Introduce HTTP::Session for thread-safe request building

Chainable option methods (headers, timeout, cookies, etc.) now return an
HTTP::Session instead of an HTTP::Client. Session is a lightweight,
thread-safe builder that creates a fresh Client for each request, fixing
the thread-safety issue where sharing a configured client across threads
caused IOError due to shared mutable connection state.

HTTP.retriable now returns an HTTP::Retriable::Session.

HTTP.persistent still returns an HTTP::Client since persistent
connections require mutable state.

Closes #306.

Author: sferik

.rubocop/style.yml

@@ -36,9 +36,11 @@ Style/OptionHash:
   Enabled: true
   Exclude:
     - 'lib/http/chainable.rb'
+    - 'lib/http/chainable/verbs.rb'
     - 'lib/http/client.rb'
     - 'lib/http/options.rb'
     - 'lib/http/redirector.rb'
+    - 'lib/http/session.rb'
     - 'lib/http/timeout/null.rb'
     - 'test/support/dummy_server.rb'
 

CHANGELOG.md

@@ -31,6 +31,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- **BREAKING** Chainable option methods (`.headers`, `.timeout`, `.cookies`,
+  `.auth`, `.follow`, `.via`, `.use`, `.encoding`, `.nodelay`, `.basic_auth`,
+  `.accept`) now return a thread-safe `HTTP::Session` instead of `HTTP::Client`.
+  `Session` creates a new `Client` for each request, making it safe to share a
+  configured session across threads. `HTTP.persistent` still returns
+  `HTTP::Client` since persistent connections require mutable state. Code that
+  calls HTTP verb methods (`.get`, `.post`, etc.) or accesses `.default_options`
+  is unaffected. Code that checks `is_a?(HTTP::Client)` on the return value of
+  chainable methods will need to be updated to check for `HTTP::Session`
+- **BREAKING** `.retriable` now returns `HTTP::Retriable::Session` instead of
+  `HTTP::Retriable::Client`
 - Improved error message when request body size cannot be determined to suggest
   setting `Content-Length` explicitly or using chunked `Transfer-Encoding` (#560)
 - **BREAKING** `Connection#readpartial` now raises `EOFError` instead of

README.md

@@ -126,6 +126,34 @@ end
 Pattern matching is also supported on `HTTP::Response::Status`, `HTTP::Headers`,
 `HTTP::ContentType`, and `HTTP::URI`.
 
+### Thread Safety
+
+Configured sessions are safe to share across threads:
+
+```ruby
+# Build a session once, use it from any thread
+session = HTTP.headers("Accept" => "application/json")
+              .timeout(10)
+              .auth("Bearer token")
+
+threads = 10.times.map do
+  Thread.new { session.get("https://example.com/api/data") }
+end
+threads.each(&:join)
+```
+
+Chainable configuration methods (`.headers`, `.timeout`, `.auth`, etc.) return
+an `HTTP::Session`, which creates a fresh `HTTP::Client` for every request.
+
+Persistent connections (`HTTP.persistent`) return an `HTTP::Client`, which is
+**not** thread-safe. For thread-safe persistent connections, use the
+[connection_pool](https://rubygems.org/gems/connection_pool) gem:
+
+```ruby
+pool = ConnectionPool.new(size: 5) { HTTP.persistent("https://example.com") }
+pool.with { |http| http.get("/path") }
+```
+
 ## Supported Ruby Versions
 
