libropkg: implement compressed file streams and tar-writer functionality

libropkg/compress.h

@@ -0,0 +1,36 @@
+#ifndef COMPRESS_H_
+#define COMPRESS_H_
+
+#include <ropkg/compress.h>
+
+struct ropkg_compression_function {
+	const char *f_name;
+	const char *f_extension;
+	enum ropkg_status (*f_buffer_size)(
+		enum ropkg_compression_stream_mode,
+		size_t *,
+		size_t *);
+	enum ropkg_status (*f_open)(
+		const struct ropkg_compression_function *,
+		enum ropkg_compression_stream_mode,
+		void *,
+		size_t,
+		void *,
+		size_t,
+		struct ropkg_compression_stream **);
+	enum ropkg_status (*f_close)(struct ropkg_compression_stream *);
+	enum ropkg_status (*f_process)(
+		struct ropkg_compression_stream *,
+		size_t,
+		enum ropkg_compression_stream_op,
+		size_t *);
+};
+
+struct ropkg_compression_stream {
+	const struct ropkg_compression_function *s_func;
+	enum ropkg_compression_stream_mode s_mode;
+	void *s_in, *s_out;
+	size_t s_in_max, s_out_max;
+};
+
+#endif