Online PHP editor | perf for DHSWK

<?php /*TODO... parse the sql query make a query object or something to put almost everything in an object and make this code simpler return nested name-value pairs in an associative array and convert it to json before sending aa s JSON content type send all changes made from Deletes, Updates and Append (mutations) changes for passive data binding */ $sql = "SELECT * FROM 'main' WHERE 'destination' = 'Helsinki' AND 'price' > 120"; //example of sql query //the following assumes the above SQL query has been parsed into fields and conditions //main header file. Stored as JSON. $main_db_header_contents = '[{"rowlength":60},{"id":{"length":3,"datatype":"integer"}},{"name_sname":{"length":9,"datatype":"String"}},{"identity":{"length":9,"datatype":"integer"}},{"address":{"length":8,"datatype":"String"}},{"region":{"length":7,"datatype":"String"}},{"hours":{"length":5,"datatype":"Time"}},{"destination":{"length":8,"datatype":"String"}},{"price":{"length":3,"datatype":"integer"}}]'; //json string. fairly immutable so it can be cached on server $main_db_header = json_decode($main_db_header_contents,true); //main database file. Columns are fixed length and padded. Stored as strings only. ID field must be sorted alphabetically. //When fields in this file are updated/added to, their respective index file must be too $main_db_file_contents = "001|Al-Farabi|123456789|Baghdad |Iraq |21:02|Ottawa |120;002|Smith |123456788|Ottawa |Canada |22:03|Helsinki|131;003|Locke |123456787|Helsinki|Finland|23:01|Istanbul|122;004|Jones |123456786|Istanbul|Turkey |21:02|Helsinki|123;005|Steinman |123455785|Havana |Cuba |22:03|Havana |104;006|Booker |123456784|Moscow |Russia |23:01|Helsinki|115;"; //fixed-length field values //Destination index file with record id and destination value. Sorted alphabetically. //E.g., The record with the id of 004 has the destination value of 'Moscow '. $destination_index_file_contents = "005|Havana ;002|Helsinki;004|Helsinki;006|Helsinki;003|Istanbul;001|Ottawa "; //Destination index file. Sorted alphabetically despite being numberic. //E.g., The record with the id of 005 has the price value of 104. $price_index_file_contents = "005|104;006|115;001|120;003|122;004|123;002|131"; function apply_condition($index_file_contents, $ptype, $value) { //applies basic logical conditions from the the query //Uses the given index file and checks its value based on given condition and given value $found_matches = []; $index_file_contents_split = explode(";", $index_file_contents); foreach($index_file_contents_split as $key => $props){ $pairs = explode("|",$props); $id = $pairs[0]; $val = trim($pairs[1]); //removes trailing spaces for matching non-fiexed-length input value if ($ptype === "=") { //checks to see if the given value is equal to the value in the index file if ($val === $value) { array_push($found_matches,$id); //add to new array of matches } } elseif ($ptype === ">") { //checks to see if the given value is greater than the value in the index file if ($val > $value) { array_push($found_matches,$id);//add to new array of matches } } } return $found_matches; } $parsed_destinations = apply_condition($destination_index_file_contents, "=", "Helsinki"); $parsed_prices = apply_condition($price_index_file_contents, ">", "120"); $parsed_ids = array_intersect($parsed_destinations, $parsed_prices); sort($parsed_ids); //alphabetically sorts array by ascending (lowest to highest) //now go through $main_db_file_contents and get selected fields in records matching the ids in $parsed_ids. $id_length = $main_db_header[1]['id']['length']; //id, length, datatype $destination_offset = get_field_offset("destination", $main_db_header); $price_offset = get_field_offset("price", $main_db_header); $destination_length = $main_db_header[7]['destination']['length']; //8 $price_length = $main_db_header[8]['price']['length']; //3 $row_length = $main_db_header[0]['rowlength']; //147 $main_file_length = strlen($main_db_file_contents); //can be done on a text file using the OS $total_main_file_rows = ($main_file_length/$row_length); $results =[]; $starting_row = 0; for ($i = 0; $i < count($parsed_ids); $i++){ //Starting row is advanced (increased) with each loop. It advances half as far as the previous advancement $starting_row = get_starting_row($main_db_file_contents, $parsed_ids[$i], $id_length, $row_length, $total_main_file_rows, $starting_row); $destination = get_field_from_row($main_db_file_contents, $starting_row, $row_length, $destination_offset, $destination_length); $price = get_field_from_row($main_db_file_contents, $starting_row, $row_length, $price_offset, $price_length); $result = [$parsed_ids[$i], $destination, $price]; array_push($results, $result); } function get_field_from_row($db, $current_row, $row_length, $field_offset, $field_length) { //gets the row index and uses the field's offset (start) and length (end) to get its value in the database text $value = substr($db, ($current_row * $row_length) + $field_offset, $field_length); return $value; } function get_starting_row($db, $first_id, $id_length, $row_length, $total_main_file_rows, $offset){ //Finds the record that the given ID is located in and returns its row index $start_row = (int)floor($total_main_file_rows / 2) + $offset; //halfway point of file $start_row_id = substr($db, ($start_row) * $row_length , $id_length); //gets current row id while ($start_row > -1 && $start_row <= $total_main_file_rows) { if ( $first_id < $start_row_id){ //go back a bit less $start_row = (int)floor($start_row / 2); $start_row_id = substr($db, ($start_row) * $row_length , $id_length); } elseif($start_row_id < $first_id) { //go forward a bit less $start_row = $start_row + (int)round($start_row / 2); $start_row_id = substr($db, ($start_row) * $row_length , $id_length); } else { //found the row id that matches the given id. Return its index. return $start_row; } } } function get_field_offset($field, $header) { //goes through the JSON file to get length of each field preceding the given field //used to get the start of the field in the row (a row offset is needed too) $total_offset = 0; foreach ($header as $key => $value){ foreach ($value as $k => $val) { if ($k != "rowlength"){ if ($field === (string)$k){ return $total_offset; } $total_offset += $val['length'] +1; //+1 is needed for each single-character delimeter (|) } } } } var_dump($results); //works!!

