dbutils/object.h

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2024 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef DBU_OBJECT_H
#define DBU_OBJECT_H

#include "dbutils/dbutils.h"
#include "dbutils/db.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct DBUFieldMapping {
    DBUClass *cls;
    DBUField *field;
    DBUFieldType type;
    bool is_main;
} DBUFieldMapping;

typedef struct DBUBuilderQuery DBUBuilderQuery;
struct DBUBuilderQuery {
    DBUClass *type;
    DBUField *field;
    DBUQuery *query;
};

typedef struct DBUBuilderObjCache {
    DBUClass *class;
    void *obj;
} DBUBuilderObjCache;

struct DBUObjectBuilder {
    const CxAllocator *allocator;
    
    DBUContext *ctx;
    
    /*
     * Main query, that us used for generating the result list.
     */
    DBUQuery *mainQuery;
    
    /*
     * result type
     */
    DBUClass *resultType;
    
    /*
     * key: type name
     * value: DBUQuery*
     * 
     * Subqueries, that should be executed for all main result rows.
     * Before a subquery is executed, the first parameter is set to the
     * primary key of the main table.
     */
    CxMap *subQueries; // TODO: implement
    
    /*
     * value: DBUBuilderQuery
     * 
     * Additional queries are executed after the main query and the result
     * objects are added to the previous queried objects
     */
    CxList *additionalQueries;
    
    /*
     * result builder
     */
    DBUObjectResult *result;
    
    /*
     * object cache
     * 
     * key: <tablename> + <primary key>
     * value: DBUBuilderObjCache
     * 
     */
    CxMap *cache;
    
    /*
     * if true, the main result does not contain duplicated entries
     * with the same primary key
     */
    bool denseResult;
};

typedef struct DBUFK {
    char *cache_key;
    DBUClass *cls;
} DBUFK;

/*
 * an array of ResultType is used to describe, which object types
 * a result contains
 */
typedef struct DBUResultType {
    /*
     * class
     */
    
    DBUClass *cls;
    /*
     * column index of the primary key of this class
     */
    int pk_col;
    
    /*
     * previous PK value (allocated copy)
     */
    cxmutstr prev_key;
    
    /*
     * previous object pointer
     */
    void *prev_obj;
} DBUResultType;

int dbuObjectExec(DBUObjectBuilder *builder, DBUObjectResult *objresult);

int dbuObjectExecuteQuery(DBUObjectBuilder *builder, DBUQuery *query, DBUClass *type, DBUObjectResult *objresult, bool dense);

#ifdef __cplusplus
}
#endif

#endif /* DBU_OBJECT_H */