diff --git a/android/utils/vector.c b/android/utils/vector.c
new file mode 100644
index 0000000..9029d05
--- /dev/null
+++ b/android/utils/vector.c
@@ -0,0 +1,33 @@
+#include <android/utils/vector.h>
+#include <limits.h>
+
+extern void
+_avector_ensure( void**  items, size_t  itemSize, unsigned*  pMaxItems, unsigned  newCount )
+{
+    unsigned  oldMax = *pMaxItems;
+
+    if (newCount > oldMax) {
+        unsigned  newMax = oldMax;
+        unsigned  bigMax = UINT_MAX / itemSize;
+
+        if (itemSize == 0) {
+            AASSERT_FAIL("trying to reallocate array of 0-size items (count=%d)\n", newCount);
+        }
+
+        if (newCount > bigMax) {
+            AASSERT_FAIL("trying to reallocate over-sized array of %d-bytes items (%d > %d)\n",
+                         itemSize, newCount, bigMax);
+        }
+
+        while (newMax < newCount) {
+            unsigned newMax2 = newMax + (newMax >> 1) + 4;
+            if (newMax2 < newMax || newMax2 > bigMax)
+                newMax2 = bigMax;
+            newMax = newMax2;
+        }
+
+        *items     = _android_array_realloc( *items, itemSize, newMax );
+        *pMaxItems = newMax;
+    }
+}
+