/// <summary>
/// Fetches console lines from storage.
/// </summary>
/// <param name="storage">Console data accessor</param>
/// <param name="consoleId">Console identifier</param>
/// <param name="start">Offset to read lines from</param>
/// <remarks>
/// On completion, <paramref name="start"/> is set to the end of the current batch,
/// and can be used for next requests (or set to -1, if the job has finished processing).
/// </remarks>
private static IEnumerable <ConsoleLine> ReadLines(IConsoleStorage storage, ConsoleId consoleId, ref int start)
{
if (start < 0)
{
return(null);
}
var count = storage.GetLineCount(consoleId);
var result = new List <ConsoleLine>(Math.Max(1, count - start));
if (count > start)
{
// has some new items to fetch
Dictionary <string, ConsoleLine> progressBars = null;
foreach (var entry in storage.GetLines(consoleId, start, count - 1))
{
if (entry.ProgressValue.HasValue)
{
// aggregate progress value updates into single record
if (progressBars != null)
{
ConsoleLine prev;
if (progressBars.TryGetValue(entry.Message, out prev))
{
prev.ProgressValue = entry.ProgressValue;
prev.TextColor = entry.TextColor;
continue;
}
}
else
{
progressBars = new Dictionary <string, ConsoleLine>();
}
progressBars.Add(entry.Message, entry);
}
result.Add(entry);
}
}
if (count <= start || start == 0)
{
// no new items or initial load, check if the job is still performing
var state = storage.GetState(consoleId);
if (state == null)
{
// No state found for a job, probably it was deleted
count = -2;
}
else
{
if (!string.Equals(state.Name, ProcessingState.StateName, StringComparison.OrdinalIgnoreCase) ||
!consoleId.Equals(new ConsoleId(consoleId.JobId, JobHelper.DeserializeDateTime(state.Data["StartedAt"]))))
{
// Job state has changed (either not Processing, or another Processing with different console id)
count = -1;
}
}
}
start = count;
return(result);
}