support cypher parameter

src/common/expression/CMakeLists.txt

@@ -32,6 +32,7 @@ nebula_add_library(
     PredicateExpression.cpp
     ListComprehensionExpression.cpp
     ReduceExpression.cpp
+    ParameterExpression.cpp
 )
 
 nebula_add_subdirectory(test)

src/common/expression/ExprVisitor.h

@@ -21,6 +21,7 @@
 #include "common/expression/LabelExpression.h"
 #include "common/expression/ListComprehensionExpression.h"
 #include "common/expression/LogicalExpression.h"
+#include "common/expression/ParameterExpression.h"
 #include "common/expression/PathBuildExpression.h"
 #include "common/expression/PredicateExpression.h"
 #include "common/expression/PropertyExpression.h"
@@ -89,6 +90,8 @@ class ExprVisitor {
   virtual void visit(ReduceExpression *expr) = 0;
   // subscript range expression
   virtual void visit(SubscriptRangeExpression *expr) = 0;
+  // parameter expression
+  virtual void visit(ParameterExpression *expr) = 0;
 };
 
 }  // namespace nebula

src/common/expression/Expression.cpp

@@ -22,6 +22,7 @@
 #include "common/expression/LabelExpression.h"
 #include "common/expression/ListComprehensionExpression.h"
 #include "common/expression/LogicalExpression.h"
+#include "common/expression/ParameterExpression.h"
 #include "common/expression/PathBuildExpression.h"
 #include "common/expression/PredicateExpression.h"
 #include "common/expression/PropertyExpression.h"
@@ -497,6 +498,11 @@ Expression* Expression::decode(ObjectPool* pool, Expression::Decoder& decoder) {
       exp->resetFrom(decoder);
       return exp;
     }
+    case Expression::Kind::kParam: {
+      exp = ParameterExpression::make(pool);
+      exp->resetFrom(decoder);
+      return exp;
+    }
     case Expression::Kind::kTSPrefix:
     case Expression::Kind::kTSWildcard:
     case Expression::Kind::kTSRegexp:
@@ -719,6 +725,9 @@ std::ostream& operator<<(std::ostream& os, Expression::Kind kind) {
     case Expression::Kind::kReduce:
       os << "Reduce";
       break;
+    case Expression::Kind::kParam:
+      os << "Parameter";
+      break;
   }
   return os;
 }

src/common/expression/Expression.h

@@ -108,6 +108,7 @@ class Expression {
     kIsNotEmpty,
 
     kSubscriptRange,
+    kParam,
   };
 
   Expression(ObjectPool* pool, Kind kind);

src/common/expression/ParameterExpression.cpp

@@ -0,0 +1,30 @@
+/* Copyright (c) 2021 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 "common/expression/ParameterExpression.h"
+
+#include "common/expression/ExprVisitor.h"
+
+namespace nebula {
+
+const Value& ParameterExpression::eval(ExpressionContext& ectx) { return ectx.getVar(name_); }
+
+std::string ParameterExpression::toString() const { return name_; }
+
+bool ParameterExpression::operator==(const Expression& rhs) const {
+  return kind_ == rhs.kind() && name_ == rhs.toString();
+}
+
+void ParameterExpression::writeTo(Encoder& encoder) const {
+  encoder << kind_;
+  encoder << name_;
+}
+
+void ParameterExpression::resetFrom(Decoder& decoder) { name_ = decoder.readStr(); }
+
+void ParameterExpression::accept(ExprVisitor* visitor) { visitor->visit(this); }
+
+}  // namespace nebula

