github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/compiler/compile.go (about)

     1  // Copyright 2022 zGraph Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package compiler
    16  
    17  import (
    18  	"github.com/vescale/zgraph/executor"
    19  	"github.com/vescale/zgraph/parser/ast"
    20  	"github.com/vescale/zgraph/planner"
    21  	"github.com/vescale/zgraph/stmtctx"
    22  )
    23  
    24  // Compile compiles the statement AST node into an executable statement. The compiler relay
    25  // on the statement context to retrieve some environment information and set some intermediate
    26  // variables while compiling. The catalog is used to resolve names in the query.
    27  func Compile(sc *stmtctx.Context, node ast.StmtNode) (executor.Executor, error) {
    28  	// Macro expansion
    29  	macroExp := NewMacroExpansion()
    30  	node.Accept(macroExp)
    31  
    32  	// Check the AST to ensure it is valid.
    33  	preprocess := NewPreprocess(sc)
    34  	node.Accept(preprocess)
    35  	err := preprocess.Error()
    36  	if err != nil {
    37  		return nil, err
    38  	}
    39  
    40  	// Prepare missing properties
    41  	propPrep := NewPropertyPreparation(sc)
    42  	node.Accept(propPrep)
    43  	err = propPrep.CreateMissing()
    44  	if err != nil {
    45  		return nil, err
    46  	}
    47  
    48  	// Build plan tree from a valid AST.
    49  	planBuilder := planner.NewBuilder(sc)
    50  	plan, err := planBuilder.Build(node)
    51  	if err != nil {
    52  		return nil, err
    53  	}
    54  	logicalPlan, isLogicalPlan := plan.(planner.LogicalPlan)
    55  	if isLogicalPlan {
    56  		// Optimize the logical plan and generate physical plan.
    57  		plan = planner.Optimize(logicalPlan)
    58  	}
    59  
    60  	execBuilder := executor.NewBuilder(sc)
    61  	exec := execBuilder.Build(plan)
    62  	err = execBuilder.Error()
    63  	if err != nil {
    64  		return nil, err
    65  	}
    66  
    67  	return exec, nil
    68  }