1 files changed, 83 insertions, 0 deletions
diff --git a/src/iobuf.c b/src/iobuf.c
new file mode 100644
index 0000000..38aa296
--- /dev/null
+++ b/src/iobuf.c
@@ -0,0 +1,83 @@
+#include "iobuf.h"
+#include "util_ct.h"
+#include "util_rt.h"
+
+#include <string.h>
+
+
+void prne_init_iobuf (prne_iobuf_t *ib){
+	prne_memzero(ib ,sizeof(prne_iobuf_t));
+}
+
+void prne_free_iobuf (prne_iobuf_t *ib) {
+	if (ib->ownership) {
+		prne_free(ib->m);
+		ib->m = NULL;
+		ib->size = 0;
+		ib->avail = 0;
+		ib->len = 0;
+	}
+}
+
+bool prne_alloc_iobuf (prne_iobuf_t *ib, const size_t ny_size) {
+	uint8_t *ny;
+
+	ny = (uint8_t*)prne_realloc(ib->ownership ? ib->m : NULL, 1, ny_size);
+	if (ny == NULL) {
+		return false;
+	}
+
+	if (!ib->ownership) {
+		memcpy(ny, ib->m, prne_op_min(ny_size, ib->size));
+	}
+
+	if (ib->size < ny_size) {
+		ib->avail += ny_size - ib->size;
+	}
+	else {
+		ib->avail -= ib->size - ny_size;
+	}
+	ib->m = ny;
+	ib->size = ny_size;
+	ib->ownership = true;
+
+	return true;
+}
+
+void prne_iobuf_setextbuf (
+	prne_iobuf_t *ib,
+	uint8_t *m,
+	const size_t size,
+	const size_t len)
+{
+	prne_dbgast(size >= len);
+	prne_free_iobuf(ib);
+	ib->m = m;
+	ib->size = size;
+	ib->len = len;
+	ib->avail = size - len;
+	ib->ownership = false;
+}
+
+void prne_iobuf_reset (prne_iobuf_t *ib) {
+	ib->avail = ib->size;
+	ib->len = 0;
+}
+
+void prne_iobuf_shift (prne_iobuf_t *ib, const ssize_t amount) {
+	if (amount == 0) {
+		return;
+	}
+	else if (amount > 0) {
+		prne_dbgast(ib->avail >= (size_t)amount);
+	}
+	else {
+		prne_dbgast(ib->len >= (size_t)(amount * -1));
+	}
+
+	ib->len += amount;
+	ib->avail -= amount;
+	if (amount < 0) {
+		memmove(ib->m, ib->m + (-amount), ib->len);
+	}
+}