reductstore 1.19.8

ReductStore is a time series database designed specifically for storing and managing large amounts of blob data.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90

// Copyright 2021-2026 ReductSoftware UG
// Licensed under the Apache License, Version 2.0

use crate::cfg::io::IoConfig;
use crate::core::sync::AsyncRwLock;
use crate::storage::block_manager::BlockManager;
use crate::storage::entry::RecordReader;
use crate::storage::query::base::{Query, QueryOptions};
use crate::storage::query::historical::HistoricalQuery;
use async_trait::async_trait;
use reduct_base::error::ReductError;
use reduct_base::no_content;
use std::sync::Arc;

/// A query that is limited to a certain number of records.
pub(crate) struct LimitedQuery {
    query: HistoricalQuery,
    limit_count: u64,
}

impl LimitedQuery {
    pub fn try_new(
        entry_name: String,
        start: u64,
        stop: u64,
        options: QueryOptions,
        io_config: IoConfig,
    ) -> Result<Self, ReductError> {
        Ok(LimitedQuery {
            query: HistoricalQuery::try_new(entry_name, start, stop, options.clone(), io_config)?,
            limit_count: options.limit.unwrap(),
        })
    }
}

#[async_trait]
impl Query for LimitedQuery {
    async fn next(
        &mut self,
        block_manager: Arc<AsyncRwLock<BlockManager>>,
    ) -> Result<RecordReader, ReductError> {
        if self.limit_count == 0 {
            return Err(no_content!("No content"));
        }

        self.limit_count -= 1;
        self.query.next(block_manager).await
    }

    fn io_settings(&self) -> &IoConfig {
        self.query.io_settings()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::storage::query::base::tests::block_manager;
    use reduct_base::error::ErrorCode;
    use reduct_base::io::ReadRecord;
    use rstest::rstest;

    #[rstest]
    #[tokio::test]
    async fn test_limit(#[future] block_manager: Arc<AsyncRwLock<BlockManager>>) {
        let block_manager = block_manager.await;
        let mut query = LimitedQuery::try_new(
            "entry".to_string(),
            0,
            u64::MAX,
            QueryOptions {
                limit: Some(1),
                ..Default::default()
            },
            IoConfig::default(),
        )
        .unwrap();

        let reader = query.next(block_manager.clone()).await.unwrap();
        assert_eq!(reader.meta().timestamp(), 0);

        assert_eq!(
            query.next(block_manager).await.err(),
            Some(ReductError {
                status: ErrorCode::NoContent,
                message: "No content".to_string(),
            })
        );
    }
}