void AddFilePart(FilePart filePart)
{
if (filePart.IsSorted)
{
_filesToMerge.Enqueue(filePart);
return;
}
if (filePart.FileSize <= 16 * 1024 * 1024)
{
_filesToSort.Push(filePart);
return;
}
_filesToSplit.Push(filePart);
}
async Task Merge(FilePart filePart1, FilePart filePart2)
{
string path = Path.Combine(_tempDirectory, Path.GetRandomFileName());
int lineCount = 0;
using (var sr1 = new StreamReader(filePart1.FileName))
using (var sr2 = new StreamReader(filePart2.FileName))
using (var sw = new StreamWriter(path))
{
var linFromFile1 = await sr1.ReadLineAsync();
var linFromFile2 = await sr2.ReadLineAsync();
while ((linFromFile1 == null && linFromFile2 == null) == false)
{
if (linFromFile1 == null && linFromFile2 != null)
{
await sw.WriteLineAsync(linFromFile2);
lineCount++;
linFromFile2 = await sr2.ReadLineAsync();
continue;
}
if (linFromFile1 != null && linFromFile2 == null)
{
await sw.WriteLineAsync(linFromFile1);
lineCount++;
linFromFile1 = await sr1.ReadLineAsync();
continue;
}
var row1 = Row.Parse(linFromFile1);
var row2 = Row.Parse(linFromFile2);
var compareResult = row1.CompareTo(row2);
if (compareResult == -1)
{
await sw.WriteLineAsync(linFromFile1);
lineCount++;
linFromFile1 = await sr1.ReadLineAsync();
continue;
}
await sw.WriteLineAsync(linFromFile2);
lineCount++;
linFromFile2 = await sr2.ReadLineAsync();
continue;
}
}
File.Delete(filePart1.FileName);
File.Delete(filePart2.FileName);
// filePart1 and filePart2 is empty
if (lineCount == 0)
{
File.Delete(path);
return;
}
AddFilePart(new FilePart(path, lineCount, new FileInfo(path).Length, true));
}
public FileSplitResult(FilePart filePart1, FilePart filePart2)
{
FilePart1 = filePart1;
FilePart2 = filePart2;
}