mito2/sst/
version.rs

1// Copyright 2023 Greptime Team
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
15//! SST version.
16use std::collections::HashMap;
17use std::fmt;
18use std::sync::Arc;
19
20use common_time::{TimeToLive, Timestamp};
21
22use crate::sst::file::{FileHandle, FileId, FileMeta, Level, MAX_LEVEL};
23use crate::sst::file_purger::FilePurgerRef;
24
25/// A version of all SSTs in a region.
26#[derive(Debug, Clone)]
27pub(crate) struct SstVersion {
28    /// SST metadata organized by levels.
29    levels: LevelMetaArray,
30}
31
32pub(crate) type SstVersionRef = Arc<SstVersion>;
33
34impl SstVersion {
35    /// Returns a new [SstVersion].
36    pub(crate) fn new() -> SstVersion {
37        SstVersion {
38            levels: new_level_meta_vec(),
39        }
40    }
41
42    /// Returns a slice to metadatas of all levels.
43    pub(crate) fn levels(&self) -> &[LevelMeta] {
44        &self.levels
45    }
46
47    /// Add files to the version.
48    ///
49    /// # Panics
50    /// Panics if level of [FileMeta] is greater than [MAX_LEVEL].
51    pub(crate) fn add_files(
52        &mut self,
53        file_purger: FilePurgerRef,
54        files_to_add: impl Iterator<Item = FileMeta>,
55    ) {
56        for file in files_to_add {
57            let level = file.level;
58            self.levels[level as usize]
59                .files
60                .entry(file.file_id)
61                .or_insert_with(|| FileHandle::new(file, file_purger.clone()));
62        }
63    }
64
65    /// Remove files from the version.
66    ///
67    /// # Panics
68    /// Panics if level of [FileMeta] is greater than [MAX_LEVEL].
69    pub(crate) fn remove_files(&mut self, files_to_remove: impl Iterator<Item = FileMeta>) {
70        for file in files_to_remove {
71            let level = file.level;
72            if let Some(handle) = self.levels[level as usize].files.remove(&file.file_id) {
73                handle.mark_deleted();
74            }
75        }
76    }
77
78    /// Marks all SSTs in this version as deleted.
79    pub(crate) fn mark_all_deleted(&self) {
80        for level_meta in &self.levels {
81            for file_handle in level_meta.files.values() {
82                file_handle.mark_deleted();
83            }
84        }
85    }
86
87    /// Returns the number of rows in SST files.
88    /// For historical reasons, the result is not precise for old SST files.
89    pub(crate) fn num_rows(&self) -> u64 {
90        self.levels
91            .iter()
92            .map(|level_meta| {
93                level_meta
94                    .files
95                    .values()
96                    .map(|file_handle| {
97                        let meta = file_handle.meta_ref();
98                        meta.num_rows
99                    })
100                    .sum::<u64>()
101            })
102            .sum()
103    }
104
105    /// Returns SST data files'space occupied in current version.
106    pub(crate) fn sst_usage(&self) -> u64 {
107        self.levels
108            .iter()
109            .map(|level_meta| {
110                level_meta
111                    .files
112                    .values()
113                    .map(|file_handle| {
114                        let meta = file_handle.meta_ref();
115                        meta.file_size
116                    })
117                    .sum::<u64>()
118            })
119            .sum()
120    }
121
122    /// Returns SST index files'space occupied in current version.
123    pub(crate) fn index_usage(&self) -> u64 {
124        self.levels
125            .iter()
126            .map(|level_meta| {
127                level_meta
128                    .files
129                    .values()
130                    .map(|file_handle| {
131                        let meta = file_handle.meta_ref();
132                        meta.index_file_size
133                    })
134                    .sum::<u64>()
135            })
136            .sum()
137    }
138}
139
140// We only has fixed number of level, so we use array to hold elements. This implementation
141// detail of LevelMetaArray should not be exposed to users of [LevelMetas].
142type LevelMetaArray = [LevelMeta; MAX_LEVEL as usize];
143
144/// Metadata of files in the same SST level.
145#[derive(Clone)]
146pub struct LevelMeta {
147    /// Level number.
148    pub level: Level,
149    /// Handles of SSTs in this level.
150    pub files: HashMap<FileId, FileHandle>,
151}
152
153impl LevelMeta {
154    /// Returns an empty meta of specific `level`.
155    pub(crate) fn new(level: Level) -> LevelMeta {
156        LevelMeta {
157            level,
158            files: HashMap::new(),
159        }
160    }
161
162    /// Returns expired SSTs from current level.
163    pub fn get_expired_files(&self, now: &Timestamp, ttl: &TimeToLive) -> Vec<FileHandle> {
164        self.files
165            .values()
166            .filter(|v| {
167                let (_, end) = v.time_range();
168
169                match ttl.is_expired(&end, now) {
170                    Ok(expired) => expired,
171                    Err(e) => {
172                        common_telemetry::error!(e; "Failed to calculate region TTL expire time");
173                        false
174                    }
175                }
176            })
177            .cloned()
178            .collect()
179    }
180
181    pub fn files(&self) -> impl Iterator<Item = &FileHandle> {
182        self.files.values()
183    }
184}
185
186impl fmt::Debug for LevelMeta {
187    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
188        f.debug_struct("LevelMeta")
189            .field("level", &self.level)
190            .field("files", &self.files.keys())
191            .finish()
192    }
193}
194
195fn new_level_meta_vec() -> LevelMetaArray {
196    (0u8..MAX_LEVEL)
197        .map(LevelMeta::new)
198        .collect::<Vec<_>>()
199        .try_into()
200        .unwrap() // safety: LevelMetaArray is a fixed length array with length MAX_LEVEL
201}
202
203#[cfg(test)]
204mod tests {
205    use super::*;
206    use crate::test_util::new_noop_file_purger;
207
208    #[test]
209    fn test_add_files() {
210        let purger = new_noop_file_purger();
211
212        let files = (1..=3)
213            .map(|_| FileMeta {
214                file_id: FileId::random(),
215                ..Default::default()
216            })
217            .collect::<Vec<_>>();
218
219        let mut version = SstVersion::new();
220        // files[1] is added multiple times, and that's ok.
221        version.add_files(purger.clone(), files[..=1].iter().cloned());
222        version.add_files(purger, files[1..].iter().cloned());
223
224        let added_files = &version.levels()[0].files;
225        assert_eq!(added_files.len(), 3);
226        files.iter().for_each(|f| {
227            assert!(added_files.contains_key(&f.file_id));
228        });
229    }
230}
mito2/sst/version.rs

mito2/sst/
version.rs
