common/zstd_compression: simplify decompression interface

src/common/zstd_compression.cpp

@@ -13,7 +13,6 @@
 namespace Common::Compression {
 
 std::vector<u8> CompressDataZSTD(const u8* source, std::size_t source_size, s32 compression_level) {
-
     compression_level = std::clamp(compression_level, 1, ZSTD_maxCLevel());
 
     const std::size_t max_compressed_size = ZSTD_compressBound(source_size);
@@ -36,17 +35,19 @@ std::vector<u8> CompressDataZSTDDefault(const u8* source, std::size_t source_siz
     return CompressDataZSTD(source, source_size, ZSTD_CLEVEL_DEFAULT);
 }
 
-std::vector<u8> DecompressDataZSTD(const std::vector<u8>& compressed,
-                                   std::size_t uncompressed_size) {
-    std::vector<u8> uncompressed(uncompressed_size);
+std::vector<u8> DecompressDataZSTD(const std::vector<u8>& compressed) {
+    const std::size_t decompressed_size =
+        ZSTD_getDecompressedSize(compressed.data(), compressed.size());
+    std::vector<u8> decompressed(decompressed_size);
+
     const std::size_t uncompressed_result_size = ZSTD_decompress(
-        uncompressed.data(), uncompressed.size(), compressed.data(), compressed.size());
+        decompressed.data(), decompressed.size(), compressed.data(), compressed.size());
 
-    if (uncompressed_size != uncompressed_result_size || ZSTD_isError(uncompressed_result_size)) {
+    if (decompressed_size != uncompressed_result_size || ZSTD_isError(uncompressed_result_size)) {
         // Decompression failed
         return {};
     }
-    return uncompressed;
+    return decompressed;
 }
 
 } // namespace Common::Compression

src/common/zstd_compression.h

@@ -34,11 +34,9 @@ std::vector<u8> CompressDataZSTDDefault(const u8* source, std::size_t source_siz
  * Decompresses a source memory region with Zstandard and returns the uncompressed data in a vector.
  *
  * @param compressed the compressed source memory region.
- * @param uncompressed_size the size in bytes of the uncompressed data.
  *
  * @return the decompressed data.
  */
-std::vector<u8> DecompressDataZSTD(const std::vector<u8>& compressed,
-                                   std::size_t uncompressed_size);
+std::vector<u8> DecompressDataZSTD(const std::vector<u8>& compressed);
 
 } // namespace Common::Compression

src/video_core/renderer_opengl/gl_shader_disk_cache.cpp

@@ -259,7 +259,7 @@ ShaderDiskCacheOpenGL::LoadPrecompiledFile(FileUtil::IOFile& file) {
                 return {};
             }
 
-            dump.binary = Common::Compression::DecompressDataZSTD(compressed_binary, binary_length);
+            dump.binary = Common::Compression::DecompressDataZSTD(compressed_binary);
             if (dump.binary.empty()) {
                 return {};
             }
@@ -288,8 +288,7 @@ std::optional<ShaderDiskCacheDecompiled> ShaderDiskCacheOpenGL::LoadDecompiledEn
         return {};
     }
 
-    const std::vector<u8> code =
-        Common::Compression::DecompressDataZSTD(compressed_code, code_size);
+    const std::vector<u8> code = Common::Compression::DecompressDataZSTD(compressed_code);
     if (code.empty()) {
         return {};
     }