*this = Eq(internal::string(s));
}
+#if GTEST_HAS_STRING_PIECE_
+// Constructs a matcher that matches a const StringPiece& whose value is
+// equal to s.
+Matcher<const StringPiece&>::Matcher(const internal::string& s) {
+ *this = Eq(s);
+}
+
+// Constructs a matcher that matches a const StringPiece& whose value is
+// equal to s.
+Matcher<const StringPiece&>::Matcher(const char* s) {
+ *this = Eq(internal::string(s));
+}
+
+// Constructs a matcher that matches a const StringPiece& whose value is
+// equal to s.
+Matcher<const StringPiece&>::Matcher(StringPiece s) {
+ *this = Eq(s.ToString());
+}
+
+// Constructs a matcher that matches a StringPiece whose value is equal to s.
+Matcher<StringPiece>::Matcher(const internal::string& s) {
+ *this = Eq(s);
+}
+
+// Constructs a matcher that matches a StringPiece whose value is equal to s.
+Matcher<StringPiece>::Matcher(const char* s) {
+ *this = Eq(internal::string(s));
+}
+
+// Constructs a matcher that matches a StringPiece whose value is equal to s.
+Matcher<StringPiece>::Matcher(StringPiece s) {
+ *this = Eq(s.ToString());
+}
+#endif // GTEST_HAS_STRING_PIECE_
+
namespace internal {
// Joins a vector of strings as if they are fields of a tuple; returns
return negation ? "not (" + result + ")" : result;
}
+// FindMaxBipartiteMatching and its helper class.
+//
+// Uses the well-known Ford-Fulkerson max flow method to find a maximum
+// bipartite matching. Flow is considered to be from left to right.
+// There is an implicit source node that is connected to all of the left
+// nodes, and an implicit sink node that is connected to all of the
+// right nodes. All edges have unit capacity.
+//
+// Neither the flow graph nor the residual flow graph are represented
+// explicitly. Instead, they are implied by the information in 'graph' and
+// a vector<int> called 'left_' whose elements are initialized to the
+// value kUnused. This represents the initial state of the algorithm,
+// where the flow graph is empty, and the residual flow graph has the
+// following edges:
+// - An edge from source to each left_ node
+// - An edge from each right_ node to sink
+// - An edge from each left_ node to each right_ node, if the
+// corresponding edge exists in 'graph'.
+//
+// When the TryAugment() method adds a flow, it sets left_[l] = r for some
+// nodes l and r. This induces the following changes:
+// - The edges (source, l), (l, r), and (r, sink) are added to the
+// flow graph.
+// - The same three edges are removed from the residual flow graph.
+// - The reverse edges (l, source), (r, l), and (sink, r) are added
+// to the residual flow graph, which is a directional graph
+// representing unused flow capacity.
+//
+// When the method augments a flow (moving left_[l] from some r1 to some
+// other r2), this can be thought of as "undoing" the above steps with
+// respect to r1 and "redoing" them with respect to r2.
+//
+// It bears repeating that the flow graph and residual flow graph are
+// never represented explicitly, but can be derived by looking at the
+// information in 'graph' and in left_.
+//
+// As an optimization, there is a second vector<int> called right_ which
+// does not provide any new information. Instead, it enables more
+// efficient queries about edges entering or leaving the right-side nodes
+// of the flow or residual flow graphs. The following invariants are
+// maintained:
+//
+// left[l] == kUnused or right[left[l]] == l
+// right[r] == kUnused or left[right[r]] == r
+//
+// . [ source ] .
+// . ||| .
+// . ||| .
+// . ||\--> left[0]=1 ---\ right[0]=-1 ----\ .
+// . || | | .
+// . |\---> left[1]=-1 \--> right[1]=0 ---\| .
+// . | || .
+// . \----> left[2]=2 ------> right[2]=2 --\|| .
+// . ||| .
+// . elements matchers vvv .
+// . [ sink ] .
+//
+// See Also:
+// [1] Cormen, et al (2001). "Section 26.2: The Ford-Fulkerson method".
