| /* |
| * Copyright (C) 2014 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.hardware.camera2.marshal.impl; |
| |
| import android.hardware.camera2.marshal.Marshaler; |
| import android.hardware.camera2.marshal.MarshalQueryable; |
| import android.hardware.camera2.utils.TypeReference; |
| import android.util.Log; |
| |
| import java.nio.ByteBuffer; |
| import java.nio.charset.Charset; |
| |
| import static android.hardware.camera2.impl.CameraMetadataNative.*; |
| |
| /** |
| * Marshal {@link String} to/from {@link #TYPE_BYTE}. |
| */ |
| public class MarshalQueryableString implements MarshalQueryable<String> { |
| |
| private static final String TAG = MarshalQueryableString.class.getSimpleName(); |
| private static final boolean DEBUG = false; |
| |
| private static class PreloadHolder { |
| public static final Charset UTF8_CHARSET = Charset.forName("UTF-8"); |
| } |
| private static final byte NUL = (byte)'\0'; // used as string terminator |
| |
| private class MarshalerString extends Marshaler<String> { |
| |
| protected MarshalerString(TypeReference<String> typeReference, int nativeType) { |
| super(MarshalQueryableString.this, typeReference, nativeType); |
| } |
| |
| @Override |
| public void marshal(String value, ByteBuffer buffer) { |
| byte[] arr = value.getBytes(PreloadHolder.UTF8_CHARSET); |
| |
| buffer.put(arr); |
| buffer.put(NUL); // metadata strings are NUL-terminated |
| } |
| |
| @Override |
| public int calculateMarshalSize(String value) { |
| byte[] arr = value.getBytes(PreloadHolder.UTF8_CHARSET); |
| |
| return arr.length + 1; // metadata strings are NUL-terminated |
| } |
| |
| @Override |
| public String unmarshal(ByteBuffer buffer) { |
| buffer.mark(); // save the current position |
| |
| boolean foundNull = false; |
| int stringLength = 0; |
| while (buffer.hasRemaining()) { |
| if (buffer.get() == NUL) { |
| foundNull = true; |
| break; |
| } |
| |
| stringLength++; |
| } |
| |
| if (DEBUG) { |
| Log.v(TAG, |
| "unmarshal - scanned " + stringLength + " characters; found null? " |
| + foundNull); |
| } |
| |
| if (!foundNull) { |
| throw new UnsupportedOperationException("Strings must be null-terminated"); |
| } |
| |
| buffer.reset(); // go back to the previously marked position |
| |
| byte[] strBytes = new byte[stringLength + 1]; |
| buffer.get(strBytes, /*dstOffset*/0, stringLength + 1); // including null character |
| |
| // not including null character |
| return new String(strBytes, /*offset*/0, stringLength, PreloadHolder.UTF8_CHARSET); |
| } |
| |
| @Override |
| public int getNativeSize() { |
| return NATIVE_SIZE_DYNAMIC; |
| } |
| } |
| |
| @Override |
| public Marshaler<String> createMarshaler( |
| TypeReference<String> managedType, int nativeType) { |
| return new MarshalerString(managedType, nativeType); |
| } |
| |
| @Override |
| public boolean isTypeMappingSupported(TypeReference<String> managedType, int nativeType) { |
| return nativeType == TYPE_BYTE && String.class.equals(managedType.getType()); |
| } |
| } |