lang/java/avro/src/main/java/org/apache/avro/io/JsonDecoder.java - avro - Git at Google

 /*
  * 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
  *
  *     https://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.avro.io;

 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Stack;

 import org.apache.avro.AvroTypeException;
 import org.apache.avro.Schema;
 import org.apache.avro.io.parsing.JsonGrammarGenerator;
 import org.apache.avro.io.parsing.Parser;
 import org.apache.avro.io.parsing.Symbol;
 import org.apache.avro.util.Utf8;
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.databind.util.TokenBuffer;

 /**
  * A {@link Decoder} for Avro's JSON data encoding.
  * </p>
  * Construct using {@link DecoderFactory}.
  * </p>
  * JsonDecoder is not thread-safe.
  */
 public class JsonDecoder extends ParsingDecoder implements Parser.ActionHandler {
   private JsonParser in;
   private static JsonFactory jsonFactory = new JsonFactory();
   Stack<ReorderBuffer> reorderBuffers = new Stack<>();
   ReorderBuffer currentReorderBuffer;

   private static class ReorderBuffer {
     public Map<String, TokenBuffer> savedFields = new HashMap<>();
     public JsonParser origParser = null;
   }

   private JsonDecoder(Symbol root, InputStream in) throws IOException {
     super(root);
     configure(in);
   }

   private JsonDecoder(Symbol root, String in) throws IOException {
     super(root);
     configure(in);
   }

   JsonDecoder(Schema schema, InputStream in) throws IOException {
     this(getSymbol(schema), in);
   }

   JsonDecoder(Schema schema, String in) throws IOException {
     this(getSymbol(schema), in);
   }

   private static Symbol getSymbol(Schema schema) {
     Objects.requireNonNull(schema, "Schema cannot be null");
     return new JsonGrammarGenerator().generate(schema);
   }

   /**
    * Reconfigures this JsonDecoder to use the InputStream provided.
    * <p/>
    * If the InputStream provided is null, a NullPointerException is thrown.
    * <p/>
    * Otherwise, this JsonDecoder will reset its state and then reconfigure its
    * input.
    *
    * @param in The InputStream to read from. Cannot be null.
    * @throws IOException
    * @throws NullPointerException if {@code in} is {@code null}
    * @return this JsonDecoder
    */
   public JsonDecoder configure(InputStream in) throws IOException {
     Objects.requireNonNull(in, "InputStream cannot be null");
     parser.reset();
     reorderBuffers.clear();
     currentReorderBuffer = null;
     this.in = jsonFactory.createParser(in);
     this.in.nextToken();
     return this;
   }

   /**
    * Reconfigures this JsonDecoder to use the String provided for input.
    * <p/>
    * If the String provided is null, a NullPointerException is thrown.
    * <p/>
    * Otherwise, this JsonDecoder will reset its state and then reconfigure its
    * input.
    *
    * @param in The String to read from. Cannot be null.
    * @throws IOException
    * @throws NullPointerException if {@code in} is {@code null}
    * @return this JsonDecoder
    */
   public JsonDecoder configure(String in) throws IOException {
     Objects.requireNonNull(in, "String to read from cannot be null");
     parser.reset();
     reorderBuffers.clear();
     currentReorderBuffer = null;
     this.in = new JsonFactory().createParser(in);
     this.in.nextToken();
     return this;
   }

   private void advance(Symbol symbol) throws IOException {
     this.parser.processTrailingImplicitActions();
     if (in.getCurrentToken() == null && this.parser.depth() == 1)
       throw new EOFException();
     parser.advance(symbol);
   }

   @Override
   public void readNull() throws IOException {
     advance(Symbol.NULL);
     if (in.getCurrentToken() == JsonToken.VALUE_NULL) {
       in.nextToken();
     } else {
       throw error("null");
     }
   }

   @Override
   public boolean readBoolean() throws IOException {
     advance(Symbol.BOOLEAN);
     JsonToken t = in.getCurrentToken();
     if (t == JsonToken.VALUE_TRUE || t == JsonToken.VALUE_FALSE) {
       in.nextToken();
       return t == JsonToken.VALUE_TRUE;
     } else {
       throw error("boolean");
     }
   }

