libdap Updated for version 3.20.5
libdap4 is an implementation of OPeNDAP's DAP protocol.
D4ConstraintEvaluator.cc
1// -*- mode: c++; c-basic-offset:4 -*-
2
3// This file is part of libdap, A C++ implementation of the OPeNDAP Data
4// Access Protocol.
5
6// Copyright (c) 2002,2003 OPeNDAP, Inc.
7// Author: James Gallagher <jgallagher@opendap.org>
8//
9// This library is free software; you can redistribute it and/or
10// modify it under the terms of the GNU Lesser General Public
11// License as published by the Free Software Foundation; either
12// version 2.1 of the License, or (at your option) any later version.
13//
14// This library is distributed in the hope that it will be useful,
15// but WITHOUT ANY WARRANTY; without even the implied warranty of
16// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17// Lesser General Public License for more details.
18//
19// You should have received a copy of the GNU Lesser General Public
20// License along with this library; if not, write to the Free Software
21// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22//
23// You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
24
25#include <string>
26#include <sstream>
27#include <iterator>
28
29//#define DODS_DEBUG
30
31#include "D4CEScanner.h"
32#include "D4ConstraintEvaluator.h"
33#include "d4_ce_parser.tab.hh"
34
35#include "DMR.h"
36#include "D4Group.h"
37#include "D4Dimensions.h"
38#include "D4Maps.h"
39#include "BaseType.h"
40#include "Array.h"
41#include "Constructor.h"
42#include "D4Sequence.h"
43
44#include "D4RValue.h"
45#include "D4FilterClause.h"
46
47#include "escaping.h"
48#include "parser.h" // for get_ull()
49#include "debug.h"
50
51namespace libdap {
52
53bool D4ConstraintEvaluator::parse(const std::string &expr)
54{
55 d_expr = expr; // set for error messages. See the %initial-action section of .yy
56
57 std::istringstream iss(expr);
58 D4CEScanner scanner(iss);
59 D4CEParser parser(scanner, *this /* driver */);
60
61 if (trace_parsing()) {
62 parser.set_debug_level(1);
63 parser.set_debug_stream(std::cerr);
64 }
65
66 return parser.parse() == 0;
67}
68
69void D4ConstraintEvaluator::throw_not_found(const string &id, const string &ident)
70{
71 throw Error(no_such_variable, d_expr + ": The variable " + id + " was not found in the dataset (" + ident + ").");
72}
73
74void D4ConstraintEvaluator::throw_not_array(const string &id, const string &ident)
75{
76 throw Error(no_such_variable, d_expr + ": The variable '" + id + "' is not an Array variable (" + ident + ").");
77}
78
79void D4ConstraintEvaluator::search_for_and_mark_arrays(BaseType *btp)
80{
81 DBG(cerr << "Entering D4ConstraintEvaluator::search_for_and_mark_arrays...(" << btp->name() << ")" << endl);
82
83 assert(btp->is_constructor_type());
84
85 Constructor *ctor = static_cast<Constructor*>(btp);
86 for (Constructor::Vars_iter i = ctor->var_begin(), e = ctor->var_end(); i != e; ++i) {
87 switch ((*i)->type()) {
88 case dods_array_c:
89 DBG(cerr << "Found an array: " << (*i)->name() << endl);
90 mark_array_variable(*i);
91 break;
92 case dods_structure_c:
93 case dods_sequence_c:
94 DBG(cerr << "Found a ctor: " << (*i)->name() << endl);
95 search_for_and_mark_arrays(*i);
96 break;
97 default:
98 break;
99 }
100 }
101}
102
112BaseType *
113D4ConstraintEvaluator::mark_variable(BaseType *btp)
114{
115 assert(btp);
116
117 DBG(cerr << "In D4ConstraintEvaluator::mark_variable... (" << btp->name() << "; " << btp->type_name() << ")" << endl);
118
119 btp->set_send_p(true);
120
121 if (btp->type() == dods_array_c) {
122 mark_array_variable(btp);
123 }
124
125 // Test for Constructors and marks arrays they contain
126 if (btp->is_constructor_type()) {
127 search_for_and_mark_arrays(btp);
128 }
129 else if (btp->type() == dods_array_c && btp->var() && btp->var()->is_constructor_type()) {
130 search_for_and_mark_arrays(btp->var());
131 }
132
133 // Now set the parent variables
134 BaseType *parent = btp->get_parent();
135 while (parent) {
136 parent->BaseType::set_send_p(true); // Just set the parent using BaseType's impl.
137 parent = parent->get_parent();
138 }
139
140 return btp;
141}
142
143static bool array_uses_shared_dimension(Array *map, D4Dimension *source_dim)
144{
145 for (Array::Dim_iter d = map->dim_begin(), e = map->dim_end(); d != e; ++d) {
146 if (source_dim->name() == (*d).name) return true;
147 }
148
149 return false;
150}
151
165// Note: If a Map is not part of the current projection, do not include mention of it
166// in the response DMR (CDMR)
167BaseType *
168D4ConstraintEvaluator::mark_array_variable(BaseType *btp)
169{
170 assert(btp->type() == dods_array_c);
171
172 Array *a = static_cast<Array*>(btp);
173
174 // If an array appears in a CE without the slicing operators ([]) we still have to
175 // call add_constraint(...) for all of it's sdims for them to appear in
176 // the Constrained DMR.
