public IXTable ReadSource(string tableName, XDatabaseContext context)
{
List <IXTable> sources = new List <IXTable>();
// Find the latest source of this type
ItemVersions sourceVersions = context.StreamProvider.ItemVersions(LocationType.Source, tableName);
ItemVersion latestFullSource = sourceVersions.LatestBeforeCutoff(CrawlType.Full, context.RequestedAsOfDateTime);
// If there are no sources, there's nothing to rebuild from
if (sourceVersions.Versions == null || sourceVersions.Versions.Count == 0)
{
return(null);
}
// Find the latest already converted table
ItemVersions tableVersions = context.StreamProvider.ItemVersions(LocationType.Table, tableName);
ItemVersion latestBuiltTable = tableVersions.LatestBeforeCutoff(CrawlType.Full, context.RequestedAsOfDateTime);
// If no source or table was found, throw
if (latestFullSource == null && latestBuiltTable == null)
{
throw new UsageException(tableName, "[Table]", context.StreamProvider.SourceNames());
}
// Read the Table or the Full Crawl Source, whichever is newer
DateTime incrementalNeededAfterCutoff;
if (latestBuiltTable != null &&
(latestFullSource == null || !IsOutOfDate(latestBuiltTable.AsOfDate, latestFullSource.AsOfDate)) &&
TableMetadataSerializer.UncachedExists(context.StreamProvider, latestBuiltTable.Path))
{
// If the table is current, reuse it
sources.Add(BinaryTableReader.Build(context.StreamProvider, latestBuiltTable.Path));
incrementalNeededAfterCutoff = latestBuiltTable.AsOfDate;
}
else
{
// Otherwise, build a new table from the latest source full crawl
sources.AddRange(context.StreamProvider.Enumerate(latestFullSource.Path, EnumerateTypes.File, true).Select((sa) => new TabularFileReader(context.StreamProvider, sa.Path)));
incrementalNeededAfterCutoff = latestFullSource.AsOfDate;
}
// Add incremental crawls between the full source and the reporting date
DateTime latestComponent = incrementalNeededAfterCutoff;
foreach (ItemVersion incrementalCrawl in sourceVersions.VersionsInRange(CrawlType.Inc, incrementalNeededAfterCutoff, context.RequestedAsOfDateTime))
{
sources.AddRange(context.StreamProvider.Enumerate(incrementalCrawl.Path, EnumerateTypes.File, true).Select((sa) => new TabularFileReader(context.StreamProvider, sa.Path)));
latestComponent = latestComponent.BiggestOf(incrementalCrawl.AsOfDate);
}
// Report the latest incorporated source back
context.NewestDependency = latestComponent;
// Return the source (if a single) or concatenated group (if multiple parts)
return(ConcatenatedTable.Build(sources));
}
private void Run(string query, string format, int rowCountLimit, int colCountLimit, DateTime asOfDate, IHttpResponse response)
{
IXTable pipeline = null;
try
{
XDatabaseContext context = _xDatabaseContext;
// Build for another moment in time if requested
if (asOfDate != _xDatabaseContext.RequestedAsOfDateTime)
{
context = new XDatabaseContext(_xDatabaseContext)
{
RequestedAsOfDateTime = asOfDate
};
}
// Build a Pipeline for the Query
pipeline = context.Query(query);
// If there was no query, return an empty result
if (pipeline == null)
{
return;
}
// Restrict the row and column count if requested
if (rowCountLimit >= 0 || colCountLimit > 0)
{
pipeline = new Verbs.Limit(pipeline, rowCountLimit, colCountLimit);
}
// Build a writer for the desired format
pipeline = new TabularFileWriter(pipeline, WriterForFormat(format, response));
// Run the query and return the output
pipeline.RunWithoutDispose();
}
catch (ColumnDataNotFoundException ex)
{
// If column data is missing, delete the table to try to spur re-creating it
// NOTE: This logic will likely need to be updated when columns are downloaded remotely; multi-threaded scenarios will be complex.
