From 6991f819f3f7e292a8f7d714062229420c2f4bc0 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Tue, 12 Apr 2022 18:41:22 +1000
Subject: [PATCH] SaveState: Switch to zstd compression

zstd can be 10x+ fast compressing, 2x+ decompressing at default levels,
and provides slightly better ratios.

There's a hidden option in the config, SavestateZstdCompression, which
you can set to false if you want to use deflate.
---
 pcsx2/Config.h        | 1 +
 pcsx2/Pcsx2Config.cpp | 2 ++
 pcsx2/SaveState.cpp   | 7 +++----
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/pcsx2/Config.h b/pcsx2/Config.h
index 8ee823d5e1..c771b2a291 100644
--- a/pcsx2/Config.h
+++ b/pcsx2/Config.h
@@ -939,6 +939,7 @@ struct Pcsx2Config
 		// when enabled uses BOOT2 injection, skipping sony bios splashes
 		UseBOOT2Injection : 1,
 		BackupSavestate : 1,
+		SavestateZstdCompression : 1,
 		// enables simulated ejection of memory cards when loading savestates
 		McdEnableEjection : 1,
 		McdFolderAutoManage : 1,
diff --git a/pcsx2/Pcsx2Config.cpp b/pcsx2/Pcsx2Config.cpp
index 2a3d2a9988..efa4c69a22 100644
--- a/pcsx2/Pcsx2Config.cpp
+++ b/pcsx2/Pcsx2Config.cpp
@@ -1021,6 +1021,7 @@ Pcsx2Config::Pcsx2Config()
 	EnableGameFixes = true;
 #endif
 	BackupSavestate = true;
+	SavestateZstdCompression = true;
 
 #ifdef __WXMSW__
 	McdCompressNTFS = true;
@@ -1060,6 +1061,7 @@ void Pcsx2Config::LoadSave(SettingsWrapper& wrap)
 	SettingsWrapBitBool(HostFs);
 
 	SettingsWrapBitBool(BackupSavestate);
+	SettingsWrapBitBool(SavestateZstdCompression);
 	SettingsWrapBitBool(McdEnableEjection);
 	SettingsWrapBitBool(McdFolderAutoManage);
 	SettingsWrapBitBool(MultitapPort0_Enabled);
diff --git a/pcsx2/SaveState.cpp b/pcsx2/SaveState.cpp
index bb7cddb13a..a9d5d78878 100644
--- a/pcsx2/SaveState.cpp
+++ b/pcsx2/SaveState.cpp
@@ -806,10 +806,9 @@ static void ZipStateToDiskOnThread(std::unique_ptr<ArchiveEntryList> srclist, st
 	// discard zip file if we fail saving something
 	ScopedGuard zip_discarder([&zf]() { zip_discard(zf.release()); });
 
-	// use deflate compression by default
-	// TODO: switch to zstd
-	constexpr u32 compression = ZIP_CM_DEFLATE;
-	constexpr u32 compression_level = 0;
+	// use zstd compression, it can be 10x+ faster for saving.
+	const u32 compression = EmuConfig.SavestateZstdCompression ? ZIP_CM_ZSTD : ZIP_CM_DEFLATE;
+	const u32 compression_level = 0;
 
 	// version indicator
 	{