   @Override
   public int readInt() throws IOException {
     advance(Symbol.INT);
     if (in.getCurrentToken().isNumeric()) {
       int result = in.getIntValue();
       in.nextToken();
       return result;
     } else {
       throw error("int");
     }
   }

   @Override
   public long readLong() throws IOException {
     advance(Symbol.LONG);
     if (in.getCurrentToken().isNumeric()) {
       long result = in.getLongValue();
       in.nextToken();
       return result;
     } else {
       throw error("long");
     }
   }

   @Override
   public float readFloat() throws IOException {
     advance(Symbol.FLOAT);
     if (in.getCurrentToken().isNumeric()) {
       float result = in.getFloatValue();
       in.nextToken();
       return result;
     } else {
       throw error("float");
     }
   }

   @Override
   public double readDouble() throws IOException {
     advance(Symbol.DOUBLE);
     if (in.getCurrentToken().isNumeric()) {
       double result = in.getDoubleValue();
       in.nextToken();
       return result;
     } else {
       throw error("double");
     }
   }

   @Override
   public Utf8 readString(Utf8 old) throws IOException {
     return new Utf8(readString());
   }

   @Override
   public String readString() throws IOException {
     advance(Symbol.STRING);
     if (parser.topSymbol() == Symbol.MAP_KEY_MARKER) {
       parser.advance(Symbol.MAP_KEY_MARKER);
       if (in.getCurrentToken() != JsonToken.FIELD_NAME) {
         throw error("map-key");
       }
     } else {
       if (in.getCurrentToken() != JsonToken.VALUE_STRING) {
         throw error("string");
       }
     }
     String result = in.getText();
     in.nextToken();
     return result;
   }

   @Override
   public void skipString() throws IOException {
     advance(Symbol.STRING);
     if (parser.topSymbol() == Symbol.MAP_KEY_MARKER) {
       parser.advance(Symbol.MAP_KEY_MARKER);
       if (in.getCurrentToken() != JsonToken.FIELD_NAME) {
         throw error("map-key");
       }
     } else {
       if (in.getCurrentToken() != JsonToken.VALUE_STRING) {
         throw error("string");
       }
     }
     in.nextToken();
   }

   @Override
   public ByteBuffer readBytes(ByteBuffer old) throws IOException {
     advance(Symbol.BYTES);
     if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
       byte[] result = readByteArray();
       in.nextToken();
       return ByteBuffer.wrap(result);
     } else {
       throw error("bytes");
     }
   }

   private byte[] readByteArray() throws IOException {
     byte[] result = in.getText().getBytes(StandardCharsets.ISO_8859_1);
     return result;
   }

   @Override
   public void skipBytes() throws IOException {
     advance(Symbol.BYTES);
     if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
       in.nextToken();
     } else {
       throw error("bytes");
     }
   }

   private void checkFixed(int size) throws IOException {
     advance(Symbol.FIXED);
     Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
     if (size != top.size) {
       throw new AvroTypeException(
           "Incorrect length for fixed binary: expected " + top.size + " but received " + size + " bytes.");
     }
   }

   @Override
   public void readFixed(byte[] bytes, int start, int len) throws IOException {
     checkFixed(len);
     if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
       byte[] result = readByteArray();
       in.nextToken();
       if (result.length != len) {
         throw new AvroTypeException("Expected fixed length " + len + ", but got" + result.length);
       }
       System.arraycopy(result, 0, bytes, start, len);
     } else {
       throw error("fixed");
     }
   }

   @Override
   public void skipFixed(int length) throws IOException {
     checkFixed(length);
     doSkipFixed(length);
   }

   private void doSkipFixed(int length) throws IOException {
     if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
       byte[] result = readByteArray();
       in.nextToken();
       if (result.length != length) {
         throw new AvroTypeException("Expected fixed length " + length + ", but got" + result.length);
       }
     } else {
       throw error("fixed");
     }
   }

   @Override
   protected void skipFixed() throws IOException {
     advance(Symbol.FIXED);
     Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
     doSkipFixed(top.size);
   }

