libropkg: implement compressed file streams and tar-writer functionality

libropkg/stream.h

@@ -0,0 +1,39 @@
+#ifndef _ROPKG_STREAM_H_
+#define _ROPKG_STREAM_H_
+
+#include <ropkg/stream.h>
+#include <stdio.h>
+
+struct ropkg_compression_function;
+struct ropkg_compression_stream;
+
+enum ropkg_stream_flags {
+	ROPKG_STREAM_F_CURSOR_MOVED = 0x01u,
+};
+
+struct ropkg_stream_compressor {
+	const struct ropkg_compression_function *c_func;
+	struct ropkg_compression_stream *c_stream;
+
+	size_t c_in_max, c_out_max;
+	void *c_in_buf, *c_out_buf;
+	size_t c_in_count;
+
+	size_t c_nr_written_compressed, c_nr_written_uncompressed;
+};
+
+struct ropkg_stream {
+	FILE *s_fp;
+	enum ropkg_stream_flags s_flags;
+	enum ropkg_stream_mode s_mode;
+
+	unsigned int s_compression_depth;
+	struct ropkg_stream_compressor s_compressor;
+
+	size_t s_saved_cursor;
+	size_t s_nr_written;
+	size_t s_nr_written_compressed;
+	size_t s_nr_written_uncompressed;
+};
+
+#endif