private static async Task PrepareToSortFiles(
string input1File = "file1.txt",
string input2File = "file2.txt",
string output1File = "shuffle1.txt",
string output2File = "shuffle2.txt")
{
using (var readerFirst = new StreamReader(input1File))
using (var readerSecond = new StreamReader(input2File))
using (var writerFirst = new StreamWriter(output1File))
using (var writerSecond = new StreamWriter(output2File))
{
while (!readerFirst.EndOfStream)
{
var line = await readerFirst.ReadLineAsync();
if (Char.ToLower(line[0]) < 'n')
{
await writerFirst.WriteLineAsync(line);
}
else
{
await writerSecond.WriteLineAsync(line);
}
}
while (!readerSecond.EndOfStream)
{
var line = await readerSecond.ReadLineAsync();
if (Char.ToLower(line[0]) < 'n')
{
await writerFirst.WriteLineAsync(line);
}
else
{
await writerSecond.WriteLineAsync(line);
}
}
await StreamExtensions.RemoveNewLineFromEndOfFileAsync(writerFirst);
await StreamExtensions.RemoveNewLineFromEndOfFileAsync(writerSecond);
}
}
public static async Task SortMapReduceFileAsync(string sortedFile)
{
var tmpFile1 = $"{Guid.NewGuid().ToString()}.txt";
var tmpFile2 = $"{Guid.NewGuid().ToString()}.txt";
var seriesSize = 1;
var fileCountOfLines = await FileExtensions.GetCountOfLinesInFile(sortedFile);
while (seriesSize < fileCountOfLines)
{
using (var reader = new StreamReader(sortedFile))
using (var writerFirst = new StreamWriter(tmpFile1, false))
using (var writerSecond = new StreamWriter(tmpFile2, false))
{
while (!reader.EndOfStream)
{
for (int i = 0; i < seriesSize && !reader.EndOfStream; i++)
{
var line = await reader.ReadLineAsync();
await writerFirst.WriteLineAsync(line);
}
for (int i = 0; i < seriesSize && !reader.EndOfStream; i++)
{
var line = await reader.ReadLineAsync();
await writerSecond.WriteLineAsync(line);
}
}
await StreamExtensions.RemoveNewLineFromEndOfFileAsync(writerFirst);
await StreamExtensions.RemoveNewLineFromEndOfFileAsync(writerSecond);
}
using (var writer = new StreamWriter(sortedFile, false))
using (var readerFirst = new StreamReader(tmpFile1))
using (var readerSecond = new StreamReader(tmpFile2))
{
var isReadFromFirst = true;
var isReadFromSecond = true;
var fromFirstLine = "";
var fromSecondLine = "";
while (!readerFirst.EndOfStream && !readerSecond.EndOfStream)
{
var writedFromFirstLines = 0;
var writedFromSecondLines = 0;
isReadFromFirst = true;
isReadFromSecond = true;
while (
writedFromFirstLines < seriesSize &&
writedFromSecondLines < seriesSize &&
(!readerFirst.EndOfStream || !isReadFromFirst) &&
(!readerSecond.EndOfStream || !isReadFromSecond))
{
if (isReadFromFirst)
{
fromFirstLine = await readerFirst.ReadLineAsync();
isReadFromFirst = false;
}
if (isReadFromSecond)
{
fromSecondLine = await readerSecond.ReadLineAsync();
isReadFromSecond = false;
}
if (CompareMapReduceStr(fromFirstLine, fromSecondLine) < 1)
{
await writer.WriteLineAsync(fromFirstLine);
writedFromFirstLines++;
isReadFromFirst = true;
}
else
{
await writer.WriteLineAsync(fromSecondLine);
writedFromSecondLines++;
isReadFromSecond = true;
}
}
if (!isReadFromFirst && writedFromFirstLines < seriesSize)
{
await writer.WriteLineAsync(fromFirstLine);
writedFromFirstLines++;
isReadFromFirst = true;
}
while (writedFromFirstLines < seriesSize && !readerFirst.EndOfStream)
{
fromFirstLine = await readerFirst.ReadLineAsync();
await writer.WriteLineAsync(fromFirstLine);
writedFromFirstLines++;
isReadFromFirst = true;
}
if (!isReadFromSecond && writedFromSecondLines < seriesSize)
{
await writer.WriteLineAsync(fromSecondLine);
writedFromSecondLines++;
isReadFromSecond = true;
}
while (writedFromSecondLines < seriesSize && !readerSecond.EndOfStream)
{
fromSecondLine = await readerSecond.ReadLineAsync();
await writer.WriteLineAsync(fromSecondLine);
writedFromSecondLines++;
isReadFromSecond = true;
}
}
if (!isReadFromFirst)
{
await writer.WriteLineAsync(fromFirstLine);
}
if (!isReadFromSecond)
{
await writer.WriteLineAsync(fromSecondLine);
}
while (!readerFirst.EndOfStream)
{
fromFirstLine = await readerFirst.ReadLineAsync();
await writer.WriteLineAsync(fromFirstLine);
}
while (!readerSecond.EndOfStream)
{
fromSecondLine = await readerSecond.ReadLineAsync();
await writer.WriteLineAsync(fromSecondLine);
}
await StreamExtensions.RemoveNewLineFromEndOfFileAsync(writer);
}
seriesSize *= 2;
}
File.Delete(tmpFile1);
File.Delete(tmpFile2);
}
