Saving ruby's benchmark output to a file - ruby

I wrote a short ruby script to time the run of a command line utility I have. I'm using the ruby's Benchmarkmodule as so:
Benchmark.bm(" "*7 + CAPTION, 7, FMTSTR, ">avg:") do |bench|
#this loops over a couple of runs
bench.report("Run #{run}: ") do
begin
Timeout::timeout(time) {
res = `#{command}`
}
rescue Timeout::Error
end
end
end
The timeout use is probably a bit crude but should be ok for my needs. The problem is Benchmark.bm just prints the benchmark results. I'd like to be able to save them to a file for further processing (it's run a couple of times in a single script so I don't want to just consume the terminal output - seems way too much effort for something this simple)

That is easier than you might think, just add the following lines to the beginning of your script.
$stdout = File.new('benchmark.log', 'w')
$stdout.sync = true
And everything is redirected to the file, off course if you need some output to the console you will have to stop the redirection like this.
$stdout = STDOUT
EDIT: here the scipt i used to test this
require 'benchmark'
$stdout = File.new('console.out', 'w')
$stdout.sync = true
array = (1..100000).to_a
hash = Hash[*array]
Benchmark.bm(15) do |x|
x.report("Array.include?") { 1000.times { array.include?(50000) } }
x.report("Hash.include?") { 1000.times { hash.include?(50000) } }
end

Related

Run benchmark but don't print the result

I have a benchmark like follows:
benchmark_result = Benchmark.bm do |x|
x.report { send(test_name) }
end
When I run this, I'm seeing output from two places:
The send(test_name) in the report block. I want to continue seeing this output.
The output from the Benchmark block, i.e. the resulting benchmark report is printed to the console. I don't want this to happen.
I've seen from here how to temporarily hide the console output. But the problem is that I want the inner block to continue printing its output. I just don't want to see the benchmark results.
When you call the report method on the Benchmark::Report object sent to the block by Benchmark.bm or Benchmark.benchmark, it will print to STDOUT. If you're just interested in the benchmark metrics without printing a report, you can do this:
benchmark_result = Benchmark.measure do
send(test_name)
end
It returns a Benchmark::Tms object that looks like this:
=> #<Benchmark::Tms:0x007fb5b1b40118
#cstime=0.0,
#cutime=0.0,
#label="",
#real=4.5693013817071915e-05,
#stime=0.0,
#total=0.0,
#utime=0.0>
If you're just interested in the elapsed real time used to execute your block, do the following (returns a Float):
benchmark_result = Benchmark.realtime do
send(test_name)
end
I've accepted Amit's answer because it seems canonical, but I did figure out another way to do it in the meantime.
From this question I have added the following code (slightly modified to include the touch/rm calls on the null.txt file):
def silence_output
# Store the original stderr and stdout in order to restore them later
#original_stderr = $stderr
#original_stdout = $stdout
# Redirect stderr and stdout
`touch null.txt`
$stderr = File.new(File.join(File.dirname(__FILE__), 'null.txt'), 'w')
$stdout = File.new(File.join(File.dirname(__FILE__), 'null.txt'), 'w')
end
# Replace stderr and stdout so anything else is output correctly
def enable_output
$stderr = #original_stderr
$stdout = #original_stdout
#original_stderr = nil
#original_stdout = nil
`rm null.txt`
end
With this, I can accomplish my goal using the following:
silence_output
benchmark_result = Benchmark.bm do |x|
x.report do
enable_output
send(test_name)
silence_output
end
end
enable_output
Although after seeing a better way to do it, this seems very hacky.