+// "Introduction to Algorithms (Second ed.)", pp. 651-664.
+// [2] "Ford-Fulkerson algorithm", Wikipedia,
+// 'http://en.wikipedia.org/wiki/Ford%E2%80%93Fulkerson_algorithm'
+class MaxBipartiteMatchState {
+ public:
+ explicit MaxBipartiteMatchState(const MatchMatrix& graph)
+ : graph_(&graph),
+ left_(graph_->LhsSize(), kUnused),
+ right_(graph_->RhsSize(), kUnused) {
+ }
+
+ // Returns the edges of a maximal match, each in the form {left, right}.
+ ElementMatcherPairs Compute() {
+ // 'seen' is used for path finding { 0: unseen, 1: seen }.
+ ::std::vector<char> seen;
+ // Searches the residual flow graph for a path from each left node to
+ // the sink in the residual flow graph, and if one is found, add flow
+ // to the graph. It's okay to search through the left nodes once. The
+ // edge from the implicit source node to each previously-visited left
+ // node will have flow if that left node has any path to the sink
+ // whatsoever. Subsequent augmentations can only add flow to the
+ // network, and cannot take away that previous flow unit from the source.
+ // Since the source-to-left edge can only carry one flow unit (or,
+ // each element can be matched to only one matcher), there is no need
+ // to visit the left nodes more than once looking for augmented paths.
+ // The flow is known to be possible or impossible by looking at the
+ // node once.
+ for (size_t ilhs = 0; ilhs < graph_->LhsSize(); ++ilhs) {
+ // Reset the path-marking vector and try to find a path from
+ // source to sink starting at the left_[ilhs] node.
+ GTEST_CHECK_(left_[ilhs] == kUnused)
+ << "ilhs: " << ilhs << ", left_[ilhs]: " << left_[ilhs];
+ // 'seen' initialized to 'graph_->RhsSize()' copies of 0.
+ seen.assign(graph_->RhsSize(), 0);
+ TryAugment(ilhs, &seen);
+ }
+ ElementMatcherPairs result;
+ for (size_t ilhs = 0; ilhs < left_.size(); ++ilhs) {
+ size_t irhs = left_[ilhs];
+ if (irhs == kUnused) continue;
+ result.push_back(ElementMatcherPair(ilhs, irhs));
+ }
+ return result;
+ }
+
+ private:
+ static const size_t kUnused = static_cast<size_t>(-1);
+
+ // Perform a depth-first search from left node ilhs to the sink. If a
+ // path is found, flow is added to the network by linking the left and
+ // right vector elements corresponding each segment of the path.
+ // Returns true if a path to sink was found, which means that a unit of
+ // flow was added to the network. The 'seen' vector elements correspond
+ // to right nodes and are marked to eliminate cycles from the search.
+ //
+ // Left nodes will only be explored at most once because they
+ // are accessible from at most one right node in the residual flow
+ // graph.
+ //
+ // Note that left_[ilhs] is the only element of left_ that TryAugment will
+ // potentially transition from kUnused to another value. Any other
+ // left_ element holding kUnused before TryAugment will be holding it
+ // when TryAugment returns.
+ //
+ bool TryAugment(size_t ilhs, ::std::vector<char>* seen) {
+ for (size_t irhs = 0; irhs < graph_->RhsSize(); ++irhs) {
+ if ((*seen)[irhs])
+ continue;
+ if (!graph_->HasEdge(ilhs, irhs))
+ continue;
+ // There's an available edge from ilhs to irhs.
+ (*seen)[irhs] = 1;
+ // Next a search is performed to determine whether
+ // this edge is a dead end or leads to the sink.
+ //
+ // right_[irhs] == kUnused means that there is residual flow from
+ // right node irhs to the sink, so we can use that to finish this
+ // flow path and return success.
+ //
+ // Otherwise there is residual flow to some ilhs. We push flow
+ // along that path and call ourselves recursively to see if this
+ // ultimately leads to sink.
+ if (right_[irhs] == kUnused || TryAugment(right_[irhs], seen)) {
+ // Add flow from left_[ilhs] to right_[irhs].