Version	System time (s)	User time (s)	Memory (MiB)
8.3.6	0.013	0.007	17.00
8.3.5	0.009	0.009	16.65
8.3.4	0.011	0.004	21.85
8.3.3	0.009	0.009	18.70
8.3.2	0.003	0.010	24.18
8.3.1	0.006	0.003	24.66
8.3.0	0.008	0.000	26.16
8.2.18	0.013	0.009	25.92
8.2.17	0.011	0.004	19.17
8.2.16	0.007	0.010	22.96
8.2.15	0.000	0.007	25.66
8.2.14	0.004	0.004	24.66
8.2.13	0.011	0.004	26.16
8.2.12	0.008	0.000	26.35
8.2.11	0.010	0.000	20.86
8.2.10	0.006	0.006	17.97
8.2.9	0.003	0.005	18.00
8.2.8	0.006	0.003	19.07
8.2.7	0.000	0.008	17.63
8.2.6	0.004	0.004	17.88
8.2.5	0.000	0.008	18.05
8.2.4	0.000	0.009	18.30
8.2.3	0.000	0.008	18.27
8.2.2	0.003	0.005	18.20
8.2.1	0.004	0.004	19.32
8.2.0	0.000	0.008	19.32
8.1.28	0.015	0.006	25.92
8.1.27	0.003	0.006	23.99
8.1.26	0.008	0.000	28.09
8.1.25	0.005	0.003	28.09
8.1.24	0.003	0.007	19.26
8.1.23	0.003	0.009	22.73
8.1.22	0.006	0.003	18.81
8.1.21	0.008	0.000	18.77
8.1.20	0.004	0.004	17.64
8.1.19	0.003	0.005	17.35
8.1.18	0.010	0.000	18.10
8.1.17	0.000	0.008	18.75
8.1.16	0.000	0.008	18.96
8.1.15	0.004	0.004	19.02
8.1.14	0.004	0.004	18.91
8.1.13	0.003	0.003	20.34
8.1.12	0.004	0.004	17.60
8.1.11	0.006	0.003	17.62
8.1.10	0.003	0.005	17.50
8.1.9	0.005	0.002	17.62
8.1.8	0.007	0.000	17.59
8.1.7	0.004	0.004	17.48
8.1.6	0.003	0.005	17.62
8.1.5	0.000	0.008	17.64
8.1.4	0.004	0.004	17.67
8.1.3	0.000	0.008	17.69
8.1.2	0.005	0.003	17.80
8.1.1	0.008	0.000	17.72
8.1.0	0.008	0.000	17.70
8.0.30	0.000	0.008	18.77
8.0.29	0.005	0.003	16.63
8.0.28	0.005	0.002	18.58
8.0.27	0.000	0.007	18.22
8.0.26	0.000	0.007	20.17
8.0.25	0.003	0.003	17.09
8.0.24	0.000	0.008	17.09
8.0.23	0.000	0.007	17.08
8.0.22	0.000	0.008	17.01
8.0.21	0.004	0.004	17.05
8.0.20	0.007	0.000	16.96
8.0.19	0.005	0.003	17.09
8.0.18	0.004	0.004	17.08
8.0.17	0.006	0.003	16.95
8.0.16	0.003	0.005	17.13
8.0.15	0.000	0.008	16.98
8.0.14	0.005	0.002	17.06
8.0.13	0.003	0.003	13.46
8.0.12	0.004	0.004	17.07
8.0.11	0.004	0.004	16.98
8.0.10	0.007	0.000	16.95
8.0.9	0.004	0.004	16.95
8.0.8	0.005	0.009	17.01
8.0.7	0.006	0.003	16.98
8.0.6	0.000	0.007	17.11
8.0.5	0.004	0.004	17.10
8.0.3	0.009	0.009	17.14
8.0.2	0.009	0.010	17.09
8.0.1	0.000	0.007	17.27
8.0.0	0.016	0.003	17.01
7.4.33	0.000	0.005	15.55
7.4.32	0.000	0.007	16.57
7.4.30	0.003	0.003	16.51
