Picohttp

Fast HTTP request parser using picohttpparser.

Installation

Install the gem and add to the application's Gemfile by executing:

bundle add picohttp

Usage

require 'picohttp'

request = "GET /api/users?limit=10 HTTP/1.1\r\n" +
          "Host: api.example.com\r\n" +
          "User-Agent: MyApp/1.0\r\n" +
          "\r\n"

# Rack-compatible environment hash
env = Picohttp.parse_request_env(request)
# => {
#      "REQUEST_METHOD" => "GET",
#      "PATH_INFO" => "/api/users",
#      "QUERY_STRING" => "limit=10",
#      "SERVER_PROTOCOL" => "HTTP/1.1",
#      "HTTP_HOST" => "api.example.com",
#      "HTTP_USER_AGENT" => "MyApp/1.0"
#    }

Returns nil for incomplete requests, raises Picohttp::ParseError for invalid ones.

Environment fields

The produced hash uses CGI/Rack-style keys:

Key	Value	Set when
`REQUEST_METHOD`	The request method, e.g. `"GET"`, `"POST"`.	always
`SCRIPT_NAME`	Always `""`.	always
`PATH_INFO`	The request path with any query string removed, e.g. `"/api/users"`.	always
`QUERY_STRING`	The part of the target after `?`, or `""` when there is none.	always
`REQUEST_URI`	The full request target, e.g. `"/api/users?limit=10"`.	always
`SERVER_PROTOCOL`	`"HTTP/1.0"` or `"HTTP/1.1"`.	always
`SERVER_NAME`	The host portion of the `Host` header, with brackets kept for IPv6 literals (`"[::1]"`).	`Host` present
`SERVER_PORT`	The port from the `Host` header, e.g. `"8080"`.	`Host` has a port
`CONTENT_TYPE`	The `Content-Type` header (note: no `HTTP_` prefix).	header present
`CONTENT_LENGTH`	The `Content-Length` header (note: no `HTTP_` prefix).	header present

Every other request header becomes an HTTP_-prefixed key: the name is uppercased and - becomes _ (e.g. User-Agent → HTTP_USER_AGENT). Repeated headers are joined with , . A repeated Host header, or an HTTP/1.1 request without one, raises Picohttp::ParseError (RFC 7230 §5.4).

Starting from a template

Servers usually add the same constant keys to every env. parse_request_env_with_template starts from a copy of a template hash instead, which is faster than merging the constants in afterwards:

RACK_ENV_CONST = {
  "rack.url_scheme" => "http",
  "SERVER_SOFTWARE" => "MyServer/1.0",
}.freeze

env = Picohttp.parse_request_env_with_template(request, RACK_ENV_CONST)
# => {
#      "rack.url_scheme" => "http",
#      "SERVER_SOFTWARE" => "MyServer/1.0",
#      "REQUEST_METHOD" => "GET",
#      ...
#    }

The template is never modified and may be frozen. If a key is in both the template and the request, the request wins, but this isn't recommended.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/jhawthorn/picohttp. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Picohttp project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.