space.h

/* Jazz (c) 2018-2025 kaalam.ai (The Authors of Jazz), using (under the same license):
 
    1. Biomodelling - The AATBlockQueue class (c) Jacques Basaldúa, 2009-2012 licensed
      exclusively for the use in the Jazz server software.
 
      Copyright 2009-2012 Jacques Basaldúa
 
    2. BBVA - Jazz: A lightweight analytical web server for data-driven applications.
 
      Copyright 2016-2017 Banco Bilbao Vizcaya Argentaria, S.A.
 
      This product includes software developed at
 
      BBVA (https://www.bbva.com/)
 
    3. LMDB, Copyright 2011-2017 Howard Chu, Symas Corp. All rights reserved.
 
      Licensed under http://www.OpenLDAP.org/license.html
 
 
      Licensed 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.
*/
 
 
#include "src/jazz_bebop/locators.h"
 
#if defined CATCH_TEST
#ifndef INCLUDED_JAZZ_CATCH2
#define INCLUDED_JAZZ_CATCH2
 
#include "src/catch2/catch.hpp"
 
#endif
#endif
 
 
#ifndef INCLUDED_JAZZ_BEBOP_SPACE
#define INCLUDED_JAZZ_BEBOP_SPACE
 
 
namespace jazz_bebop
{
 
typedef uint64_t RowNumber;     
typedef Name     ColumnName;    
 
#define SPACE_NOT_A_ROW             0xffffFFFFffffFFFE  
#define SPACE_ROW_STOP_ITERATOR     0xffffFFFFffffFFFF  
 
 
class Space;                    
typedef Space *pSpace;          
 
 
class stdName {
 
    public:
        stdName() {}
 
        stdName(const pChar &name) {
            strncpy(this->name, name, NAME_SIZE);
            this->name[NAME_LENGTH] = 0;
        }
 
        stdName(const stdName &name) {
            memcpy(&this->name, &name, sizeof(stdName));
        }
 
        bool operator==(const stdName &o) const {
            return strcmp(name, o.name) == 0;
        }
 
        bool operator<(const stdName &o) const {
            return strcmp(name, o.name) < 0;
        }
 
        Name name;              
};
 
typedef std::vector<stdName> stdNames;  
 
 
class RowSelection {
 
    RowSelection(pChar query, pSpace p_space) {}
 
    virtual bool restart() {
        return false;
    }
 
    virtual RowNumber next() {
        return SPACE_ROW_STOP_ITERATOR;
    }
 
    bool is_valid = false;  
};
typedef RowSelection *pRowSelection;    
 
 
class ColSelection {
 
    public:
 
        ColSelection(pChar query, pSpace p_space);
 
        virtual bool restart();
 
        virtual int   next_index();
        virtual pName next_name();
 
        bool is_valid = false;  
 
#ifndef CATCH_TEST
    private:
#endif
 
        int current_col = 0;            
        stdNames name = {};             
        std::vector<int>  index = {};   
};
typedef ColSelection *pColSelection;    
 
 
class Caster {
    public:
 
    Caster(pBaseAPI api) {}
 
    virtual StatusCode get(pTransaction &p_txn, pBlock p_block) {
        return SERVICE_NOT_IMPLEMENTED;
    }
 
    stdName name;       
};
typedef Caster *pCaster;                        
typedef std::map<stdName, pCaster> Casters;     
typedef Casters *pCasters;                      
 
 
//TODO: Clarify why space is a Service. Spoiler: It is not!
//TODO: Clarify how spaces build a tree.
//TODO: Clarify why we need singular/plural like collections of, because we want to have just one service for all the spaces at a level.
//TODO: Think that in Bop, a space is something that accepts then [] and the '.' the latter being just a property of what is on its left:
        // (E.g.: this.is.just.a.hierarchy.defining.some.path.on.a.tree)
//TODO: Is row the appropriate abstraction? Is a space somehow always tabular? A row is a key
 
class Space : public Service {
 
    public:
 
    // Service interface
 
        Space(pBaseAPI api, pName a_name);
 
        virtual StatusCode start    ();
        virtual StatusCode shut_down();
 
    // Persistence interface
 
        virtual StatusCode load_meta() {
            return SERVICE_NOT_IMPLEMENTED;
        }
 
        virtual StatusCode save_meta() {
            return SERVICE_NOT_IMPLEMENTED;
        }
 
    // Internal interface for ColSelection to have access to data by rows.
 
        virtual RowNumber num_rows() {
            return SPACE_NOT_A_ROW;
        }
 
        virtual void* get_index_data(RowNumber row) {
            return nullptr;
        }
 
    // Space interface
 
        virtual int num_cols() {
            return 0;
        }
 
        virtual pName col_name(int col) {
            return nullptr;
        }
 
        virtual int col_index(pName name) {
            return -1;
        }
 
        virtual pLocator locator(RowNumber row, int col, int &index) {
            return nullptr;
        }
 
        virtual pRowSelection where(pChar query) {
            return nullptr;
        }
 
        virtual pColSelection select(pChar query) {
            return new ColSelection(query, this);
        }
 
        virtual pCaster as(pChar query) {
            stdName name(query);
            Casters::iterator it = casters.find(name);
            if (it == casters.end())
                return nullptr;
 
            return it->second;
        }
 
        virtual bool register_caster(pCaster cast) {
            Casters::iterator it = casters.find(cast->name);
            if (it != casters.end())
                return false;
 
            casters[cast->name] = cast;
            return true;
        }
 
        virtual StatusCode get_row(pTransaction &p_txn, RowNumber row, pColSelection cols = nullptr, pCaster cast = nullptr) {
            return SERVICE_NOT_IMPLEMENTED;
        }
 
#ifndef CATCH_TEST
    protected:
#endif
 
        char storage_base [SHORT_NAME_SIZE];    
        Name     name;                          
        pBaseAPI p_api;                         
        Casters  casters;                       
};
 
} // namespace jazz_bebop
 
#endif // ifndef INCLUDED_JAZZ_BEBOP_SPACE