casacore
TaQLNodeHandler.h
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1 //# TaQLNodeHandler.h: Classes to handle the nodes in the raw TaQL parse tree
2 //# Copyright (C) 2005
3 //# Associated Universities, Inc. Washington DC, USA.
4 //#
5 //# This library is free software; you can redistribute it and/or modify it
6 //# under the terms of the GNU Library General Public License as published by
7 //# the Free Software Foundation; either version 2 of the License, or (at your
8 //# option) any later version.
9 //#
10 //# This library is distributed in the hope that it will be useful, but WITHOUT
11 //# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 //# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13 //# License for more details.
14 //#
15 //# You should have received a copy of the GNU Library General Public License
16 //# along with this library; if not, write to the Free Software Foundation,
17 //# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18 //#
19 //# Correspondence concerning AIPS++ should be addressed as follows:
20 //# Internet email: aips2-request@nrao.edu.
21 //# Postal address: AIPS++ Project Office
22 //# National Radio Astronomy Observatory
23 //# 520 Edgemont Road
24 //# Charlottesville, VA 22903-2475 USA
25 //#
26 //# $Id$
27 
28 #ifndef TABLES_TAQLNODEHANDLER_H
29 #define TABLES_TAQLNODEHANDLER_H
30 
31 //# Includes
32 #include <casacore/casa/aips.h>
33 #include <casacore/tables/TaQL/TaQLNodeVisitor.h>
34 #include <casacore/tables/TaQL/TaQLNodeDer.h>
35 #include <casacore/tables/TaQL/TableParse.h>
36 #include <casacore/tables/TaQL/ExprNode.h>
37 #include <casacore/tables/TaQL/ExprNodeSet.h>
38 #include <casacore/casa/Containers/Record.h>
39 #include <casacore/casa/Containers/ValueHolder.h>
40 #include <vector>
41 
42 namespace casacore { //# NAMESPACE CASACORE - BEGIN
43 
44 //# Forward Declarations
45 class TaQLNodeHRValue;
46 
47 
48 // <summary>
49 // Class to handle the nodes in the raw TaQL parse tree.
50 // </summary>
51 
52 // <use visibility=local>
53 
54 // <reviewed reviewer="" date="" tests="tTableGram">
55 // </reviewed>
56 
57 // <prerequisite>
58 //# Classes you should understand before using this one.
59 // <li> <linkto class=TaQLNode>TaQLNode</linkto>
60 // <li> Note 199 describing
61 // <a href="../notes/199.html">
62 // TaQL</a>
63 // </prerequisite>
64 
65 // <synopsis>
66 // TaQLNodeHandler is a specialization of class
67 // <linkto class=TaQLNodeVisitor>TaQLNodeVisitor</linkto>.
68 // It processes the raw TaQL parse tree generated by TableGram.
69 // The processing is done in a recursive way. It starts at the top
70 // (which is a SELECT, UPDATE, etc. expression) and the processing
71 // results of a query are stored in a TableParseSelect object.
72 // These objects are kept in a stack for possible nested queries.
73 // After a query is fully processed, it is executed. Usually the result
74 // is a table; only a CALC command gives a TableExprNode as result.
75 // </synopsis>
76 
77 // <motivation>
78 // Separating the raw query parsing from the query processing has
79 // several advantages compared to the old situation where parsing
80 // and processing were combined.
81 // <ul>
82 // <li> The full command is parsed before any processing is done.
83 // So in case of a parse error, no possibly expensive processing
84 // has been done yet.
85 // <li> In the future query optimization can be done in an easier way.
86 // <li> Nested parsing is not possible. In case a Table is opened
87 // with a virtual TaQL column, the parsing of that TaQL string
88 // does not interfere with parsing the TaQL command.
89 // <li> It is possible to use expressions in the column list.
90 // That could not be done before, because the column list was
91 // parsed/processed before the table list.
