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30 // Author: wan@google.com (Zhanyong Wan)
32 // Google Mock - a framework for writing C++ mock classes.
34 // This file implements Matcher<const string&>, Matcher<string>, and
35 // utilities for defining matchers.
37 #include "gmock/gmock-matchers.h"
38 #include "gmock/gmock-generated-matchers.h"
46 // Constructs a matcher that matches a const string& whose value is
48 Matcher
<const internal::string
&>::Matcher(const internal::string
& s
) {
52 // Constructs a matcher that matches a const string& whose value is
54 Matcher
<const internal::string
&>::Matcher(const char* s
) {
55 *this = Eq(internal::string(s
));
58 // Constructs a matcher that matches a string whose value is equal to s.
59 Matcher
<internal::string
>::Matcher(const internal::string
& s
) { *this = Eq(s
); }
61 // Constructs a matcher that matches a string whose value is equal to s.
62 Matcher
<internal::string
>::Matcher(const char* s
) {
63 *this = Eq(internal::string(s
));
66 #if GTEST_HAS_STRING_PIECE_
67 // Constructs a matcher that matches a const StringPiece& whose value is
69 Matcher
<const StringPiece
&>::Matcher(const internal::string
& s
) {
73 // Constructs a matcher that matches a const StringPiece& whose value is
75 Matcher
<const StringPiece
&>::Matcher(const char* s
) {
76 *this = Eq(internal::string(s
));
79 // Constructs a matcher that matches a const StringPiece& whose value is
81 Matcher
<const StringPiece
&>::Matcher(StringPiece s
) {
82 *this = Eq(s
.ToString());
85 // Constructs a matcher that matches a StringPiece whose value is equal to s.
86 Matcher
<StringPiece
>::Matcher(const internal::string
& s
) {
90 // Constructs a matcher that matches a StringPiece whose value is equal to s.
91 Matcher
<StringPiece
>::Matcher(const char* s
) {
92 *this = Eq(internal::string(s
));
95 // Constructs a matcher that matches a StringPiece whose value is equal to s.
96 Matcher
<StringPiece
>::Matcher(StringPiece s
) {
97 *this = Eq(s
.ToString());
99 #endif // GTEST_HAS_STRING_PIECE_
103 // Joins a vector of strings as if they are fields of a tuple; returns
104 // the joined string.
105 GTEST_API_ string
JoinAsTuple(const Strings
& fields
) {
106 switch (fields
.size()) {
112 string result
= "(" + fields
[0];
113 for (size_t i
= 1; i
< fields
.size(); i
++) {
122 // Returns the description for a matcher defined using the MATCHER*()
123 // macro where the user-supplied description string is "", if
124 // 'negation' is false; otherwise returns the description of the
125 // negation of the matcher. 'param_values' contains a list of strings
126 // that are the print-out of the matcher's parameters.
127 GTEST_API_ string
FormatMatcherDescription(bool negation
,
128 const char* matcher_name
,
129 const Strings
& param_values
) {
130 string result
= ConvertIdentifierNameToWords(matcher_name
);
131 if (param_values
.size() >= 1)
132 result
+= " " + JoinAsTuple(param_values
);
133 return negation
? "not (" + result
+ ")" : result
;
136 // FindMaxBipartiteMatching and its helper class.
138 // Uses the well-known Ford-Fulkerson max flow method to find a maximum
139 // bipartite matching. Flow is considered to be from left to right.
140 // There is an implicit source node that is connected to all of the left
141 // nodes, and an implicit sink node that is connected to all of the
142 // right nodes. All edges have unit capacity.
144 // Neither the flow graph nor the residual flow graph are represented
145 // explicitly. Instead, they are implied by the information in 'graph' and
146 // a vector<int> called 'left_' whose elements are initialized to the
147 // value kUnused. This represents the initial state of the algorithm,
148 // where the flow graph is empty, and the residual flow graph has the
150 // - An edge from source to each left_ node
151 // - An edge from each right_ node to sink
152 // - An edge from each left_ node to each right_ node, if the
153 // corresponding edge exists in 'graph'.