177 if (d_indexes.empty()) {
178 for (Array::Dim_iter d = a->dim_begin(), de = a->dim_end(); d != de; ++d) {
179 D4Dimension *dim = a->dimension_D4dim(d);
180 if (dim) {
181 a->add_constraint(d, dim);
182 }
183 }
184 }
185 else {
186 // Test that the indexes and dimensions match in number
187 if (d_indexes.size() != a->dimensions())
188 throw Error(malformed_expr, "The index constraint for '" + btp->name() + "' does not match its rank.");
189
190 Array::Dim_iter d = a->dim_begin();
191 for (vector<index>::iterator i = d_indexes.begin(), e = d_indexes.end(); i != e; ++i) {
192 if ((*i).stride > (unsigned long long) (a->dimension_stop(d, false) - a->dimension_start(d, false)) + 1)
193 throw Error(malformed_expr,
194 "For '" + btp->name()
195 + "', the index stride value is greater than the number of elements in the Array");
196 if (!(*i).rest
197 && ((*i).stop) > (unsigned long long) (a->dimension_stop(d, false) - a->dimension_start(d, false)) + 1)
198 throw Error(malformed_expr,
199 "For '" + btp->name()
200 + "', the index stop value is greater than the number of elements in the Array");
201
202 D4Dimension *dim = a->dimension_D4dim(d);
203
204 // In a DAP4 CE, specifying '[]' as an array dimension slice has two meanings.
205 // It can mean 'all the elements' of the dimension or 'apply the slicing inherited
206 // from the shared dimension'. The latter might be provide 'all the elements'
207 // but regardless, the Array object must record the CE correctly.
208
209 if (dim && (*i).empty) {
210 // This case corresponds to a CE that uses the '[]' notation for a
211 // particular dimension - meaning, use the Shared Dimension size for
212 // this dimension's 'slice'.
213 a->add_constraint(d, dim); // calls set_used_by_projected_var(true) + more
214 }
215 else {
216 // This case corresponds to a 'local dimension slice' (See sections 8.6.2 and
217 // 8.7 of the spec as of 4/12/16). When a local dimension slice is used, drop
218 // the Map(s) that include that dimension. This enables people to constrain
219 // an Array when some of the Array's dimensions don't use Shared Dimensions
220 // but others do.
221
222 // First apply the constraint to the Array's dimension
223 a->add_constraint(d, (*i).start, (*i).stride, (*i).rest ? -1 : (*i).stop);
224
225 // Then, if the Array has Maps, scan those Maps for any that use dimensions
226 // that match the name of this particular dimension. If any such Maps are found
227 // remove them. This ensure that the Array can be constrained using the 'local
228 // dimension slice' without the constrained DMR containing references to Maps
229 // that don't exist (or are otherwise nonsensical).
230 //
231 // This code came about as a fix for problems discovered during testing of
232 // local dimension slices. See https://opendap.atlassian.net/browse/HYRAX-98
233 // jhrg 4/12/16
234 if (!a->maps()->empty()) {
235 for (D4Maps::D4MapsIter m = a->maps()->map_begin(), e = a->maps()->map_end(); m != e; ++m) {
236 if ((*m)->array() == 0)
237 throw Error(malformed_expr,
238 "An array with Maps was found, but one of the Maps was not defined correctly.");
239
240 Array *map = const_cast<Array*>((*m)->array()); // Array lacks const iterator support
241 // Added a test to ensure 'dim' is not null. This could be the case if
242 // execution gets here and the index *i was not empty. jhrg 4/18/17
243 if (dim && array_uses_shared_dimension(map, dim)) {
244 D4Map *map_to_be_removed = *m;
245 a->maps()->remove_map(map_to_be_removed); // Invalidates the iterator
246 delete map_to_be_removed; // removed from container; delete
247 break; // must leave the for loop because 'm' is now invalid
248 }
249 }
250 }
251 }
252
253 ++d;
254 }
255 }
256
257 d_indexes.clear(); // Clear the info so the next slice expression can be parsed.
