portapack-mayhem/firmware/application/database.cpp
2022-01-28 10:24:49 -05:00

98 lines
3.1 KiB
C++

/*
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
* Copyright (C) 2016 Furrtek
* Copyright (C) 2022 Arjan Onwezen
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "database.hpp"
#include "file.hpp"
#include <cstring>
namespace std {
int database::retrieve_airline_record(AirlinesDBRecord* record, std::string search_term){
file_path = "ADSB/airlines.db";
index_item_length = 4;
record_length = 64;
result = std::database::retrieve_record(file_path, index_item_length, record_length, record, search_term);
return(result);
}
int database::retrieve_aircraft_record(AircraftDBRecord* record, std::string search_term){
file_path = "ADSB/icao24.db";
index_item_length = 7;
record_length = 146;
result = std::database::retrieve_record(file_path, index_item_length, record_length, record, search_term);
return(result);
}
int database::retrieve_record(std::string file_path, int index_item_length, int record_length, void* record, std::string search_term)
{
auto result = db_file.open(file_path);
if (!result.is_valid()) {
number_of_records = (db_file.size() / (index_item_length + record_length)); // determine number of records in file
// binary search tree
int first = 0, // First search element
last = number_of_records - 1, // Last search element
middle, // Mid point of search
position = -1; // Position of search value
while (!found && first <= last) {
middle = (first + last) / 2; // Calculate mid point
db_file.seek(middle * index_item_length);
db_file.read(file_buffer, search_term.length());
if (file_buffer == search_term) { // If value is found at mid
found = true;
position = middle;
}
else if (file_buffer > search_term) // If value is in lower half
last = middle - 1;
else
first = middle + 1; // If value is in upper half
}
if(found == true) {
db_file.seek((number_of_records * index_item_length) + (position * record_length)); // seek starting after index
db_file.read(record, record_length);
return(DATABASE_RECORD_FOUND);
}
else {
return(DATABASE_RECORD_NOT_FOUND);
}
}
else return(DATABASE_NOT_FOUND);
}
} /* namespace std */