content: /*
   * 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.IOException;
  import java.nio.ByteBuffer;
  
  import org.apache.avro.AvroTypeException;
  import org.apache.avro.Schema;
  import org.apache.avro.io.parsing.ValidatingGrammarGenerator;
  import org.apache.avro.io.parsing.Parser;
  import org.apache.avro.io.parsing.Symbol;
  import org.apache.avro.util.Utf8;
  
  /**
   * An implementation of {@link Encoder} that wraps another Encoder and ensures
   * that the sequence of operations conforms to the provided schema.
   * <p/>
   * Use {@link EncoderFactory#validatingEncoder(Schema, Encoder)} to construct
   * and configure.
   * <p/>
   * ValidatingEncoder is not thread-safe.
   *
   * @see Encoder
   * @see EncoderFactory
   */
  public class ValidatingEncoder extends ParsingEncoder implements Parser.ActionHandler {
    protected Encoder out;
    protected final Parser parser;
  
    ValidatingEncoder(Symbol root, Encoder out) {
      this.out = out;
      this.parser = new Parser(root, this);
    }
  
    ValidatingEncoder(Schema schema, Encoder in) {
      this(new ValidatingGrammarGenerator().generate(schema), in);
    }
  
    @Override
    public void flush() throws IOException {
      out.flush();
    }
  
    /**
     * Reconfigures this ValidatingEncoder to wrap the encoder provided.
     *
     * @param encoder The Encoder to wrap for validation.
     * @return This ValidatingEncoder.
     */
    public ValidatingEncoder configure(Encoder encoder) {
      this.parser.reset();
      this.out = encoder;
      return this;
    }
  
    @Override
    public void writeNull() throws IOException {
      parser.advance(Symbol.NULL);
      out.writeNull();
    }
  
    @Override
    public void writeBoolean(boolean b) throws IOException {
      parser.advance(Symbol.BOOLEAN);
      out.writeBoolean(b);
    }
  
    @Override
    public void writeInt(int n) throws IOException {
      parser.advance(Symbol.INT);
      out.writeInt(n);
    }
  
    @Override
    public void writeLong(long n) throws IOException {
      parser.advance(Symbol.LONG);
      out.writeLong(n);
    }
  
    @Override
    public void writeFloat(float f) throws IOException {
      parser.advance(Symbol.FLOAT);
      out.writeFloat(f);
    }
  
    @Override
    public void writeDouble(double d) throws IOException {
      parser.advance(Symbol.DOUBLE);
      out.writeDouble(d);
    }
  
    @Override
    public void writeString(Utf8 utf8) throws IOException {
      parser.advance(Symbol.STRING);
      out.writeString(utf8);
    }
  
    @Override
    public void writeString(String str) throws IOException {
      parser.advance(Symbol.STRING);
      out.writeString(str);
    }
  
    @Override
    public void writeString(CharSequence charSequence) throws IOException {
      parser.advance(Symbol.STRING);
      out.writeString(charSequence);
    }
  
    @Override
    public void writeBytes(ByteBuffer bytes) throws IOException {
      parser.advance(Symbol.BYTES);
      out.writeBytes(bytes);
    }
  
    @Override
    public void writeBytes(byte[] bytes, int start, int len) throws IOException {
      parser.advance(Symbol.BYTES);
      out.writeBytes(bytes, start, len);
    }
  
    @Override
    public void writeFixed(byte[] bytes, int start, int len) throws IOException {
      parser.advance(Symbol.FIXED);
      Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
      if (len != top.size) {
        throw new AvroTypeException(
            "Incorrect length for fixed binary: expected " + top.size + " but received " + len + " bytes.");
      }
      out.writeFixed(bytes, start, len);
    }
  
    @Override
    public void writeEnum(int e) throws IOException {
      parser.advance(Symbol.ENUM);
      Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
      if (e < 0 || e >= top.size) {
        throw new AvroTypeException("Enumeration out of range: max is " + top.size + " but received " + e);
      }
      out.writeEnum(e);
    }
  
    @Override
    public void writeArrayStart() throws IOException {
      push();
      parser.advance(Symbol.ARRAY_START);
      out.writeArrayStart();
    }
  
    @Override
    public void writeArrayEnd() throws IOException {
      parser.advance(Symbol.ARRAY_END);
      out.writeArrayEnd();
      pop();
    }
  
    @Override
    public void writeMapStart() throws IOException {
      push();
      parser.advance(Symbol.MAP_START);
      out.writeMapStart();
    }
  
    @Override
    public void writeMapEnd() throws IOException {
      parser.advance(Symbol.MAP_END);
      out.writeMapEnd();
      pop();
    }
  
    @Override
    public void setItemCount(long itemCount) throws IOException {
      super.setItemCount(itemCount);
      out.setItemCount(itemCount);
    }
  
    @Override
    public void startItem() throws IOException {
      super.startItem();
      out.startItem();
    }
  
    @Override
    public void writeIndex(int unionIndex) throws IOException {
      parser.advance(Symbol.UNION);
      Symbol.Alternative top = (Symbol.Alternative) parser.popSymbol();
      parser.pushSymbol(top.getSymbol(unionIndex));
      out.writeIndex(unionIndex);
    }
  
    @Override
    public Symbol doAction(Symbol input, Symbol top) throws IOException {
      return null;
    }
  
  }
  