Executing program from command line

I have done a program that sends requests to a url and saves them in a file. The program is this, and is working perfectly:
require 'open-uri'
n = gets.to_i
out = gets.chomp
output = File.open( out, "w" )
for i in 1..n
response = open('http://slowapi.com/delay/10').read
output << (response +"\n")
puts response
end
output.close
I want to modify it so that I can execute it from command line. I must run it like this:
fle --test abc -n 300 -f output
What must I do?
Something like this should do the trick:
#!/usr/bin/env ruby
require 'open-uri'
require 'optparse'
# Prepare the parser
options = {}
oparser = OptionParser.new do |opts|
opts.banner = "Usage: fle [options]"
opts.on('-t', '--test [STRING]', 'Test string') { |v| options[:test] = v }
opts.on('-n', '--count COUNT', 'Number of times to send request') { |v| options[:count] = v.to_i }
opts.on('-f', '--file FILE', 'Output file', :REQUIRED) { |v| options[:out_file] = v }
end
# Parse our options
oparser.parse! ARGV
# Check if required options have been filled, print help and exit otherwise.
if options[:count].nil? || options[:out_file].nil?
$stderr.puts oparser.help
exit 1
end
File::open(options[:out_file], 'w') do |output|
options[:count].times do
response = open('http://slowapi.com/delay/10').read
output.puts response # Puts the response into the file
puts response # Puts the response to $stdout
end
end
Here's a more idiomatic way of writing your code:
require 'open-uri'
n = gets.to_i
out = gets.chomp
File.open(out, 'w') do |fo|
n.times do
response = open('http://slowapi.com/delay/10').read
fo.puts response
puts response
end
end
This uses File.open with a block, which allows Ruby to close the file once the block exits. It's a much better practice than assigning the file handle to a variable and use that to close the file later.
How to handle passing in variables from the command-line as options is handled in the other answers.
The first step would be to save you program in a file, add #!/usr/bin/env ruby at the top and chmod +x yourfilename to be able to execute your file.
Now you are able to run your script from the command line.
Secondly, you need to modify your script a little bit to pick up command line arguments. In Ruby, the command line arguments are stored inside ARGV, so something like
ARGV.each do|a|
puts "Argument: #{a}"
end
allows you to retrieve command line arguments.

Why is Ruby's popen3 crashing because "Too many files open"?

I am using Popen3 to run some Perl scrips and then dump their output into a text file. Once in the text file, I search for the result of the Perl script. I get the error after running for about 40 minutes, which is about 220 files.
ruby/1.8/open3.rb:49:in `pipe': Too many open files (Errno::EMFILE)
from /ruby/1.8/open3.rb:49:in `popen3'
from ./RunAtfs.rb:9
from ./RunAtfs.rb:8:in `glob'
from ./RunAtfs.rb:8
The script is below.
require 'logger'
require 'open3'
atfFolder = ARGV[0]
testResult = ARGV[1]
res = "result.txt"
open('result.txt', 'w') { }
Dir.glob(atfFolder+'/*.pl') do |atfTest|
Open3.popen3("atf.pl -c run-config.pl -t #{atfTest}") do |i, o, e, t|
while line = e.gets
$testFile = testResult + line[/^[0-9]+$/].to_s + "testOutput.txt"
log = Logger.new($testFile)
log.info(line)
end
log.close
end
lastLine = `tail +1 #{$testFile}`
file = File.open(res, 'a')
if(lastLine.include? "(PASSED)")
file.puts("Test #{atfTest} --> Passed")
file.close
File.delete($testFile)
else
file.puts("Test #{atfTest} --> Failed!")
file.close
end
end
This script is processing 4900 Perl files so I don't know if that is just too many files for popen3 or I am not using it correctly.
Thanks for helping me!
I refactored my script after some very helpful pointers! The code is working great!
require 'open3'
atf_folder, test_result = ARGV[0, 2]
File.open('result.txt', 'w') do |file| end
Dir.glob("#{ atf_folder }/*.pl") do |atf_test|
test_file = atf_test[/\/\w+.\./][1..-2].to_s + ".txt"
comp_test_path = test_result + test_file
File.open(comp_test_path, 'w') do |file| end
Open3.popen3("atf.pl -c run-config.pl -t #{ atf_test }") do |i, o, e, t|
while line = e.gets
File.open(comp_test_path, 'a') do |file|
file.puts(line)
end
end
end
last_line = `tail +1 #{comp_test_path}`
File.open('result.txt', 'a') do |file|
output_str = if (last_line.include? "(PASSED)")
File.delete(comp_test_path)
"Passed"
else
"Failed!"
end
file.puts "Test #{ atf_test } --> #{ output_str }"
end
end
Consider this:
require 'logger'
require 'open3'
atf_folder, test_result = ARGV[0, 2]
Dir.glob("#{ atf_folder }/*.pl") do |atf_test|
Open3.popen3("atf.pl -c run-config.pl -t #{ atf_test }") do |i, o, e, t|
while line = e.gets
$testFile = test_result + line[/^[0-9]+$/].to_s + "testOutput.txt"
log = Logger.new($testFile)
log.info(line)
log.close
end
end
lastLine = `tail +1 #{ $testFile }`
File.open('result.txt', 'a') do |file|
output_str = if (lastLine.include? "(PASSED)")
File.delete($testFile)
"Passed"
else
"Failed!"
end
file.puts "Test #{ atf_test } --> #{ output_str }"
end
end
It's untested, of course, since there's no sample data, but it's written more idomatically for Ruby.
Things to note:
atf_folder, test_result = ARGV[0, 2] slices the ARGV array and uses parallel assignment to retrieve both parameters at once. You should test to see that you got values for them. And, as you move to more complex scripts, take advantage of the OptionParser class that comes in Ruby's STDLIB.
Ruby lets us pass a block to File.open, which automatically closes the file when the block exits. This is a major strength of Ruby and helps reduce errors like you're seeing. Logger doesn't do that, so extra care has to be take to avoid leaving hanging file-handles, like you're doing. Instead, use:
log = Logger.new($testFile)
log.info(line)
log.close
to immediately close the handle. You are doing it outside the loop, not inside it, so you had a bunch of open handles.
Also consider whether you need Logger, or if a regular File.open would suffice. Logger has additional overhead.
Your use of $testFile is questionable. $variables are globals, and their use is generally an indicator you're doing something wrong, at least until you understand why and when you should use them. I'd refactor the code using that.
In Ruby, variables and methods are in snake_case, not CamelCase, which is used for classes and modules. That doesn't seem like much until_you_run_into CodeDoingTheWrongThing and_have_to_read_it. (Notice how your brain bogged down deciphering the camel-case?)
In general, I question whether this is the fastest way to do what you want. I suspect you could write a shell script using grep or tail that would at least keep up, and maybe run faster. You might sit down with your sysadmin and do some brain-pickin'.