   @Override
   public int readEnum() throws IOException {
     advance(Symbol.ENUM);
     Symbol.EnumLabelsAction top = (Symbol.EnumLabelsAction) parser.popSymbol();
     if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
       in.getText();
       int n = top.findLabel(in.getText());
       if (n >= 0) {
         in.nextToken();
         return n;
       }
       throw new AvroTypeException("Unknown symbol in enum " + in.getText());
     } else {
       throw error("fixed");
     }
   }

   @Override
   public long readArrayStart() throws IOException {
     advance(Symbol.ARRAY_START);
     if (in.getCurrentToken() == JsonToken.START_ARRAY) {
       in.nextToken();
       return doArrayNext();
     } else {
       throw error("array-start");
     }
   }

   @Override
   public long arrayNext() throws IOException {
     advance(Symbol.ITEM_END);
     return doArrayNext();
   }

   private long doArrayNext() throws IOException {
     if (in.getCurrentToken() == JsonToken.END_ARRAY) {
       parser.advance(Symbol.ARRAY_END);
       in.nextToken();
       return 0;
     } else {
       return 1;
     }
   }

   @Override
   public long skipArray() throws IOException {
     advance(Symbol.ARRAY_START);
     if (in.getCurrentToken() == JsonToken.START_ARRAY) {
       in.skipChildren();
       in.nextToken();
       advance(Symbol.ARRAY_END);
     } else {
       throw error("array-start");
     }
     return 0;
   }

   @Override
   public long readMapStart() throws IOException {
     advance(Symbol.MAP_START);
     if (in.getCurrentToken() == JsonToken.START_OBJECT) {
       in.nextToken();
       return doMapNext();
     } else {
       throw error("map-start");
     }
   }

   @Override
   public long mapNext() throws IOException {
     advance(Symbol.ITEM_END);
     return doMapNext();
   }

   private long doMapNext() throws IOException {
     if (in.getCurrentToken() == JsonToken.END_OBJECT) {
       in.nextToken();
       advance(Symbol.MAP_END);
       return 0;
     } else {
       return 1;
     }
   }

   @Override
   public long skipMap() throws IOException {
     advance(Symbol.MAP_START);
     if (in.getCurrentToken() == JsonToken.START_OBJECT) {
       in.skipChildren();
       in.nextToken();
       advance(Symbol.MAP_END);
     } else {
       throw error("map-start");
     }
     return 0;
   }

   @Override
   public int readIndex() throws IOException {
     advance(Symbol.UNION);
     Symbol.Alternative a = (Symbol.Alternative) parser.popSymbol();

     String label;
     if (in.getCurrentToken() == JsonToken.VALUE_NULL) {
       label = "null";
     } else if (in.getCurrentToken() == JsonToken.START_OBJECT && in.nextToken() == JsonToken.FIELD_NAME) {
       label = in.getText();
       in.nextToken();
       parser.pushSymbol(Symbol.UNION_END);
     } else {
       throw error("start-union");
     }
     int n = a.findLabel(label);
     if (n < 0)
       throw new AvroTypeException("Unknown union branch " + label);
     parser.pushSymbol(a.getSymbol(n));
     return n;
   }

