| /* |
| * Copyright (C) 2020 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; |
| |
| import android.annotation.NonNull; |
| |
| import com.android.modules.utils.ModifiedUtf8; |
| |
| import dalvik.annotation.optimization.FastNative; |
| |
| /** |
| * Specializations of {@code libcore.util.CharsetUtils} which enable efficient |
| * in-place encoding without making any new allocations. |
| * <p> |
| * These methods purposefully accept only non-movable byte array addresses to |
| * avoid extra JNI overhead. |
| * <p> |
| * Callers are cautioned that there is a long-standing ART bug that emits |
| * non-standard 4-byte sequences, as described by {@code kUtfUse4ByteSequence} |
| * in {@code art/runtime/jni/jni_internal.cc}. If precise modified UTF-8 |
| * encoding is required, use {@link ModifiedUtf8} instead. |
| * |
| * @hide |
| */ |
| public class CharsetUtils { |
| /** |
| * Attempt to encode the given string as modified UTF-8 into the destination |
| * byte array without making any new allocations. |
| * <p> |
| * Callers are cautioned that there is a long-standing ART bug that emits |
| * non-standard 4-byte sequences, as described by |
| * {@code kUtfUse4ByteSequence} in {@code art/runtime/jni/jni_internal.cc}. |
| * If precise modified UTF-8 encoding is required, use {@link ModifiedUtf8} |
| * instead. |
| * |
| * @param src string value to be encoded |
| * @param dest destination byte array to encode into |
| * @param destOff offset into destination where encoding should begin |
| * @param destLen length of destination |
| * @return positive value when encoding succeeded, or negative value when |
| * failed; the magnitude of the value is the number of bytes |
| * required to encode the string. |
| */ |
| public static int toModifiedUtf8Bytes(@NonNull String src, |
| long dest, int destOff, int destLen) { |
| return toModifiedUtf8Bytes(src, src.length(), dest, destOff, destLen); |
| } |
| |
| /** |
| * Attempt to encode the given string as modified UTF-8 into the destination |
| * byte array without making any new allocations. |
| * <p> |
| * Callers are cautioned that there is a long-standing ART bug that emits |
| * non-standard 4-byte sequences, as described by |
| * {@code kUtfUse4ByteSequence} in {@code art/runtime/jni/jni_internal.cc}. |
| * If precise modified UTF-8 encoding is required, use {@link ModifiedUtf8} |
| * instead. |
| * |
| * @param src string value to be encoded |
| * @param srcLen exact length of string to be encoded |
| * @param dest destination byte array to encode into |
| * @param destOff offset into destination where encoding should begin |
| * @param destLen length of destination |
| * @return positive value when encoding succeeded, or negative value when |
| * failed; the magnitude of the value is the number of bytes |
| * required to encode the string. |
| */ |
| @FastNative |
| private static native int toModifiedUtf8Bytes(@NonNull String src, int srcLen, |
| long dest, int destOff, int destLen); |
| |
| /** |
| * Attempt to decode a modified UTF-8 string from the source byte array. |
| * <p> |
| * Callers are cautioned that there is a long-standing ART bug that emits |
| * non-standard 4-byte sequences, as described by |
| * {@code kUtfUse4ByteSequence} in {@code art/runtime/jni/jni_internal.cc}. |
| * If precise modified UTF-8 encoding is required, use {@link ModifiedUtf8} |
| * instead. |
| * |
| * @param src source byte array to decode from |
| * @param srcOff offset into source where decoding should begin |
| * @param srcLen length of source that should be decoded |
| * @return the successfully decoded string |
| */ |
| @FastNative |
| public static native @NonNull String fromModifiedUtf8Bytes( |
| long src, int srcOff, int srcLen); |
| } |