+ left_[ilhs] = irhs;
+ right_[irhs] = ilhs;
+ return true;
+ }
+ }
+ return false;
+ }
+
+ const MatchMatrix* graph_; // not owned
+ // Each element of the left_ vector represents a left hand side node
+ // (i.e. an element) and each element of right_ is a right hand side
+ // node (i.e. a matcher). The values in the left_ vector indicate
+ // outflow from that node to a node on the the right_ side. The values
+ // in the right_ indicate inflow, and specify which left_ node is
+ // feeding that right_ node, if any. For example, left_[3] == 1 means
+ // there's a flow from element #3 to matcher #1. Such a flow would also
+ // be redundantly represented in the right_ vector as right_[1] == 3.
+ // Elements of left_ and right_ are either kUnused or mutually
+ // referent. Mutually referent means that left_[right_[i]] = i and
+ // right_[left_[i]] = i.
+ ::std::vector<size_t> left_;
+ ::std::vector<size_t> right_;
+
+ GTEST_DISALLOW_ASSIGN_(MaxBipartiteMatchState);
+};
+
+const size_t MaxBipartiteMatchState::kUnused;
+
+GTEST_API_ ElementMatcherPairs
+FindMaxBipartiteMatching(const MatchMatrix& g) {
+ return MaxBipartiteMatchState(g).Compute();
+}
+
+static void LogElementMatcherPairVec(const ElementMatcherPairs& pairs,
+ ::std::ostream* stream) {
+ typedef ElementMatcherPairs::const_iterator Iter;
+ ::std::ostream& os = *stream;
+ os << "{";
+ const char *sep = "";
+ for (Iter it = pairs.begin(); it != pairs.end(); ++it) {
+ os << sep << "\n ("
+ << "element #" << it->first << ", "
+ << "matcher #" << it->second << ")";
+ sep = ",";
+ }
+ os << "\n}";
+}
+
+// Tries to find a pairing, and explains the result.
+GTEST_API_ bool FindPairing(const MatchMatrix& matrix,
+ MatchResultListener* listener) {
+ ElementMatcherPairs matches = FindMaxBipartiteMatching(matrix);
+
+ size_t max_flow = matches.size();
+ bool result = (max_flow == matrix.RhsSize());
+
+ if (!result) {
+ if (listener->IsInterested()) {
+ *listener << "where no permutation of the elements can "
+ "satisfy all matchers, and the closest match is "
+ << max_flow << " of " << matrix.RhsSize()
+ << " matchers with the pairings:\n";
+ LogElementMatcherPairVec(matches, listener->stream());
+ }
+ return false;
+ }
+
+ if (matches.size() > 1) {
+ if (listener->IsInterested()) {
+ const char *sep = "where:\n";
+ for (size_t mi = 0; mi < matches.size(); ++mi) {
+ *listener << sep << " - element #" << matches[mi].first
+ << " is matched by matcher #" << matches[mi].second;
+ sep = ",\n";
+ }
+ }
+ }
+ return true;
+}
+
+bool MatchMatrix::NextGraph() {
+ for (size_t ilhs = 0; ilhs < LhsSize(); ++ilhs) {
+ for (size_t irhs = 0; irhs < RhsSize(); ++irhs) {
+ char& b = matched_[SpaceIndex(ilhs, irhs)];
+ if (!b) {
+ b = 1;
+ return true;
+ }
+ b = 0;
+ }
+ }
+ return false;
+}
+
+void MatchMatrix::Randomize() {
+ for (size_t ilhs = 0; ilhs < LhsSize(); ++ilhs) {
+ for (size_t irhs = 0; irhs < RhsSize(); ++irhs) {
+ char& b = matched_[SpaceIndex(ilhs, irhs)];
+ b = static_cast<char>(rand() & 1); // NOLINT
+ }
+ }
+}
+
+string MatchMatrix::DebugString() const {
+ ::std::stringstream ss;
+ const char *sep = "";
+ for (size_t i = 0; i < LhsSize(); ++i) {
+ ss << sep;
+ for (size_t j = 0; j < RhsSize(); ++j) {
