1 files changed, 65 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..47bf7a7
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,65 @@
+#include <errno.h>
+#include "defs.h"
+#include "util.h"
+#include "cache.h"
+#include "stream.h"
+
+int stream_rewind(struct stream * const restrict in)
+{
+	int ret = 0;
+
+	in->cnode = in->cnode ? in->cache_l : NULL;
+	in->index = 0;
+
+	return ret;
+}
+
+int split(struct stream * const src, struct stream * const A, struct stream * const B)
+{
+	int ret = 0;
+	struct settings tmp_settings[2];
+
+	try(src->n < 2, err, EINVAL, "cannot split single element stream.");
+
+	/* setting up minimal stream basics */
+	A->n = src->n / 2;
+	B->n = src->n / 2 + (src->n & 1ul);
+	A->index = B->index = 0;
+	/* we only care about these three functions for these temporary streams */
+	A->get = B->get = src->get;
+	A->put = B->put = src->put;
+	A->copy = B->copy = src->copy;
+
+	tmp_settings[0] = *src->settings;
+	tmp_settings[1] = *src->settings;
+	A->settings = tmp_settings;
+	B->settings = tmp_settings + 1;
+
+	/* setting up A */
+	tmp_settings[0].ss = 0;
+	tmp_settings[0].to = A->n;
+	/* setting up B */
+	tmp_settings[1].ss = A->n;
+	tmp_settings[1].to = src->n;
+
+	if (src->settings->access == cached) {
+		A->fd = B->fd = -1; /* if we're splitting, these are for holding cache only */
+		A->type = B->type = stream_cache;
+		try_s((ret = cache_create(A)), err);
+		try_s((ret = src->copy(src, A)), err);
+		try_s((ret = cache_create(B)), err);
+		try_s((ret = src->copy(src, B)), err);
+	} else {
+		A->name = B->name = src->name;
+		A->type = B->type = stream_lite;
+		try_s((ret = stream_open(A)), err);
+		try_s((ret = src->copy(src, A)), err);
+		try_s((ret = stream_open(B)), err);
+		try_s((ret = src->copy(src, B)), err);
+	}
+
+	A->settings = B->settings = src->settings;
+
+err:
+	return ret;
+}