string tablePath = Path.Combine(ex.ColumnPath, @"..\..\..");
TableMetadataSerializer.Delete(_xDatabaseContext.StreamProvider, tablePath);
}
finally
{
if (pipeline != null)
{
pipeline.Dispose();
pipeline = null;
}
}
}
public IXTable Build(string tableName, XDatabaseContext outerContext, bool deferred)
{
// Validate the source name is recognized
if (!Sources.Contains(tableName))
{
// If it wasn't in cache, check individually for it live
if (!XDatabaseContext.StreamProvider.ContainsTable(tableName))
{
throw new UsageException(tableName, "Table", Sources);
}
// If found, update the cache
UpdateSources();
}
// If only a Date was passed for AsOfDate, look for the last version as of that day
if (outerContext.RequestedAsOfDateTime.TimeOfDay == TimeSpan.Zero)
{
outerContext.RequestedAsOfDateTime = outerContext.RequestedAsOfDateTime.AddDays(1).AddSeconds(-1);
}
// If we previously found the latest for this table, just return it again
LatestTableForCutoff previousLatest;
if (_currentTableVersions.TryGet(tableName, out previousLatest) &&
previousLatest.Cutoff >= outerContext.RequestedAsOfDateTime &&
previousLatest.TableVersion.AsOfDate <= outerContext.RequestedAsOfDateTime &&
TableMetadataSerializer.UncachedExists(outerContext.StreamProvider, previousLatest.TableVersion.Path))
{
outerContext.NewestDependency = previousLatest.TableVersion.AsOfDate;
return(BinaryTableReader.Build(outerContext.StreamProvider, previousLatest.TableVersion.Path));
}
// Create a context to track what we're building now
XDatabaseContext innerContext = XDatabaseContext.Push(outerContext);
innerContext.CurrentTable = tableName;
// If this is a query, there won't be a cached table - just build a pipeline to make it
StreamAttributes queryAttributes = innerContext.StreamProvider.Attributes(innerContext.StreamProvider.Path(LocationType.Query, tableName, ".xql"));
if (queryAttributes.Exists)
{
IXTable queryPipeline = innerContext.Query(innerContext.StreamProvider.ReadAllText(queryAttributes.Path));
innerContext.Pop(outerContext);
return(queryPipeline);
}
// Find the latest already built result, and associated query
ItemVersions tableVersions = innerContext.StreamProvider.ItemVersions(LocationType.Table, tableName);
ItemVersion latestTable = tableVersions.LatestBeforeCutoff(CrawlType.Full, outerContext.RequestedAsOfDateTime);
string latestTableQuery = null;
if (latestTable != null)
{
latestTableQuery = TableMetadataSerializer.Read(outerContext.StreamProvider, latestTable.Path).Query;
}
// Set the dependency date to the latest table we've already built (if any)
innerContext.NewestDependency = (latestTable == null ? DateTime.MinValue : latestTable.AsOfDate);
// Determine the XQL to build the table and construct a builder which can do so
string xql;
IXTable builder;
// Find the config to build the table and scan dependency versions to determine whether table is out-of-date
StreamAttributes configAttributes = innerContext.StreamProvider.Attributes(innerContext.StreamProvider.Path(LocationType.Config, tableName, ".xql"));
if (!configAttributes.Exists)
{
// If this is a simple source, just reading it is how to build it
xql = $"read {XqlScanner.Escape(tableName, TokenType.Value)}";
// Build a reader concatenating all needed pieces
builder = ReadSource(tableName, innerContext);
}
else
{
// If there is a config, the config is how to build it
xql = innerContext.StreamProvider.ReadAllText(configAttributes.Path);
// Build a pipeline for the query, recursively creating dependencies
builder = innerContext.Query(xql);
}
// If we don't have the table or the source, we have to throw
if (latestTable == null && builder == null)
{
throw new UsageException(tableName, "Table", innerContext.StreamProvider.Tables());
}
// Get the path we're either reading or building
string tablePath = innerContext.StreamProvider.Path(LocationType.Table, tableName, CrawlType.Full, innerContext.NewestDependency);
// If we can rebuild this table and we need to (sources rebuilt, query changed, out-of-date, deleted), rebuild it
if (builder != null)
{
if (latestTable == null ||
innerContext.RebuiltSomething ||
(latestTableQuery != null && xql != latestTableQuery) ||
IsOutOfDate(latestTable.AsOfDate, innerContext.NewestDependency) ||
!TableMetadataSerializer.UncachedExists(outerContext.StreamProvider, latestTable.Path))
{
// If we're not running now, just return how to build it
if (deferred)
{
return(builder);
}
// Otherwise, build it now; we'll return the query to read the output
innerContext.CurrentQuery = xql;
Trace.WriteLine($"COMPUTE: [{innerContext.NewestDependency.ToString(StreamProviderExtensions.DateTimeFolderFormat)}] {tableName}");
BinaryTableWriter.Build(builder, innerContext, tablePath).RunAndDispose();
innerContext.RebuiltSomething = true;
}
}
// Report the newest dependency in this chain to the components above
innerContext.Pop(outerContext);
_currentTableVersions.Add(tableName, new LatestTableForCutoff(outerContext.RequestedAsOfDateTime, new ItemVersion(LocationType.Table, tableName, CrawlType.Full, innerContext.NewestDependency)));
return(BinaryTableReader.Build(innerContext.StreamProvider, tablePath));
}
