added mbuf_remove_range() to remove data other than at index 0

Author: rtrue983

common/mbuf.c

@@ -137,6 +137,21 @@ void mbuf_remove(struct mbuf *mb, size_t n) {
   }
 }
 
+size_t mbuf_remove_range(struct mbuf *mb, size_t i, size_t n) WEAK;
+size_t mbuf_remove_range(struct mbuf *mb, size_t i, size_t n) {
+  size_t ret = 0;
+  if (n > 0 && n <= (mb->len - i)) {
+    memmove(&mb->buf[i], &mb->buf[i] + n, mb->len - n);
+    mb->len -= n;
+    ret = n;
+  }
+  else if (n > 0 && n >= (mb->len - i)) {
+    ret = mb->len - i;
+    mb->len -= ret;
+  }
+  return ret;
+}
+
 void mbuf_clear(struct mbuf *mb) WEAK;
 void mbuf_clear(struct mbuf *mb) {
   mb->len = 0;

common/mbuf.h

@@ -87,6 +87,9 @@ size_t mbuf_insert(struct mbuf *, size_t, const void *, size_t);
 /* Removes `data_size` bytes from the beginning of the buffer. */
 void mbuf_remove(struct mbuf *, size_t data_size);
 
+/* Removes 'data_size' bytes from index of the buffer */
+size_t mbuf_remove_range(struct mbuf *, size_t index, size_t data_size);
+
 /*
  * Resizes an Mbuf.
  *