7.4.29	0.007	0.000	16.66
7.4.28	0.000	0.008	16.64
7.4.27	0.000	0.007	16.66
7.4.26	0.000	0.006	13.44
7.4.25	0.005	0.003	16.73
7.4.24	0.005	0.002	16.70
7.4.23	0.000	0.007	16.50
7.4.22	0.002	0.005	16.45
7.4.21	0.006	0.010	16.79
7.4.20	0.004	0.004	16.72
7.4.13	0.011	0.011	16.59
7.4.12	0.006	0.013	16.71
7.4.11	0.013	0.009	16.52
7.4.10	0.012	0.012	16.78
7.4.9	0.014	0.008	16.58
7.4.8	0.013	0.011	16.66
7.4.7	0.015	0.007	16.39
7.4.6	0.013	0.009	16.52
7.4.5	0.010	0.012	16.65
7.4.4	0.011	0.008	16.63
7.4.3	0.013	0.009	16.52
7.4.2	0.014	0.009	16.53
7.4.1	0.010	0.011	16.41
7.4.0	0.013	0.006	16.58
7.3.33	0.007	0.000	16.47
7.3.32	0.003	0.003	13.37
7.3.31	0.004	0.004	16.59
7.3.30	0.004	0.004	16.51
7.3.29	0.008	0.008	16.47
7.3.26	0.011	0.007	16.48
7.3.23	0.016	0.008	16.52
7.3.22	0.012	0.015	16.57
7.3.21	0.015	0.010	16.59
7.3.20	0.014	0.012	16.47
7.3.19	0.011	0.011	16.50
7.3.18	0.013	0.010	16.35
7.3.17	0.011	0.009	16.44
7.3.16	0.013	0.011	16.53
7.3.15	0.012	0.007	16.41
7.3.14	0.012	0.011	16.46
7.3.13	0.011	0.009	16.44
7.3.12	0.013	0.008	16.40
7.3.11	0.011	0.010	16.40
7.3.10	0.010	0.009	16.45
7.3.9	0.010	0.011	16.49
7.3.8	0.013	0.006	16.40
7.3.7	0.013	0.007	16.38
7.3.6	0.009	0.012	16.47
7.3.5	0.013	0.008	16.47
7.3.4	0.014	0.010	16.50
7.3.3	0.010	0.011	16.66
7.3.2	0.015	0.007	16.60
7.3.1	0.013	0.010	16.54
7.3.0	0.013	0.006	16.43
7.2.34	0.016	0.009	16.75
7.2.33	0.019	0.009	16.73
7.2.32	0.012	0.012	16.84
7.2.31	0.013	0.010	16.78
7.2.30	0.011	0.008	16.81
7.2.29	0.012	0.008	16.63
7.2.28	0.010	0.010	16.77
7.2.27	0.012	0.011	16.74
7.2.26	0.015	0.008	16.61
7.2.25	0.012	0.010	16.65
7.2.24	0.006	0.015	16.73
7.2.23	0.008	0.012	16.60
7.2.22	0.009	0.011	16.71
7.2.21	0.013	0.008	16.54
7.2.20	0.013	0.008	16.64
7.2.19	0.016	0.008	16.81
7.2.18	0.011	0.012	16.76
7.2.17	0.011	0.010	16.79
7.2.16	0.013	0.008	16.71
7.2.15	0.016	0.009	16.90
7.2.14	0.017	0.006	16.83
7.2.13	0.013	0.009	16.79
7.2.12	0.012	0.011	16.81
7.2.11	0.010	0.013	16.79
7.2.10	0.012	0.011	16.61
7.2.9	0.013	0.012	16.75
7.2.8	0.017	0.008	16.63
7.2.7	0.014	0.011	16.63
7.2.6	0.016	0.009	16.79
7.2.5	0.009	0.010	16.74
7.2.4	0.007	0.015	16.81
7.2.3	0.011	0.010	16.79
7.2.2	0.018	0.013	16.72
7.2.1	0.027	0.008	16.79
7.2.0	0.013	0.008	16.74