src/common/expression/ParameterExpression.h

@@ -0,0 +1,47 @@
+/* Copyright (c) 2021 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.
+ */
+
+#pragma once
+
+#include "common/expression/Expression.h"
+
+// The ParameterExpression use for parameterized statement
+namespace nebula {
+
+class ParameterExpression : public Expression {
+ public:
+  ParameterExpression& operator=(const ParameterExpression& rhs) = delete;
+  ParameterExpression& operator=(ParameterExpression&&) = delete;
+
+  static ParameterExpression* make(ObjectPool* pool, const std::string& name = "") {
+    return pool->add(new ParameterExpression(pool, name));
+  }
+
+  bool operator==(const Expression& rhs) const override;
+
+  const Value& eval(ExpressionContext& ctx) override;
+
+  const std::string& name() const { return name_; }
+
+  std::string toString() const override;
+
+  void accept(ExprVisitor* visitor) override;
+
+  Expression* clone() const override { return ParameterExpression::make(pool_, name()); }
+
+ protected:
+  explicit ParameterExpression(ObjectPool* pool, const std::string& name = "")
+      : Expression(pool, Kind::kParam), name_(name) {}
+
+  void writeTo(Encoder& encoder) const override;
+  void resetFrom(Decoder& decoder) override;
+
+ protected:
+  std::string name_;
+  Value result_;
+};
+
+}  // namespace nebula

src/common/expression/test/CMakeLists.txt

@@ -272,6 +272,24 @@ nebula_add_test(
         ${THRIFT_LIBRARIES}
 )
 
+nebula_add_test(
+    NAME param_expression_test
+    SOURCES ParameterExpressionTest.cpp
+    OBJECTS
+        $<TARGET_OBJECTS:base_obj>
+        $<TARGET_OBJECTS:expression_obj>
+        $<TARGET_OBJECTS:datatypes_obj>
+        $<TARGET_OBJECTS:expr_ctx_mock_obj>
+        $<TARGET_OBJECTS:function_manager_obj>
+        $<TARGET_OBJECTS:agg_function_manager_obj>
+        $<TARGET_OBJECTS:time_obj>
+        $<TARGET_OBJECTS:time_utils_obj>
+        $<TARGET_OBJECTS:fs_obj>
+    LIBRARIES
+        gtest
+        ${THRIFT_LIBRARIES}
+)
+
 nebula_add_test(
     NAME list_comprehension_expression_test
     SOURCES ListComprehensionExpressionTest.cpp

src/common/expression/test/EncodeDecodeTest.cpp

@@ -303,6 +303,12 @@ TEST(ExpressionEncodeDecode, LabelExpression) {
   ASSERT_EQ(*origin, *decoded);
 }
 
+TEST(ExpressionEncodeDecode, ParameterExpression) {
+  auto origin = ParameterExpression::make(&pool, "name");
+  auto decoded = Expression::decode(&pool, Expression::encode(*origin));
+  ASSERT_EQ(*origin, *decoded);
+}
+
 TEST(ExpressionEncodeDecode, CaseExpression) {
   {
     // CASE 23 WHEN 24 THEN 1 END

src/common/expression/test/ExpressionContextMock.cpp

@@ -43,6 +43,8 @@ std::unordered_map<std::string, Value> ExpressionContextMock::vals_ = {
     {"path_edge2", Value(Edge("2", "3", 1, "edge", 0, {}))},
     {"path_v2", Value(Vertex("3", {}))},
     {"path_edge3", Value(Edge("3", "4", 1, "edge", 0, {}))},
+    {"param1", Value(1)},
+    {"param2", Value(List(std::vector<Value>{1, 2, 3, 4, 5, 6, 7, 8}))},
 };
 
 Value ExpressionContextMock::getColumn(int32_t index) const {

src/common/expression/test/ParameterExpressionTest.cpp

@@ -0,0 +1,31 @@
+/* Copyright (c) 2021 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 "common/expression/test/TestBase.h"
+
+namespace nebula {
+
+class ParameterExpressionTest : public ExpressionTest {};
+
+TEST_F(ParameterExpressionTest, ParamExprToString) {
+  auto expr = ParameterExpression::make(&pool, "$param1");
+  ASSERT_EQ("$param1", expr->toString());
+}
+
+TEST_F(ParameterExpressionTest, ParamEvaluate) {
+  auto expr = ParameterExpression::make(&pool, "param1");
+  auto value = Expression::eval(expr, gExpCtxt);
+  ASSERT_TRUE(value.isInt());
+  ASSERT_EQ(1, value.getInt());
+}
+}  // namespace nebula
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+  folly::init(&argc, &argv, true);
+  google::SetStderrLogging(google::INFO);
+
+  return RUN_ALL_TESTS();
+}

