gflambe 🧯

Generate flame graphs from Gleam programs. This is a wrapper for the Erlang library eflambe

Installation

gleam add gflambe

Usage

This library provides two main functions. We’ll use string.append as an example subject for the graph.

apply

This method takes a function that returns Nil and a list of options, and generates a flame graph from its execution.

import gflambe
import gleam/string

pub fn main() {
  gflambe.apply(
    fn() {
      let _ = string.append("hello", "world")
      Nil
    },
    [gflambe.OutputDirectory("./test")],
  )
}

capture

This method takes: a tuple with the module name, function name and arity, a number of calls to capture and a list of options. It waits for the function to be called number_of_calls_to_capture times but doesn’t run it itself.

import gflambe
import gleam/erlang/process
import gleam/string

pub fn main() {
  process.spawn(fn() {
    process.sleep(500)
    string.append("hello", "world")
  })

  gflambe.capture(GflambeFunction("gleam@string", "append", 2), 1, [])
}

See the eflambe documentation for more information about how the library works and how it gets the data from the execution.