From 23d638b90a960d04803bcfadc4b5c76eaf5053ef Mon Sep 17 00:00:00 2001
From: Danis Kirasirov <dbgbbu@gmail.com>
Date: Fri, 26 Jan 2024 19:30:14 +0300
Subject: [PATCH] =?UTF-8?q?=D0=A0=D0=B5=D0=B0=D0=BB=D0=B8=D0=B7=D0=BE?=
=?UTF-8?q?=D0=B2=D0=B0=D0=BD=D0=B0=20=D1=84=D1=83=D0=BD=D0=BA=D1=86=D0=B8?=
=?UTF-8?q?=D1=8F=20len(arr)=20=D0=B4=D0=BB=D1=8F=20<,=20>,=20=3D=3D?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
---
pkg/expr/mongo.go | 40 +++++++++++++++++++++++++++++++++++++++-
pkg/expr/mongo_test.go | 5 +++++
2 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/pkg/expr/mongo.go b/pkg/expr/mongo.go
index 0aa9b29b..303ec125 100644
--- a/pkg/expr/mongo.go
+++ b/pkg/expr/mongo.go
@@ -4,6 +4,7 @@ import (
"context"
"fmt"
"regexp"
+ "strconv"
"strings"
"github.com/expr-lang/expr"
@@ -232,6 +233,17 @@ func (c *compiler) identifier(node ast.Node) string {
func (c *compiler) BinaryNode(node *ast.BinaryNode) interface{} {
switch node.Operator {
case "==":
+ op := c.eval(node.Right)
+ lenNode, ok := node.Left.(*ast.BuiltinNode)
+ if ok && lenNode.Name == "len" && len(lenNode.Arguments) == 1 {
+ // Оптимизация для случая len(arr) == 0, т.к. $size не использует индекс
+ if op == 0 {
+ return bson.M{c.identifier(lenNode.Arguments[0]): bson.M{"$eq": bson.A{}}}
+ }
+
+ return bson.M{c.identifier(lenNode.Arguments[0]): bson.M{"$size": op}}
+ }
+
return bson.M{c.identifier(node.Left): c.eval(node.Right)}
case "!=":
@@ -250,10 +262,36 @@ func (c *compiler) BinaryNode(node *ast.BinaryNode) interface{} {
return bson.M{c.identifier(node.Left): bson.M{"$nin": c.eval(node.Right)}}
case "<":
+ op := c.eval(node.Right)
+ lenNode, ok := node.Left.(*ast.BuiltinNode)
+ if ok && lenNode.Name == "len" && len(lenNode.Arguments) == 1 {
+ length, ok := op.(int)
+ if !ok {
+ panic("len must be compared with an integer")
+ }
+ return bson.M{c.identifier(lenNode.Arguments[0]) + "." + strconv.Itoa(length): bson.M{"$exists": false}}
+ }
+
return bson.M{c.identifier(node.Left): bson.M{"$lt": c.eval(node.Right)}}
case ">":
- return bson.M{c.identifier(node.Left): bson.M{"$gt": c.eval(node.Right)}}
+ op := c.eval(node.Right)
+ lenNode, ok := node.Left.(*ast.BuiltinNode)
+ if ok && lenNode.Name == "len" && len(lenNode.Arguments) == 1 {
+ length, ok := op.(int)
+ if !ok {
+ panic("len must be compared with an integer")
+ }
+
+ // Оптимизация для случая len(arr) > 0
+ if length == 0 {
+ return bson.M{c.identifier(lenNode.Arguments[0]): bson.M{"$exists": true, "$type": "array", "$ne": bson.A{}}}
+ }
+
+ return bson.M{c.identifier(lenNode.Arguments[0]) + "." + strconv.Itoa(length): bson.M{"$exists": true}}
+ }
+
+ return bson.M{c.identifier(node.Left): bson.M{"$gt": op}}
case "<=":
return bson.M{c.identifier(node.Left): bson.M{"$lte": c.eval(node.Right)}}
diff --git a/pkg/expr/mongo_test.go b/pkg/expr/mongo_test.go
index f50b27c2..3e77e0d4 100644
--- a/pkg/expr/mongo_test.go
+++ b/pkg/expr/mongo_test.go
@@ -31,6 +31,11 @@ func TestConvertToMongo(t *testing.T) {
{"in array", "s in [1,2,3]", nil, bson.M{"s": bson.M{"$in": []interface{}{1, 2, 3}}}, false},
{"not in array", "s not in [1,2,3]", nil, bson.M{"s": bson.M{"$nin": []interface{}{1, 2, 3}}}, false},
{"exists", "exists(s)", nil, bson.M{"$or": bson.A{bson.M{"s": bson.M{"$exists": true, "$type": "array"}}, bson.M{"s": bson.M{"$ne": nil}}}}, false},
+ {"len equal", "len(s) == 1", nil, bson.M{"s": bson.M{"$size": 1}}, false},
+ {"len equal empty", "len(s) == 0", nil, bson.M{"s": bson.M{"$eq": bson.A{}}}, false},
+ {"len gt", "len(s) > 1", nil, bson.M{"s.1": bson.M{"$exists": true}}, false},
+ {"len gt 0", "len(s) > 0", nil, bson.M{"s": bson.M{"$exists": true, "$type": "array", "$ne": bson.A{}}}, false},
+ {"len lt", "len(s) < 1", nil, bson.M{"s.1": bson.M{"$exists": false}}, false},
{"field#1", "s.test > 3", nil, bson.M{"s.test": bson.M{"$gt": 3}}, false},
{"field#2", "s['test'] > 3", nil, bson.M{"s.test": bson.M{"$gt": 3}}, false},
{"field#3", "s[test] > 3", nil, bson.M{"s.test": bson.M{"$gt": 3}}, false},
--
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