Merge branch 'main' into sb/zen-helpsb/zen-help

- Combine HelpCommand (this branch) with HistoryCommand (main) in zen CLI dispatcher
- Keep filter-aware TuiPickOne rewrite; adopt main's ASCII arrow glyphs in doc comment

1 files changed, 228 insertions, 0 deletions

diff --git a/src/zenhttp/zipfs.cpp b/src/zenhttp/zipfs.cpp
new file mode 100644
index 000000000..c0ffa2052
--- /dev/null
+++ b/src/zenhttp/zipfs.cpp
@@ -0,0 +1,228 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "zenhttp/zipfs.h"
+
+#include <zencore/logging.h>
+
+ZEN_THIRD_PARTY_INCLUDES_START
+#include <zlib.h>
+ZEN_THIRD_PARTY_INCLUDES_END
+
+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 || Cd.CompressionMethod == 8);	 // stored or deflate
+		if (Acceptable)
+		{
+			const uint8_t* Lfh = Cursor + Cd.Offset;
+			if (uintptr_t(Lfh - Cursor) < View.GetSize())
+			{
+				std::string_view FileName(Cd.FileName, Cd.FileNameLength);
+				FileItem		 Item;
+				Item.View			   = MemoryView{Lfh, size_t(0)};
+				Item.CompressionMethod = Cd.CompressionMethod;
+				Item.CompressedSize	   = Cd.CompressedSize;
+				Item.UncompressedSize  = Cd.OriginalSize;
+				m_Files.insert(std::make_pair(FileName, std::move(Item)));
+			}
+		}
+
+		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
+{
+	{
+		RwLock::SharedLockScope _(m_FilesLock);
+
+		FileMap::const_iterator Iter = m_Files.find(FileName);
+		if (Iter == m_Files.end())
+		{
+			return {};
+		}
+
+		const FileItem& Item = Iter->second;
+		if (Item.View.GetSize() > 0)
+		{
+			return IoBuffer(IoBuffer::Wrap, Item.View.GetData(), Item.View.GetSize());
+		}
+	}
+
+	RwLock::ExclusiveLockScope _(m_FilesLock);
+
+	FileItem& Item = m_Files.find(FileName)->second;
+	if (Item.View.GetSize() > 0)
+	{
+		return IoBuffer(IoBuffer::Wrap, Item.View.GetData(), Item.View.GetSize());
+	}
+
+	const auto*	   Lfh		= (LocalFileHeader*)(Item.View.GetData());
+	const uint8_t* FileData = (const uint8_t*)(Lfh->FileName + Lfh->FileNameLength + Lfh->ExtraFieldLength);
+
+	if (Item.CompressionMethod == 0)
+	{
+		// Stored - point directly into the buffer
+		Item.View = MemoryView(FileData, Item.UncompressedSize);
+	}
+	else
+	{
+		// Deflate - decompress using zlib
+		Item.DecompressedData = IoBuffer(Item.UncompressedSize);
+
+		z_stream Stream	 = {};
+		Stream.next_in	 = const_cast<Bytef*>(FileData);
+		Stream.avail_in	 = Item.CompressedSize;
+		Stream.next_out	 = (Bytef*)Item.DecompressedData.GetMutableView().GetData();
+		Stream.avail_out = Item.UncompressedSize;
+
+		// Use raw inflate (-MAX_WBITS) since zip stores raw deflate streams
+		if (inflateInit2(&Stream, -MAX_WBITS) != Z_OK)
+		{
+			ZEN_WARN("failed to initialize inflate for '{}'", FileName);
+			return {};
+		}
+
+		int Result = inflate(&Stream, Z_FINISH);
+		inflateEnd(&Stream);
+
+		if (Result != Z_STREAM_END)
+		{
+			ZEN_WARN("failed to decompress '{}' (zlib error {})", FileName, Result);
+			return {};
+		}
+
+		Item.View = Item.DecompressedData.GetView();
+	}
+
+	return IoBuffer(IoBuffer::Wrap, Item.View.GetData(), Item.View.GetSize());
+}
+
+}  // namespace zen