   @Override
   public Symbol doAction(Symbol input, Symbol top) throws IOException {
     if (top instanceof Symbol.FieldAdjustAction) {
       Symbol.FieldAdjustAction fa = (Symbol.FieldAdjustAction) top;
       String name = fa.fname;
       if (currentReorderBuffer != null) {
         try (TokenBuffer tokenBuffer = currentReorderBuffer.savedFields.get(name)) {
           if (tokenBuffer != null) {
             currentReorderBuffer.savedFields.remove(name);
             currentReorderBuffer.origParser = in;
             in = tokenBuffer.asParser();
             in.nextToken();
             return null;
           }
         }
       }
       if (in.getCurrentToken() == JsonToken.FIELD_NAME) {
         do {
           String fn = in.getText();
           in.nextToken();
           if (name.equals(fn) || fa.aliases.contains(fn)) {
             return null;
           } else {
             if (currentReorderBuffer == null) {
               currentReorderBuffer = new ReorderBuffer();
             }
             try (TokenBuffer tokenBuffer = new TokenBuffer(in)) {
               // Moves the parser to the end of the current event e.g. END_OBJECT
               tokenBuffer.copyCurrentStructure(in);
               currentReorderBuffer.savedFields.put(fn, tokenBuffer);
             }
             in.nextToken();
           }
         } while (in.getCurrentToken() == JsonToken.FIELD_NAME);
         throw new AvroTypeException("Expected field name not found: " + fa.fname);
       }
     } else if (top == Symbol.FIELD_END) {
       if (currentReorderBuffer != null && currentReorderBuffer.origParser != null) {
         in = currentReorderBuffer.origParser;
         currentReorderBuffer.origParser = null;
       }
     } else if (top == Symbol.RECORD_START) {
       if (in.getCurrentToken() == JsonToken.START_OBJECT) {
         in.nextToken();
         reorderBuffers.push(currentReorderBuffer);
         currentReorderBuffer = null;
       } else {
         throw error("record-start");
       }
     } else if (top == Symbol.RECORD_END || top == Symbol.UNION_END) {
       // AVRO-2034 advance to the end of our object
       while (in.getCurrentToken() != JsonToken.END_OBJECT) {
         in.nextToken();
       }

       if (top == Symbol.RECORD_END) {
         if (currentReorderBuffer != null && !currentReorderBuffer.savedFields.isEmpty()) {
           throw error("Unknown fields: " + currentReorderBuffer.savedFields.keySet());
         }
         currentReorderBuffer = reorderBuffers.pop();
       }

       // AVRO-2034 advance beyond the end object for the next record.
       in.nextToken();

     } else {
       throw new AvroTypeException("Unknown action symbol " + top);
     }
     return null;
   }

   private AvroTypeException error(String type) {
     return new AvroTypeException("Expected " + type + ". Got " + in.getCurrentToken());
   }

 }
	/*
	* 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
	*
	* https://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.avro.io;

	import java.io.EOFException;
	import java.io.IOException;
	import java.io.InputStream;
	import java.nio.ByteBuffer;
	import java.nio.charset.StandardCharsets;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Stack;

	import org.apache.avro.AvroTypeException;
	import org.apache.avro.Schema;
	import org.apache.avro.io.parsing.JsonGrammarGenerator;
	import org.apache.avro.io.parsing.Parser;
	import org.apache.avro.io.parsing.Symbol;
	import org.apache.avro.util.Utf8;
	import com.fasterxml.jackson.core.JsonFactory;
	import com.fasterxml.jackson.core.JsonParser;
	import com.fasterxml.jackson.core.JsonToken;
	import com.fasterxml.jackson.databind.util.TokenBuffer;

	/**
	* A {@link Decoder} for Avro's JSON data encoding.
	* </p>
	* Construct using {@link DecoderFactory}.
	* </p>
	* JsonDecoder is not thread-safe.
	*/
	public class JsonDecoder extends ParsingDecoder implements Parser.ActionHandler {
	private JsonParser in;
	private static JsonFactory jsonFactory = new JsonFactory();
	Stack<ReorderBuffer> reorderBuffers = new Stack<>();
	ReorderBuffer currentReorderBuffer;

	private static class ReorderBuffer {
	public Map<String, TokenBuffer> savedFields = new HashMap<>();
	public JsonParser origParser = null;
	}

	private JsonDecoder(Symbol root, InputStream in) throws IOException {
	super(root);
	configure(in);
	}

	private JsonDecoder(Symbol root, String in) throws IOException {
	super(root);
	configure(in);
	}

	JsonDecoder(Schema schema, InputStream in) throws IOException {
	this(getSymbol(schema), in);
	}

	JsonDecoder(Schema schema, String in) throws IOException {
	this(getSymbol(schema), in);
	}

	private static Symbol getSymbol(Schema schema) {
	Objects.requireNonNull(schema, "Schema cannot be null");
	return new JsonGrammarGenerator().generate(schema);
	}

