private static ScannedResult ScanLines(string[] lines, PagedLogItems currentPage)
{
var result = new ScannedResult();
if (lines == null || lines.Length <= 0)
{
return(result);
}
if (currentPage == null || currentPage.LogItems == null)
{
return(result);
}
if (currentPage.LogItems.Count >= PAGED_LINES_COUNT)
{
currentPage.LogItems.Clear();
}
foreach (var line in lines)
{
if (currentPage.LogItems.Count >= PAGED_LINES_COUNT)
{
break;
}
var logItem = line.ToLogItem(currentPage.LogType);
if (logItem == null)
{
result.ScannedByteLength += System.Text.Encoding.UTF8.GetBytes(line + "\n").LongLength;
continue;
}
else
{
result.ScannedItemsCount++;
currentPage.LogItems.Add(logItem);
result.ScannedByteLength += System.Text.Encoding.UTF8.GetBytes(line + "\n").LongLength;
}
}
return(result);
}
private static PagedLogItems LoadLogItemByPage(PagedLogItems currentPage)
{
var stopWatch = new Stopwatch();
Console.WriteLine("Start load log items from file \"test.log\"....");
stopWatch.Start();
var buffer = new byte[BUFFER_SIZE_OF_96_KB];
using (var fs = new FileStream("test.log", FileMode.Open, FileAccess.Read, FileShare.Read))
{
currentPage.TotalSize = fs.Length;
var errorCount = 0;
SetPositionOfFileStream(currentPage, fs);
while (fs.Read(buffer, 0, BUFFER_SIZE_OF_96_KB) > 0)
{
var content = System.Text.Encoding.UTF8.GetString(buffer);
content = content.TrimEnd('\0');
if (string.IsNullOrEmpty(content))
{
break;
}
var lines = content.Split('\n');
if (lines == null || lines.Length <= 0)
{
break;
}
ScannedResult scannedResult = null;
try
{
scannedResult = ScanLines(lines, currentPage);
}
catch (Exception ex)
{
Console.WriteLine("ScanLines Failed! error message:{0}", ex.Message);
errorCount++;
currentPage.LogItems = currentPage.LogItems.Take(currentPage.LogItems.Count - scannedResult.ScannedItemsCount).ToList();
buffer = new byte[BUFFER_SIZE_OF_96_KB];
var newStartPosition = (fs.Position - BUFFER_SIZE_OF_96_KB - errorCount) > 0 ? (fs.Position - BUFFER_SIZE_OF_96_KB - errorCount) : 0;
fs.Position = newStartPosition;
continue;
}
errorCount = 0;
var currentStartPosition = (fs.Position - BUFFER_SIZE_OF_96_KB);
var currentEndPosition = (currentStartPosition + scannedResult.ScannedByteLength) >= fs.Length ? fs.Length : currentStartPosition + scannedResult.ScannedByteLength;
if (currentPage.CurrentStartPosition == null || currentPage.CurrentStartPosition.Count <= 0)
{
currentPage.PreviousStartPosition = 0;
}
else
{
currentPage.PreviousStartPosition = currentPage.CurrentStartPosition.Last().Position;
}
//Load give count of log items in the first loading
if (currentPage.LogItems.Count >= PAGED_LINES_COUNT)
{
currentPage.CurrentStartPosition.Add(new PositionWithStatus()
{
Position = currentStartPosition, LoadCompleted = true
});
currentPage.CurrentEndPosition.Add(new PositionWithStatus()
{
Position = currentEndPosition, LoadCompleted = true
});
break;
}
else
{
currentPage.CurrentStartPosition.Add(new PositionWithStatus()
{
Position = currentStartPosition, LoadCompleted = false
});
currentPage.CurrentEndPosition.Add(new PositionWithStatus()
{
Position = currentEndPosition, LoadCompleted = false
});
buffer = new byte[BUFFER_SIZE_OF_96_KB];
SetPositionOfFileStream(currentPage, fs);
}
}
}
stopWatch.Stop();
Console.WriteLine("Loading log items from file \"test.log\" ended.");
Console.WriteLine("Time consumed:{0} milliseconds", stopWatch.ElapsedMilliseconds);
return(currentPage);
}