How to test stdin for a CLI using rspec

I'm making a small Ruby program and can't figure out how to write RSpec specs that simulate multiple user command line inputs (the functionality itself works). I think this StackOverflow answer probably covers ground that is closest to where I am, but it's not quite what I need. I am using Thor for the command line interface, but I don't think this is an issue with anything in Thor.
The program can read in commands either from a file or the command line, and I've been able to successfully write tests to read in an execute them. Here's some code:
cli.rb
class CLI < Thor
# ...
method_option :filename, aliases: ['-f'],
desc: "name of the file containing instructions",
banner: 'FILE'
desc "execute commands", "takes actions as per commands"
def execute
thing = Thing.new
instruction_set do |instructions|
instructions.each do |instruction|
command, args = parse_instruction(instruction) # private helper method
if valid_command?(command, args) # private helper method
response = thing.send(command, *args)
puts format(response) if response
end
end
end
end
# ...
no_tasks do
def instruction_set
if options[:filename]
yield File.readlines(options[:filename]).map { |a| a.chomp }
else
puts usage
print "> "
while line = gets
break if line =~ /EXIT/i
yield [line]
print "> "
end
end
end
# ..
end
I've tested successfully for executing commands contained in a file with this code:
spec/cli_spec.rb
describe CLI do
let(:cli) { CLI.new }
subject { cli }
describe "executing instructions from a file" do
let(:default_file) { "instructions.txt" }
let(:output) { capture(:stdout) { cli.execute } }
context "containing valid test data" do
valid_test_data.each do |data|
expected_output = data[:output]
it "should parse the file contents and output a result" do
cli.stub(:options) { { filename: default_file } } # Thor options hash
File.stub(:readlines).with(default_file) do
StringIO.new(data[:input]).map { |a| a.strip.chomp }
end
output.should == expected_output
end
end
end
end
# ...
end
and the valid_test_data referred to above is in the following form:
support/utilities.rb
def valid_test_data
[
{
input: "C1 ARGS\r
C2\r
C3\r
C4",
output: "OUTPUT\n"
}
# ...
]
end
What I want to do now is exactly the same thing but instead of reading each command from the 'file' and executing it, I want to somehow simulate a user typing in to stdin. The code below is utterly wrong, but I hope it can convey the direction I want to go.
spec/cli_spec.rb
# ...
# !!This code is wrong and doesn't work and needs rewriting!!
describe "executing instructions from the command line" do
let(:output) { capture(:stdout) { cli.execute } }
context "with valid commands" do
valid_test_data.each do |data|
let(:expected_output) { data[:output] }
let(:commands) { StringIO.new(data[:input]).map { |a| a.strip } }
it "should process the commands and output the results" do
commands.each do |command|
cli.stub!(:gets) { command }
if command == :report
STDOUT.should_receive(:puts).with(expected_output)
else
STDOUT.should_receive(:puts).with("> ")
end
end
output.should include(expected_output)
end
end
end
end
I've tried using cli.stub(:puts) in various places, and generally rearranging this code around a lot, but can't seem to get any of my stubs to put data in stdin. I don't know if I can parse the set of inputs I expect from the command line in the same way as I do with a file of commands, or what code structure I should be using to solve this issue. If someone who has spec-ed up command-line apps could chime in, that would be great. Thanks.
Rather than stubbing the universe, I think a few bits of indirection would help you write a unit test for this code. The simplest thing you can do is to allow the IO object for output to be injected, and default it to STDOUT:
class CLI < Thor
def initialize(stdout=STDOUT)
#stdout = stdout
end
# ...
#stdout.puts # instead of raw puts
end
Then, in your tests, you can use a StringIO to examine what was printed:
let(:stdout) { StringIO.new }
let(:cli) { CLI.new(stdout) }
Another option is to use Aruba or something like it, and write full-on integration tests, where you actually run your program. This has other challenges as well (such as being nondestructive and making sure not to squash/use system or user files), but will be a better test of your app.
Aruba is Cucumber, but the assertions can use RSPec matchers. Or, you can use Aruba's Ruby API (which is undocumented, but public and works great) to do this without the hassle of Gherkin.
Either way, you will benefit from making your code a bit more test-friendly.
I ended up finding a solution that I think fairly closely mirrors the code for executing instructions from a file. I overcame the main hurdle by finally realizing that I could write cli.stub(:gets).and_return and pass it in the array of commands I wanted to execute (as parameters thanks to the splat * operator), and then pass it the "EXIT" command to finish. So simple, yet so elusive. Many thanks go to this StackOverflow question and answer for pushing me over the line.
Here is the code:
describe "executing instructions from the command line" do
let(:output) { capture(:stdout) { cli.execute } }
context "with valid commands" do
valid_test_data.each do |data|
let(:expected_output) { data[:output] }
let(:commands) { StringIO.new(data[:input]).map { |a| a.strip } }
it "should process the commands and output the results" do
cli.stub(:gets).and_return(*commands, "EXIT")
output.should include(expected_output)
end
end
end
# ...
end
Have you looked at Aruba? It lets you write Cucumber feature tests for command line programs. You can define the input to your CLI that way.
You can write you feature definitions with RSpec, so it's not completely new.
You can stub all Thor::Actions with Rspec's allow_any_instance_of
here is one example:
it "should import list" do
allow_any_instance_of(Thor::Actions).to receive(:yes?).and_return(true)
end

