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drasi_core/evaluation/functions/
context_mutators.rs

1// Copyright 2024 The Drasi Authors.
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 async_trait::async_trait;
16use drasi_query_ast::ast;
17
18use crate::evaluation::{context::SideEffects, ExpressionEvaluationContext, FunctionError};
19
20use super::ContextMutatorFunction;
21
22pub struct RetainHistory {}
23
24#[async_trait]
25impl ContextMutatorFunction for RetainHistory {
26    async fn call<'a>(
27        &self,
28        context: &ExpressionEvaluationContext<'a>,
29        _expression: &ast::FunctionExpression,
30    ) -> Result<ExpressionEvaluationContext<'a>, FunctionError> {
31        let mut new_context = context.clone();
32        match new_context.get_side_effects() {
33            SideEffects::RevertForUpdate => new_context.set_side_effects(SideEffects::Snapshot),
34            SideEffects::RevertForDelete => new_context.set_side_effects(SideEffects::Snapshot),
35            _ => {}
36        }
37
38        Ok(new_context)
39    }
40}