1 files changed, 126 insertions, 0 deletions
diff --git a/service/java/com/android/server/deviceconfig/DeviceConfigBootstrapValues.java b/service/java/com/android/server/deviceconfig/DeviceConfigBootstrapValues.java
new file mode 100644
index 0000000..b480bc2
--- /dev/null
+++ b/service/java/com/android/server/deviceconfig/DeviceConfigBootstrapValues.java
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2023 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 com.android.server.deviceconfig;
+
+import android.annotation.SuppressLint;
+import android.provider.DeviceConfig;
+import android.util.Slog;
+
+import java.io.IOException;
+import java.net.URI;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.stream.Stream;
+
+/**
+ * @hide
+ */
+public class DeviceConfigBootstrapValues {
+    private static final String TAG = "DeviceConfig";
+    private static final String SYSTEM_OVERRIDES_PATH = "file:///system/etc/device-config-defaults";
+    private static final String META_NAMESPACE = "DeviceConfigBootstrapValues";
+    private static final String META_KEY = "processed_values";
+
+    private final String defaultValuesPath;
+
+    public DeviceConfigBootstrapValues() {
+        this(SYSTEM_OVERRIDES_PATH);
+    }
+
+    public DeviceConfigBootstrapValues(String defaultValuesPath) {
+        this.defaultValuesPath = defaultValuesPath;
+    }
+
+    /**
+     * Performs the logic to apply bootstrap values when needed.
+     *
+     * If a file with the bootstrap values exists and they haven't been parsed before,
+     * it will parse the file and apply the values.
+     *
+     * @throws IOException if there's a problem reading the bootstrap file
+     * @throws RuntimeException if setting the values in DeviceConfig throws an exception
+     */
+    public void applyValuesIfNeeded() throws IOException {
+        if (getPath().toFile().exists()) {
+            if (checkIfHasAlreadyParsedBootstrapValues()) {
+                Slog.i(TAG, "Bootstrap values already parsed, not processing again");
+            } else {
+                parseAndApplyBootstrapValues();
+                Slog.i(TAG, "Parsed bootstrap values");
+            }
+        } else {
+            Slog.i(TAG, "Bootstrap values not found");
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private boolean checkIfHasAlreadyParsedBootstrapValues() {
+        DeviceConfig.Properties properties = DeviceConfig.getProperties(META_NAMESPACE);
+        return properties.getKeyset().size() > 0;
+    }
+
+    @SuppressLint("MissingPermission")
+    private void parseAndApplyBootstrapValues() throws IOException {
+        Path path = getPath();
+        try (Stream<String> lines = Files.lines(path)) {
+            lines.forEach(line -> processLine(line));
+        }
+        // store a property in DeviceConfig so that we know we have successufully
+        // processed this
+        writeToDeviceConfig(META_NAMESPACE, META_KEY, "true");
+    }
+
+    private void processLine(String line) {
+        // contents for each line:
+        // <namespace>:<package>.<flag-name>=[enabled|disabled]
+        // we actually use <package>.<flag-name> combined in calls into DeviceConfig
+        int namespaceDelimiter = line.indexOf(':');
+        String namespace = line.substring(0, namespaceDelimiter);
+        if (namespaceDelimiter < 1) {
+            throw new IllegalArgumentException("Unexpectedly found : at index "
+                    + namespaceDelimiter);
+        }
+        int valueDelimiter = line.indexOf('=');
+        if (valueDelimiter < 5) {
+            throw new IllegalArgumentException("Unexpectedly found = at index " + valueDelimiter);
+        }
+        String key = line.substring(namespaceDelimiter + 1, valueDelimiter);
+        String value = line.substring(valueDelimiter + 1);
+        String val;
+        if ("enabled".equals(value)) {
+            val = "true";
+        } else if ("disabled".equals(value)) {
+            val = "false";
+        } else {
+            throw new IllegalArgumentException("Received unexpected value: " + value);
+        }
+        writeToDeviceConfig(namespace, key, val);
+    }
+
+    @SuppressLint("MissingPermission")
+    private void writeToDeviceConfig(String namespace, String key, String value) {
+        boolean result = DeviceConfig.setProperty(namespace, key, value, /* makeDefault= */ true);
+        if (!result) {
+            throw new RuntimeException("Failed to set DeviceConfig property [" + namespace + "] "
+                    + key + "=" + value);
+        }
+    }
+
+    private Path getPath() {
+        return Path.of(URI.create(defaultValuesPath));
+    }
+}