92 // </ul>
93 // </motivation>
94 
96 {
97 public:
98  virtual ~TaQLNodeHandler();
99 
100  // Handle and process the raw parse tree.
101  // The result contains a Table or TableExprNode object.
103  const std::vector<const Table*>&);
104 
105  // Define the functions to visit each node type.
106  // <group>
143  // </group>
144 
145  // Get the actual result object from the result.
146  static const TaQLNodeHRValue& getHR (const TaQLNodeResult&);
147 
148 private:
149  // Push a new TableParseSelect on the stack.
151 
152  // Get the top of the TableParseSelect stack.
154 
155  // Pop the top from the TableParseSelect stack.
156  void popStack();
157 
158  // Clear the select stack.
159  void clearStack();
160 
161  // Handle the select command.
162  // Optionally the command is not executed (needed for the EXISTS operator).
164 
165  // Handle a table name or temptable number in the given node
166  // and put it in the value result.
167  void handleTableName (TaQLNodeHRValue* hrval, const TaQLNode& node);
168 
169  // Handle a MultiNode containing table info.
170  void handleTables (const TaQLMultiNode&, Bool addToFromList=True);
171 
172  // Make a ConcatTable from a nested set of tables.
174 
175  // Handle the WHERE clause.
176  void handleWhere (const TaQLNode&);
177 
178  // Handle the HAVING clause.
179  void handleHaving (const TaQLNode&);
180 
181  // Handle the UPDATE SET clause.
183 
184  // Handle the INSERT columns.
186 
187  // Handle the INSERT values.
188  void handleInsVal (const TaQLNode&);
189 
190  // Handle a column specification in a create table.
192 
193  // Handle a Multi RecFld representing a Record.
195 
196 
197  //# Use vector instead of stack because it has random access
198  //# (which is used in TableParse.cc).
199  std::vector<TableParseSelect*> itsStack;
200  //# The temporary tables referred to by $i in the TaQL string.
201  std::vector<const Table*> itsTempTables;
202 };
203 
204 
205 // <summary>
206 // Class containing the result value of the handling of a TaQLNode.
207 // </summary>
208 
209 // <use visibility=local>
210 
211 // <reviewed reviewer="" date="" tests="tTableGram">
212 // </reviewed>
213 
214 // <prerequisite>
215 //# Classes you should understand before using this one.
216 // <li> <linkto class=TaQLNode>TaQLNodeResult</linkto>
217 // <li> <linkto class=TaQLNode>TaQLNodeHandler</linkto>
218 // <li> Note 199 describing
219 // <a href="../notes/199.html">
220 // TaQL</a>
221 // </prerequisite>
222 
223 // <synopsis>
224 // TaQLNodeHRValue is a specialization of class
225 // <linkto class=TaQLNodeResultRep>TaQLNodeResultRep</linkto>.
226 // It contains the values resulting from handling a particular node.
227 // The object is effectively a collection of all possible values that
228 // need to be returned. Which values are filled in, depends on which node
229 // has been processed.
230 // <note> The getHR function in TaQLNodeHandler is very useful to
231 // extract/cast the TaQLNodeHRValue object from the general
232 // TaQLNodeResult object.
233 // </note>
234 // </synopsis>
235 
237 {
238 public:
240  : itsInt(-1), itsElem(0), itsSet(0), itsNames(0) {}
242  : itsInt(-1), itsExpr(expr), itsElem(0), itsSet(0), itsNames(0) {}
243  virtual ~TaQLNodeHRValue();
244 
245  // Get the values.
246  // <group>
247  Int getInt() const
248  { return itsInt; }
249  const String& getString() const
250  { return itsString; }
251  const String& getAlias() const
252  { return itsAlias; }
253  const String& getNameMask() const
254  { return itsNameMask; }
255  const String& getDtype() const
256  { return itsDtype; }
257  const Record& getRecord() const
258  { return itsRecord; }
260  { return itsVH; }
261  const Table& getTable() const
262  { return itsTable; }
263  const TableExprNode& getExpr() const
264  { return itsExpr; }
266  { return itsElem; }
268  { return *itsSet; }
269  const Vector<String>* getNames() const
270  { return itsNames; }
271  // </group>
272 
273  // Set the values.