src/common/expression/test/TestBase.h

@@ -34,6 +34,7 @@
 #include "common/expression/LabelExpression.h"
 #include "common/expression/ListComprehensionExpression.h"
 #include "common/expression/LogicalExpression.h"
+#include "common/expression/ParameterExpression.h"
 #include "common/expression/PathBuildExpression.h"
 #include "common/expression/PredicateExpression.h"
 #include "common/expression/PropertyExpression.h"

src/graph/context/QueryContext.cpp

@@ -30,6 +30,12 @@ void QueryContext::init() {
   objPool_ = std::make_unique<ObjectPool>();
   ep_ = std::make_unique<ExecutionPlan>();
   ectx_ = std::make_unique<ExecutionContext>();
+  // copy parameterMap into ExecutionContext
+  if (rctx_) {
+    for (auto item : rctx_->parameterMap()) {
+      ectx_->setValue(std::move(item.first), std::move(item.second));
+    }
+  }
   idGen_ = std::make_unique<IdGenerator>(0);
   symTable_ = std::make_unique<SymbolTable>(objPool_.get());
   vctx_ = std::make_unique<ValidateContext>(std::make_unique<AnonVarGenerator>(symTable_.get()));

src/graph/context/QueryContext.h

@@ -97,6 +97,8 @@ class QueryContext {
 
   bool isKilled() const { return killed_.load(); }
 
+  bool existParameter(const std::string& param) const { return ectx_->exist(param); }
+
  private:
   void init();
 

src/graph/context/QueryExpressionContext.h

@@ -54,7 +54,7 @@ class QueryExpressionContext final : public ExpressionContext {
 
   void setVar(const std::string&, Value val) override;
 
-  QueryExpressionContext& operator()(Iterator* iter) {
+  QueryExpressionContext& operator()(Iterator* iter = nullptr) {
     iter_ = iter;
     return *this;
   }

src/graph/service/GraphService.cpp

@@ -116,6 +116,14 @@ void GraphService::signout(int64_t sessionId) {
 
 folly::Future<ExecutionResponse> GraphService::future_execute(int64_t sessionId,
                                                               const std::string& query) {
+  std::unordered_map<std::string, Value> params;
+  return future_executeWithParameter(sessionId, query, std::move(params)).get();
+}
+
+folly::Future<ExecutionResponse> GraphService::future_executeWithParameter(
+    int64_t sessionId,
+    const std::string& query,
+    const std::unordered_map<std::string, Value>& parameterMap) {
   auto ctx = std::make_unique<RequestContext<ExecutionResponse>>();
   ctx->setQuery(query);
   ctx->setRunner(getThreadManager());
@@ -129,7 +137,7 @@ folly::Future<ExecutionResponse> GraphService::future_execute(int64_t sessionId,
     ctx->finish();
     return future;
   }
-  auto cb = [this, sessionId, ctx = std::move(ctx)](
+  auto cb = [this, sessionId, ctx = std::move(ctx), parameterMap = std::move(parameterMap)](
                 StatusOr<std::shared_ptr<ClientSession>> ret) mutable {
     if (!ret.ok()) {
       LOG(ERROR) << "Get session for sessionId: " << sessionId << " failed: " << ret.status();
@@ -147,6 +155,7 @@ folly::Future<ExecutionResponse> GraphService::future_execute(int64_t sessionId,
       return ctx->finish();
     }
     ctx->setSession(std::move(sessionPtr));
+    ctx->setParameterMap(parameterMap);
     queryEngine_->execute(std::move(ctx));
   };
   sessionManager_->findSession(sessionId, getThreadManager()).thenValue(std::move(cb));
@@ -155,7 +164,17 @@ folly::Future<ExecutionResponse> GraphService::future_execute(int64_t sessionId,
 
 folly::Future<std::string> GraphService::future_executeJson(int64_t sessionId,
                                                             const std::string& query) {
-  auto rawResp = future_execute(sessionId, query).get();
+  std::unordered_map<std::string, Value> params;
+  auto rawResp = future_executeWithParameter(sessionId, query, std::move(params)).get();
+  auto respJsonObj = rawResp.toJson();
+  return folly::toJson(respJsonObj);
+}
+
+folly::Future<std::string> GraphService::future_executeJsonWithParameter(
+    int64_t sessionId,
+    const std::string& query,
+    const std::unordered_map<std::string, Value>& parameterMap) {
+  auto rawResp = future_executeWithParameter(sessionId, query, parameterMap).get();
   auto respJsonObj = rawResp.toJson();
   return folly::toJson(respJsonObj);
 }

src/graph/service/GraphService.h

@@ -36,9 +36,19 @@ class GraphService final : public cpp2::GraphServiceSvIf {
   folly::Future<ExecutionResponse> future_execute(int64_t sessionId,
                                                   const std::string& stmt) override;
 