258
259 return btp;
260}
261
270D4Dimension *
271D4ConstraintEvaluator::slice_dimension(const std::string &id, const index &i)
272{
273 D4Dimension *dim = dmr()->root()->find_dim(id);
274
275 if (i.stride > dim->size())
276 throw Error(malformed_expr,
277 "For '" + id + "', the index stride value is greater than the size of the dimension");
278 if (!i.rest && (i.stop > dim->size() - 1))
279 throw Error(malformed_expr, "For '" + id + "', the index stop value is greater than the size of the dimension");
280
281 dim->set_constraint(i.start, i.stride, i.rest ? dim->size() - 1 : i.stop);
282
283 return dim;
284}
285
286D4ConstraintEvaluator::index D4ConstraintEvaluator::make_index(const std::string &i)
287{
288 unsigned long long v = get_int64(i.c_str());
289 return index(v, 1, v, false, false /*empty*/, "");
290}
291
292D4ConstraintEvaluator::index D4ConstraintEvaluator::make_index(const std::string &i, const std::string &s,
293 const std::string &e)
294{
295 return index(get_int64(i.c_str()), get_int64(s.c_str()), get_int64(e.c_str()), false, false /*empty*/, "");
296}
297
298D4ConstraintEvaluator::index D4ConstraintEvaluator::make_index(const std::string &i, unsigned long long s,
299 const std::string &e)
300{
301 return index(get_int64(i.c_str()), s, get_int64(e.c_str()), false, false /*empty*/, "");
302}
303
304D4ConstraintEvaluator::index D4ConstraintEvaluator::make_index(const std::string &i, const std::string &s)
305{
306 return index(get_int64(i.c_str()), get_int64(s.c_str()), 0, true, false /*empty*/, "");
307}
308
309D4ConstraintEvaluator::index D4ConstraintEvaluator::make_index(const std::string &i, unsigned long long s)
310{
311 return index(get_uint64(i.c_str()), s, 0, true, false /*empty*/, "");
312}
313
314static string expr_msg(const std::string &op, const std::string &arg1, const std::string &arg2)
315{
316 return "(" + arg1 + " " + op + " " + arg2 + ").";
317}
318
336static D4FilterClause::ops get_op_code(const std::string &op)
337{
338 DBGN(cerr << "Entering " << __PRETTY_FUNCTION__ << endl << "op: " << op << endl);
339
340 if (op == "<")
341 return D4FilterClause::less;
342 else if (op == ">")
343 return D4FilterClause::greater;
344 else if (op == "<=")
345 return D4FilterClause::less_equal;
346 else if (op == ">=")
347 return D4FilterClause::greater_equal;
348 else if (op == "==")
349 return D4FilterClause::equal;
350 else if (op == "!=")
351 return D4FilterClause::not_equal;
352 else if (op == "~=")
353 return D4FilterClause::match;
354 else
355 throw Error(malformed_expr, "The opertator '" + op + "' is not supported.");
356}
357
379void D4ConstraintEvaluator::add_filter_clause(const std::string &op, const std::string &arg1, const std::string &arg2)
380{
381 DBG(cerr << "Entering: " << __PRETTY_FUNCTION__ << endl);
382
383 // Check that there really is a D4Sequence associated with this filter clause.
384 D4Sequence *s = dynamic_cast<D4Sequence*>(top_basetype());
385 if (!s)
386 throw Error(malformed_expr,
387 "When a filter expression is used, it must be bound to a Sequence variable: " + expr_msg(op, arg1, arg2));
388
389 DBG(cerr << "s->name(): " << s->name() << endl);
390
391 // Check that arg1 and 2 are valid
392 BaseType *a1 = s->var(arg1);
393 BaseType *a2 = s->var(arg2);
394 DBG(cerr << "a1: " << a1 << ", a2: " << a2 << endl);
395
396 if (a1 && a2)
397 throw Error(malformed_expr,
398 "One of the arguments in a filter expression must be a constant: " + expr_msg(op, arg1, arg2));
399 if (!(a1 || a2))
400 throw Error(malformed_expr,
401 "One of the arguments in a filter expression must be a variable in a Sequence: "
402 + expr_msg(op, arg1, arg2));
403
404 // Now we know a1 XOR a2 is true
405 if (a1) {
406 s->clauses().add_clause(new D4FilterClause(get_op_code(op), new D4RValue(a1), D4RValueFactory(arg2)));
407 }
408 else {
409 s->clauses().add_clause(new D4FilterClause(get_op_code(op), D4RValueFactory(arg1), new D4RValue(a2)));
410 }
411}
412
419string &
420D4ConstraintEvaluator::remove_quotes(string &s)
421{
422 if (*s.begin() == '\"' && *(s.end() - 1) == '\"') {
423 s.erase(s.begin());
424 s.erase(s.end() - 1);
425 }
426
427 return s;
428}
429
430// This method is called from the parser (see d4_ce_parser.yy, down in the code
431// section). This will be called during the call to D4CEParser::parse(), that
432// is inside D4ConstraintEvaluator::parse(...)
433void D4ConstraintEvaluator::error(const libdap::location &l, const std::string &m)
434{
435 ostringstream oss;
436 oss << l << ": " << m << ends;
437 throw Error(malformed_expr, oss.str());
438}
439
440} /* namespace libdap */
std::vector< dimension >::iterator Dim_iter
Definition: Array.h:206
D4Dimension * find_dim(const string &path)
Find the dimension using a path. Using the DAP4 name syntax, lookup a dimension. The dimension must b...
Definition: D4Group.cc:277
D4Group * root()
Definition: DMR.cc:407
top level DAP object to house generic methods
Definition: AlarmHandler.h:36
D4RValue * D4RValueFactory(std::string cpps)
Build an appropriate RValue.
Definition: D4RValue.cc:218