/// <summary>
/// Loads the first available entries starting at a given time.
/// </summary>
/// <param name="firstLogTime">The first log time.</param>
/// <param name="pageLength">The length of pages. Must be greater than 0.</param>
/// <returns>The first <see cref="LivePage"/> from which next pages can be retrieved.</returns>
public LivePage ReadFirstPage(DateTimeStamp firstLogTime, int pageLength)
{
Throw.CheckOutOfRangeArgument(pageLength > 0);
MultiFileReader r = new MultiFileReader(firstLogTime, _files);
if (r.MoveNext())
{
return(new LivePage(_firstDepth, new ParentedLogEntry[pageLength], r, pageLength));
}
return(new LivePage(_firstDepth, Array.Empty <ParentedLogEntry>(), null, pageLength));
}
/// <summary>
/// Loads the first available entries starting at a given time.
/// </summary>
/// <param name="firstLogTime">The first log time.</param>
/// <param name="pageLength">The length of pages. Must be greater than 0.</param>
/// <returns>The first <see cref="LivePage"/> from which next pages can be retrieved.</returns>
public LivePage ReadFirstPage(DateTimeStamp firstLogTime, int pageLength)
{
if (pageLength < 1)
{
throw new ArgumentOutOfRangeException("pageLength");
}
MultiFileReader r = new MultiFileReader(firstLogTime, _files);
if (r.MoveNext())
{
return(new LivePage(_firstDepth, new ParentedLogEntry[pageLength], r, pageLength));
}
return(new LivePage(_firstDepth, Util.Array.Empty <ParentedLogEntry>(), null, pageLength));
}
/// <summary>
/// Loads the next page.
/// </summary>
/// <returns>The number of entries.</returns>
public int ForwardPage()
{
if (_r != null)
{
if (_r.MoveNext())
{
_entries.FillPage(_r, _currentPath);
}
else
{
_entries.Count = 0;
}
}
return(Entries.Count);
}
int DoFillPage(MultiFileReader r, List <ParentedLogEntry> path, ILogEntry lastPrevEntry)
{
ParentedLogEntry parent = path.Count > 0 ? path[path.Count - 1] : null;
int i = 0;
do
{
var entry = r.Current;
if (entry.GroupDepth < path.Count)
{
// Adds a MissingCloseGroup with an unknown time for tail groups: handles the
// last closing group specifically.
while (entry.GroupDepth < path.Count - 1)
{
if (AppendEntry(path, ref parent, ref i, LogEntry.CreateMissingCloseGroup(DateTimeStamp.Unknown)))
{
return(i);
}
}
// Handles the last auto-close group: we may know its time thanks to our current entry (if its previous type is a CloseGroup).
Debug.Assert(entry.GroupDepth == path.Count - 1, "We are on the last group to auto-close.");
DateTimeStamp prevTime = entry.PreviousEntryType == LogEntryType.CloseGroup ? entry.PreviousLogTime : DateTimeStamp.Unknown;
if (AppendEntry(path, ref parent, ref i, LogEntry.CreateMissingCloseGroup(prevTime)))
{
return(i);
}
}
else if (entry.GroupDepth > path.Count)
{
// Adds a MissingOpenGroup with an unknown time for head groups: handles the
// last opening group specifically.
while (entry.GroupDepth > path.Count + 1)
{
if (AppendEntry(path, ref parent, ref i, LogEntry.CreateMissingOpenGroup(DateTimeStamp.Unknown)))
{
return(i);
}
}
// Handles the last auto-open group: we may know its time thanks to our current entry (if its previous type is a OpenGroup).
Debug.Assert(entry.GroupDepth == path.Count + 1, "We are on the last group to auto-open.");
DateTimeStamp prevTime = entry.PreviousEntryType == LogEntryType.OpenGroup ? entry.PreviousLogTime : DateTimeStamp.Unknown;
if (AppendEntry(path, ref parent, ref i, LogEntry.CreateMissingOpenGroup(prevTime)))
{
return(i);
}
}
// If we know the the time and type of the previous entry and this does not correspond to
// our predecessor, we inject a missing line.
// This is necessarily a line that we inject here thanks to the open/close adjustment above.
// If the log type of the known previous entry is Open or Close group, it means that there are incoherent group depths... and
// we ignore this pathological case.
if (entry.PreviousEntryType != LogEntryType.None)
{
ILogEntry prevEntry = i > 0 ? Entries[i - 1].Entry : lastPrevEntry;
if (prevEntry == null || prevEntry.LogTime != entry.PreviousLogTime)
{
if (AppendEntry(path, ref parent, ref i, LogEntry.CreateMissingLine(entry.PreviousLogTime)))
{
return(i);
}
}
}
// Now that missing data has been handled, appends the line itself.
if (AppendEntry(path, ref parent, ref i, entry.CreateUnicastLogEntry()))
{
return(i);
}
}while(r.MoveNext());
return(i);
}
