libropkg: implement compressed file streams and tar-writer functionality

libropkg/compress.c

@@ -0,0 +1,86 @@
+#include "compress.h"
+
+#include <ropkg/compress.h>
+#include <stdio.h>
+
+extern const struct ropkg_compression_function ropkg_zstd;
+
+static const struct ropkg_compression_function *functions[] = {
+	[ROPKG_COMPRESSION_ZSTD] = &ropkg_zstd,
+};
+static const size_t nr_functions = sizeof functions / sizeof functions[0];
+
+const struct ropkg_compression_function *ropkg_compression_function_for_type(
+	enum ropkg_compression_type type)
+{
+	if (type >= nr_functions) {
+		return NULL;
+	}
+
+	return functions[type];
+}
+
+enum ropkg_status ropkg_compression_function_get_buffer_size(
+	const struct ropkg_compression_function *func,
+	enum ropkg_compression_stream_mode mode,
+	size_t *in_buffer_size,
+	size_t *out_buffer_size)
+{
+	if (!func->f_buffer_size) {
+		return ROPKG_ERR_NOT_SUPPORTED;
+	}
+
+	return func->f_buffer_size(mode, in_buffer_size, out_buffer_size);
+}
+
+const char *ropkg_compression_function_get_file_extension(
+	const struct ropkg_compression_function *func)
+{
+	return func->f_extension;
+}
+
+enum ropkg_status ropkg_compression_stream_open(
+	const struct ropkg_compression_function *func,
+	void *in_buffer,
+	size_t in_max,
+	void *out_buffer,
+	size_t out_max,
+	enum ropkg_compression_stream_mode mode,
+	struct ropkg_compression_stream **out)
+{
+	if (!func->f_open) {
+		return ROPKG_ERR_NOT_SUPPORTED;
+	}
+
+	return func->f_open(
+		func,
+		mode,
+		in_buffer,
+		in_max,
+		out_buffer,
+		out_max,
+		out);
+}
+
+enum ropkg_status ropkg_compression_stream_process(
+	struct ropkg_compression_stream *stream,
+	size_t in_size,
+	enum ropkg_compression_stream_op op,
+	size_t *out_size)
+{
+	if (!stream->s_func->f_process) {
+		return ROPKG_ERR_NOT_SUPPORTED;
+	}
+
+	return stream->s_func->f_process(stream, in_size, op, out_size);
+}
+
+enum ropkg_status ropkg_compression_stream_close(
+	struct ropkg_compression_stream *stream)
+{
+	if (!stream->s_func->f_close) {
+		return ROPKG_ERR_NOT_SUPPORTED;
+	}
+
+	return stream->s_func->f_close(stream);
+}