155 // When the TryAugment() method adds a flow, it sets left_[l] = r for some
156 // nodes l and r. This induces the following changes:
157 // - The edges (source, l), (l, r), and (r, sink) are added to the
159 // - The same three edges are removed from the residual flow graph.
160 // - The reverse edges (l, source), (r, l), and (sink, r) are added
161 // to the residual flow graph, which is a directional graph
162 // representing unused flow capacity.
164 // When the method augments a flow (moving left_[l] from some r1 to some
165 // other r2), this can be thought of as "undoing" the above steps with
166 // respect to r1 and "redoing" them with respect to r2.
168 // It bears repeating that the flow graph and residual flow graph are
169 // never represented explicitly, but can be derived by looking at the
170 // information in 'graph' and in left_.
172 // As an optimization, there is a second vector<int> called right_ which
173 // does not provide any new information. Instead, it enables more
174 // efficient queries about edges entering or leaving the right-side nodes
175 // of the flow or residual flow graphs. The following invariants are
178 // left[l] == kUnused or right[left[l]] == l
179 // right[r] == kUnused or left[right[r]] == r
184 // . ||\--> left[0]=1 ---\ right[0]=-1 ----\ .
186 // . |\---> left[1]=-1 \--> right[1]=0 ---\| .
188 // . \----> left[2]=2 ------> right[2]=2 --\|| .
190 // . elements matchers vvv .
194 // [1] Cormen, et al (2001). "Section 26.2: The Ford-Fulkerson method".
195 // "Introduction to Algorithms (Second ed.)", pp. 651-664.
196 // [2] "Ford-Fulkerson algorithm", Wikipedia,
197 // 'http://en.wikipedia.org/wiki/Ford%E2%80%93Fulkerson_algorithm'
198 class MaxBipartiteMatchState
{
200 explicit MaxBipartiteMatchState(const MatchMatrix
& graph
)
202 left_(graph_
->LhsSize(), kUnused
),
203 right_(graph_
->RhsSize(), kUnused
) {
206 // Returns the edges of a maximal match, each in the form {left, right}.
207 ElementMatcherPairs
Compute() {
208 // 'seen' is used for path finding { 0: unseen, 1: seen }.
209 ::std::vector
<char> seen
;
210 // Searches the residual flow graph for a path from each left node to
211 // the sink in the residual flow graph, and if one is found, add flow
212 // to the graph. It's okay to search through the left nodes once. The
213 // edge from the implicit source node to each previously-visited left
214 // node will have flow if that left node has any path to the sink
215 // whatsoever. Subsequent augmentations can only add flow to the
216 // network, and cannot take away that previous flow unit from the source.
217 // Since the source-to-left edge can only carry one flow unit (or,
218 // each element can be matched to only one matcher), there is no need
219 // to visit the left nodes more than once looking for augmented paths.
220 // The flow is known to be possible or impossible by looking at the
222 for (size_t ilhs
= 0; ilhs
< graph_
->LhsSize(); ++ilhs
) {
223 // Reset the path-marking vector and try to find a path from
224 // source to sink starting at the left_[ilhs] node.
225 GTEST_CHECK_(left_
[ilhs
] == kUnused
)
226 << "ilhs: " << ilhs
<< ", left_[ilhs]: " << left_
[ilhs
];
227 // 'seen' initialized to 'graph_->RhsSize()' copies of 0.
228 seen
.assign(graph_
->RhsSize(), 0);
229 TryAugment(ilhs
, &seen
);
231 ElementMatcherPairs result
;
232 for (size_t ilhs
= 0; ilhs
< left_
.size(); ++ilhs
) {
233 size_t irhs
= left_
[ilhs
];
234 if (irhs
== kUnused
) continue;
235 result
.push_back(ElementMatcherPair(ilhs
, irhs
));
241 static const size_t kUnused
= static_cast<size_t>(-1);
243 // Perform a depth-first search from left node ilhs to the sink. If a
244 // path is found, flow is added to the network by linking the left and
245 // right vector elements corresponding each segment of the path.
246 // Returns true if a path to sink was found, which means that a unit of
247 // flow was added to the network. The 'seen' vector elements correspond
248 // to right nodes and are marked to eliminate cycles from the search.
