loader/util: support regular zstd alongside zbic

libraries/libstratosphere/source/util/util_compression_zstd.cpp

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#define ZSTD_STATIC_LINKING_ONLY
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#define ZSTDLIB_VISIBLE   static
+#define ZSTDLIB_HIDDEN    static
+#include "zstd.h"
+#include "zstd.inc"
+#pragma GCC diagnostic pop
+
+namespace ams::util {
+
+    size_t CompressZstd(void *dst, size_t dst_size, const void *src, size_t src_size) {
+        /* Basic size checks. */
+        AMS_ABORT_UNLESS(dst_size <= std::numeric_limits<int>::max());
+        AMS_ABORT_UNLESS(src_size <= std::numeric_limits<int>::max());
+        
+        /* Additionally, we must check the compression boundary. */ 
+        auto bound = ZSTD_compressBound(src_size);
+        AMS_ABORT_UNLESS(!ZSTD_isError(bound));
+        AMS_ABORT_UNLESS(dst_size >= bound);
+
+        /* Use Zstd default level. */
+        int compressionLevel = 3;
+        
+        /* This is just a wrapper around Zstd. */
+        return ZSTD_compress(dst, dst_size, src, src_size, compressionLevel);
+    }
+    
+    size_t DecompressZstd(void *dst, size_t dst_size, const void *src, size_t src_size) {
+        /* Basic size checks. */
+        AMS_ABORT_UNLESS(dst_size <= std::numeric_limits<int>::max());
+        AMS_ABORT_UNLESS(src_size <= std::numeric_limits<int>::max());
+        
+        /* Additionally, we must check the decompression boundary. */ 
+        auto bound = ZSTD_decompressBound(src, src_size);
+        AMS_ABORT_UNLESS(!ZSTD_isError(bound));
+        AMS_ABORT_UNLESS(dst_size >= bound);
+        
+        /* This is just a wrapper around Zstd. */
+        return ZSTD_decompress(dst, dst_size, src, src_size);
+    }
+
+}