-void compressZlib(SharedBuffer<u8> data, std::ostream &os);
-void compressZlib(const std::string &data, std::ostream &os);
-void decompressZlib(std::istream &is, std::ostream &os);
+void compressZlib(const u8 *data, size_t data_size, std::ostream &os, int level = -1);
+void compressZlib(const std::string &data, std::ostream &os, int level = -1);
+void decompressZlib(std::istream &is, std::ostream &os, size_t limit = 0);