250 // Left nodes will only be explored at most once because they
251 // are accessible from at most one right node in the residual flow
254 // Note that left_[ilhs] is the only element of left_ that TryAugment will
255 // potentially transition from kUnused to another value. Any other
256 // left_ element holding kUnused before TryAugment will be holding it
257 // when TryAugment returns.
259 bool TryAugment(size_t ilhs
, ::std::vector
<char>* seen
) {
260 for (size_t irhs
= 0; irhs
< graph_
->RhsSize(); ++irhs
) {
263 if (!graph_
->HasEdge(ilhs
, irhs
))
265 // There's an available edge from ilhs to irhs.
267 // Next a search is performed to determine whether
268 // this edge is a dead end or leads to the sink.
270 // right_[irhs] == kUnused means that there is residual flow from
271 // right node irhs to the sink, so we can use that to finish this
272 // flow path and return success.
274 // Otherwise there is residual flow to some ilhs. We push flow
275 // along that path and call ourselves recursively to see if this
276 // ultimately leads to sink.
277 if (right_
[irhs
] == kUnused
|| TryAugment(right_
[irhs
], seen
)) {
278 // Add flow from left_[ilhs] to right_[irhs].
287 const MatchMatrix
* graph_
; // not owned
288 // Each element of the left_ vector represents a left hand side node
289 // (i.e. an element) and each element of right_ is a right hand side
290 // node (i.e. a matcher). The values in the left_ vector indicate
291 // outflow from that node to a node on the the right_ side. The values
292 // in the right_ indicate inflow, and specify which left_ node is
293 // feeding that right_ node, if any. For example, left_[3] == 1 means
294 // there's a flow from element #3 to matcher #1. Such a flow would also
295 // be redundantly represented in the right_ vector as right_[1] == 3.
296 // Elements of left_ and right_ are either kUnused or mutually
297 // referent. Mutually referent means that left_[right_[i]] = i and
298 // right_[left_[i]] = i.
299 ::std::vector
<size_t> left_
;
300 ::std::vector
<size_t> right_
;
302 GTEST_DISALLOW_ASSIGN_(MaxBipartiteMatchState
);
305 const size_t MaxBipartiteMatchState::kUnused
;
307 GTEST_API_ ElementMatcherPairs
308 FindMaxBipartiteMatching(const MatchMatrix
& g
) {
309 return MaxBipartiteMatchState(g
).Compute();
312 static void LogElementMatcherPairVec(const ElementMatcherPairs
& pairs
,
313 ::std::ostream
* stream
) {
314 typedef ElementMatcherPairs::const_iterator Iter
;
315 ::std::ostream
& os
= *stream
;
317 const char *sep
= "";
318 for (Iter it
= pairs
.begin(); it
!= pairs
.end(); ++it
) {
320 << "element #" << it
->first
<< ", "
321 << "matcher #" << it
->second
<< ")";
327 // Tries to find a pairing, and explains the result.
328 GTEST_API_
bool FindPairing(const MatchMatrix
& matrix
,
329 MatchResultListener
* listener
) {
330 ElementMatcherPairs matches
= FindMaxBipartiteMatching(matrix
);
332 size_t max_flow
= matches
.size();
333 bool result
= (max_flow
== matrix
.RhsSize());
336 if (listener
->IsInterested()) {
337 *listener
<< "where no permutation of the elements can "
338 "satisfy all matchers, and the closest match is "
339 << max_flow
<< " of " << matrix
.RhsSize()
340 << " matchers with the pairings:\n";
341 LogElementMatcherPairVec(matches
, listener
->stream());
346 if (matches
.size() > 1) {
347 if (listener
->IsInterested()) {
348 const char *sep
= "where:\n";
349 for (size_t mi
= 0; mi
< matches
.size(); ++mi
) {
350 *listener
<< sep
<< " - element #" << matches
[mi
].first
351 << " is matched by matcher #" << matches
