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Commit 172c97db authored by Bernardo Rufino's avatar Bernardo Rufino
Browse files

Add range-based Parcel.hasFileDescriptors(offset, length) 

To be used by lazy values in bundle. I ended up opening up as public API
for apps to use it too because I saw no reason not to, can change if
folks prefer it to be @hide though.

Test: atest -d android.os.cts.ParcelTest android.os.cts.BundleTest android.os.BundleTest android.os.ParcelTest
Bug: 195622897
Change-Id: I7bf580f94313669fe67998b32b2723544c594cde
parent fa565ffc

core/api/current.txt

+1 −0
Original line number Diff line number Diff line
@@ -29976,6 +29976,7 @@ package android.os { 
    method public int dataSize();

    method public void enforceInterface(@NonNull String);

    method public boolean hasFileDescriptors();

    method public boolean hasFileDescriptors(int, int);

    method public byte[] marshall();

    method @NonNull public static android.os.Parcel obtain();

    method @NonNull public static android.os.Parcel obtain(@NonNull android.os.IBinder);

core/java/android/os/Parcel.java

+35 −10
Original line number Diff line number Diff line
@@ -361,6 +361,8 @@ public final class Parcel { 
            long thisNativePtr, long otherNativePtr, int offset, int length);

    @CriticalNative

    private static native boolean nativeHasFileDescriptors(long nativePtr);

    private static native boolean nativeHasFileDescriptorsInRange(

            long nativePtr, int offset, int length);

    private static native void nativeWriteInterfaceToken(long nativePtr, String interfaceName);

    private static native void nativeEnforceInterface(long nativePtr, String interfaceName);
@@ -687,10 +689,25 @@ public final class Parcel { 
    /**

     * Report whether the parcel contains any marshalled file descriptors.

     */

    public final boolean hasFileDescriptors() {

    public boolean hasFileDescriptors() {

        return nativeHasFileDescriptors(mNativePtr);

    }



    /**

     * Report whether the parcel contains any marshalled file descriptors in the range defined by

     * {@code offset} and {@code length}.

     *

     * @param offset The offset from which the range starts. Should be between 0 and

     *     {@link #dataSize()}.

     * @param length The length of the range. Should be between 0 and {@link #dataSize()} - {@code

     *     offset}.

     * @return whether there are file descriptors or not.

     * @throws IllegalArgumentException if the parameters are out of the permitted ranges.

     */

    public boolean hasFileDescriptors(int offset, int length) {

        return nativeHasFileDescriptorsInRange(mNativePtr, offset, length);

    }



    /**

     * Check if the object used in {@link #readValue(ClassLoader)} / {@link #writeValue(Object)}

     * has file descriptors.
@@ -3495,15 +3512,26 @@ public final class Parcel { 
        int start = dataPosition();

        int type = readInt();

        if (isLengthPrefixed(type)) {

            int length = readInt();

            setDataPosition(MathUtils.addOrThrow(dataPosition(), length));

            return new LazyValue(this, start, length, type, loader);

            int objectLength = readInt();

            int end = MathUtils.addOrThrow(dataPosition(), objectLength);

            int valueLength = end - start;

            setDataPosition(end);

            return new LazyValue(this, start, valueLength, type, loader);

        } else {

            return readValue(type, loader, /* clazz */ null);

        }

    }





    private static final class LazyValue implements Supplier<Object> {

        /**

         *                      |   4B   |   4B   |

         * mSource = Parcel{... |  type  | length | object | ...}

         *                      a        b        c        d

         * length = d - c

         * mPosition = a

         * mLength = d - a

         */

        private final int mPosition;

        private final int mLength;

        private final int mType;
@@ -3551,7 +3579,7 @@ public final class Parcel { 
        public void writeToParcel(Parcel out) {

            Parcel source = mSource;

            if (source != null) {

                out.appendFrom(source, mPosition, mLength + 8);

                out.appendFrom(source, mPosition, mLength);

            } else {

                out.writeValue(mObject);

            }
@@ -3560,7 +3588,7 @@ public final class Parcel { 
        public boolean hasFileDescriptors() {

            Parcel source = mSource;

            return (source != null)

                    ? getValueParcel(source).hasFileDescriptors()

                    ? source.hasFileDescriptors(mPosition, mLength)

                    : Parcel.hasFileDescriptors(mObject);

        }
@@ -3621,10 +3649,7 @@ public final class Parcel { 
            Parcel parcel = mValueParcel;

            if (parcel == null) {

                parcel = Parcel.obtain();

                // mLength is the length of object representation, excluding the type and length.

                // mPosition is the position of the entire value container, right before the type.

                // So, we add 4 bytes for the type + 4 bytes for the length written.

                parcel.appendFrom(source, mPosition, mLength + 8);

                parcel.appendFrom(source, mPosition, mLength);

                mValueParcel = parcel;

            }

            return parcel;

core/jni/android_os_Parcel.cpp

+17 −0
Original line number Diff line number Diff line
@@ -655,6 +655,22 @@ static jboolean android_os_Parcel_hasFileDescriptors(jlong nativePtr) 
    return ret;

}



static jboolean android_os_Parcel_hasFileDescriptorsInRange(JNIEnv* env, jclass clazz,

                                                            jlong nativePtr, jint offset,

                                                            jint length) {

    Parcel* parcel = reinterpret_cast<Parcel*>(nativePtr);

    if (parcel != NULL) {

        bool result;

        status_t err = parcel->hasFileDescriptorsInRange(offset, length, result);

        if (err != NO_ERROR) {

            signalExceptionForError(env, clazz, err);

            return JNI_FALSE;

        }

        return result ? JNI_TRUE : JNI_FALSE;

    }

    return JNI_FALSE;

}



// String tries to allocate itself on the stack, within a known size, but will

// make a heap allocation if not.

template <size_t StackReserve>
@@ -847,6 +863,7 @@ static const JNINativeMethod gParcelMethods[] = { 
    {"nativeAppendFrom",          "(JJII)J", (void*)android_os_Parcel_appendFrom},

    // @CriticalNative

    {"nativeHasFileDescriptors",  "(J)Z", (void*)android_os_Parcel_hasFileDescriptors},

    {"nativeHasFileDescriptorsInRange",  "(JII)Z", (void*)android_os_Parcel_hasFileDescriptorsInRange},

    {"nativeWriteInterfaceToken", "(JLjava/lang/String;)V", (void*)android_os_Parcel_writeInterfaceToken},

    {"nativeEnforceInterface",    "(JLjava/lang/String;)V", (void*)android_os_Parcel_enforceInterface},