| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.vxquery.datamodel.accessors.jsonitem; |
| |
| import java.io.IOException; |
| |
| import org.apache.hyracks.api.dataflow.value.ITypeTraits; |
| import org.apache.hyracks.data.std.api.AbstractPointable; |
| import org.apache.hyracks.data.std.api.IMutableValueStorage; |
| import org.apache.hyracks.data.std.api.IPointable; |
| import org.apache.hyracks.data.std.api.IPointableFactory; |
| import org.apache.hyracks.data.std.primitive.IntegerPointable; |
| import org.apache.hyracks.data.std.primitive.UTF8StringPointable; |
| import org.apache.hyracks.data.std.primitive.VoidPointable; |
| import org.apache.hyracks.util.string.UTF8StringUtil; |
| import org.apache.vxquery.datamodel.builders.sequence.SequenceBuilder; |
| import org.apache.vxquery.datamodel.values.ValueTag; |
| import org.apache.vxquery.runtime.functions.util.FunctionHelper; |
| |
| /** |
| * The datamodel of the JSON object is represented in this class: |
| * Byte 1: Value tag of object (109) |
| * Byte 2 to 5: number of key-value pairs in the object |
| * Next few bytes: Offsets for each key-value pair in the object in the order appearing in the json data |
| * Next bytes: The keys in the object each followed by the value of the key. Each key is a StringPointable and the value |
| * of the key will be the respective pointable starting with its valuetag. |
| */ |
| public class ObjectPointable extends AbstractPointable { |
| public static final IPointableFactory FACTORY = new IPointableFactory() { |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public ITypeTraits getTypeTraits() { |
| return VoidPointable.TYPE_TRAITS; |
| } |
| |
| @Override |
| public IPointable createPointable() { |
| return new ObjectPointable(); |
| } |
| }; |
| private static final int ENTRY_COUNT_SIZE = IntegerPointable.TYPE_TRAITS.getFixedLength(); |
| private static final int SLOT_SIZE = IntegerPointable.TYPE_TRAITS.getFixedLength(); |
| private final SequenceBuilder sb = new SequenceBuilder(); |
| private final UTF8StringPointable key = (UTF8StringPointable) UTF8StringPointable.FACTORY.createPointable(); |
| |
| private static int getSlotValue(byte[] bytes, int start, int idx) { |
| return IntegerPointable.getInteger(bytes, getSlotArrayOffset(start) + idx * SLOT_SIZE); |
| } |
| |
| private static int getEntryCount(byte[] bytes, int start) { |
| return IntegerPointable.getInteger(bytes, start); |
| } |
| |
| private static int getKeyLength(byte[] bytes, int start) { |
| int utfLength = UTF8StringUtil.getUTFLength(bytes, start); |
| return utfLength + UTF8StringUtil.getNumBytesToStoreLength(utfLength); |
| } |
| |
| private static int getSlotArrayOffset(int start) { |
| return start + ENTRY_COUNT_SIZE; |
| } |
| |
| private static int getDataAreaOffset(byte[] bytes, int start) { |
| return getSlotArrayOffset(start) + getEntryCount(bytes, start) * SLOT_SIZE; |
| } |
| |
| public void getKeys(IMutableValueStorage abvs) throws IOException { |
| abvs.reset(); |
| sb.reset(abvs); |
| int dataAreaOffset = getDataAreaOffset(bytes, start); |
| int entryCount = getEntryCount(); |
| int s; |
| for (int i = 0; i < entryCount; i++) { |
| s = dataAreaOffset + getRelativeEntryStartOffset(i); |
| key.set(bytes, s, getKeyLength(bytes, s)); |
| sb.addItem(ValueTag.XS_STRING_TAG, key); |
| } |
| sb.finish(); |
| } |
| |
| //here the UTF8StringPointable of key is without the tag |
| public boolean getValue(UTF8StringPointable key, IPointable result) { |
| int dataAreaOffset = getDataAreaOffset(bytes, start); |
| int entryCount = getEntryCount(); |
| int start; |
| int length; |
| int i; |
| for (i = 0; i < entryCount; i++) { |
| start = dataAreaOffset + getRelativeEntryStartOffset(i); |
| length = getKeyLength(bytes, start); |
| if (FunctionHelper.arraysEqual(bytes, start, length, key.getByteArray(), key.getStartOffset(), |
| key.getLength())) { |
| result.set(bytes, start + length, getEntryLength(i) - length); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private int getRelativeEntryStartOffset(int idx) { |
| return idx == 0 ? 0 : getSlotValue(bytes, start, idx - 1); |
| } |
| |
| private int getEntryLength(int idx) { |
| return getSlotValue(bytes, start, idx) - getRelativeEntryStartOffset(idx); |
| } |
| |
| public int getEntryCount() { |
| return getEntryCount(bytes, start); |
| } |
| |
| } |