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using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
namespace TestBigFile
{
class Program
{
static void Main(string[] args)
{
Random rnd = new Random();
//File.Delete("csv.txt");
//File.Delete("rec.txt");
DateTime tst = DateTime.Today.AddDays(rnd.Next(0, 36500));
DateTime start = DateTime.Now;
//Benchmark.CreateFiles();
//Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
//GC.Collect();
start = DateTime.Now;
Console.WriteLine("SimpleTextReader");
Benchmark.SimpleTextReader("csv.txt", tst);
Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
Console.WriteLine();
GC.Collect();
start = DateTime.Now;
Console.WriteLine("DichotomyTextReader");
Benchmark.DichotomyTextReader("csv.txt", tst);
Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
Console.WriteLine();
GC.Collect();
start = DateTime.Now;
Console.WriteLine("SimpleBlockReader");
Benchmark.SimpleBlockReader("csv.txt", tst);
Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
Console.WriteLine();
GC.Collect();
start = DateTime.Now;
Console.WriteLine("DichotomyBlockReader");
Benchmark.DichotomyBlockReader("csv.txt", tst);
Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
Console.WriteLine();
GC.Collect();
start = DateTime.Now;
Console.WriteLine("SimpleRecordReader");
Benchmark.SimpleRecordReader("rec.txt", tst);
Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
Console.WriteLine();
GC.Collect();
start = DateTime.Now;
Console.WriteLine("DichotomyRecordReader");
Benchmark.DichotomyRecordReader("rec.txt", tst);
Console.WriteLine("Used time : {0:mm\\:ss\\.ff}", DateTime.Now.Subtract(start));
Console.WriteLine();
GC.Collect();
Console.WriteLine("Finished");
Console.ReadKey(true);
}
}
static class Benchmark
{
const int BUFFER_SIZE = 360;
const int RECORD_SIZE = 18;
const int RECORD_PER_BUFFER = 20;
public static void SimpleTextReader(string filename, DateTime dte)
{
int nbFound = 0;
DateTime currentDate;
string[] lines = File.ReadAllLines(filename);
for (int i = 0, cpt = lines.Length; i < cpt; i++)
{
currentDate = DateTime.Parse(lines[i].Split(';')[0]);
if (dte == currentDate)
{
//Console.WriteLine(lines[i]);
nbFound++;
}
else if (dte < currentDate)
{
break;
}
}
Console.WriteLine("Trouvé : {0}", nbFound);
}
public static void DichotomyTextReader(string filename, DateTime dte)
{
int nbFound = 0;
string[] lines = File.ReadAllLines(filename);
int min = 0, max = lines.Length;
int first = -1;
DateTime currentDate;
while (true)
{
int idx = min + ((max - min) / 2);
currentDate = DateTime.Parse(lines[idx].Split(';')[0]);
if (currentDate > dte)
{
max = idx;
}
else if (currentDate < dte)
{
min = idx;
}
else
{
while (idx-- > min)
{
currentDate = DateTime.Parse(lines[idx].Split(';')[0]);
if (currentDate < dte)
{
first = idx + 1;
break;
}
}
first = idx + 1;
break;
}
}
for (int i = first, cpt = max; i < cpt; i++)
{
currentDate = DateTime.Parse(lines[i].Split(';')[0]);
if (dte == currentDate)
{
//Console.WriteLine(lines[i]);
nbFound++;
}
else
{
break;
}
}
Console.WriteLine("Trouvé : {0}", nbFound);
}
public static void SimpleBlockReader(string filename, DateTime dte)
{
int nbFound = 0;
int count = 0;
string data = string.Empty;
bool exitWhile = false;
char[] buffer = new char[BUFFER_SIZE];
StreamReader sr = File.OpenText(filename);
count = sr.Read(buffer, 0, BUFFER_SIZE);
DateTime currentDate;
while (count > 0)
{
