Ethon

In Greek mythology, Ethon, the son of Typhoeus and Echidna, is a gigantic eagle. So much for the history. In the modern world, Ethon is a very basic libcurl wrapper using ffi.

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With bundler:

gem "ethon"

With rubygems:

gem install ethon

Making the first request is simple:

easy = Ethon::Easy.new(url: "www.example.com")
easy.perform
#=> :ok

You have access to various options, such as following redirects:

easy = Ethon::Easy.new(url: "www.example.com", followlocation: true)
easy.perform
#=> :ok

Once you're done you can inspect the response code and body:

easy = Ethon::Easy.new(url: "www.example.com", followlocation: true)
easy.perform
easy.response_code
#=> 200
easy.response_body
#=> "<!doctype html><html ..."

In order to make life easier, there are some helpers for making HTTP requests:

easy = Ethon::Easy.new
easy.http_request("www.example.com", :get, { params: {a: 1} })
easy.perform
#=> :ok

easy = Ethon::Easy.new
easy.http_request("www.example.com", :post, { params: { a: 1 }, body: { b: 2 } })
easy.perform
#=> :ok

This is really handy when making requests since you don't have to care about setting everything up correctly.

Standard http2 servers require the client to connect once and create a session (multi) and then add simple requests to the multi handler. The perform method then takes all the requests in the multi handler and sends them to the server.

See the following example

multi = Ethon::Multi.new
easy = Ethon::Easy.new

easy.http_request("www.example.com/get", :get, { http_version: :httpv2_0 })

# Sending a request with http version 2 will send an Upgrade header to the server, which many older servers will not support
# See below for more info: https://everything.curl.dev/http/http2
# If this is a problem, send the below:
easy.http_request("www.example.com/get", :get, { http_version: :httpv2_prior_knowledge })

# To set the server to use http2 with https and http1 with http, send the following:
easy.http_request("www.example.com/get", :get, { http_version: :httpv2_tls })

multi.add(easy)
multi.perform

Ethon can be used from multiple threads, but it does not synchronize access to individual handles. Follow libcurl's thread-safety rules:

• Separate Ethon::Easy and Ethon::Multi instances may run concurrently in different threads.
• Do not use the same Easy or Multi instance from more than one thread at a time. This includes changing its options while a transfer is running.
• Callbacks run on the thread performing the transfer. Synchronize any shared application state accessed by a callback.
• When using threads, set nosignal: true unless your libcurl uses a threaded or c-ares resolver. See libcurl's signal guidance for the associated DNS timeout and SIGPIPE considerations.

With libcurl older than 7.84.0, create an Ethon handle before starting other application threads so libcurl's global initialization happens while the process is still single-threaded.

Ethon handles and initialized libcurl state must not be inherited across a fork. Create all Easy and Multi instances after worker processes fork, or use fork followed by exec. Ethon raises Ethon::Errors::ForkSafety when a child process tries to use a handle created by its parent.

(The MIT License)

Copyright © 2012-2016 Hans Hasselberg

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.