274  // If a pointer is given, it takes over the pointer.
275  // <group>
276  void setInt (Int ival)
277  { itsInt = ival; }
278  void setString (const String& str)
279  { itsString = str; }
280  void setAlias (const String& alias)
281  { itsAlias = alias; }
282  void setNameMask (const String& nameMask)
283  { itsNameMask = nameMask; }
284  void setDtype (const String& dtype)
285  { itsDtype = dtype; }
286  void setRecord (const Record& record)
287  { itsRecord = record; }
288  void setValueHolder (const ValueHolder& vh)
289  { itsVH = vh; }
290  void setTable (const Table& table)
291  { itsTable = table; }
292  void setExpr (const TableExprNode& expr)
293  { itsExpr = expr; }
295  { itsElem = elem; }
297  { itsSet = set; }
298  void setNames (Vector<String>* names)
299  { itsNames = names; }
300  // </group>
301 
302 private:
315 };
316 
317 
318 //# This function can only be implemented after TaQLNodeHRBase is declared.
320 {
321  return *(TaQLNodeHRValue*)(res.getRep());
322 }
323 
324 
325 
326 } //# NAMESPACE CASACORE - END
327 
328 #endif
String: the storage and methods of handling collections of characters.
Definition: String.h:223
Raw TaQL parse tree node defining an alter table add column command.
Definition: TaQLNodeDer.h:1197
Raw TaQL parse tree node defining an alter table add rows command.
Definition: TaQLNodeDer.h:1283
Raw TaQL parse tree node defining an alter table command.
Definition: TaQLNodeDer.h:1164
Raw TaQL parse tree node defining a binary operator.
Definition: TaQLNodeDer.h:195
Raw TaQL parse tree node defining a calc command.
Definition: TaQLNodeDer.h:999
Raw TaQL parse tree node defining a select column expression.
Definition: TaQLNodeDer.h:492
Raw TaQL parse tree node defining a create column specification.
Definition: TaQLNodeDer.h:1069
Raw TaQL parse tree node defining a select column list.
Definition: TaQLNodeDer.h:525
Raw TaQL parse tree node defining an alter table command.
Definition: TaQLNodeDer.h:1311
Raw TaQL parse tree node defining a count command.
Definition: TaQLNodeDer.h:857
Raw TaQL parse tree node defining a create table command.
Definition: TaQLNodeDer.h:1034
Raw TaQL parse tree node defining a delete command.
Definition: TaQLNodeDer.h:965
Raw TaQL parse tree node defining a function.
Definition: TaQLNodeDer.h:300
Raw TaQL parse tree node defining a giving expression list.
Definition: TaQLNodeDer.h:686
Raw TaQL parse tree node defining a groupby list.
Definition: TaQLNodeDer.h:555
Raw TaQL parse tree node defining an index in a array.
Definition: TaQLNodeDer.h:366
Raw TaQL parse tree node defining an insert command.
Definition: TaQLNodeDer.h:929
Raw TaQL parse tree node defining a join operation.
Definition: TaQLNodeDer.h:398
Raw TaQL parse tree node defining a keyword or column name.
Definition: TaQLNodeDer.h:428
Raw TaQL parse tree node defining a limit/offset expression.
Definition: TaQLNodeDer.h:656
Raw TaQL parse tree node defining a list of nodes.
Definition: TaQLNodeDer.h:252
Envelope class for a node containing a list of nodes.
