// Reads //
public static StagedReadName RenderStagedReadPlan(Workspace Home, HScriptParser.Crudam_readContext context)
{
// Get the data source //
DataSet data = VisitorHelper.GetData(Home, context.full_table_name());
string alias =
(context.K_AS() != null)
? context.IDENTIFIER().GetText()
: data.Name;
// Create a local heap to work off of //
MemoryStruct local_heap = new MemoryStruct(true);
// Create a record register //
StreamRegister memory = new StreamRegister(null);
// Create expression visitor //
ExpressionVisitor exp_vis = new ExpressionVisitor(local_heap, Home, alias, data.Columns, memory);
// Where clause //
Predicate where = VisitorHelper.GetWhere(exp_vis, context.where_clause());
// Create a reader //
RecordReader reader = data.OpenReader(where);
// Attach the reader to the register //
memory.BaseStream = reader;
// Create the action visitor //
ActionVisitor act_vis = new ActionVisitor(Home, local_heap, exp_vis);
// Get the declarations //
if (context.crudam_declare_many() != null)
{
VisitorHelper.AllocateMemory(Home, local_heap, exp_vis, context.crudam_declare_many());
}
// Get the initial actionset //
TNode pre_run =
(context.init_action() != null)
? act_vis.ToNode(context.init_action().query_action())
: new TNodeNothing(null);
// Get the main actionset //
TNode run = act_vis.ToNode(context.main_action().query_action());
// Get the final actionset //
TNode post_run =
(context.final_action() != null)
? act_vis.ToNode(context.final_action().query_action())
: new TNodeNothing(null);
return new StagedReadName(reader, pre_run, run, post_run);
}