	/**
	* Reconfigures this JsonDecoder to use the InputStream provided.
	* <p/>
	* If the InputStream provided is null, a NullPointerException is thrown.
	* <p/>
	* Otherwise, this JsonDecoder will reset its state and then reconfigure its
	* input.
	*
	* @param in The InputStream to read from. Cannot be null.
	* @throws IOException
	* @throws NullPointerException if {@code in} is {@code null}
	* @return this JsonDecoder
	*/
	public JsonDecoder configure(InputStream in) throws IOException {
	Objects.requireNonNull(in, "InputStream cannot be null");
	parser.reset();
	reorderBuffers.clear();
	currentReorderBuffer = null;
	this.in = jsonFactory.createParser(in);
	this.in.nextToken();
	return this;
	}

	/**
	* Reconfigures this JsonDecoder to use the String provided for input.
	* <p/>
	* If the String provided is null, a NullPointerException is thrown.
	* <p/>
	* Otherwise, this JsonDecoder will reset its state and then reconfigure its
	* input.
	*
	* @param in The String to read from. Cannot be null.
	* @throws IOException
	* @throws NullPointerException if {@code in} is {@code null}
	* @return this JsonDecoder
	*/
	public JsonDecoder configure(String in) throws IOException {
	Objects.requireNonNull(in, "String to read from cannot be null");
	parser.reset();
	reorderBuffers.clear();
	currentReorderBuffer = null;
	this.in = new JsonFactory().createParser(in);
	this.in.nextToken();
	return this;
	}

	private void advance(Symbol symbol) throws IOException {
	this.parser.processTrailingImplicitActions();
	if (in.getCurrentToken() == null && this.parser.depth() == 1)
	throw new EOFException();
	parser.advance(symbol);
	}

	@Override
	public void readNull() throws IOException {
	advance(Symbol.NULL);
	if (in.getCurrentToken() == JsonToken.VALUE_NULL) {
	in.nextToken();
	} else {
	throw error("null");
	}
	}

	@Override
	public boolean readBoolean() throws IOException {
	advance(Symbol.BOOLEAN);
	JsonToken t = in.getCurrentToken();
	if (t == JsonToken.VALUE_TRUE \|\| t == JsonToken.VALUE_FALSE) {
	in.nextToken();
	return t == JsonToken.VALUE_TRUE;
	} else {
	throw error("boolean");
	}
	}

	@Override
	public int readInt() throws IOException {
	advance(Symbol.INT);
	if (in.getCurrentToken().isNumeric()) {
	int result = in.getIntValue();
	in.nextToken();
	return result;
	} else {
	throw error("int");
	}
	}

	@Override
	public long readLong() throws IOException {
	advance(Symbol.LONG);
	if (in.getCurrentToken().isNumeric()) {
	long result = in.getLongValue();
	in.nextToken();
	return result;
	} else {
	throw error("long");
	}
	}

	@Override
	public float readFloat() throws IOException {
	advance(Symbol.FLOAT);
	if (in.getCurrentToken().isNumeric()) {
	float result = in.getFloatValue();
	in.nextToken();
	return result;
	} else {
	throw error("float");
	}
	}

	@Override
	public double readDouble() throws IOException {
	advance(Symbol.DOUBLE);
	if (in.getCurrentToken().isNumeric()) {
	double result = in.getDoubleValue();
	in.nextToken();
	return result;
	} else {
	throw error("double");
	}
	}

	@Override
	public Utf8 readString(Utf8 old) throws IOException {
	return new Utf8(readString());
	}

	@Override
	public String readString() throws IOException {
	advance(Symbol.STRING);
	if (parser.topSymbol() == Symbol.MAP_KEY_MARKER) {
	parser.advance(Symbol.MAP_KEY_MARKER);
	if (in.getCurrentToken() != JsonToken.FIELD_NAME) {
	throw error("map-key");
	}
	} else {
	if (in.getCurrentToken() != JsonToken.VALUE_STRING) {
	throw error("string");
	}
	}
	String result = in.getText();
	in.nextToken();
	return result;
	}

