// -*- mode: c++; c-basic-offset:4 -*- // This file is part of libdap, A C++ implementation of the OPeNDAP Data // Access Protocol. // Copyright (c) 2013 OPeNDAP, Inc. // Author: James Gallagher // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2.1 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA // // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112. #ifndef _d4sequence_h #define _d4sequence_h 1 #include "Constructor.h" // DAP2 Sequence supported subsetting using the array notation. This might // be introduced into DAP4 later on. #define INDEX_SUBSETTING 0 class Crc32; namespace libdap { class BaseType; class D4FilterClauseList; /** The type BaseTypeRow is used to store single rows of values in an instance of D4Sequence. Values are stored in instances of BaseType. */ typedef vector D4SeqRow; /** This type holds all of the values of a D4Sequence. */ typedef vector D4SeqValues; /** The type BaseTypeRow is used to store single rows of values in an instance of Sequence. Values are stored in instances of BaseType. */ typedef vector BaseTypeRow; /** This type holds all of the values of a Sequence. */ typedef vector SequenceValues; /** This is the interface for the class D4Sequence. A sequence contains a single set of variables, all at the same lexical level just like a Structure. Like a Structure, a D4Sequence may contain other compound types, including other D4Sequences. Unlike a Structure, a D4Sequence defines a pattern that is repeated N times for a sequence of N elements. It is useful to think of a D4Sequence as representing a table of values (like a relational database), with each row of the table corresponding to a D4Sequence ``instance.'' (This usage can be confusing, since ``instance'' also refers to a particular item of class D4Sequence.) For example:
    D4Sequence {
      String name;
      Int32 age;
    } person;
    
This represents a Sequence of ``person'' records, each instance of which contains a name and an age:
    Fred       34
    Ralph      23
    Andrea     29
    ...
    
A D4Sequence can be arbitrarily long, which is to say that its length is not part of its declaration. A D4Sequence can contain other D4Sequences:
    D4Sequence {
      String name;
      Int32 age;
      D4Sequence {
        String friend;
      } friend_list;
    } person;
    
    Fred       34     Norman
                      Andrea
                      Ralph
                      Lisa
    Ralph      23     Norman
                      Andrea
                      Lisa
                      Marth
                      Throckmorton
                      Helga
                      Millicent
    Andrea     29     Ralph
                      Natasha
                      Norman
    ...        ..     ...
    
