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authorStefan Boberg <[email protected]>2023-05-02 10:01:47 +0200
committerGitHub <[email protected]>2023-05-02 10:01:47 +0200
commit075d17f8ada47e990fe94606c3d21df409223465 (patch)
treee50549b766a2f3c354798a54ff73404217b4c9af /src/zenserver/frontend/zipfs.cpp
parentfix: bundle shouldn't append content zip to zen (diff)
downloadzen-075d17f8ada47e990fe94606c3d21df409223465.tar.xz
zen-075d17f8ada47e990fe94606c3d21df409223465.zip
moved source directories into `/src` (#264)
* moved source directories into `/src` * updated bundle.lua for new `src` path * moved some docs, icon * removed old test trees
Diffstat (limited to 'src/zenserver/frontend/zipfs.cpp')
-rw-r--r--src/zenserver/frontend/zipfs.cpp169
1 files changed, 169 insertions, 0 deletions
diff --git a/src/zenserver/frontend/zipfs.cpp b/src/zenserver/frontend/zipfs.cpp
new file mode 100644
index 000000000..f9c2bc8ff
--- /dev/null
+++ b/src/zenserver/frontend/zipfs.cpp
@@ -0,0 +1,169 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "zipfs.h"
+
+namespace zen {
+
+//////////////////////////////////////////////////////////////////////////
+namespace {
+
+#if ZEN_COMPILER_MSC
+# pragma warning(push)
+# pragma warning(disable : 4200)
+#endif
+
+ using ZipInt16 = uint16_t;
+
+ struct ZipInt32
+ {
+ operator uint32_t() const { return *(uint32_t*)Parts; }
+ uint16_t Parts[2];
+ };
+
+ struct EocdRecord
+ {
+ enum : uint32_t
+ {
+ Magic = 0x0605'4b50,
+ };
+ ZipInt32 Signature;
+ ZipInt16 ThisDiskIndex;
+ ZipInt16 CdStartDiskIndex;
+ ZipInt16 CdRecordThisDiskCount;
+ ZipInt16 CdRecordCount;
+ ZipInt32 CdSize;
+ ZipInt32 CdOffset;
+ ZipInt16 CommentSize;
+ char Comment[];
+ };
+
+ struct CentralDirectoryRecord
+ {
+ enum : uint32_t
+ {
+ Magic = 0x0201'4b50,
+ };
+
+ ZipInt32 Signature;
+ ZipInt16 VersionMadeBy;
+ ZipInt16 VersionRequired;
+ ZipInt16 Flags;
+ ZipInt16 CompressionMethod;
+ ZipInt16 LastModTime;
+ ZipInt16 LastModDate;
+ ZipInt32 Crc32;
+ ZipInt32 CompressedSize;
+ ZipInt32 OriginalSize;
+ ZipInt16 FileNameLength;
+ ZipInt16 ExtraFieldLength;
+ ZipInt16 CommentLength;
+ ZipInt16 DiskIndex;
+ ZipInt16 InternalFileAttr;
+ ZipInt32 ExternalFileAttr;
+ ZipInt32 Offset;
+ char FileName[];
+ };
+
+ struct LocalFileHeader
+ {
+ enum : uint32_t
+ {
+ Magic = 0x0403'4b50,
+ };
+
+ ZipInt32 Signature;
+ ZipInt16 VersionRequired;
+ ZipInt16 Flags;
+ ZipInt16 CompressionMethod;
+ ZipInt16 LastModTime;
+ ZipInt16 LastModDate;
+ ZipInt32 Crc32;
+ ZipInt32 CompressedSize;
+ ZipInt32 OriginalSize;
+ ZipInt16 FileNameLength;
+ ZipInt16 ExtraFieldLength;
+ char FileName[];
+ };
+
+#if ZEN_COMPILER_MSC
+# pragma warning(pop)
+#endif
+
+} // namespace
+
+//////////////////////////////////////////////////////////////////////////
+ZipFs::ZipFs(IoBuffer&& Buffer)
+{
+ MemoryView View = Buffer.GetView();
+
+ uint8_t* Cursor = (uint8_t*)(View.GetData()) + View.GetSize();
+ if (View.GetSize() < sizeof(EocdRecord))
+ {
+ return;
+ }
+
+ const auto* EocdCursor = (EocdRecord*)(Cursor - sizeof(EocdRecord));
+
+ // It is more correct to search backwards for EocdRecord::Magic as the
+ // comment can be of a variable length. But here we're not going to support
+ // zip files with comments.
+ if (EocdCursor->Signature != EocdRecord::Magic)
+ {
+ return;
+ }
+
+ // Zip64 isn't supported either
+ if (EocdCursor->ThisDiskIndex == 0xffff)
+ {
+ return;
+ }
+
+ Cursor = (uint8_t*)EocdCursor - uint32_t(EocdCursor->CdOffset) - uint32_t(EocdCursor->CdSize);
+
+ const auto* CdCursor = (CentralDirectoryRecord*)(Cursor + EocdCursor->CdOffset);
+ for (int i = 0, n = EocdCursor->CdRecordCount; i < n; ++i)
+ {
+ const CentralDirectoryRecord& Cd = *CdCursor;
+
+ bool Acceptable = true;
+ Acceptable &= (Cd.OriginalSize > 0); // has some content
+ Acceptable &= (Cd.CompressionMethod == 0); // is stored uncomrpessed
+ if (Acceptable)
+ {
+ const uint8_t* Lfh = Cursor + Cd.Offset;
+ if (uintptr_t(Lfh - Cursor) < View.GetSize())
+ {
+ std::string_view FileName(Cd.FileName, Cd.FileNameLength);
+ m_Files.insert(std::make_pair(FileName, FileItem{Lfh, size_t(0)}));
+ }
+ }
+
+ uint32_t ExtraBytes = Cd.FileNameLength + Cd.ExtraFieldLength + Cd.CommentLength;
+ CdCursor = (CentralDirectoryRecord*)(Cd.FileName + ExtraBytes);
+ }
+
+ m_Buffer = std::move(Buffer);
+}
+
+//////////////////////////////////////////////////////////////////////////
+IoBuffer
+ZipFs::GetFile(const std::string_view& FileName) const
+{
+ FileMap::iterator Iter = m_Files.find(FileName);
+ if (Iter == m_Files.end())
+ {
+ return {};
+ }
+
+ FileItem& Item = Iter->second;
+ if (Item.GetSize() > 0)
+ {
+ return IoBuffer(IoBuffer::Wrap, Item.GetData(), Item.GetSize());
+ }
+
+ const auto* Lfh = (LocalFileHeader*)(Item.GetData());
+ Item = MemoryView(Lfh->FileName + Lfh->FileNameLength + Lfh->ExtraFieldLength, Lfh->OriginalSize);
+ return IoBuffer(IoBuffer::Wrap, Item.GetData(), Item.GetSize());
+}
+
+} // namespace zen