risingwave_frontend/expr/
pure.rs

1// Copyright 2025 RisingWave Labs
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
15use expr_node::Type;
16use risingwave_pb::expr::expr_node;
17
18use super::{ExprImpl, ExprVisitor};
19use crate::expr::FunctionCall;
20
21#[derive(Default)]
22pub(crate) struct ImpureAnalyzer {
23    pub(crate) impure: bool,
24}
25
26impl ExprVisitor for ImpureAnalyzer {
27    fn visit_user_defined_function(&mut self, _func_call: &super::UserDefinedFunction) {
28        self.impure = true;
29    }
30
31    fn visit_now(&mut self, _: &super::Now) {
32        self.impure = true;
33    }
34
35    fn visit_function_call(&mut self, func_call: &super::FunctionCall) {
36        match func_call.func_type() {
37            Type::Unspecified => unreachable!(),
38            Type::Add
39            | Type::Subtract
40            | Type::Multiply
41            | Type::Divide
42            | Type::Modulus
43            | Type::Equal
44            | Type::NotEqual
45            | Type::LessThan
46            | Type::LessThanOrEqual
47            | Type::GreaterThan
48            | Type::GreaterThanOrEqual
49            | Type::And
50            | Type::Or
51            | Type::Not
52            | Type::In
53            | Type::Some
54            | Type::All
55            | Type::BitwiseAnd
56            | Type::BitwiseOr
57            | Type::BitwiseXor
58            | Type::BitwiseNot
59            | Type::BitwiseShiftLeft
60            | Type::BitwiseShiftRight
61            | Type::Extract
62            | Type::DatePart
63            | Type::TumbleStart
64            | Type::SecToTimestamptz
65            | Type::AtTimeZone
66            | Type::DateTrunc
67            | Type::DateBin
68            | Type::MakeDate
69            | Type::MakeTime
70            | Type::MakeTimestamp
71            | Type::CharToTimestamptz
72            | Type::CharToDate
73            | Type::CastWithTimeZone
74            | Type::AddWithTimeZone
75            | Type::SubtractWithTimeZone
76            | Type::Cast
77            | Type::Substr
78            | Type::Length
79            | Type::Like
80            | Type::ILike
81            | Type::SimilarToEscape
82            | Type::Upper
83            | Type::Lower
84            | Type::Trim
85            | Type::Replace
86            | Type::Position
87            | Type::Ltrim
88            | Type::Rtrim
89            | Type::Case
90            | Type::ConstantLookup
91            | Type::RoundDigit
92            | Type::Round
93            | Type::Ascii
94            | Type::Translate
95            | Type::Coalesce
96            | Type::ConcatWs
97            | Type::ConcatWsVariadic
98            | Type::Abs
99            | Type::SplitPart
100            | Type::Ceil
101            | Type::Floor
102            | Type::Trunc
103            | Type::ToChar
104            | Type::Md5
105            | Type::CharLength
106            | Type::Repeat
107            | Type::ConcatOp
108            | Type::Concat
109            | Type::ConcatVariadic
110            | Type::BoolOut
111            | Type::OctetLength
112            | Type::BitLength
113            | Type::Overlay
114            | Type::RegexpMatch
115            | Type::RegexpReplace
116            | Type::RegexpCount
117            | Type::RegexpSplitToArray
118            | Type::RegexpEq
119            | Type::Pow
120            | Type::Exp
121            | Type::Ln
122            | Type::Log10
123            | Type::Chr
124            | Type::StartsWith
125            | Type::Initcap
126            | Type::Lpad
127            | Type::Rpad
128            | Type::Reverse
129            | Type::Strpos
130            | Type::ToAscii
131            | Type::ToHex
132            | Type::QuoteIdent
133            | Type::Sin
134            | Type::Cos
135            | Type::Tan
136            | Type::Cot
137            | Type::Asin
138            | Type::Acos
139            | Type::Acosd
140            | Type::Atan
141            | Type::Atan2
142            | Type::Atand
143            | Type::Atan2d
144            | Type::Sqrt
145            | Type::Cbrt
146            | Type::Sign
147            | Type::Scale
148            | Type::MinScale
149            | Type::TrimScale
150            | Type::Left
151            | Type::Right
152            | Type::Degrees
153            | Type::Radians
154            | Type::IsTrue
155            | Type::IsNotTrue
156            | Type::IsFalse
157            | Type::IsNotFalse
158            | Type::IsNull
159            | Type::IsNotNull
160            | Type::IsDistinctFrom
161            | Type::IsNotDistinctFrom
162            | Type::Neg
163            | Type::Field
164            | Type::Array
165            | Type::ArrayAccess
166            | Type::ArrayRangeAccess
167            | Type::Row
168            | Type::ArrayToString
169            | Type::ArrayCat
170            | Type::ArrayMax
171            | Type::ArraySum
172            | Type::ArraySort
173            | Type::ArrayAppend
174            | Type::ArrayPrepend
175            | Type::FormatType
176            | Type::ArrayDistinct
177            | Type::ArrayMin
178            | Type::ArrayDims
179            | Type::ArrayLength
180            | Type::Cardinality
181            | Type::TrimArray
182            | Type::ArrayRemove
183            | Type::ArrayReplace
184            | Type::ArrayPosition
185            | Type::ArrayContains
186            | Type::ArrayContained
187            | Type::ArrayFlatten
188            | Type::HexToInt256
189            | Type::JsonbConcat
190            | Type::JsonbAccess
191            | Type::JsonbAccessStr
192            | Type::JsonbExtractPath
193            | Type::JsonbExtractPathVariadic
