
fol.MergeNext = file;
}
if (file.Header.FolderIndex == FileFlags.CONTINUED_FROM_PREV || file.Header.FolderIndex == FileFlags.CONTINUED_PREV_AND_NEXT)
{
// Get first folder
file.Folder = cab.Folders;
// Set "merge prev" pointer
fol = file.Folder;
if (fol.MergePrev == null)
fol.MergePrev = file;
}
}
// Get filename
file.Filename = ReadString(fh, false, ref err);
// If folder index or filename are bad, either skip it or fail
if (err != Error.MSPACK_ERR_OK || file.Folder == null)
{
if (salvage)
continue;
return err != Error.MSPACK_ERR_OK ? err : Error.MSPACK_ERR_DATAFORMAT;
}
// Link file entry into file list
if (linkfile == null)
cab.Files = file;
else
linkfile.Next = file;
linkfile = file;
return Error = err;
}
if (cab.Files == null)
{
// We never actually added any files to the file list. Something went wrong.
// The file header may have been invalid */
// The file header may have been invalid
Console.WriteLine($"No files found, even though header claimed to have {cab.Header.NumFiles} files");
return Error.MSPACK_ERR_DATAFORMAT;
}
#endregion
return Error.MSPACK_ERR_OK;
}
/// <summary>
/// Read and process a single file
/// </summary>
private Error ReadSingleFile(FileStream fh, Cabinet cab, bool salvage, ref InternalFile linkfile)
{
// Read in the FIHEADER
byte[] buf = new byte[64];
if (System.Read(fh, buf, 0, _FileHeader.Size) != _FileHeader.Size)
return Error.MSPACK_ERR_READ;
InternalFile file = new InternalFile() { Next = null };
// Create a new header based on that
Error err = _FileHeader.Create(buf, out _FileHeader fileHeader);
if (err != Error.MSPACK_ERR_OK)
return err;
// Assign the header
file.Header = fileHeader;
// Set folder pointer
if (file.Header.FolderIndex < FileFlags.CONTINUED_FROM_PREV)
{
// Normal folder index; count up to the correct folder
if ((int)file.Header.FolderIndex < cab.Header.NumFolders)
{
Folder ifol = cab.Folders;
while (file.Header.FolderIndex-- != 0)
{
if (ifol != null)
ifol = ifol.Next;
}
file.Folder = ifol;
}
else
{
Console.WriteLine("Invalid folder index");
file.Folder = null;
}
}
else
{
// Either CONTINUED_TO_NEXT, CONTINUED_FROM_PREV or CONTINUED_PREV_AND_NEXT
if (file.Header.FolderIndex == FileFlags.CONTINUED_TO_NEXT || file.Header.FolderIndex == FileFlags.CONTINUED_PREV_AND_NEXT)
{
// Get last folder
Folder ifol = cab.Folders;
while (ifol.Next != null)
{
ifol = ifol.Next;
}
file.Folder = ifol;
// Set "merge next" pointer
Folder fol = ifol;
if (fol.MergeNext == null)
fol.MergeNext = file;
}
if (file.Header.FolderIndex == FileFlags.CONTINUED_FROM_PREV || file.Header.FolderIndex == FileFlags.CONTINUED_PREV_AND_NEXT)
{
// Get first folder
file.Folder = cab.Folders;
// Set "merge prev" pointer
Folder fol = file.Folder;
if (fol.MergePrev == null)
fol.MergePrev = file;
}
}
// Get filename
file.Filename = ReadString(fh, false, ref err);
// If folder index or filename are bad, either skip it or fail
if (err != Error.MSPACK_ERR_OK || file.Folder == null)
{
if (salvage)
return Error.MSPACK_ERR_OK;
return err != Error.MSPACK_ERR_OK ? err : Error.MSPACK_ERR_DATAFORMAT;
}
// Link file entry into file list
if (linkfile == null)
cab.Files = file;
else
linkfile.Next = file;
linkfile = file;
return Error.MSPACK_ERR_OK;
}
/// <summary>
/// Read and process a single folder
/// </summary>
private Error ReadSingleFolder(FileStream fh, Cabinet cab, long offset, ref Folder linkfol)
{
// Read in the FOHEADER
byte[] buf = new byte[64];
if (System.Read(fh, buf, 0, _FolderHeader.Size) != _FolderHeader.Size)
return Error.MSPACK_ERR_READ;
if (cab.Header.FolderReserved != 0)
{
if (!System.Seek(fh, cab.Header.FolderReserved, SeekMode.MSPACK_SYS_SEEK_CUR))
return Error.MSPACK_ERR_SEEK;
}
// Create an empty folder
Folder fol = new Folder()
{
Next = null,
MergePrev = null,
MergeNext = null,
};
// Create a new header based on that
Error err = _FolderHeader.Create(buf, out _FolderHeader folderHeader);
if (err != Error.MSPACK_ERR_OK)
return err;
// Assign the header
fol.Header = folderHeader;
// Set the folder data fields
fol.Data = new FolderData()
{
Next = null,
Cab = cab,
Offset = offset + fol.Header.DataOffset,
};
// Link folder into list of folders
if (linkfol == null)
cab.Folders = fol;
else
linkfol.Next = fol;
linkfol = fol;
return Error.MSPACK_ERR_OK;
}
/// <summary>
/// Read a possibly empty string from the input
/// </summary>
private string ReadString(FileStream fh, bool permitEmpty, ref Error error)
{
long position = System.Tell(fh);