test/android/org/webrtc/native_test/StrictModeContext.java

/*
 *  Copyright 2024 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

// Based on Chromium's https://source.chromium.org/chromium/chromium/src/+/main:base/android/java/src/org/chromium/base/StrictModeContext.java

package org.webrtc.native_test;

import android.os.Build;
import android.os.StrictMode;

import java.io.Closeable;

/**
 * Enables try-with-resources compatible StrictMode violation allowlisting.
 *
 * <p>Prefer "ignored" as the variable name to appease Android Studio's "Unused symbol" inspection.
 *
 * <p>Example:
 *
 * <pre>
 *     try (StrictModeContext ignored = StrictModeContext.allowDiskWrites()) {
 *         return Example.doThingThatRequiresDiskWrites();
 *     }
 * </pre>
 */
public class StrictModeContext implements Closeable {
    private static class Impl extends StrictModeContext {
        private final StrictMode.ThreadPolicy mThreadPolicy;
        private final StrictMode.VmPolicy mVmPolicy;

        private Impl(StrictMode.ThreadPolicy threadPolicy, StrictMode.VmPolicy vmPolicy) {
            mThreadPolicy = threadPolicy;
            mVmPolicy = vmPolicy;
        }

        private Impl(StrictMode.ThreadPolicy threadPolicy) {
            this(threadPolicy, null);
        }

        private Impl(StrictMode.VmPolicy vmPolicy) {
            this(null, vmPolicy);
        }

        @Override
        public void close() {
            if (mThreadPolicy != null) {
                StrictMode.setThreadPolicy(mThreadPolicy);
            }
            if (mVmPolicy != null) {
                StrictMode.setVmPolicy(mVmPolicy);
            }
        }
    }

    /**
     * Convenience method for disabling all VM-level StrictMode checks with try-with-resources.
     * Includes everything listed here:
     * https://developer.android.com/reference/android/os/StrictMode.VmPolicy.Builder.html
     */
    public static StrictModeContext allowAllVmPolicies() {
        StrictMode.VmPolicy oldPolicy = StrictMode.getVmPolicy();
        StrictMode.setVmPolicy(StrictMode.VmPolicy.LAX);
        return new Impl(oldPolicy);
    }

    /**
     * Convenience method for disabling all thread-level StrictMode checks with try-with-resources.
     * Includes everything listed here:
     * https://developer.android.com/reference/android/os/StrictMode.ThreadPolicy.Builder.html
     */
    public static StrictModeContext allowAllThreadPolicies() {
        StrictMode.ThreadPolicy oldPolicy = StrictMode.getThreadPolicy();
        StrictMode.setThreadPolicy(StrictMode.ThreadPolicy.LAX);
        return new Impl(oldPolicy);
    }

    /** Convenience method for disabling StrictMode for disk-writes with try-with-resources. */
    public static StrictModeContext allowDiskWrites() {
        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
        return new Impl(oldPolicy);
    }

    /** Convenience method for disabling StrictMode for disk-reads with try-with-resources. */
    public static StrictModeContext allowDiskReads() {
        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
        return new Impl(oldPolicy);
    }

    /** Convenience method for disabling StrictMode for slow calls with try-with-resources. */
    public static StrictModeContext allowSlowCalls() {
        StrictMode.ThreadPolicy oldPolicy = StrictMode.getThreadPolicy();
        StrictMode.setThreadPolicy(
                new StrictMode.ThreadPolicy.Builder(oldPolicy).permitCustomSlowCalls().build());
        return new Impl(oldPolicy);
    }

    /**
     * Convenience method for disabling StrictMode for unbuffered input/output operations with
     * try-with-resources. For API level 25- this method will do nothing; because
     * StrictMode.ThreadPolicy.Builder#permitUnbufferedIo is added in API level 26.
     */
    public static StrictModeContext allowUnbufferedIo() {
        StrictMode.ThreadPolicy oldPolicy = StrictMode.getThreadPolicy();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            StrictMode.setThreadPolicy(
                    new StrictMode.ThreadPolicy.Builder(oldPolicy)
                            .permitUnbufferedIo()
                            .build());
        }
        return new Impl(oldPolicy);
    }

    @Override
    public void close() {}
}