1 files changed, 55 insertions, 0 deletions
diff --git a/core/java/android/util/TrustedTime.java b/core/java/android/util/TrustedTime.java
new file mode 100644
index 000000000000..263d7821a085
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+++ b/core/java/android/util/TrustedTime.java
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+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package android.util;
+
+/**
+ * Interface that provides trusted time information, possibly coming from an NTP
+ * server. Implementations may cache answers until {@link #forceRefresh()}.
+ *
+ * @hide
+ */
+public interface TrustedTime {
+    /**
+     * Force update with an external trusted time source, returning {@code true}
+     * when successful.
+     */
+    public boolean forceRefresh();
+
+    /**
+     * Check if this instance has cached a response from a trusted time source.
+     */
+    public boolean hasCache();
+
+    /**
+     * Return time since last trusted time source contact, or
+     * {@link Long#MAX_VALUE} if never contacted.
+     */
+    public long getCacheAge();
+
+    /**
+     * Return certainty of cached trusted time in milliseconds, or
+     * {@link Long#MAX_VALUE} if never contacted. Smaller values are more
+     * precise.
+     */
+    public long getCacheCertainty();
+
+    /**
+     * Return current time similar to {@link System#currentTimeMillis()},
+     * possibly using a cached authoritative time source.
+     */
+    public long currentTimeMillis();
+}