Internally, the D4Sequence is represented by a vector of vectors. The members of the outer vector are the members of the D4Sequence. This includes the nested D4Sequences, as in the above example. Because the length of a D4Sequence is indeterminate, there are changes to the behavior of the functions to read this class of data. The read() function for D4Sequence must be written so that successive calls return values for successive rows of the D4Sequence. Similar to a C structure, you refer to members of D4Sequence elements with a ``.'' notation. For example, if the D4Sequence has a member D4Sequence called ``Tom'' and Tom has a member Float32 called ``shoe_size'', you can refer to Tom's shoe size as ``Tom.shoe_size''. @brief Holds a sequence. */ class D4Sequence: public Constructor { private: // This may be zero (nullptr) but the accessor (clauses()) allocates an // instance if that is the case. D4FilterClauseList *d_clauses; // Use this to control if ptr_duplicate(), ..., copy the filter clauses. // Because the values of a child sequence are held in copies of the Seq // object they clauses will bound to the 'master' instance will be copied // but the copies will never be used. This field can be used to control // that. ...purely an optimization. bool d_copy_clauses; protected: // This holds the values of the sequence. Values are stored in // instances of BaseTypeRow objects which hold instances of BaseType. // // Allow these values to be accessed by subclasses D4SeqValues d_values; int64_t d_length; // How many elements are in the sequence; -1 if not currently known #if INDEX_SUBSETTING int d_starting_row_number; int d_row_stride; int d_ending_row_number; #endif void m_duplicate(const D4Sequence &s); // Specialize this if you have a data source that requires read() // recursively call itself for child sequences. void read_sequence_values(bool filter); friend class D4SequenceTest; public: D4Sequence(const string &n); D4Sequence(const string &n, const string &d); D4Sequence(const D4Sequence &rhs); virtual ~D4Sequence(); D4Sequence &operator=(const D4Sequence &rhs); virtual BaseType *ptr_duplicate(); virtual void clear_local_data(); /** * @brief The number of elements in a Sequence object. * @note This is not the number of items in a row, but the number * of rows in the complete sequence object. * * @return 0 if the number of elements is unknown, else * return the number of elements. */ virtual int length() const { return (int)d_length; } /** * Set the length of the sequence. * @param count */ virtual void set_length(int count) { d_length = (int64_t)count; } virtual bool read_next_instance(bool filter); virtual void intern_data(ConstraintEvaluator &, DDS &) { throw InternalErr(__FILE__, __LINE__, "Not implemented for DAP4"); } virtual bool serialize(ConstraintEvaluator &, DDS &, Marshaller &, bool ) { throw InternalErr(__FILE__, __LINE__, "Not implemented for DAP4"); } virtual bool deserialize(UnMarshaller &, DDS *, bool ) { throw InternalErr(__FILE__, __LINE__, "Not implemented for DAP4"); } // DAP4 virtual void intern_data(/*Crc32 &checksum, DMR &dmr, ConstraintEvaluator &eval*/); virtual void serialize(D4StreamMarshaller &m, DMR &dmr, /*ConstraintEvaluator &eval,*/ bool filter = false); virtual void deserialize(D4StreamUnMarshaller &um, DMR &dmr); D4FilterClauseList &clauses(); #if INDEX_SUBSETTING /** Return the starting row number if the sequence was constrained using row numbers (instead of, or in addition to, a relational constraint). If a relational constraint was also given, the row number corresponds to the row number of the sequence after applying the relational constraint. If the bracket notation was not used to constrain this sequence, this method returns -1. @brief Get the starting row number. @return The starting row number. */ virtual int get_starting_row_number() const { return d_starting_row_number; } /** Return the row stride number if the sequence was constrained using row numbers (instead of, or in addition to, a relational constraint). If a relational constraint was also given, the row stride is applied to the sequence after applying the relational constraint. If the bracket notation was not used to constrain this sequence, this method returns -1. @brief Get the row stride. @return The row stride. */ virtual int get_row_stride() const { return d_row_stride; } /** Return the ending row number if the sequence was constrained using row numbers (instead of, or in addition to, a relational constraint). If a relational constraint was also given, the row number corresponds to the row number of the sequence after applying the relational constraint. If the bracket notation was not used to constrain this sequence, this method returns -1. @brief Get the ending row number. @return The ending row number. */ virtual int get_ending_row_number() const { return d_ending_row_number; } virtual void set_row_number_constraint(int start, int stop, int stride = 1); #endif /** * @brief Set the internal value. * The 'values' of a D4Sequence is a vector of vectors of BaseType* objects. * Using this method does not perform a deep copy; the BaseType*s are * copied so the caller should not free them. Note that this does set * d_length but the read_p flag for the BaseTypes should all be set to * keep the serializer from trying to read each of them. * @param values */ virtual void set_value(D4SeqValues &values) { d_values = values; d_length = d_values.size(); } /** * @brief Get the values for this D4Sequence * This method returns a reference to the values held by the instance. * You should make sure that the instance really holds values before * calling it! Do not free the BaseType*s contained in the vector of * vectors. * @return A reference tp the vector of vector of BaseType* */ virtual D4SeqValues value() const { return d_values; } /** * @brief Get the sequence values by reference * This method returns a reference to the D4Sequence's values, * eliminating the copy of all the pointers. For large sequences, * that could be a substantial number of values (even though * they are 'just' pointers). * @return A reference to the vector of vector of BaseType* */ virtual D4SeqValues &value_ref() { return d_values; } virtual D4SeqRow *row_value(size_t row); virtual BaseType *var_value(size_t row, const string &name); virtual BaseType *var_value(size_t row, size_t i); virtual void print_one_row(ostream &out, int row, string space, bool print_row_num = false); virtual void print_val_by_rows(ostream &out, string space = "", bool print_decl_p = true, bool print_row_numbers = true); virtual void print_val(ostream &out, string space = "", bool print_decl_p = true); virtual void dump(ostream &strm) const ; }; } // namespace libdap #endif //_sequence_h