int p = data.LastIndexOf('\n') + 1;
if (p > 0)
{
data = string.Concat(data.Substring(p), (new string(buffer)).Substring(0, count).Replace("\r", string.Empty));
}
else
{
data = (new string(buffer)).Substring(0, count).Replace("\r", string.Empty);
}
p = data.LastIndexOf('\n');
string[] lines = data.Substring(0, p).Split('\n');
for (int i = 0, cpt = lines.Length; i < cpt; i++)
{
currentDate = DateTime.Parse(lines[i].Split(';')[0]);
if (currentDate == dte)
{
//Console.WriteLine(lines[i]);
nbFound++;
}
else if (currentDate > dte)
{
exitWhile = true;
break;
}
}
if (exitWhile)
{
break;
}
count = sr.Read(buffer, 0, BUFFER_SIZE);
}
sr.Close();
Console.WriteLine("Trouvé : {0}", nbFound);
}
public static void DichotomyBlockReader(string filename, DateTime dte)
{
int nbFound = 0;
int count = 0;
bool found = false;
bool rewind = false;
string data = string.Empty;
bool exitWhile = false;
byte[] buffer = new byte[BUFFER_SIZE];
FileStream fs = File.OpenRead(filename);
int nbBlocks = (int)(fs.Length / (long)BUFFER_SIZE);
int min = 0, max = nbBlocks;
int idx = -1;
DateTime currentDate = DateTime.Now;
while (true)
{
if (found)
{
idx++;
}
else
{
idx = min + ((max - min) / 2);
}
fs.Seek(idx * BUFFER_SIZE, SeekOrigin.Begin);
count = fs.Read(buffer, 0, BUFFER_SIZE);
if (count == 0)
{
break;
}
if (found && !rewind && data.Length > 0)
{
data = string.Concat(data.Substring(data.LastIndexOf('\n') + 1), ASCIIEncoding.ASCII.GetString(buffer, 0, count).Replace("\r", ""));
currentDate = DateTime.Parse(data.Substring(0, 10));
}
else
{
data = ASCIIEncoding.ASCII.GetString(buffer, 0, count).Replace("\r", "");
currentDate = DateTime.Parse(data.Substring(data.IndexOf('\n') + 1, 10));
}
if (currentDate > dte)
{
max = idx;
}
else if (currentDate < dte)
{
rewind = false;
string[] lines = data.Substring(0, data.LastIndexOf('\n')).Split('\n');
for (int i = 1, cpt = lines.Length; i < cpt - 1; i++)
{
currentDate = DateTime.Parse(lines[i].Split(';')[0]);
if (currentDate == dte)
{
//Console.WriteLine(lines[i]);
nbFound++;
if (!found && !rewind)
{
found = true;
rewind = true;
}
}
else if (currentDate > dte)
{
exitWhile = true;
break;
}
}
min = idx + 1;
}
else if (currentDate == dte && (!found || rewind) && idx > 0)
{
idx -= 2;
found = true;
rewind = true;
}
else if (currentDate == dte && found)
{
string[] lines = data.Split('\n');
for (int i = 0, cpt = lines.Length; i < cpt - 1; i++)
{
currentDate = DateTime.Parse(lines[i].Split(';')[0]);
if (currentDate == dte)
{
//Console.WriteLine(lines[i]);
nbFound++;
}
else if (currentDate > dte)
{
exitWhile = true;
break;
}
}
}
else if (currentDate == dte && (!found || rewind) && idx == 0)
{
found = true;
data = string.Empty;
idx--;
}
if (exitWhile)
{
break;
}
}
fs.Close();
Console.WriteLine("Trouvé : {0}", nbFound);
}
public static void SimpleRecordReader(string filename, DateTime dte)
{
int nbFound = 0;
FileStream fs = File.OpenRead(filename);
byte[] buffer = new byte[RECORD_SIZE * RECORD_PER_BUFFER];
int count = 0;
bool dowork = true;
string data = string.Empty;
DateTime currentDate;
while (dowork)
{
count = fs.Read(buffer, 0, RECORD_SIZE * RECORD_PER_BUFFER);
if (count == 0)
{
break;
}
for (int i = 0, cpt = count / RECORD_SIZE; i < cpt; i++)
{
data = ASCIIEncoding.ASCII.GetString(buffer).Substring(0, count);
currentDate = DateTime.Parse(data.Substring(i * RECORD_SIZE, 10));
if (dte == currentDate)
{
