/// <summary>
/// Gets message metadata.
/// </summary>
/// <param name="query">Query.</param>
/// <param name="maxItems">The maximum number of items to return.</param>
/// <returns>Metadata.</returns>
/// <exception cref="ArgumentException">Thrown if DateTime kind is not UTC.</exception>
/// <exception cref="ObjectDisposedException">Thrown if disposed.</exception>
public SysColl.List <Metadata> Get(MetadataQuery query, int maxItems)
{
ExpectNotDisposed(); // throws ObjectDisposedException
var retval = new SysColl.List <Metadata>();
// Setting query defaults for the timestamps
var startForQuery = DateTime.SpecifyKind(DateTime.MinValue, DateTimeKind.Utc);
var endForQuery = DateTime.SpecifyKind(DateTime.MaxValue, DateTimeKind.Utc);
// Getting the actual datetime values in the query
if (query.TimeWindowStart.HasValue)
{
startForQuery = query.TimeWindowStart.Value;
}
if (query.TimeWindowEnd.HasValue)
{
endForQuery = query.TimeWindowEnd.Value;
}
// Requiring UTC as the DateTime kind
ExpectUtc(startForQuery);
ExpectUtc(endForQuery);
var discoveredItems = from md in m_messageContext.DbMetadataItem
select md;
// Filtering by host and exchange;
// filtering by start and end time
discoveredItems = discoveredItems.Where(md =>
md.Host == query.Host &&
md.Exchange == query.Exchange &&
md.ReceivedAt >= startForQuery.Ticks &&
md.ReceivedAt <= endForQuery.Ticks
);
// Filtering by topic if specified
if (!string.IsNullOrEmpty(query.Topic))
{
discoveredItems = discoveredItems.Where(md => md.Topic == query.Topic);
}
// Limiting the number of items
discoveredItems = discoveredItems.Take(maxItems);
// Converting to the Entify-Framework-independent format
foreach (var efMeta in discoveredItems.ToList()) // ToList() requires System.Linq
{
var metadata = ConvertForOutput(efMeta);
retval.Add(metadata);
}
return(retval);
}
private AppLogic.MetadataState GetMetadataUsingFilters()
{
// Clear any previous filter status and messages
FiltersExpander.Header = "Filters";
SetStatusText(FiltersHintTextBlock, "", isProblem: false);
TimeWindowBuilder timeWindow;
// Trying to build time window for the query
try
{
timeWindow = GetTimeWindowForFilter();
}
catch (ArgumentException e)
{
SetStatusText(FiltersHintTextBlock, e.Message, isProblem: true);
return(null);
}
// Create query object
var query = new MetadataQuery(m_host, m_exchange)
{
TimeWindowStart = timeWindow.TimeWindowStart,
TimeWindowEnd = timeWindow.TimeWindowEnd
};
// Adding topic for filtering if selected
if (FilterTopicComboBox.SelectedValue != null)
{
var selectedValue = (string)FilterTopicComboBox.SelectedValue;
query.Topic = selectedValue;
}
// Getting metadata and topics
var metadataState = m_appLogic.GetMetadataState(query);
// Refreshing message count
FiltersExpander.Header = string.Format("Filters (showing {0} messages out of {1})",
metadataState.Items.Count, metadataState.TotalItemCount);
// Is the item limit applied? Set hint if yes.
if (metadataState.IsLimitApplied)
{
SetStatusText(FiltersHintTextBlock, "Too many items found. Not showing all.", isProblem: false);
}
return(metadataState);
}
/// <summary>
/// Returns information about the currently stored metadata.
/// </summary>
/// <param name="query">Query for the metadata items to return.</param>
/// <returns>Information about metadata.</returns>
public MetadataState GetMetadataState(MetadataQuery query)
{
const int MaxItemsToReturn = 200;
using (var metadataMgr = new MetadataManager(m_exeFolder))
{
var items = metadataMgr.Get(query, MaxItemsToReturn);
return(new MetadataState()
{
Items = items,
Topics = metadataMgr.GetTopics(host: query.Host, exc: query.Exchange),
TotalItemCount = metadataMgr.GetTotalCount(host: query.Host, exc: query.Exchange),
IsLimitApplied = items.Count >= MaxItemsToReturn // Max item count reached?
});
}
}
