Import of the watch repository from Pebble

src/libutil/sort.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <util/sort.h>
+
+#include <stdint.h>
+#include <stddef.h>
+
+static void prv_swap(void *a, void *b, size_t elem_size) {
+  uint8_t *a_ptr = (uint8_t *)a;
+  uint8_t *b_ptr = (uint8_t *)b;
+  for (size_t i = 0; i < elem_size; i++) {
+    uint8_t tmp = *a_ptr;
+    *a_ptr++ = *b_ptr;
+    *b_ptr++ = tmp;
+  }
+}
+
+void sort_bubble(void *array, size_t num_elem, size_t elem_size, SortComparator comp) {
+  // as the number of sessions is expected to be small (<=16), and we don't seem to have a generic
+  // sort implementation, we do a simple bubble sort here
+  for (uint32_t i = 0; i + 1 < num_elem; i++) {
+    for (uint32_t j = i + 1; j < num_elem; j++) {
+      uint8_t *val1 = ((uint8_t *)array) + (i * elem_size);
+      uint8_t *val2 = ((uint8_t *)array) + (j * elem_size);
+      if (comp(val1, val2) > 0) {
+        prv_swap(val1, val2, elem_size);
+      }
+    }
+  }
+}