+  folly::Future<ExecutionResponse> future_executeWithParameter(
+      int64_t sessionId,
+      const std::string& stmt,
+      const std::unordered_map<std::string, Value>& parameterMap) override;
+
   folly::Future<std::string> future_executeJson(int64_t sessionId,
                                                 const std::string& stmt) override;
 
+  folly::Future<std::string> future_executeJsonWithParameter(
+      int64_t sessionId,
+      const std::string& stmt,
+      const std::unordered_map<std::string, Value>& parameterMap) override;
+
  private:
   bool auth(const std::string& username, const std::string& password);
 

src/graph/service/RequestContext.h

@@ -68,6 +68,12 @@ class RequestContext final : public cpp::NonCopyable, public cpp::NonMovable {
 
   GraphSessionManager* sessionMgr() const { return sessionMgr_; }
 
+  void setParameterMap(std::unordered_map<std::string, Value> parameterMap) {
+    parameterMap_ = std::move(parameterMap);
+  }
+
+  const std::unordered_map<std::string, Value>& parameterMap() const { return parameterMap_; }
+
  private:
   time::Duration duration_;
   std::string query_;
@@ -76,6 +82,7 @@ class RequestContext final : public cpp::NonCopyable, public cpp::NonMovable {
   std::shared_ptr<ClientSession> session_;
   folly::Executor* runner_{nullptr};
   GraphSessionManager* sessionMgr_{nullptr};
+  std::unordered_map<std::string, Value> parameterMap_;
 };
 
 }  // namespace graph

src/graph/visitor/DeducePropsVisitor.h

@@ -100,6 +100,7 @@ class DeducePropsVisitor : public ExprVisitorImpl {
   void visit(VertexExpression* expr) override;
   void visit(EdgeExpression* expr) override;
   void visit(ColumnExpression* expr) override;
+  void visit(ParameterExpression*) override {}
 
   void visitEdgePropExpr(PropertyExpression* expr);
   void reportError(const Expression* expr);

src/graph/visitor/DeduceTypeVisitor.cpp

@@ -116,6 +116,11 @@ void DeduceTypeVisitor::visit(ConstantExpression *expr) {
   type_ = expr->eval(ctx(nullptr)).type();
 }
 
+void DeduceTypeVisitor::visit(ParameterExpression *expr) {
+  QueryExpressionContext ctx(qctx_->ectx());
+  type_ = expr->eval(ctx()).type();
+}
+
 void DeduceTypeVisitor::visit(UnaryExpression *expr) {
   expr->operand()->accept(this);
   if (!ok()) return;

src/graph/visitor/DeduceTypeVisitor.h

@@ -85,6 +85,8 @@ class DeduceTypeVisitor final : public ExprVisitor {
   void visit(ReduceExpression *expr) override;
   // subscript range
   void visit(SubscriptRangeExpression *expr) override;
+  // parameter expression
+  void visit(ParameterExpression *expr) override;
 
   void visitVertexPropertyExpr(PropertyExpression *expr);
 

src/graph/visitor/EvaluableExprVisitor.h

@@ -29,6 +29,11 @@ class EvaluableExprVisitor : public ExprVisitorImpl {
 
   void visit(VersionedVariableExpression *) override { isEvaluable_ = false; }
 
+  void visit(ParameterExpression *) override {
+    // TODO: ParameterExpression is evaluable but not foldable (czp)
+    isEvaluable_ = false;
+  }
+
   void visit(TagPropertyExpression *) override { isEvaluable_ = false; }
 
   void visit(EdgePropertyExpression *) override { isEvaluable_ = false; }