[mi
].second
;
359 bool MatchMatrix::NextGraph() {
360 for (size_t ilhs
= 0; ilhs
< LhsSize(); ++ilhs
) {
361 for (size_t irhs
= 0; irhs
< RhsSize(); ++irhs
) {
362 char& b
= matched_
[SpaceIndex(ilhs
, irhs
)];
373 void MatchMatrix::Randomize() {
374 for (size_t ilhs
= 0; ilhs
< LhsSize(); ++ilhs
) {
375 for (size_t irhs
= 0; irhs
< RhsSize(); ++irhs
) {
376 char& b
= matched_
[SpaceIndex(ilhs
, irhs
)];
377 b
= static_cast<char>(rand() & 1); // NOLINT
382 string
MatchMatrix::DebugString() const {
383 ::std::stringstream ss
;
384 const char *sep
= "";
385 for (size_t i
= 0; i
< LhsSize(); ++i
) {
387 for (size_t j
= 0; j
< RhsSize(); ++j
) {
395 void UnorderedElementsAreMatcherImplBase::DescribeToImpl(
396 ::std::ostream
* os
) const {
397 if (matcher_describers_
.empty()) {
401 if (matcher_describers_
.size() == 1) {
402 *os
<< "has " << Elements(1) << " and that element ";
403 matcher_describers_
[0]->DescribeTo(os
);
406 *os
<< "has " << Elements(matcher_describers_
.size())
407 << " and there exists some permutation of elements such that:\n";
408 const char* sep
= "";
409 for (size_t i
= 0; i
!= matcher_describers_
.size(); ++i
) {
410 *os
<< sep
<< " - element #" << i
<< " ";
411 matcher_describers_
[i
]->DescribeTo(os
);
416 void UnorderedElementsAreMatcherImplBase::DescribeNegationToImpl(
417 ::std::ostream
* os
) const {
418 if (matcher_describers_
.empty()) {
419 *os
<< "isn't empty";
422 if (matcher_describers_
.size() == 1) {
423 *os
<< "doesn't have " << Elements(1)
424 << ", or has " << Elements(1) << " that ";
425 matcher_describers_
[0]->DescribeNegationTo(os
);
428 *os
<< "doesn't have " << Elements(matcher_describers_
.size())
429 << ", or there exists no permutation of elements such that:\n";
430 const char* sep
= "";
431 for (size_t i
= 0; i
!= matcher_describers_
.size(); ++i
) {
432 *os
<< sep
<< " - element #" << i
<< " ";
433 matcher_describers_
[i
]->DescribeTo(os
);
438 // Checks that all matchers match at least one element, and that all
439 // elements match at least one matcher. This enables faster matching
440 // and better error reporting.
441 // Returns false, writing an explanation to 'listener', if and only
442 // if the success criteria are not met.
443 bool UnorderedElementsAreMatcherImplBase::
444 VerifyAllElementsAndMatchersAreMatched(
445 const ::std::vector
<string
>& element_printouts
,
446 const MatchMatrix
& matrix
,
447 MatchResultListener
* listener
) const {
449 ::std::vector
<char> element_matched(matrix
.LhsSize(), 0);
450 ::std::vector
<char> matcher_matched(matrix
.RhsSize(), 0);
452 for (size_t ilhs
= 0; ilhs
< matrix
.LhsSize(); ilhs
++) {
453 for (size_t irhs
= 0; irhs
< matrix
.RhsSize(); irhs
++) {
454 char matched
= matrix
.HasEdge(ilhs
, irhs
);
455 element_matched
[ilhs
] |= matched
;
456 matcher_matched
[irhs
] |= matched
;
462 "where the following matchers don't match any elements:\n";
463 for (size_t mi
= 0; mi
< matcher_matched
.size(); ++mi
) {
464 if (matcher_matched
[mi
])
467 if (listener
->IsInterested()) {
468 *listener
<< sep
<< "matcher #" << mi
<< ": ";
469 matcher_describers_
[mi
]->DescribeTo(listener
->stream());
477 "where the following elements don't match any matchers:\n";
478 const char* outer_sep
= "";
480 outer_sep
= "\nand ";
482 for (size_t ei
= 0; ei
< element_matched
.size(); ++ei
) {
483 if (element_matched
[ei
])
486 if (listener
->IsInterested()) {
487 *listener
<< outer_sep
<< sep
<< "element #" << ei
<< ": "
488 << element_printouts
[ei
];
497 } // namespace internal
498 } // namespace testing