Sinatra 1.3 Streaming w/ Ruby stdout redirection

I would like to use Sinatra's Streaming capability introduced in 1.3 coupled with some stdout redirection. It would basically be a live streaming output of a long running job. I looked into this question and the Sinatra streaming sample in the README.
Running 1.8.7 on OSX:
require 'stringio'
require 'sinatra'
$stdout.sync = true
module Kernel
def capture_stdout
out = StringIO.new
$stdout = out
yield out
ensure
$stdout = STDOUT
end
end
get '/' do
stream do |out|
out << "Part one of a three part series... <br>\n"
sleep 1
out << "...part two... <br>\n"
sleep 1
out << "...and now the conclusion...\n"
Kernel.capture_stdout do |stream|
Thread.new do
until (line = stream.gets).nil? do
out << line
end
end
method_that_prints_text
end
end
end
def method_that_prints_text
puts "starting long running job..."
sleep 3
puts "almost there..."
sleep 3
puts "work complete!"
end
So this bit of code prints out the first three strings properly, and blocks while the method_that_prints_text executes and does not print anything to the browser. My feeling is that stdout is empty on the first call and it never outputs to the out buffer. I'm not quite sure what the proper ordering would be and would appreciate any suggestions.
I tried a few of the EventMachine implementations mentioned in the question above, but couldn't get them to work.
UPDATE
I tried something slightly different to where I had the method run in a new thread, and override STDOUT for that thread as described here...
Instead of Kernel.capture_stdout above...
s = StringIO.new
Thread.start do
Thread.current[:stdout] = s
method_that_prints_text
end.join
while line = s.gets do
out << line
end
out << s.string
With the ThreadOut module listed in the link above, this seems to work a bit better. However it doesn't stream. The only time something is printed to the browser is on the final line out << s.string. Does StringIO not have the capability to stream?
I ended up solving this by discovering that s.string was updated periodically as time went on, so I just captured the output in a separate thread and grabbed the differences and streamed them out. It appears as though string redirection doesn't behave like a normal IO object.
s = StringIO.new
t = Thread.start do
Thread.current[:stdout] = s
method_that_prints_text
sleep 2
end
displayed_text = ''
while t.alive? do
current_text = s.string
unless (current_text.eql?(displayed_text))
new_text = current_text[displayed_text.length..current_text.length]
out << new_text
displayed_text = current_text * 1
end
sleep 2
end

Resources