/// <summary>
/// Logs an error to the application memory.
/// </summary>
/// <remarks>
/// If the log is full then the oldest error entry is removed.
/// </remarks>
public override string Log(Error error)
{
if (error == null)
{
throw new ArgumentNullException(nameof(error));
}
//
// Make a copy of the error to log since the source is mutable.
// Assign a new GUID and create an entry for the error.
//
error = error.Clone();
error.ApplicationName = ApplicationName;
var newId = Guid.NewGuid();
var entry = new ErrorLogEntry(this, newId.ToString(), error);
Lock.EnterWriteLock();
try
{
var entries = _entries ??= new EntryCollection(_size);
entries.Add(entry);
}
finally
{
Lock.ExitWriteLock();
}
return(newId.ToString());
}
private static void RenderError(TextWriter writer, ErrorLogEntry entry, Uri baseUrl)
{
Debug.Assert(writer != null);
Debug.Assert(entry != null);
Debug.Assert(baseUrl != null);
Debug.Assert(baseUrl.IsAbsoluteUri);
var error = entry.Error;
writer.Write("<li>");
var errorType = ErrorDisplay.HumaneExceptionErrorType(error);
if (errorType.Length > 0)
{
var abbreviated = errorType.Length < error.Type.Length;
if (abbreviated)
{
writer.Write("<span title='{0}'>", Html.Encode(error.Type).ToHtmlString());
}
writer.Write(Html.Encode(errorType).ToHtmlString());
if (abbreviated)
{
writer.Write("</span>");
}
writer.Write(": ");
}
writer.Write("<a href='{0}'>", Html.Encode(baseUrl + "detail?id=" + Uri.EscapeDataString(entry.Id)).ToHtmlString());
writer.Write(Html.Encode(error.Message).ToHtmlString());
writer.Write("</a>");
writer.Write("</li>");
}
/// <summary>
/// Returns a page of errors from the application memory in
/// descending order of logged time.
/// </summary>
public override int GetErrors(int pageIndex, int pageSize, ICollection <ErrorLogEntry> errorEntryList)
{
if (pageIndex < 0)
{
throw new ArgumentOutOfRangeException("pageIndex", pageIndex, null);
}
if (pageSize < 0)
{
throw new ArgumentOutOfRangeException("pageSize", pageSize, null);
}
//
// To minimize the time for which we hold the lock, we'll first
// grab just references to the entries we need to return. Later,
// we'll make copies and return those to the caller. Since Error
// is mutable, we don't want to return direct references to our
// internal versions since someone could change their state.
//
ErrorLogEntry[] selectedEntries = null;
int totalCount;
_lock.EnterReadLock();
try
{
if (_entries == null)
{
return(0);
}
totalCount = _entries.Count;
var startIndex = totalCount - ((pageIndex + 1) * Math.Min(pageSize, totalCount));
var endIndex = Math.Min(startIndex + pageSize, totalCount);
var count = Math.Max(0, endIndex - startIndex);
if (count > 0)
{
selectedEntries = new ErrorLogEntry[count];
var sourceIndex = endIndex;
var targetIndex = 0;
while (sourceIndex > startIndex)
{
selectedEntries[targetIndex++] = _entries[--sourceIndex];
}
}
}
finally
{
_lock.ExitReadLock();
}
if (errorEntryList != null && selectedEntries != null)
{
//
// Return copies of fetched entries. If the Error class would
// be immutable then this step wouldn't be necessary.
//
foreach (var entry in selectedEntries)
{
var error = entry.Error.CloneObject();
errorEntryList.Add(new ErrorLogEntry(this, entry.Id, error));
}
}
return(totalCount);
}
protected void LogException(Exception e, HttpContext context)
{
if (e == null)
{
throw new ArgumentNullException(nameof(e));
}
//
// Fire an event to check if listeners want to filter out
// logging of the uncaught exception.
//
ErrorLogEntry entry = null;
try
{
var args = new ExceptionFilterEventArgs(e, context);
if (_filters.Any())
{
OnFiltering(args);
if (args.Dismissed && !args.DismissedNotifiers.Any())
{
return;
}
}
//
// Log away...
//
var error = new Error(e, context);
var log = GetErrorLog(context);
error.ApplicationName = log.ApplicationName;
var id = log.Log(error);
entry = new ErrorLogEntry(log, id, error);
//Send notification
foreach (var notifier in _notifiers)
{
if (!args.DismissedNotifiers.Any(i => i.Equals(notifier.Name, StringComparison.InvariantCultureIgnoreCase)))
{
notifier.Notify(error);
}
}
}
catch (Exception localException)
{
//
// IMPORTANT! We swallow any exception raised during the
// logging and send them out to the trace . The idea
// here is that logging of exceptions by itself should not
// be critical to the overall operation of the application.
// The bad thing is that we catch ANY kind of exception,
// even system ones and potentially let them slip by.
//
_logger.LogError("Elmah local exception", localException);
}
if (entry != null)
{
OnLogged(new ErrorLoggedEventArgs(entry));
}
}
public ErrorLoggedEventArgs(ErrorLogEntry entry)
{
_entry = entry ?? throw new ArgumentNullException(nameof(entry));
}