Say I've got:
get '/' do
$random = Random.rand()
response.body = $random
end
If I have thousands of requests per second coming to /, will the $random be shared and 'leak' outside the context or will it act like a 'local' variable to the get block?
I imagine if it was defined outside of the context of get '/' do
it would indeed be shared but I wonder if there's a mechanic to $ in ruby that I'm not aware of.
This part of the Sinatra README about scope is always helpful to read but if you only need the variable to persist for the request then I think there are 3 main ways I'd suggest going about this, and really the key is a filter
before do
@my_log = []
end
get "/" do
@my_log << "hello"
@my_log << "world"
@my_log.inspect
end
get "/something-else" do
@my_log << "is visible here too"
end
# => output is ["hello", "world"]
@my_log
will go out of scope at the end of the request and be re-initialised at the beginning of the next one. It will be accessible by any route, so if for example you used pass
to pass it on to another route that would be the only time the other blocks could see what had been set by the prior route block.
set :mylog, []
Then same as above, just replace @my_log
with settings.my_log
. Without the before
block reinitialising it then the contents of @my_log
would be persisted across requests.
# I always do this within a config block as then it's only initialised once
config do
uri = URI.parse(ENV["URL_TO_REDIS"])
set :redis, Redis.new(:host => uri.host, :port => uri.port, :password => uri.password)
end
Now the redis instance is available via settings.redis
. No need to worry about variable scope (I'd use locals with it), just push straight to Redis. You get the best of both worlds then, but if you want you could do:
before do
@my_log = []
end
get "/" do
@my_log << "hello"
@my_log << "world"
"Hello, World"
end
after do
settings.redis.set "some_key", @my_log
settings.redis.expire "some_key", 600 # or whatever
end
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With