// Get a catalog value by entry from database or catalog
public TypedValue GetValue(CatalogEntry entry)
{
if (entry.IsDatabase)
{
if (_catalog.SqlFlag)
{
// Database sql comes from external table
var table = DataTableSql.Create(entry.Name, entry.DataType.Heading);
return(RelationValue.Create(table));
}
else if (!entry.IsLoaded) // lazy load
// Database non-sql lazy loaded from store on path, then in catalog
{
var value = Persist.Create(_catalog.DatabasePath, true).Load(entry.Name);
if (entry.DataType != value.DataType)
{
throw ProgramError.Fatal("Catalog", "Type mismatch for variable {0}", entry.Name);
}
entry.IsLoaded = true;
return(Persist.Create(_catalog.DatabasePath, true).Load(entry.Name));
}
}
// Non-database exists only in the catalog
return(entry.Value);
}
// get the type of a relation from some persistence store
// Used during compilation or startup -- if successful, variable will be created with flags
// Then use AddRelvar to import the value
public DataType GetRelvarType(string source, string what)
{
var islinked = (source == DefaultDatabaseSource);
if (islinked)
{
if (SqlFlag)
{
var heading = SqlTarget.Current.GetTableHeading(what);
return((heading == null) ? null : DataTypeRelation.Get(heading));
}
else
{
var type = Persist.Create(DatabasePath, false).Peek(what);
return(type);
}
}
else
{
var heading = DataSourceStream.Create(source, SourcePath).Peek(what);
if (heading != null)
{
return(DataTypeRelation.Get(heading));
}
}
return(null);
}
//--- persistence Mk II
// Store the persistent catalog and modified tables, local only
// note: for Sql, only used to create new empty catalog
public void StoreToTable()
{
Logger.WriteLine(2, "Save catalog for '{0}'", DatabaseName);
var ctm = CatalogTableMaker.Create(_catalogtableheading);
var table = ctm.AddEntries(PersistentVars.GetEntries()).Table;
if (SqlFlag)
{
DataTableSql.Create(CatalogTableName, table);
}
else
{
Persist.Create(DatabasePath, true).Store(CatalogTableName, RelationValue.Create(table));
var savers = PersistentVars.GetEntries().Where(e => e.IsUnsaved);
Logger.WriteLine(2, $"Persist {savers.Count()} entries");
foreach (var entry in savers)
{
Persist.Create(DatabasePath, true).Store(entry.Name, entry.Value);
}
}
}
// Get the value of a relation from a database
// Entry previously created by peeking
public bool LinkRelvar(string name)
{
var entry = GlobalVars.FindEntry(name);
Logger.Assert(entry != null && entry.IsDatabase);
var heading = entry.DataType.Heading;
if (SqlFlag)
{
var sqlheading = SqlTarget.Current.GetTableHeading(name);
if (sqlheading == null)
{
throw ProgramError.Fatal("Catalog", "sql table not found: '{0}'", name);
}
// TODO: smarter test, but still may not match exactly
//if (!heading.Equals(sqlheading))
if (heading.Degree != sqlheading.Degree)
{
throw ProgramError.Fatal("Catalog", "sql table schema mismatch: '{0}'", name);
}
var table = DataTableSql.Create(name, heading);
GlobalVars.SetValue(entry, RelationValue.Create(table));
}
else
{
var tablev = Persist.Create(DatabasePath, false).Load(name);
if (tablev == null)
{
throw ProgramError.Fatal("Catalog", "local table not found: '{0}'", name);
}
if (!heading.Equals(tablev.Heading))
{
throw ProgramError.Fatal("Catalog", "local table schema mismatch: '{0}'", name);
}
GlobalVars.SetValue(entry, RelationValue.Create(tablev.AsTable()));
}
return(true);
}
