aga: Add aga_node_needs_update() internal function

[ccan] / ccan / mem / mem.c

diff --git a/ccan/mem/mem.c b/ccan/mem/mem.c
index 5b4b3508090dfb10dc7eea9236eb42ed54b92834..5eb15070ed3c3f9f5bf8d2dd8b0d0f060ffa1766 100644 (file)
--- a/ccan/mem/mem.c
+++ b/ccan/mem/mem.c
@@ -88,3 +88,22 @@ void memswap(void *a, void *b, size_t n)
                n -= m;
        }
 }
+
+bool memeqzero(const void *data, size_t length)
+{
+       const unsigned char *p = data;
+       size_t len;
+
+       /* Check first 16 bytes manually */
+       for (len = 0; len < 16; len++) {
+               if (!length)
+                       return true;
+               if (*p)
+                       return false;
+               p++;
+               length--;
+       }
+
+       /* Now we know that's zero, memcmp with self. */
+       return memcmp(data, p, length) == 0;
+}