	@Override
	public void skipString() throws IOException {
	advance(Symbol.STRING);
	if (parser.topSymbol() == Symbol.MAP_KEY_MARKER) {
	parser.advance(Symbol.MAP_KEY_MARKER);
	if (in.getCurrentToken() != JsonToken.FIELD_NAME) {
	throw error("map-key");
	}
	} else {
	if (in.getCurrentToken() != JsonToken.VALUE_STRING) {
	throw error("string");
	}
	}
	in.nextToken();
	}

	@Override
	public ByteBuffer readBytes(ByteBuffer old) throws IOException {
	advance(Symbol.BYTES);
	if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
	byte[] result = readByteArray();
	in.nextToken();
	return ByteBuffer.wrap(result);
	} else {
	throw error("bytes");
	}
	}

	private byte[] readByteArray() throws IOException {
	byte[] result = in.getText().getBytes(StandardCharsets.ISO_8859_1);
	return result;
	}

	@Override
	public void skipBytes() throws IOException {
	advance(Symbol.BYTES);
	if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
	in.nextToken();
	} else {
	throw error("bytes");
	}
	}

	private void checkFixed(int size) throws IOException {
	advance(Symbol.FIXED);
	Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
	if (size != top.size) {
	throw new AvroTypeException(
	"Incorrect length for fixed binary: expected " + top.size + " but received " + size + " bytes.");
	}
	}

	@Override
	public void readFixed(byte[] bytes, int start, int len) throws IOException {
	checkFixed(len);
	if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
	byte[] result = readByteArray();
	in.nextToken();
	if (result.length != len) {
	throw new AvroTypeException("Expected fixed length " + len + ", but got" + result.length);
	}
	System.arraycopy(result, 0, bytes, start, len);
	} else {
	throw error("fixed");
	}
	}

	@Override
	public void skipFixed(int length) throws IOException {
	checkFixed(length);
	doSkipFixed(length);
	}

	private void doSkipFixed(int length) throws IOException {
	if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
	byte[] result = readByteArray();
	in.nextToken();
	if (result.length != length) {
	throw new AvroTypeException("Expected fixed length " + length + ", but got" + result.length);
	}
	} else {
	throw error("fixed");
	}
	}

	@Override
	protected void skipFixed() throws IOException {
	advance(Symbol.FIXED);
	Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
	doSkipFixed(top.size);
	}

	@Override
	public int readEnum() throws IOException {
	advance(Symbol.ENUM);
	Symbol.EnumLabelsAction top = (Symbol.EnumLabelsAction) parser.popSymbol();
	if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
	in.getText();
	int n = top.findLabel(in.getText());
	if (n >= 0) {
	in.nextToken();
	return n;
	}
	throw new AvroTypeException("Unknown symbol in enum " + in.getText());
	} else {
	throw error("fixed");
	}
	}

	@Override
	public long readArrayStart() throws IOException {
	advance(Symbol.ARRAY_START);
	if (in.getCurrentToken() == JsonToken.START_ARRAY) {
	in.nextToken();
	return doArrayNext();
	} else {
	throw error("array-start");
	}
	}

	@Override
	public long arrayNext() throws IOException {
	advance(Symbol.ITEM_END);
	return doArrayNext();
	}

	private long doArrayNext() throws IOException {
	if (in.getCurrentToken() == JsonToken.END_ARRAY) {
	parser.advance(Symbol.ARRAY_END);
	in.nextToken();
	return 0;
	} else {
	return 1;
	}
	}

	@Override
	public long skipArray() throws IOException {
	advance(Symbol.ARRAY_START);
	if (in.getCurrentToken() == JsonToken.START_ARRAY) {
	in.skipChildren();
	in.nextToken();
	advance(Symbol.ARRAY_END);
	} else {
	throw error("array-start");
	}
	return 0;
	}

	@Override
	public long readMapStart() throws IOException {
	advance(Symbol.MAP_START);
	if (in.getCurrentToken() == JsonToken.START_OBJECT) {
	in.nextToken();
	return doMapNext();
	} else {
	throw error("map-start");
	}
	}

	@Override
	public long mapNext() throws IOException {
	advance(Symbol.ITEM_END);
	return doMapNext();
	}

	private long doMapNext() throws IOException {
	if (in.getCurrentToken() == JsonToken.END_OBJECT) {
	in.nextToken();
	advance(Symbol.MAP_END);
	return 0;
	} else {
	return 1;
	}
	}

