Find path validator. (vesoft-inc#245)

* Add find path validator.

* Implement validate.

* Remove useless vlog.

* Add test.

* Refactor.

* Address comment.

* Rebase and address comment.

* Rebase.

Co-authored-by: dutor <[email protected]>

src/parser/parser.yy

@@ -1133,9 +1133,9 @@ find_path_sentence
     ;
 
 find_path_upto_clause
-    : %empty { $$ = new StepClause(5, true); }
+    : %empty { $$ = new StepClause(5); }
     | KW_UPTO legal_integer KW_STEPS {
-        $$ = new StepClause($2, true);
+        $$ = new StepClause($2);
     }
     ;
 

src/validator/CMakeLists.txt

@@ -28,6 +28,7 @@ nebula_add_library(
     TraversalValidator.cpp
     ExplainValidator.cpp
     GroupByValidator.cpp
+    FindPathValidator.cpp
 )
 
 nebula_add_subdirectory(test)

src/validator/FindPathValidator.cpp

@@ -0,0 +1,31 @@
+/* Copyright (c) 2020 vesoft inc. All rights reserved.
+ *
+ * This source code is licensed under Apache 2.0 License,
+ * attached with Common Clause Condition 1.0, found in the LICENSES directory.
+ */
+
+#include "validator/FindPathValidator.h"
+#include "planner/Logic.h"
+
+namespace nebula {
+namespace graph {
+Status FindPathValidator::validateImpl() {
+    auto fpSentence = static_cast<FindPathSentence*>(sentence_);
+    isShortest_ = fpSentence->isShortest();
+
+    NG_RETURN_IF_ERROR(validateStarts(fpSentence->from(), from_));
+    NG_RETURN_IF_ERROR(validateStarts(fpSentence->to(), to_));
+    NG_RETURN_IF_ERROR(validateOver(fpSentence->over(), over_));
+    NG_RETURN_IF_ERROR(validateStep(fpSentence->step(), steps_));
+    return Status::OK();
+}
+
+Status FindPathValidator::toPlan() {
+    // TODO: Implement the path plan.
+    auto* passThrough = PassThroughNode::make(qctx_, nullptr);
+    tail_ = passThrough;
+    root_ = tail_;
+    return Status::OK();
+}
+}  // namespace graph
+}  // namespace nebula

src/validator/FindPathValidator.h

@@ -0,0 +1,36 @@
+/* Copyright (c) 2020 vesoft inc. All rights reserved.
+ *
+ * This source code is licensed under Apache 2.0 License,
+ * attached with Common Clause Condition 1.0, found in the LICENSES directory.
+ */
+
+#ifndef VALIDATOR_FINDPATHVALIDATOR_H_
+#define VALIDATOR_FINDPATHVALIDATOR_H_
+
+#include "common/base/Base.h"
+#include "validator/TraversalValidator.h"
+
+namespace nebula {
+namespace graph {
+
+
+class FindPathValidator final : public TraversalValidator {
+public:
+    FindPathValidator(Sentence* sentence, QueryContext* context)
+        : TraversalValidator(sentence, context) {}
+
+private:
+    Status validateImpl() override;
+
+    Status toPlan() override;
+
+private:
+    bool            isShortest_{false};
+    Starts          from_;
+    Starts          to_;
+    Over            over_;
+    Steps           steps_;
+};
+}  // namespace graph
+}  // namespace nebula
+#endif

src/validator/GetSubgraphValidator.cpp

@@ -22,12 +22,12 @@ Status GetSubgraphValidator::validateImpl() {
     Status status;
     auto* gsSentence = static_cast<GetSubgraphSentence*>(sentence_);
     do {
-        status = validateStep(gsSentence->step());
+        status = validateStep(gsSentence->step(), steps_);
         if (!status.ok()) {
             break;
         }
 
-        status = validateFrom(gsSentence->from());
+        status = validateStarts(gsSentence->from(), from_);
         if (!status.ok()) {
             return status;
         }
@@ -136,7 +136,7 @@ Status GetSubgraphValidator::toPlan() {
 
     std::string startVidsVar;
     PlanNode* projectStartVid = nullptr;
-    if (!starts_.empty() && srcRef_ == nullptr) {
+    if (!from_.vids.empty() && from_.srcRef == nullptr) {
         startVidsVar = buildConstantInput();
     } else {
         projectStartVid = buildRuntimeInput();
@@ -162,7 +162,7 @@ Status GetSubgraphValidator::toPlan() {
 
     // ++counter{0} <= steps
     // TODO(shylock) add condition when gn get empty result
-    auto* condition = buildNStepLoopCondition(steps_);
+    auto* condition = buildNStepLoopCondition(steps_.steps);
     // The input of loop will set by father validator.
     auto* loop = Loop::make(qctx_, nullptr, projectVids, condition);