From 4f8305de5f30909d3ae3fb99a8ee00a52975bc17 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sun, 20 Aug 2023 02:04:19 +0200
Subject: [PATCH] - use the lump cache directly for FileData.

This was the final puzzle piece to allow using memory mapped files. :)
---
 src/common/filesystem/filesystem.cpp | 23 -------------------
 src/common/filesystem/filesystem.h   | 34 ++++++++++++++++++++--------
 2 files changed, 25 insertions(+), 32 deletions(-)

diff --git a/src/common/filesystem/filesystem.cpp b/src/common/filesystem/filesystem.cpp
index 6c67b9f455..097b6ffe5a 100644
--- a/src/common/filesystem/filesystem.cpp
+++ b/src/common/filesystem/filesystem.cpp
@@ -1518,29 +1518,6 @@ bool FileSystem::CreatePathlessCopy(const char *name, int id, int /*flags*/)
 	return true;
 }
 
-// FileData -----------------------------------------------------------------
-
-FileData::FileData (const FileData &copy)
-{
-	Block = copy.Block;
-}
-
-FileData &FileData::operator = (const FileData &copy)
-{
-	Block = copy.Block;
-	return *this;
-}
-
-FileData::FileData (FResourceLump* lump)
-{
-	auto size = lump->LumpSize;
-	Block.resize(1 + size);
-	memcpy(Block.data(), lump->Lock(), size);
-	Block[size] = 0;
-	lump->Unlock();
-}
-
-
 //==========================================================================
 //
 // PrintLastError
diff --git a/src/common/filesystem/filesystem.h b/src/common/filesystem/filesystem.h
index eb3b119a6a..29b9b8b4ec 100644
--- a/src/common/filesystem/filesystem.h
+++ b/src/common/filesystem/filesystem.h
@@ -28,18 +28,34 @@ union LumpShortName
 class FileData
 {
 public:
-	FileData () = default;
-	FileData (const FileData &copy);
-	FileData &operator= (const FileData &copy);
-	const void *GetMem () { return Block.size() <= 1 ? NULL : (void *)Block.data(); }
-	size_t GetSize () { return Block.size(); }
-	const char* GetString () const { return (const char*)Block.data(); }
-	const uint8_t* GetBytes() const { return Block.data(); }
+	FileData() { lump = nullptr; }
+	const void *GetMem () { return lump->Cache; }
+	size_t GetSize () { return lump->LumpSize; }
+	const char* GetString () const { return (const char*)lump->Cache; }
+	const uint8_t* GetBytes() const { return (const uint8_t*)lump->Cache; }
+
+	FileData& operator = (const FileData& copy) = delete;
+
+	FileData(const FileData& copy)
+	{
+		lump = copy.lump;
+		lump->Lock();
+	}
+
+	~FileData()
+	{
+		if (lump) lump->Unlock();
+	}
+
 
 private:
-	FileData (FResourceLump* lump);
+	FileData(FResourceLump* nlump)
+	{
+		lump = nlump;
+		if (lump) lump->Lock();
+	}
 
-	std::vector<uint8_t> Block;
+	FResourceLump* lump;
 
 	friend class FileSystem;
 };