194            | Type::JsonbExtractPathText
195            | Type::JsonbExtractPathTextVariadic
196            | Type::JsonbTypeof
197            | Type::JsonbArrayLength
198            | Type::JsonbObject
199            | Type::JsonbPretty
200            | Type::JsonbDeletePath
201            | Type::JsonbContains
202            | Type::JsonbContained
203            | Type::JsonbExists
204            | Type::JsonbExistsAny
205            | Type::JsonbExistsAll
206            | Type::JsonbStripNulls
207            | Type::JsonbBuildArray
208            | Type::JsonbBuildArrayVariadic
209            | Type::JsonbBuildObject
210            | Type::JsonbPopulateRecord
211            | Type::JsonbToRecord
212            | Type::JsonbBuildObjectVariadic
213            | Type::JsonbPathExists
214            | Type::JsonbPathMatch
215            | Type::JsonbPathQueryArray
216            | Type::JsonbPathQueryFirst
217            | Type::JsonbSet
218            | Type::JsonbPopulateMap
219            | Type::IsJson
220            | Type::ToJsonb
221            | Type::Sind
222            | Type::Cosd
223            | Type::Cotd
224            | Type::Asind
225            | Type::Sinh
226            | Type::Cosh
227            | Type::Coth
228            | Type::Tanh
229            | Type::Atanh
230            | Type::Asinh
231            | Type::Acosh
232            | Type::Decode
233            | Type::Encode
234            | Type::Sha1
235            | Type::Sha224
236            | Type::Sha256
237            | Type::Sha384
238            | Type::Sha512
239            | Type::Hmac
240            | Type::SecureCompare
241            | Type::Decrypt
242            | Type::Encrypt
243            | Type::Tand
244            | Type::ArrayPositions
245            | Type::StringToArray
246            | Type::Format
247            | Type::FormatVariadic
248            | Type::PgwireSend
249            | Type::PgwireRecv
250            | Type::ArrayTransform
251            | Type::Greatest
252            | Type::Least
253            | Type::ConvertFrom
254            | Type::ConvertTo
255            | Type::IcebergTransform
256            | Type::InetNtoa
257            | Type::InetAton
258            | Type::QuoteLiteral
259            | Type::QuoteNullable
260            | Type::MapFromEntries
261            | Type::MapAccess
262            | Type::MapKeys
263            | Type::MapValues
264            | Type::MapEntries
265            | Type::MapFromKeyValues
266            | Type::MapCat
267            | Type::MapContains
268            | Type::MapDelete
269            | Type::MapInsert
270            | Type::MapLength
271            | Type::VnodeUser
272            | Type::RwEpochToTs
273            | Type::CheckNotNull =>
274            // expression output is deterministic(same result for the same input)
275            {
276                func_call
277                    .inputs()
278                    .iter()
279                    .for_each(|expr| self.visit_expr(expr));
280            }
281            // expression output is not deterministic
282            Type::Vnode // obtain vnode count from the context
283            | Type::TestPaidTier
284            | Type::License
285            | Type::Proctime
286            | Type::PgSleep
287            | Type::PgSleepFor
288            | Type::PgSleepUntil
289            | Type::CastRegclass
290            | Type::PgGetIndexdef
291            | Type::ColDescription
292            | Type::PgGetViewdef
293            | Type::PgGetUserbyid
294            | Type::PgIndexesSize
295            | Type::PgRelationSize
296            | Type::PgGetSerialSequence
297            | Type::PgIndexColumnHasProperty
298            | Type::HasTablePrivilege
299            | Type::HasAnyColumnPrivilege
300            | Type::HasSchemaPrivilege
301            | Type::MakeTimestamptz
302            | Type::PgIsInRecovery
303            | Type::RwRecoveryStatus
304            | Type::PgTableIsVisible
305            | Type::HasFunctionPrivilege => self.impure = true,
306        }
307    }
308}
309
310pub fn is_pure(expr: &ExprImpl) -> bool {
311    !is_impure(expr)
312}
313
314pub fn is_impure(expr: &ExprImpl) -> bool {
315    let mut a = ImpureAnalyzer::default();
316    a.visit_expr(expr);
317    a.impure
318}
319
320pub fn is_impure_func_call(func_call: &FunctionCall) -> bool {
321    let mut a = ImpureAnalyzer::default();
322    a.visit_function_call(func_call);
323    a.impure
324}
325
326#[cfg(test)]
327mod tests {
328    use risingwave_common::types::DataType;
329    use risingwave_pb::expr::expr_node::Type;
330
331    use crate::expr::{ExprImpl, FunctionCall, InputRef, is_impure, is_pure};
332
333    fn expect_pure(expr: &ExprImpl) {
334        assert!(is_pure(expr));
335        assert!(!is_impure(expr));
336    }
337
338    fn expect_impure(expr: &ExprImpl) {
339        assert!(!is_pure(expr));
340        assert!(is_impure(expr));
341    }
342
343    #[test]
344    fn test_pure_funcs() {
345        let e: ExprImpl = FunctionCall::new(
346            Type::Add,
347            vec![
348                InputRef::new(0, DataType::Int16).into(),
349                InputRef::new(0, DataType::Int16).into(),
350            ],
351        )
352        .unwrap()
353        .into();
354        expect_pure(&e);
355
356        let e: ExprImpl = FunctionCall::new(
357            Type::GreaterThan,
358            vec![
359                InputRef::new(0, DataType::Timestamptz).into(),
360                FunctionCall::new(Type::Proctime, vec![]).unwrap().into(),
361            ],
362        )
363        .unwrap()
364        .into();
365        expect_impure(&e);
366    }
367}
risingwave_frontend/expr/pure.rs

risingwave_frontend/expr/
pure.rs
