Coverage Report

Created: 2024-10-13 08:39

/Users/andrewlamb/Software/datafusion/datafusion/common/src/alias.rs
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// Licensed to the Apache Software Foundation (ASF) under one
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// or more contributor license agreements.  See the NOTICE file
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// distributed with this work for additional information
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// regarding copyright ownership.  The ASF licenses this file
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// to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance
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// with the License.  You may obtain a copy of the License at
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//
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//   http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied.  See the License for the
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// specific language governing permissions and limitations
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// under the License.
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use std::sync::atomic::{AtomicUsize, Ordering};
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/// A utility struct that can be used to generate unique aliases when optimizing queries
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#[derive(Debug)]
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pub struct AliasGenerator {
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    next_id: AtomicUsize,
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}
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impl Default for AliasGenerator {
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    fn default() -> Self {
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        Self {
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            next_id: AtomicUsize::new(1),
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        }
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    }
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}
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impl AliasGenerator {
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    /// Create a new [`AliasGenerator`]
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    pub fn new() -> Self {
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        Self::default()
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    }
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    /// Return a unique alias with the provided prefix
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    pub fn next(&self, prefix: &str) -> String {
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        let id = self.next_id.fetch_add(1, Ordering::Relaxed);
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        format!("{prefix}_{id}")
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    }
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}