Files
nushell/crates/nu-command/src/debug/profile.rs
Stefan Holderbach 95b78eee25 Change the usage misnomer to "description" (#13598)
# Description
    
The meaning of the word usage is specific to describing how a command
function is *used* and not a synonym for general description. Usage can
be used to describe the SYNOPSIS or EXAMPLES sections of a man page
where the permitted argument combinations are shown or example *uses*
are given.
Let's not confuse people and call it what it is a description.

Our `help` command already creates its own *Usage* section based on the
available arguments and doesn't refer to the description with usage.

# User-Facing Changes

`help commands` and `scope commands` will now use `description` or
`extra_description`
`usage`-> `description`
`extra_usage` -> `extra_description`

Breaking change in the plugin protocol:

In the signature record communicated with the engine.
`usage`-> `description`
`extra_usage` -> `extra_description`

The same rename also takes place for the methods on
`SimplePluginCommand` and `PluginCommand`

# Tests + Formatting
- Updated plugin protocol specific changes
# After Submitting
- [ ] update plugin protocol doc
2024-08-22 12:02:08 +02:00

160 lines
6.1 KiB
Rust

use nu_engine::{command_prelude::*, ClosureEvalOnce};
use nu_protocol::{
debugger::{Profiler, ProfilerOptions},
engine::Closure,
};
#[derive(Clone)]
pub struct DebugProfile;
impl Command for DebugProfile {
fn name(&self) -> &str {
"debug profile"
}
fn signature(&self) -> nu_protocol::Signature {
Signature::build("debug profile")
.required(
"closure",
SyntaxShape::Closure(None),
"The closure to profile.",
)
.switch("spans", "Collect spans of profiled elements", Some('s'))
.switch(
"expand-source",
"Collect full source fragments of profiled elements",
Some('e'),
)
.switch(
"values",
"Collect pipeline element output values",
Some('v'),
)
.switch("expr", "Collect expression types", Some('x'))
.switch("instructions", "Collect IR instructions", Some('i'))
.switch("lines", "Collect line numbers", Some('l'))
.named(
"max-depth",
SyntaxShape::Int,
"How many blocks/closures deep to step into (default 2)",
Some('m'),
)
.input_output_types(vec![(Type::Any, Type::table())])
.category(Category::Debug)
}
fn description(&self) -> &str {
"Profile pipeline elements in a closure."
}
fn extra_description(&self) -> &str {
r#"The profiler profiles every evaluated pipeline element inside a closure, stepping into all
commands calls and other blocks/closures.
The output can be heavily customized. By default, the following columns are included:
- depth : Depth of the pipeline element. Each entered block adds one level of depth. How many
blocks deep to step into is controlled with the --max-depth option.
- id : ID of the pipeline element
- parent_id : ID of the parent element
- source : Source code of the pipeline element. If the element has multiple lines, only the
first line is used and `...` is appended to the end. Full source code can be shown
with the --expand-source flag.
- duration_ms : How long it took to run the pipeline element in milliseconds.
- (optional) span : Span of the element. Can be viewed via the `view span` command. Enabled with
the --spans flag.
- (optional) expr : The type of expression of the pipeline element. Enabled with the --expr flag.
- (optional) output : The output value of the pipeline element. Enabled with the --values flag.
To illustrate the depth and IDs, consider `debug profile { if true { echo 'spam' } }`. There are
three pipeline elements:
depth id parent_id
0 0 0 debug profile { do { if true { 'spam' } } }
1 1 0 if true { 'spam' }
2 2 1 'spam'
Each block entered increments depth by 1 and each block left decrements it by one. This way you can
control the profiling granularity. Passing --max-depth=1 to the above would stop at
`if true { 'spam' }`. The id is used to identify each element. The parent_id tells you that 'spam'
was spawned from `if true { 'spam' }` which was spawned from the root `debug profile { ... }`.
Note: In some cases, the ordering of piepeline elements might not be intuitive. For example,
`[ a bb cc ] | each { $in | str length }` involves some implicit collects and lazy evaluation
confusing the id/parent_id hierarchy. The --expr flag is helpful for investigating these issues."#
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let closure: Closure = call.req(engine_state, stack, 0)?;
let collect_spans = call.has_flag(engine_state, stack, "spans")?;
let collect_expanded_source = call.has_flag(engine_state, stack, "expanded-source")?;
let collect_values = call.has_flag(engine_state, stack, "values")?;
let collect_exprs = call.has_flag(engine_state, stack, "expr")?;
let collect_instructions = call.has_flag(engine_state, stack, "instructions")?;
let collect_lines = call.has_flag(engine_state, stack, "lines")?;
let max_depth = call
.get_flag(engine_state, stack, "max-depth")?
.unwrap_or(2);
let profiler = Profiler::new(
ProfilerOptions {
max_depth,
collect_spans,
collect_source: true,
collect_expanded_source,
collect_values,
collect_exprs,
collect_instructions,
collect_lines,
},
call.span(),
);
let lock_err = |_| ShellError::GenericError {
error: "Profiler Error".to_string(),
msg: "could not lock debugger, poisoned mutex".to_string(),
span: Some(call.head),
help: None,
inner: vec![],
};
engine_state
.activate_debugger(Box::new(profiler))
.map_err(lock_err)?;
let result = ClosureEvalOnce::new(engine_state, stack, closure).run_with_input(input);
// Return potential errors
let pipeline_data = result?;
// Collect the output
let _ = pipeline_data.into_value(call.span());
Ok(engine_state
.deactivate_debugger()
.map_err(lock_err)?
.report(engine_state, call.span())?
.into_pipeline_data())
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Profile config evaluation",
example: "debug profile { source $nu.config-path }",
result: None,
},
Example {
description: "Profile config evaluation with more granularity",
example: "debug profile { source $nu.config-path } --max-depth 4",
result: None,
},
]
}
}