+ ss << HasEdge(i, j);
+ }
+ sep = ";";
+ }
+ return ss.str();
+}
+
+void UnorderedElementsAreMatcherImplBase::DescribeToImpl(
+ ::std::ostream* os) const {
+ if (matcher_describers_.empty()) {
+ *os << "is empty";
+ return;
+ }
+ if (matcher_describers_.size() == 1) {
+ *os << "has " << Elements(1) << " and that element ";
+ matcher_describers_[0]->DescribeTo(os);
+ return;
+ }
+ *os << "has " << Elements(matcher_describers_.size())
+ << " and there exists some permutation of elements such that:\n";
+ const char* sep = "";
+ for (size_t i = 0; i != matcher_describers_.size(); ++i) {
+ *os << sep << " - element #" << i << " ";
+ matcher_describers_[i]->DescribeTo(os);
+ sep = ", and\n";
+ }
+}
+
+void UnorderedElementsAreMatcherImplBase::DescribeNegationToImpl(
+ ::std::ostream* os) const {
+ if (matcher_describers_.empty()) {
+ *os << "isn't empty";
+ return;
+ }
+ if (matcher_describers_.size() == 1) {
+ *os << "doesn't have " << Elements(1)
+ << ", or has " << Elements(1) << " that ";
+ matcher_describers_[0]->DescribeNegationTo(os);
+ return;
+ }
+ *os << "doesn't have " << Elements(matcher_describers_.size())
+ << ", or there exists no permutation of elements such that:\n";
+ const char* sep = "";
+ for (size_t i = 0; i != matcher_describers_.size(); ++i) {
+ *os << sep << " - element #" << i << " ";
+ matcher_describers_[i]->DescribeTo(os);
+ sep = ", and\n";
+ }
+}
+
+// Checks that all matchers match at least one element, and that all
+// elements match at least one matcher. This enables faster matching
+// and better error reporting.
+// Returns false, writing an explanation to 'listener', if and only
+// if the success criteria are not met.
+bool UnorderedElementsAreMatcherImplBase::
+VerifyAllElementsAndMatchersAreMatched(
+ const ::std::vector<string>& element_printouts,
+ const MatchMatrix& matrix,
+ MatchResultListener* listener) const {
+ bool result = true;
+ ::std::vector<char> element_matched(matrix.LhsSize(), 0);
+ ::std::vector<char> matcher_matched(matrix.RhsSize(), 0);
+
+ for (size_t ilhs = 0; ilhs < matrix.LhsSize(); ilhs++) {
+ for (size_t irhs = 0; irhs < matrix.RhsSize(); irhs++) {
+ char matched = matrix.HasEdge(ilhs, irhs);
+ element_matched[ilhs] |= matched;
+ matcher_matched[irhs] |= matched;
+ }
+ }
+
+ {
+ const char* sep =
+ "where the following matchers don't match any elements:\n";
+ for (size_t mi = 0; mi < matcher_matched.size(); ++mi) {
+ if (matcher_matched[mi])
+ continue;
+ result = false;
+ if (listener->IsInterested()) {
+ *listener << sep << "matcher #" << mi << ": ";
+ matcher_describers_[mi]->DescribeTo(listener->stream());
+ sep = ",\n";
+ }
+ }
+ }
+
+ {
+ const char* sep =
+ "where the following elements don't match any matchers:\n";
+ const char* outer_sep = "";
+ if (!result) {
+ outer_sep = "\nand ";
+ }
+ for (size_t ei = 0; ei < element_matched.size(); ++ei) {
+ if (element_matched[ei])
+ continue;
+ result = false;
+ if (listener->IsInterested()) {
+ *listener << outer_sep << sep << "element #" << ei << ": "
+ << element_printouts[ei];
+ sep = ",\n";
+ outer_sep = "";
+ }
+ }
+ }
+ return result;
+}
+
} // namespace internal
} // namespace testing
projects / platform / framework / web / crosswalk.git / blobdiff