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 if `--output` is not set."
21    }
22
23    fn signature(&self) -> nu_protocol::Signature {
24        Signature::build("timeit")
25            .required("command", SyntaxShape::Closure(None), "The closure to run.")
26            .switch("output", "Include the closure output.", Some('o'))
27            .input_output_types(vec![
28                (Type::Any, Type::Duration),
29                (Type::Nothing, Type::Duration),
30                (
31                    Type::Any,
32                    Type::Record(Box::new([
33                        ("time".into(), Type::Duration),
34                        ("output".into(), Type::Any),
35                    ])),
36                ),
37                (
38                    Type::Nothing,
39                    Type::Record(Box::new([
40                        ("time".into(), Type::Duration),
41                        ("output".into(), Type::Any),
42                    ])),
43                ),
44            ])
45            .allow_variants_without_examples(true)
46            .category(Category::Debug)
47    }
48
49    fn search_terms(&self) -> Vec<&str> {
50        vec!["timing", "timer", "benchmark", "measure"]
51    }
52
53    fn requires_ast_for_arguments(&self) -> bool {
54        true
55    }
56
57    fn run(
58        &self,
59        engine_state: &EngineState,
60        stack: &mut Stack,
61        call: &Call,
62        input: PipelineData,
63    ) -> Result<PipelineData, ShellError> {
64        // reset outdest, so the command can write to stdout and stderr.
65        let stack = &mut stack.push_redirection(None, None);
66
67        let include_output = call.has_flag(engine_state, stack, "output")?;
68        let closure: Closure = call.req(engine_state, stack, 0)?;
69        let closure = ClosureEvalOnce::new_preserve_out_dest(engine_state, stack, closure);
70
71        // Get the start time after all other computation has been done.
72        let start_time = Instant::now();
73        let closure_output = closure.run_with_input(input)?.into_value(call.head)?;
74        let time = Value::duration(start_time.elapsed().as_nanos() as i64, call.head);
75
76        let output = if include_output {
77            Value::record(
78                record! {
79                "time" => time,
80                "output" => closure_output
81                },
82                call.head,
83            )
84        } else {
85            time
86        };
87
88        Ok(output.into_pipeline_data())
89    }
90
91    fn examples(&self) -> Vec<Example<'_>> {
92        vec![
93            #[cfg(not(test))]
94            Example {
95                description: "Time a closure containing one command",
96                example: "timeit { sleep 500ms }",
97                result: Some(Value::test_duration(500_631_800)),
98            },
99            Example {
100                description: "Time a closure with an input value",
101                example: "'A really long string' | timeit { split chars }",
102                result: None,
103            },
104            Example {
105                description: "Time a closure with an input stream",
106                example: "open some_file.txt | collect | timeit { split chars }",
107                result: None,
108            },
109            Example {
110                description: "Time a closure containing a pipeline",
111                example: "timeit { open some_file.txt | split chars }",
112                result: None,
113            },
114            #[cfg(not(test))]
115            Example {
116                description: "Time a closure and also return the output",
117                example: "timeit --output { 'example text' }",
118                result: Some(Value::test_record(record! {
119                "time" => Value::test_duration(14328),
120                "output" => Value::test_string("example text")})),
121            },
122        ]
123    }
124}
125
126#[test]
127// Due to difficulty in observing side-effects from time closures,
128// checks that the closures have run correctly must use the filesystem.
129fn test_time_block() {
130    use nu_test_support::{nu, nu_repl_code, playground::Playground};
131    Playground::setup("test_time_block", |dirs, _| {
132        let inp = [
133            r#"[2 3 4] | timeit {to nuon | save foo.txt }"#,
134            "open foo.txt",
135        ];
136        let actual_repl = nu!(cwd: dirs.test(), nu_repl_code(&inp));
137        assert_eq!(actual_repl.err, "");
138        assert_eq!(actual_repl.out, "[2, 3, 4]");
139    });
140}
141
142#[test]
143fn test_time_block_2() {
144    use nu_test_support::{nu, nu_repl_code, playground::Playground};
145    Playground::setup("test_time_block", |dirs, _| {
146        let inp = [
147            r#"[2 3 4] | timeit {{result: $in} | to nuon | save foo.txt }"#,
148            "open foo.txt",
149        ];
150        let actual_repl = nu!(cwd: dirs.test(), nu_repl_code(&inp));
151        assert_eq!(actual_repl.err, "");
152        assert_eq!(actual_repl.out, "{result: [2, 3, 4]}");
153    });
154}
nu_command/debug/timeit.rs

nu_command/debug/
timeit.rs