Definition: TaQLNode.h:227
Class containing the result value of the handling of a TaQLNode.
void setTable(const Table &table)
void setString(const String &str)
void setExprSet(TableExprNodeSet *set)
TaQLNodeHRValue(const TableExprNode &expr)
const String & getDtype() const
const Record & getRecord() const
const String & getString() const
const TableExprNodeSet & getExprSet() const
const Vector< String > * getNames() const
TableExprNodeSet * itsSet
const Table & getTable() const
Vector< String > * itsNames
const TableExprNode & getExpr() const
const String & getAlias() const
const TableExprNodeSetElem * getElem() const
void setRecord(const Record &record)
void setValueHolder(const ValueHolder &vh)
void setNameMask(const String &nameMask)
const String & getNameMask() const
void setDtype(const String &dtype)
void setElem(TableExprNodeSetElem *elem)
void setExpr(const TableExprNode &expr)
void setAlias(const String &alias)
void setInt(Int ival)
Set the values.
Int getInt() const
Get the values.
TableExprNodeSetElem * itsElem
void setNames(Vector< String > *names)
const ValueHolder & getValueHolder() const
std::vector< TableParseSelect * > itsStack
virtual TaQLNodeResult visitTableNode(const TaQLTableNodeRep &node)
virtual TaQLNodeResult visitRangeNode(const TaQLRangeNodeRep &node)
Record handleMultiRecFld(const TaQLNode &node)
Handle a Multi RecFld representing a Record.
virtual TaQLNodeResult visitMultiNode(const TaQLMultiNodeRep &node)
void handleInsCol(const TaQLMultiNode &)
Handle the INSERT columns.
void handleColSpecs(const TaQLMultiNode &)
Handle a column specification in a create table.
virtual TaQLNodeResult visitInsertNode(const TaQLInsertNodeRep &node)
virtual TaQLNodeResult visitRegexNode(const TaQLRegexNodeRep &node)
virtual TaQLNodeResult visitCalcNode(const TaQLCalcNodeRep &node)
virtual TaQLNodeResult visitColNode(const TaQLColNodeRep &node)
virtual TaQLNodeResult visitUnitNode(const TaQLUnitNodeRep &node)
void handleHaving(const TaQLNode &)
Handle the HAVING clause.
virtual TaQLNodeResult visitJoinNode(const TaQLJoinNodeRep &node)
virtual TaQLNodeResult visitFuncNode(const TaQLFuncNodeRep &node)
virtual TaQLNodeResult visitColSpecNode(const TaQLColSpecNodeRep &node)
void handleUpdate(const TaQLMultiNode &)
Handle the UPDATE SET clause.
void handleTableName(TaQLNodeHRValue *hrval, const TaQLNode &node)
Handle a table name or temptable number in the given node and put it in the value result.
void clearStack()
Clear the select stack.
TaQLNodeResult handleTree(const TaQLNode &tree, const std::vector< const Table * > &)
Handle and process the raw parse tree.
virtual TaQLNodeResult visitBinaryNode(const TaQLBinaryNodeRep &node)
virtual TaQLNodeResult visitDeleteNode(const TaQLDeleteNodeRep &node)
virtual TaQLNodeResult visitSortNode(const TaQLSortNodeRep &node)
virtual TaQLNodeResult visitShowNode(const TaQLShowNodeRep &node)
TableParseSelect * topStack() const
Get the top of the TableParseSelect stack.
virtual TaQLNodeResult visitKeyColNode(const TaQLKeyColNodeRep &node)
virtual TaQLNodeResult visitSortKeyNode(const TaQLSortKeyNodeRep &node)
Table makeConcatTable(const TaQLMultiNodeRep &node)
Make a ConcatTable from a nested set of tables.
virtual TaQLNodeResult visitAddRowNode(const TaQLAddRowNodeRep &node)
virtual TaQLNodeResult visitColumnsNode(const TaQLColumnsNodeRep &node)
virtual TaQLNodeResult visitLimitOffNode(const TaQLLimitOffNodeRep &node)
virtual TaQLNodeResult visitCreTabNode(const TaQLCreTabNodeRep &node)
TableParseSelect * pushStack(TableParseSelect::CommandType)
Push a new TableParseSelect on the stack.
