base: add CachedProperty.
Copy bionic's CachedProperty with some minor API tweaks, to allow for
efficient querying of properties that rarely change.
Bug: http://b/141959374
Test: treehugger
Change-Id: I4dfc3f527d30262b35e871d256cec69e69f2e1d7
(cherry picked from commit 891e6dad73699d7b67861705843f95ba19ca5c4d)
diff --git a/base/properties_test.cpp b/base/properties_test.cpp
index e7d4880..c30c41e 100644
--- a/base/properties_test.cpp
+++ b/base/properties_test.cpp
@@ -230,3 +230,28 @@
GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
#endif
}
+
+TEST(properties, CachedProperty) {
+#if defined(__BIONIC__)
+ android::base::CachedProperty cached_property("debug.libbase.CachedProperty_test");
+ bool changed;
+ cached_property.Get(&changed);
+
+ android::base::SetProperty("debug.libbase.CachedProperty_test", "foo");
+ ASSERT_STREQ("foo", cached_property.Get(&changed));
+ ASSERT_TRUE(changed);
+
+ ASSERT_STREQ("foo", cached_property.Get(&changed));
+ ASSERT_FALSE(changed);
+
+ android::base::SetProperty("debug.libbase.CachedProperty_test", "bar");
+ ASSERT_STREQ("bar", cached_property.Get(&changed));
+ ASSERT_TRUE(changed);
+
+ ASSERT_STREQ("bar", cached_property.Get(&changed));
+ ASSERT_FALSE(changed);
+
+#else
+ GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
+}