/**
* 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.avro.io;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.BitSet;
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 ensures that the sequence
* of operations conforms to a schema.
*/
public class ValidatingEncoder extends ParsingEncoder
implements Parser.ActionHandler {
protected Encoder out;
protected final Parser parser;
/**
* Has anything been written into the collections?
*/
protected BitSet isEmpty = new BitSet();
ValidatingEncoder(Symbol root, Encoder out) throws IOException {
this.out = out;
this.parser = new Parser(root, this);
}
public ValidatingEncoder(Schema schema, Encoder in) throws IOException {
this(new ValidatingGrammarGenerator().generate(schema), in);
}
@Override
public void flush() throws IOException {
out.flush();
}
@Override
public void init(OutputStream out) throws IOException {
flush();
parser.reset();
this.out.init(out);
}
@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 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 Symbol.CONTINUE;
}
/** Have we written at least one item into the current collection? */
protected final boolean isTopEmpty() {
return isEmpty.get(pos);
}
}