## Coverage Report

#### Created: 2025-11-22 06:00

next uncovered line (L), next uncovered region (R), next uncovered branch (B)

    /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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    }