reifydb-engine 0.4.12

Query execution and processing engine for ReifyDB
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

// SPDX-License-Identifier: Apache-2.0
// Copyright (c) 2025 ReifyDB

use std::sync::Arc;

use reifydb_core::value::column::{columns::Columns, headers::ColumnHeaders};
use reifydb_transaction::transaction::Transaction;

use crate::{
	Result,
	environment::create_env_columns,
	vm::volcano::query::{QueryContext, QueryNode},
};

pub(crate) struct EnvironmentNode {
	context: Option<Arc<QueryContext>>,
	executed: bool,
}

impl EnvironmentNode {
	pub fn new() -> Self {
		Self {
			context: None,
			executed: false,
		}
	}
}

impl QueryNode for EnvironmentNode {
	fn initialize<'a>(&mut self, _rx: &mut Transaction<'a>, ctx: &QueryContext) -> Result<()> {
		// Store context for environment access
		self.context = Some(Arc::new(ctx.clone()));
		Ok(())
	}

	fn next<'a>(&mut self, _rx: &mut Transaction<'a>, _ctx: &mut QueryContext) -> Result<Option<Columns>> {
		debug_assert!(self.context.is_some(), "EnvironmentNode::next() called before initialize()");

		// Environment executes once and returns environment dataframe
		if self.executed {
			return Ok(None);
		}

		let columns = create_env_columns();
		self.executed = true;

		Ok(Some(columns))
	}

	fn headers(&self) -> Option<ColumnHeaders> {
		// Environment headers are known: "name" and "value" columns
		None
	}
}