virtual TaQLNodeResult visitRecFldNode(const TaQLRecFldNodeRep &node)
virtual TaQLNodeResult visitConcTabNode(const TaQLConcTabNodeRep &node)
virtual TaQLNodeResult visitGivingNode(const TaQLGivingNodeRep &node)
virtual TaQLNodeResult visitSelectNode(const TaQLSelectNodeRep &node)
std::vector< const Table * > itsTempTables
virtual TaQLNodeResult visitIndexNode(const TaQLIndexNodeRep &node)
virtual TaQLNodeResult visitCountNode(const TaQLCountNodeRep &node)
virtual TaQLNodeResult visitAltTabNode(const TaQLAltTabNodeRep &node)
void handleTables(const TaQLMultiNode &, Bool addToFromList=True)
Handle a MultiNode containing table info.
virtual TaQLNodeResult visitAddColNode(const TaQLAddColNodeRep &node)
virtual TaQLNodeResult visitGroupNode(const TaQLGroupNodeRep &node)
virtual TaQLNodeResult visitUnaryNode(const TaQLUnaryNodeRep &node)
virtual TaQLNodeResult visitUpdExprNode(const TaQLUpdExprNodeRep &node)
void popStack()
Pop the top from the TableParseSelect stack.
void handleInsVal(const TaQLNode &)
Handle the INSERT values.
virtual TaQLNodeResult visitSetKeyNode(const TaQLSetKeyNodeRep &node)
static const TaQLNodeHRValue & getHR(const TaQLNodeResult &)
Get the actual result object from the result.
TaQLNodeResult handleSelect(const TaQLSelectNodeRep &node, Bool doExec)
Handle the select command.
virtual TaQLNodeResult visitRenDropNode(const TaQLRenDropNodeRep &node)
void handleWhere(const TaQLNode &)
Handle the WHERE clause.
virtual TaQLNodeResult visitConstNode(const TaQLConstNodeRep &node)
Define the functions to visit each node type.
virtual TaQLNodeResult visitUpdateNode(const TaQLUpdateNodeRep &node)
Envelope class to hold the result of a visit to the node tree.
const TaQLNodeResultRep * getRep() const
Get the actual underlying object.
Raw TaQL parse tree node defining a range.
Definition: TaQLNodeDer.h:331
Raw TaQL parse tree node defining a record field.
Definition: TaQLNodeDer.h:1100
Raw TaQL parse tree node defining a constant regex value.
Definition: TaQLNodeDer.h:120
Raw TaQL parse tree node defining an alter table rename or drop command.
Definition: TaQLNodeDer.h:1226
Raw TaQL parse tree node defining a select command.
Definition: TaQLNodeDer.h:809
Raw TaQL parse tree node defining an alter table set keyword command.
Definition: TaQLNodeDer.h:1255
Raw TaQL parse tree node defining a show command.
Definition: TaQLNodeDer.h:1343
Raw TaQL parse tree node defining a sort key.
Definition: TaQLNodeDer.h:588
Raw TaQL parse tree node defining a sort list.
Definition: TaQLNodeDer.h:622
Raw TaQL parse tree node defining a table.
Definition: TaQLNodeDer.h:459
Raw TaQL parse tree node defining a unary operator.
Definition: TaQLNodeDer.h:157
Raw TaQL parse tree node defining a unit.
Definition: TaQLNodeDer.h:1135
Raw TaQL parse tree node defining a column update expression.
Definition: TaQLNodeDer.h:720
Raw TaQL parse tree node defining an update command.
Definition: TaQLNodeDer.h:891
Class to hold multiple table expression nodes.
Definition: ExprNodeSet.h:311
Select-class for flex/bison scanner/parser for TableParse.
Definition: TableParse.h:382
this file contains all the compiler specific defines
Definition: mainpage.dox:28
int Int
Definition: aipstype.h:50
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42
const Bool True
Definition: aipstype.h:43