Add a Java lib to read on-device proto paths

Bug: 337911453
Test: m aconfig_on_device_protos_java
Change-Id: Iac8d671acee070ed041927028ec80c7aa371bd61

Change-Id: I19e0e52d8de71207c9858305e6248b6251a20989

4 files changed, 86 insertions, 7 deletions

diff --git a/tools/aconfig/aconfig_device_paths/Android.bp b/tools/aconfig/aconfig_device_paths/Android.bp
index 21aa9a9e08..2c771e09f5 100644
--- a/tools/aconfig/aconfig_device_paths/Android.bp
+++ b/tools/aconfig/aconfig_device_paths/Android.bp
@@ -36,3 +36,16 @@ rust_library {
     host_supported: true,
     defaults: ["libaconfig_device_paths.defaults"],
 }
+
+genrule {
+    name: "libaconfig_java_device_paths_src",
+    srcs: ["src/DevicePathsTemplate.java"],
+    out: ["DevicePaths.java"],
+    tool_files: ["partition_aconfig_flags_paths.txt"],
+    cmd: "sed -e '/TEMPLATE/{r$(location partition_aconfig_flags_paths.txt)' -e 'd}' $(in) > $(out)"
+}
+
+java_library {
+    name: "aconfig_device_paths_java",
+    srcs: [":libaconfig_java_device_paths_src"],
+}
diff --git a/tools/aconfig/aconfig_device_paths/partition_aconfig_flags_paths.txt b/tools/aconfig/aconfig_device_paths/partition_aconfig_flags_paths.txt
index 3d2deb2375..140cd21ac8 100644
--- a/tools/aconfig/aconfig_device_paths/partition_aconfig_flags_paths.txt
+++ b/tools/aconfig/aconfig_device_paths/partition_aconfig_flags_paths.txt
@@ -1,6 +1,4 @@
-[
-    "/system/etc/aconfig_flags.pb",
-    "/system_ext/etc/aconfig_flags.pb",
-    "/product/etc/aconfig_flags.pb",
-    "/vendor/etc/aconfig_flags.pb",
-]
+"/system/etc/aconfig_flags.pb",
+"/system_ext/etc/aconfig_flags.pb",
+"/product/etc/aconfig_flags.pb",
+"/vendor/etc/aconfig_flags.pb",
diff --git a/tools/aconfig/aconfig_device_paths/src/DevicePathsTemplate.java b/tools/aconfig/aconfig_device_paths/src/DevicePathsTemplate.java
new file mode 100644
index 0000000000..f27b9bd360
--- /dev/null
+++ b/tools/aconfig/aconfig_device_paths/src/DevicePathsTemplate.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2024 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.aconfig;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * @hide
+ */
+public class DevicePaths {
+    static final String[] PATHS = {
+        TEMPLATE
+    };
+
+    private static final String APEX_DIR = "/apex";
+    private static final String APEX_ACONFIG_PATH_SUFFIX = "/etc/aconfig_flags.pb";
+
+
+    /**
+     * Returns the list of all on-device aconfig protos paths.
+     * @hide
+     */
+    public List<String> parsedFlagsProtoPaths() {
+        ArrayList<String> paths = new ArrayList(Arrays.asList(PATHS));
+
+        File apexDirectory = new File(APEX_DIR);
+        if (!apexDirectory.isDirectory()) {
+            return paths;
+        }
+
+        File[] subdirs = apexDirectory.listFiles();
+        if (subdirs == null) {
+            return paths;
+        }
+
+        for (File prefix : subdirs) {
+            // For each mainline modules, there are two directories, one <modulepackage>/,
+            // and one <modulepackage>@<versioncode>/. Just read the former.
+            if (prefix.getAbsolutePath().contains("@")) {
+                continue;
+            }
+
+            File protoPath = new File(prefix + APEX_ACONFIG_PATH_SUFFIX);
+            if (!protoPath.exists()) {
+                continue;
+            }
+
+            paths.add(protoPath.getAbsolutePath());
+        }
+        return paths;
+    }
+}
diff --git a/tools/aconfig/aconfig_device_paths/src/lib.rs b/tools/aconfig/aconfig_device_paths/src/lib.rs
index 7bb62f4247..c5a6bff1f7 100644
--- a/tools/aconfig/aconfig_device_paths/src/lib.rs
+++ b/tools/aconfig/aconfig_device_paths/src/lib.rs
@@ -23,7 +23,7 @@ use std::fs;
 
 /// Determine all paths that contain an aconfig protobuf file.
 pub fn parsed_flags_proto_paths() -> Result<Vec<PathBuf>> {
-    let mut result: Vec<PathBuf> = include!("../partition_aconfig_flags_paths.txt")
+    let mut result: Vec<PathBuf> = [include_str!("../partition_aconfig_flags_paths.txt")]
         .map(|s| PathBuf::from(s.to_string()))
         .to_vec();
     for dir in fs::read_dir("/apex")? {