GenericDatum.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_GenericDatum_hh__
#define avro_GenericDatum_hh__
 
#include <cstdint>
#include <map>
#include <string>
#include <vector>
 
#if __cplusplus >= 201703L
#include <any>
#else
#include "boost/any.hpp"
#endif
 
#include "LogicalType.hh"
#include "Node.hh"
#include "ValidSchema.hh"
 
namespace avro {
 
class AVRO_DECL GenericDatum {
protected:
    Type type_;
    LogicalType logicalType_;
#if __cplusplus >= 201703L
    std::any value_;
#else
    boost::any value_;
#endif
 
    explicit GenericDatum(Type t)
        : type_(t), logicalType_(LogicalType::NONE) {}
 
    GenericDatum(Type t, LogicalType logicalType)
        : type_(t), logicalType_(logicalType) {}
 
    template<typename T>
    GenericDatum(Type t, LogicalType logicalType, const T &v)
        : type_(t), logicalType_(logicalType), value_(v) {}
 
    void init(const NodePtr &schema);
 
public:
    Type type() const;
 
    LogicalType logicalType() const;
 
    template<typename T>
    const T &value() const;
 
    template<typename T>
    T &value();
 
    bool isUnion() const { return type_ == AVRO_UNION; }
 
    size_t unionBranch() const;
 
    void selectBranch(size_t branch);
 
    GenericDatum() : type_(AVRO_NULL), logicalType_(LogicalType::NONE) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(bool v)
        : type_(AVRO_BOOL), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(int32_t v)
        : type_(AVRO_INT), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(int64_t v)
        : type_(AVRO_LONG), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(float v)
        : type_(AVRO_FLOAT), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(double v)
        : type_(AVRO_DOUBLE), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(const std::string &v)
        : type_(AVRO_STRING), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(const std::vector<uint8_t> &v) : type_(AVRO_BYTES), logicalType_(LogicalType::NONE), value_(v) {}
 
    // NOLINTNEXTLINE(google-explicit-constructor)
    GenericDatum(const NodePtr &schema);
 
    template<typename T>
    GenericDatum(const NodePtr &schema, const T &v) : type_(schema->type()), logicalType_(schema->logicalType()) {
        init(schema);
#if __cplusplus >= 201703L
        *std::any_cast<T>(&value_) = v;
#else
        *boost::any_cast<T>(&value_) = v;
#endif
    }
 
    explicit GenericDatum(const ValidSchema &schema);
};
 
class AVRO_DECL GenericContainer {
    NodePtr schema_;
    static void assertType(const NodePtr &schema, Type type);
 
protected:
    GenericContainer(Type type, const NodePtr &s) : schema_(s) {
        assertType(s, type);
    }
 
public:
    const NodePtr &schema() const {
        return schema_;
    }
};
 
class AVRO_DECL GenericUnion : public GenericContainer {
    size_t curBranch_;
    GenericDatum datum_;
 
public:
    explicit GenericUnion(const NodePtr &schema) : GenericContainer(AVRO_UNION, schema), curBranch_(schema->leaves()) {
        selectBranch(0);
    }
 
    size_t currentBranch() const { return curBranch_; }
 
    void selectBranch(size_t branch) {
        if (curBranch_ != branch) {
            datum_ = GenericDatum(schema()->leafAt(branch));
            curBranch_ = branch;
        }
    }
 
    GenericDatum &datum() {
        return datum_;
    }
 
    const GenericDatum &datum() const {
        return datum_;
    }
};
 
class AVRO_DECL GenericRecord : public GenericContainer {
    std::vector<GenericDatum> fields_;
 
public:
    explicit GenericRecord(const NodePtr &schema);
 
    size_t fieldCount() const {
        return fields_.size();
    }
 
    size_t fieldIndex(const std::string &name) const {
        size_t index = 0;
        if (!schema()->nameIndex(name, index)) {
            throw Exception("Invalid field name: " + name);
        }
        return index;
    }
 
    bool hasField(const std::string &name) const {
        size_t index = 0;
        return schema()->nameIndex(name, index);
    }
 
    const GenericDatum &field(const std::string &name) const {
        return fieldAt(fieldIndex(name));
    }
 
    GenericDatum &field(const std::string &name) {
        return fieldAt(fieldIndex(name));
    }
 
    const GenericDatum &fieldAt(size_t pos) const {
        return fields_[pos];
    }
 
