Odb.h

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/*
 * (C) Copyright 2019- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */
 
 
/// @author Simon Smart
/// @date January 2019
 
#ifndef odc_api_Odb_H
#define odc_api_Odb_H
 
#include <string>
#include <memory>
#include <vector>
#include <type_traits>
#include <set>
#include <map>
 
#include "eckit/io/Length.h"
#include "eckit/io/Offset.h"
 
#include "odc/api/ColumnType.h"
#include "odc/api/ColumnInfo.h"
#include "odc/api/StridedData.h"
 
namespace eckit {
    class DataHandle;
}
 
 
namespace odc {
namespace api {
 
//----------------------------------------------------------------------------------------------------------------------
 
// Global settings
 
class Settings {
public: // methods
 
    static void treatIntegersAsDoubles(bool flag);
 
    static long integerMissingValue();
    static void setIntegerMissingValue(long val);
 
    static double doubleMissingValue();
    static void setDoubleMissingValue(double val);
 
    static const std::string& version();
    static const std::string& gitsha1();
};
 
//----------------------------------------------------------------------------------------------------------------------
 
struct SpanImpl;
 
class SpanVisitor {
public:
    virtual ~SpanVisitor();
    virtual void operator()(const std::string& columnName, const std::set<long>& vals) = 0;
    virtual void operator()(const std::string& columnName, const std::set<double>& vals) = 0;
    virtual void operator()(const std::string& columnName, const std::set<std::string>& vals) = 0;
};
 
 
class Span {
 
public: // methods
 
    Span(std::shared_ptr<SpanImpl> s);
 
    void visit(SpanVisitor& visitor) const;
 
    eckit::Offset offset() const;
    eckit::Length length() const;
 
private: // members
 
    std::shared_ptr<SpanImpl> impl_;
};
 
//----------------------------------------------------------------------------------------------------------------------
 
struct FrameImpl;
 
class ReaderImpl;
 
class Reader {
 
public: // methods
 
    Reader(const std::string& path);
    Reader(eckit::DataHandle& dh);
    Reader(eckit::DataHandle* dh); // takes ownership
    ~Reader();
 
private: // members
 
    std::shared_ptr<ReaderImpl> impl_;
 
    friend class FrameImpl;
};
 
 
//----------------------------------------------------------------------------------------------------------------------
 
class Decoder;
 
class Frame {
 
public: // methods
 
    Frame(Reader& reader);
    Frame(const Frame& reader);
    ~Frame();
 
    // Get the next frame
    bool next(bool aggregated=true, long rowlimit=-1);
 
    size_t rowCount() const;
    size_t columnCount() const;
 
    const std::vector<ColumnInfo>& columnInfo() const;
 
    void decode(Decoder& target, size_t nthreads) const;
 
    Span span(const std::vector<std::string>& columns, bool onlyConstantValues) const;
 
private: // members
 
    std::unique_ptr<FrameImpl> impl_;
};
 
//----------------------------------------------------------------------------------------------------------------------
 
struct DecoderImpl;
 
class Decoder {
 
public: // methods
 
    Decoder(const std::vector<std::string>& columns,
                 std::vector<StridedData>& columnFacades);
    ~Decoder();
 
    Decoder slice(size_t rowOffset, size_t nrows) const;
 
private: // members
 
    std::shared_ptr<DecoderImpl> impl_;
 
    friend class FrameImpl;
};
 
//----------------------------------------------------------------------------------------------------------------------
 
void encode(eckit::DataHandle& out,
            const std::vector<ColumnInfo>& columns,
            const std::vector<ConstStridedData>& data,
            const std::map<std::string, std::string>& properties = {},
            size_t maxRowsPerFrame=10000);
 
//----------------------------------------------------------------------------------------------------------------------
 
/// odbFromCSV returns number of lines imported
 
size_t odbFromCSV(eckit::DataHandle& dh_in, eckit::DataHandle& dh_out, const std::string& delimiter=",");
size_t odbFromCSV(std::istream& is, eckit::DataHandle& dh_out, const std::string& delimiter=",");
size_t odbFromCSV(const std::string& in, eckit::DataHandle& dh_out, const std::string& delimiter=",");
 
//----------------------------------------------------------------------------------------------------------------------
 
} // namespace api
} // namespace odc
 
#endif // odc_api_Odb_H