multisql/databases/memory/
base.rs

1use std::collections::{BTreeMap, HashMap};
2
3use crate::{join_iters, JoinType, Row};
4
5use {
6	crate::{
7		DBBase, IndexFilter, MemoryDatabase, MemoryDatabaseError, Plane, Result, Schema, Value,
8	},
9	async_trait::async_trait,
10};
11
12#[async_trait(?Send)]
13impl DBBase for MemoryDatabase {
14	async fn fetch_schema(&self, table_name: &str) -> Result<Option<Schema>> {
15		Ok(self.tables.get(&table_name.to_string()).cloned())
16	}
17	async fn scan_schemas(&self) -> Result<Vec<Schema>> {
18		Ok(self.tables.values().cloned().collect())
19	}
20
21	async fn scan_data(&self, table_name: &str) -> Result<Plane> {
22		self.data
23			.get(&table_name.to_string())
24			.cloned()
25			.ok_or(MemoryDatabaseError::TableNotFound.into())
26			.map(|rows| rows.into_iter().collect())
27	}
28
29	async fn scan_data_indexed(
30		&self,
31		table_name: &str,
32		index_filter: IndexFilter,
33	) -> Result<Plane> {
34		let index_results = self.scan_index(table_name, index_filter).await?;
35		let default = HashMap::new();
36		let rows = self.data.get(&table_name.to_string()).unwrap_or(&default);
37		Ok(index_results
38			.into_iter()
39			.filter_map(|pk| rows.get(&pk).map(|row| (pk.clone(), row.clone())))
40			.collect::<Vec<(Value, Row)>>())
41	}
42
43	async fn scan_index(&self, table_name: &str, index_filter: IndexFilter) -> Result<Vec<Value>> {
44		use IndexFilter::*;
45		match index_filter.clone() {
46			LessThan(index_name, ..) | MoreThan(index_name, ..) => {
47				let default = BTreeMap::new();
48				let index = self
49					.indexes
50					.get(&table_name.to_string())
51					.and_then(|indexes| indexes.get(&index_name))
52					.unwrap_or(&default);
53				let index_results = match index_filter {
54					LessThan(_, max) => index.range(..max),
55					MoreThan(_, min) => index.range(min..),
56					_ => unreachable!(),
57				}
58				.map(|(_, pk)| pk.clone())
59				.collect();
60				Ok(index_results)
61			}
62			Inner(left, right) => {
63				let (left, right) = (
64					self.scan_index(table_name, *left),
65					self.scan_index(table_name, *right),
66				);
67				let (left, right) = (left.await?, right.await?);
68				Ok(join_iters(JoinType::Inner, left, right))
69			}
70			Outer(left, right) => {
71				let (left, right) = (
72					self.scan_index(table_name, *left),
73					self.scan_index(table_name, *right),
74				);
75				let (left, right) = (left.await?, right.await?);
76				Ok(join_iters(JoinType::Outer, left, right))
77			}
78		}
79	}
80}
multisql/databases/memory/base.rs

multisql/databases/memory/
base.rs