	@Override
	public long skipMap() throws IOException {
	advance(Symbol.MAP_START);
	if (in.getCurrentToken() == JsonToken.START_OBJECT) {
	in.skipChildren();
	in.nextToken();
	advance(Symbol.MAP_END);
	} else {
	throw error("map-start");
	}
	return 0;
	}

	@Override
	public int readIndex() throws IOException {
	advance(Symbol.UNION);
	Symbol.Alternative a = (Symbol.Alternative) parser.popSymbol();

	String label;
	if (in.getCurrentToken() == JsonToken.VALUE_NULL) {
	label = "null";
	} else if (in.getCurrentToken() == JsonToken.START_OBJECT && in.nextToken() == JsonToken.FIELD_NAME) {
	label = in.getText();
	in.nextToken();
	parser.pushSymbol(Symbol.UNION_END);
	} else {
	throw error("start-union");
	}
	int n = a.findLabel(label);
	if (n < 0)
	throw new AvroTypeException("Unknown union branch " + label);
	parser.pushSymbol(a.getSymbol(n));
	return n;
	}

	@Override
	public Symbol doAction(Symbol input, Symbol top) throws IOException {
	if (top instanceof Symbol.FieldAdjustAction) {
	Symbol.FieldAdjustAction fa = (Symbol.FieldAdjustAction) top;
	String name = fa.fname;
	if (currentReorderBuffer != null) {
	try (TokenBuffer tokenBuffer = currentReorderBuffer.savedFields.get(name)) {
	if (tokenBuffer != null) {
	currentReorderBuffer.savedFields.remove(name);
	currentReorderBuffer.origParser = in;
	in = tokenBuffer.asParser();
	in.nextToken();
	return null;
	}
	}
	}
	if (in.getCurrentToken() == JsonToken.FIELD_NAME) {
	do {
	String fn = in.getText();
	in.nextToken();
	if (name.equals(fn) \|\| fa.aliases.contains(fn)) {
	return null;
	} else {
	if (currentReorderBuffer == null) {
	currentReorderBuffer = new ReorderBuffer();
	}
	try (TokenBuffer tokenBuffer = new TokenBuffer(in)) {
	// Moves the parser to the end of the current event e.g. END_OBJECT
	tokenBuffer.copyCurrentStructure(in);
	currentReorderBuffer.savedFields.put(fn, tokenBuffer);
	}
	in.nextToken();
	}
	} while (in.getCurrentToken() == JsonToken.FIELD_NAME);
	throw new AvroTypeException("Expected field name not found: " + fa.fname);
	}
	} else if (top == Symbol.FIELD_END) {
	if (currentReorderBuffer != null && currentReorderBuffer.origParser != null) {
	in = currentReorderBuffer.origParser;
	currentReorderBuffer.origParser = null;
	}
	} else if (top == Symbol.RECORD_START) {
	if (in.getCurrentToken() == JsonToken.START_OBJECT) {
	in.nextToken();
	reorderBuffers.push(currentReorderBuffer);
	currentReorderBuffer = null;
	} else {
	throw error("record-start");
	}
	} else if (top == Symbol.RECORD_END \|\| top == Symbol.UNION_END) {
	// AVRO-2034 advance to the end of our object
	while (in.getCurrentToken() != JsonToken.END_OBJECT) {
	in.nextToken();
	}

	if (top == Symbol.RECORD_END) {
	if (currentReorderBuffer != null && !currentReorderBuffer.savedFields.isEmpty()) {
	throw error("Unknown fields: " + currentReorderBuffer.savedFields.keySet());
	}
	currentReorderBuffer = reorderBuffers.pop();
	}

	// AVRO-2034 advance beyond the end object for the next record.
	in.nextToken();

	} else {
	throw new AvroTypeException("Unknown action symbol " + top);
	}
	return null;
	}

	private AvroTypeException error(String type) {
	return new AvroTypeException("Expected " + type + ". Got " + in.getCurrentToken());
	}

	}