nu_command/debug/
timeit.rs

1use nu_engine::{ClosureEvalOnce, command_prelude::*};
2use nu_protocol::engine::Closure;
3use web_time::Instant;
4
5#[derive(Clone)]
6pub struct TimeIt;
7
8impl Command for TimeIt {
9    fn name(&self) -> &str {
10        "timeit"
11    }
12
13    fn description(&self) -> &str {
14        "Time how long it takes a closure to run."
15    }
16
17    fn extra_description(&self) -> &str {
18        "Any pipeline input given to this command is passed to the closure. Note that streaming inputs may affect timing results, and it is recommended to add a `collect` command before this if the input is a stream.
19
20This command will bubble up any errors encountered when running the closure. The return pipeline of the closure is collected into a value and then discarded."
21    }
22
23    fn signature(&self) -> nu_protocol::Signature {
24        Signature::build("timeit")
25            .required("command", SyntaxShape::Closure(None), "The closure to run.")
26            .input_output_types(vec![
27                (Type::Any, Type::Duration),
28                (Type::Nothing, Type::Duration),
29            ])
30            .allow_variants_without_examples(true)
31            .category(Category::Debug)
32    }
33
34    fn search_terms(&self) -> Vec<&str> {
35        vec!["timing", "timer", "benchmark", "measure"]
36    }
37
38    fn requires_ast_for_arguments(&self) -> bool {
39        true
40    }
41
42    fn run(
43        &self,
44        engine_state: &EngineState,
45        stack: &mut Stack,
46        call: &Call,
47        input: PipelineData,
48    ) -> Result<PipelineData, ShellError> {
49        // reset outdest, so the command can write to stdout and stderr.
50        let stack = &mut stack.push_redirection(None, None);
51
52        let closure: Closure = call.req(engine_state, stack, 0)?;
53        let closure = ClosureEvalOnce::new_preserve_out_dest(engine_state, stack, closure);
54
55        // Get the start time after all other computation has been done.
56        let start_time = Instant::now();
57        closure.run_with_input(input)?.into_value(call.head)?;
58        let time = start_time.elapsed();
59
60        let output = Value::duration(time.as_nanos() as i64, call.head);
61        Ok(output.into_pipeline_data())
62    }
63
64    fn examples(&self) -> Vec<Example> {
65        vec![
66            Example {
67                description: "Time a closure containing one command",
68                example: "timeit { sleep 500ms }",
69                result: None,
70            },
71            Example {
72                description: "Time a closure with an input value",
73                example: "'A really long string' | timeit { split chars }",
74                result: None,
75            },
76            Example {
77                description: "Time a closure with an input stream",
78                example: "open some_file.txt | collect | timeit { split chars }",
79                result: None,
80            },
81            Example {
82                description: "Time a closure containing a pipeline",
83                example: "timeit { open some_file.txt | split chars }",
84                result: None,
85            },
86        ]
87    }
88}
89
90#[test]
91// Due to difficulty in observing side-effects from time closures,
92// checks that the closures have run correctly must use the filesystem.
93fn test_time_block() {
94    use nu_test_support::{nu, nu_repl_code, playground::Playground};
95    Playground::setup("test_time_block", |dirs, _| {
96        let inp = [
97            r#"[2 3 4] | timeit {to nuon | save foo.txt }"#,
98            "open foo.txt",
99        ];
100        let actual_repl = nu!(cwd: dirs.test(), nu_repl_code(&inp));
101        assert_eq!(actual_repl.err, "");
102        assert_eq!(actual_repl.out, "[2, 3, 4]");
103    });
104}
105
106#[test]
107fn test_time_block_2() {
108    use nu_test_support::{nu, nu_repl_code, playground::Playground};
109    Playground::setup("test_time_block", |dirs, _| {
110        let inp = [
111            r#"[2 3 4] | timeit {{result: $in} | to nuon | save foo.txt }"#,
112            "open foo.txt",
113        ];
114        let actual_repl = nu!(cwd: dirs.test(), nu_repl_code(&inp));
115        assert_eq!(actual_repl.err, "");
116        assert_eq!(actual_repl.out, "{result: [2, 3, 4]}");
117    });
118}
nu_command/debug/timeit.rs

nu_command/debug/
timeit.rs
