Feat: lab 3 w/o adv 2

kernel/lib/ringbuffer.c

@@ -0,0 +1,47 @@
+#include <ringbuffer.h>
+#include <utils.h>
+#include <errcode.h>
+#include <stddef.h>
+#include <kmalloc.h>
+
+ringbuffer_t *make_ringbuffer(size_t size)
+{
+  ringbuffer_t *ret = kmalloc(sizeof(ringbuffer_t));
+  uint8_t *data = kmalloc(size * sizeof(uint8_t));
+  *ret = (ringbuffer_t){
+    .size = 0,
+    .cap = size,
+    .data = data,
+    .read = data,
+    .write = data,
+  };
+  return ret;
+}
+
+int ringbuffer_push(ringbuffer_t *buf, uint8_t val)
+{
+  if (buf->size == buf->cap)
+    return ERR_OUT_OF_BOUND;
+
+  *buf->write++ = val;
+  ++buf->size;
+
+  if (buf->write == buf->data + buf->cap)
+    buf->write = buf->data;
+
+  return NO_ERROR;
+}
+
+uint8_t ringbuffer_bump(ringbuffer_t *buf)
+{
+  if (buf->size == 0)
+    exit(ERR_INVALID_OP);
+
+  uint8_t ret = *buf->read++;
+  --buf->size;
+
+  if (buf->read == buf->data + buf->cap)
+    buf->read = buf->data;
+
+  return ret;
+}