//Console.WriteLine(data.Substring(i * RECORD_SIZE, RECORD_SIZE));
nbFound++;
}
else if (dte < currentDate)
{
dowork = false;
break;
}
}
}
fs.Close();
Console.WriteLine("Trouvé : {0}", nbFound);
}
public static void DichotomyRecordReader(string filename, DateTime dte)
{
int nbFound = 0;
FileStream fs = File.OpenRead(filename);
byte[] buffer = new byte[RECORD_SIZE * RECORD_PER_BUFFER];
int count = 0;
bool dowork = true;
int min = 0;
int max = (int)(fs.Length / (long)RECORD_SIZE);
bool rewind = false;
bool found = false;
int idx = 0;
string data = string.Empty;
DateTime currentDate;
while (dowork)
{
if (rewind)
{
idx -= RECORD_PER_BUFFER;
if (idx < min)
{
idx = min;
}
}
else if (found)
{
idx += RECORD_PER_BUFFER;
if (idx > max)
{
idx = max;
}
}
else
{
idx = min + ((max - min) / 2);
}
fs.Seek(idx * RECORD_SIZE, SeekOrigin.Begin);
count = fs.Read(buffer, 0, RECORD_SIZE * RECORD_PER_BUFFER);
if (count == 0)
{
break;
}
for (int i = 0, cpt = count / RECORD_SIZE; i < cpt; i++)
{
data = ASCIIEncoding.ASCII.GetString(buffer).Substring(0, count);
currentDate = DateTime.Parse(data.Substring(i * RECORD_SIZE, 10));
if (dte == currentDate)
{
if (i == 0 && idx > 0 && !found)
{
rewind = true;
break;
}
else
{
//Console.WriteLine(data.Substring(i * RECORD_SIZE, RECORD_SIZE));
nbFound++;
found = true;
}
}
else if (currentDate < dte)
{
rewind = false;
if (i == cpt - 1 && !found)
{
min = idx;
}
}
else if (currentDate > dte)
{
if (found == true)
{
dowork = false;
break;
}
else
{
max = idx;
break;
}
}
}
}
fs.Close();
Console.WriteLine("Trouvé : {0}", nbFound);
}
public static void CreateFiles()
{
List<Record> list = new List<Record>();
Random rnd = new Random();
Console.WriteLine("Generate data in memory...");
for (int i = 0; i < 30000000; i++)
{
list.Add(new Record(DateTime.Today.AddDays(rnd.Next(0, 36500)), i));
}
Console.WriteLine("Sort data in memory...");
list.Sort();
Console.WriteLine("Write data to disk...");
using (StreamWriter csv = File.CreateText("csv.txt"), rec = File.CreateText("rec.txt"))
{
for (int i = 0; i < 30000000; i++)
{
csv.WriteLine(list[i].ToCsv());
rec.Write(list[i].ToRec());
}
csv.Close();
rec.Close();
}
Console.WriteLine("Done");
}
}
public class Record : IEquatable<Record>, IComparable<Record>
{
public DateTime date;
public int value;
public Record(DateTime date, int value)
{
this.date = date;
this.value = value;
}
public string ToCsv()
{
return string.Format("{0:dd/MM/yyyy};{1}", date, value);
}
public string ToRec()
{
return string.Format("{0:dd/MM/yyyy}{1,8}", date, value);
}
public override bool Equals(object obj)
{
if (obj == null)
{
return false;
}
Record objAsRecord = obj as Record;
if (objAsRecord == null)
{
return false;
}
else
{
return Equals(objAsRecord);
}
}
public bool Equals(Record other)
{
if (other == null)
{
return false;
}
else
{
if (this.date.Equals(other.date))
{
return this.value.Equals(other.value);
}
else
{
return false;
}
}
}
public override int GetHashCode()
{
return value;
}
public int CompareTo(Record compareRecord)
{
if (compareRecord == null)
{
return 1;
}
else
{
if (compareRecord.date == this.date)
{
return this.value.CompareTo(compareRecord.value);
}
else
{
return this.date.CompareTo(compareRecord.date);
}
}
}
}
} |
Lecture de fichiers .txt volumineux
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effectivement je ne connaissais pas ce format.
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