    GenericDatum &fieldAt(size_t pos) {
        return fields_[pos];
    }
 
    void setFieldAt(size_t pos, const GenericDatum &v) {
        // assertSameType(v, schema()->leafAt(pos));
        fields_[pos] = v;
    }
};
 
class AVRO_DECL GenericArray : public GenericContainer {
public:
    typedef std::vector<GenericDatum> Value;
 
    explicit GenericArray(const NodePtr &schema) : GenericContainer(AVRO_ARRAY, schema) {
    }
 
    const Value &value() const {
        return value_;
    }
 
    Value &value() {
        return value_;
    }
 
private:
    Value value_;
};
 
class AVRO_DECL GenericMap : public GenericContainer {
public:
    typedef std::vector<std::pair<std::string, GenericDatum>> Value;
 
    explicit GenericMap(const NodePtr &schema) : GenericContainer(AVRO_MAP, schema) {
    }
 
    const Value &value() const {
        return value_;
    }
 
    Value &value() {
        return value_;
    }
 
private:
    Value value_;
};
 
class AVRO_DECL GenericEnum : public GenericContainer {
    size_t value_;
 
    static size_t index(const NodePtr &schema, const std::string &symbol) {
        size_t result;
        if (schema->nameIndex(symbol, result)) {
            return result;
        }
        throw Exception("No such symbol");
    }
 
public:
    explicit GenericEnum(const NodePtr &schema) : GenericContainer(AVRO_ENUM, schema), value_(0) {
    }
 
    GenericEnum(const NodePtr &schema, const std::string &symbol) : GenericContainer(AVRO_ENUM, schema), value_(index(schema, symbol)) {
    }
 
    const std::string &symbol(size_t n) {
        if (n < schema()->names()) {
            return schema()->nameAt(n);
        }
        throw Exception("Not as many symbols");
    }
 
    size_t index(const std::string &symbol) const {
        return index(schema(), symbol);
    }
 
    size_t set(const std::string &symbol) {
        return value_ = index(symbol);
    }
 
    void set(size_t n) {
        if (n < schema()->names()) {
            value_ = n;
            return;
        }
        throw Exception("Not as many symbols");
    }
 
    size_t value() const {
        return value_;
    }
 
    const std::string &symbol() const {
        return schema()->nameAt(value_);
    }
};
 
class AVRO_DECL GenericFixed : public GenericContainer {
    std::vector<uint8_t> value_;
 
public:
    explicit GenericFixed(const NodePtr &schema) : GenericContainer(AVRO_FIXED, schema) {
        value_.resize(schema->fixedSize());
    }
 
    GenericFixed(const NodePtr &schema, const std::vector<uint8_t> &v);
 
    const std::vector<uint8_t> &value() const {
        return value_;
    }
 
    std::vector<uint8_t> &value() {
        return value_;
    }
};
 
inline Type GenericDatum::type() const {
    return (type_ == AVRO_UNION) ?
#if __cplusplus >= 201703L
                                 std::any_cast<GenericUnion>(&value_)->datum().type()
                                 :
#else
                                 boost::any_cast<GenericUnion>(&value_)->datum().type()
                                 :
#endif
                                 type_;
}
 
inline LogicalType GenericDatum::logicalType() const {
    return (type_ == AVRO_UNION) ?
#if __cplusplus >= 201703L
        std::any_cast<GenericUnion>(&value_)->datum().logicalType() :
#else
        boost::any_cast<GenericUnion>(&value_)->datum().logicalType() :
#endif
        logicalType_;
}
 
template<typename T>
T &GenericDatum::value() {
    return (type_ == AVRO_UNION) ?
#if __cplusplus >= 201703L
                                 std::any_cast<GenericUnion>(&value_)->datum().value<T>()
                                 : *std::any_cast<T>(&value_);
#else
                                 boost::any_cast<GenericUnion>(&value_)->datum().value<T>()
                                 : *boost::any_cast<T>(&value_);
#endif
}
 
template<typename T>
const T &GenericDatum::value() const {
    return (type_ == AVRO_UNION) ?
#if __cplusplus >= 201703L
                                 std::any_cast<GenericUnion>(&value_)->datum().value<T>()
                                 : *std::any_cast<T>(&value_);
#else
                                 boost::any_cast<GenericUnion>(&value_)->datum().value<T>()
                                 : *boost::any_cast<T>(&value_);
#endif
}
 
inline size_t GenericDatum::unionBranch() const {
#if __cplusplus >= 201703L
    return std::any_cast<GenericUnion>(&value_)->currentBranch();
#else
    return boost::any_cast<GenericUnion>(&value_)->currentBranch();
#endif
}
 
inline void GenericDatum::selectBranch(size_t branch) {
#if __cplusplus >= 201703L
    std::any_cast<GenericUnion>(&value_)->selectBranch(branch);
#else
    boost::any_cast<GenericUnion>(&value_)->selectBranch(branch);
#endif
}
 
} // namespace avro
#endif // avro_GenericDatum_hh__