Generic.hh

/*
 * 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.
 */

#ifndef avro_Generic_hh__
#define avro_Generic_hh__

#include <boost/utility.hpp>

#include "Config.hh"
#include "Types.hh"
#include "Encoder.hh"
#include "Decoder.hh"
#include "GenericDatum.hh"

namespace avro {
class AVRO_DECL GenericReader : boost::noncopyable {
    const ValidSchema schema_;
    const bool isResolving_;
    const DecoderPtr decoder_;

    static void read(GenericDatum& datum, Decoder& d, bool isResolving);
public:
    GenericReader(const ValidSchema& s, const DecoderPtr& decoder);

    GenericReader(const ValidSchema& writerSchema,
        const ValidSchema& readerSchema, const DecoderPtr& decoder);

    void read(GenericDatum& datum) const;

    void drain() {
        decoder_->drain();
    }
    static void read(Decoder& d, GenericDatum& g);

    static void read(Decoder& d, GenericDatum& g, const ValidSchema& s);
};


class AVRO_DECL GenericWriter : boost::noncopyable {
    const ValidSchema schema_;
    const EncoderPtr encoder_;

    static void write(const GenericDatum& datum, Encoder& e);
public:
    GenericWriter(const ValidSchema& s, const EncoderPtr& encoder);

    void write(const GenericDatum& datum) const;

    static void write(Encoder& e, const GenericDatum& g);

    static void write(Encoder& e, const GenericDatum& g, const ValidSchema&) {
        write(e, g);
    }
};

template <typename T> struct codec_traits;

template <> struct codec_traits<std::pair<ValidSchema, GenericDatum> > {
    static void encode(Encoder& e,
        const std::pair<ValidSchema, GenericDatum>& p) {
        GenericWriter::write(e, p.second, p.first);
    }

    static void decode(Decoder& d, std::pair<ValidSchema, GenericDatum>& p) {
        GenericReader::read(d, p.second, p.first);
    }
};

template <> struct codec_traits<GenericDatum> {
    static void encode(Encoder& e, const GenericDatum& g) {
        GenericWriter::write(e, g);
    }

    static void decode(Decoder& d, GenericDatum& g) {
        GenericReader::read(d, g);
    }
};

}   // namespace avro
#endif