1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
using System;
using System.Text;
namespace ConsoleApplication2
{
class Program
{
static void Main(string[] args)
{
bool[] cols = new bool[] { false, false, true, false, false, true, true, false, false, true,
false, false, true, true, false, true, false, false, false, true,
false, false, true, true, false, true, false, true, false, false,
false, true, false, false, true, true, false, true, false, false,
false, false, true, true, false, true, false, true, false, false,
false, true, false, false, true, true, false, true, false, false
};
string csvSource = "11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 943023, 1000000000, "+
"11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 943023, 1000000000, " +
"11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 943023, 1000000000, " +
"11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 943023, 1000000000, " +
"11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 943023, 1000000000, " +
"11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 943023, 1000000000";
int iterations = 100000;
Console.WriteLine("csv_remove_unused_data_array");
DateTime st = DateTime.Now;
char[] carr = null;
for (int i = 0; i < iterations; i++)
{
carr = csvSource.ToCharArray();
csv_remove_unused_data_array(ref carr, ',', ref cols);
}
TimeSpan ts = DateTime.Now - st;
Console.WriteLine();
Console.WriteLine("Result of csv_remove_unused_data_array: {0}", ts.TotalMilliseconds);
Console.WriteLine();
Console.WriteLine("csv_remove_unused_data_split");
DateTime st2 = DateTime.Now;
for (int i = 0; i < iterations; i++)
csv_remove_unused_data_split(csvSource, ',', ref cols);
TimeSpan ts2 = DateTime.Now - st2;
Console.WriteLine();
Console.WriteLine("Result of csv_remove_unused_data_split: {0}", ts2.TotalMilliseconds);
Console.WriteLine();
Console.WriteLine("csv_remove_unused_data");
DateTime st3 = DateTime.Now;
for (int i = 0; i < iterations; i++)
csv_remove_unused_data(csvSource, ',', ref cols);
TimeSpan ts3 = DateTime.Now - st3;
Console.WriteLine();
Console.WriteLine("Result of csv_remove_unused_data: {0}", ts3.TotalMilliseconds);
Console.ReadLine();
}
static String csv_remove_unused_data(String input, Char delimiter, ref Boolean[] columns)
{
StringBuilder output = new StringBuilder(input.Length);
int cl = columns.Length;
Int32 column = 0;
for (int i = 0; i < input.Length; i++)
{
if (input[i] == delimiter)
{
column++;
output.Append(input[i]);
}
else
{
if (!columns[column]) output.Append(input[i]);
}
}
return output.ToString();
}
static String csv_remove_unused_data_array(ref char[] input, Char delimiter, ref Boolean[] columns)
{
StringBuilder output = new StringBuilder(input.Length);
int cl = columns.Length;
Int32 column = 0;
for (int i = 0; i < input.Length; i++)
{
if (input[i] == delimiter)
{
column++;
output.Append(input[i]);
}
else
{
if (!columns[column]) output.Append(input[i]);
}
}
return output.ToString();
}
static char[] sep = new char[1];
static String csv_remove_unused_data_split(String input, Char delimiter, ref Boolean[] columns)
{
StringBuilder output = new StringBuilder(input.Length);
sep[0] = delimiter;
string[] spl = input.Split(sep);
for (int i = 0; i < spl.Length; i++)
{
if (!columns[i]) output.Append(spl[i]);
if (i < spl.Length - 1) output.Append(delimiter);
}
return output.ToString();
}
}
}