 This library aims to support and is [tested against][build-link]

lib/http.rb

@@ -5,8 +5,10 @@
 require "http/timeout/per_operation"
 require "http/timeout/global"
 require "http/chainable"
+require "http/session"
 require "http/client"
 require "http/retriable/client"
+require "http/retriable/session"
 require "http/connection"
 require "http/options"
 require "http/feature"
@@ -21,14 +23,14 @@ module HTTP
   extend Chainable
 
   class << self
-    # Set default headers and return a chainable client instance
+    # Set default headers and return a chainable session
     #
     # @example
     #   HTTP[:accept => "text/html"].get("https://example.com")
     #
     # @param headers [Hash] headers to set
     #
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     #
     # @api public
     alias [] headers

lib/http/chainable.rb

@@ -2,129 +2,14 @@
 
 require "http/base64"
 require "http/chainable/helpers"
+require "http/chainable/verbs"
 require "http/headers"
 
 module HTTP
   # HTTP verb methods and client configuration DSL
   module Chainable
     include HTTP::Base64
-
-    # Request a get sans response body
-    #
-    # @example
-    #   HTTP.head("http://example.com")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def head(uri, options = {})
-      request :head, uri, options
-    end
-
-    # Get a resource
-    #
-    # @example
-    #   HTTP.get("http://example.com")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def get(uri, options = {})
-      request :get, uri, options
-    end
-
-    # Post to a resource
-    #
-    # @example
-    #   HTTP.post("http://example.com", body: "data")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def post(uri, options = {})
-      request :post, uri, options
-    end
-
-    # Put to a resource
-    #
-    # @example
-    #   HTTP.put("http://example.com", body: "data")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def put(uri, options = {})
-      request :put, uri, options
-    end
-
-    # Delete a resource
-    #
-    # @example
-    #   HTTP.delete("http://example.com/resource")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def delete(uri, options = {})
-      request :delete, uri, options
-    end
-
-    # Echo the request back to the client
-    #
-    # @example
-    #   HTTP.trace("http://example.com")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def trace(uri, options = {})
-      request :trace, uri, options
-    end
-
-    # Return the methods supported on the given URI
-    #
-    # @example
-    #   HTTP.options("http://example.com")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def options(uri, options = {})
-      request :options, uri, options
-    end
-
-    # Convert to a transparent TCP/IP tunnel
-    #
-    # @example
-    #   HTTP.connect("http://example.com")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def connect(uri, options = {})
-      request :connect, uri, options
-    end
-
-    # Apply partial modifications to a resource
-    #
-    # @example
-    #   HTTP.patch("http://example.com/resource", body: "data")
-    #
-    # @param [String, URI] uri URI to request
-    # @param [Hash] options request options
-    # @return [HTTP::Response]
-    # @api public
-    def patch(uri, options = {})
-      request :patch, uri, options
-    end
+    include Verbs
 
     # Make an HTTP request with the given verb
     #
@@ -135,7 +20,7 @@ def patch(uri, options = {})
     # @return [HTTP::Response]
     # @api public
     def request(verb, uri, opts = {})
-      branch(default_options).request(verb, uri, opts)
+      make_client(default_options).request(verb, uri, opts)
     end
 
     # Prepare an HTTP request with the given verb
@@ -147,7 +32,7 @@ def request(verb, uri, opts = {})
     # @return [HTTP::Request]
     # @api public
     def build_request(verb, uri, opts = {})
-      branch(default_options).build_request(verb, uri, opts)
+      make_client(default_options).build_request(verb, uri, opts)
     end
 
     # Set timeout on the request
@@ -165,7 +50,7 @@ def build_request(verb, uri, opts = {})
     # @overload timeout(global_timeout)
     #   Adds a global timeout to the full request
     #   @param [Numeric] global_timeout
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def timeout(options)
       klass, options = case options
@@ -222,7 +107,8 @@ def timeout(options)
     # @return [HTTP::Client, Object]
     # @api public
     def persistent(host, timeout: 5)
-      p_client = branch default_options.merge(keep_alive_timeout: timeout).with_persistent(host)
+      options = default_options.merge(keep_alive_timeout: timeout).with_persistent(host)
+      p_client = make_client(options)
       return p_client unless block_given?
 
       yield p_client
@@ -237,7 +123,7 @@ def persistent(host, timeout: 5)
     #
     # @param [Array] proxy
     # @raise [Request::Error] if HTTP proxy is invalid
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def via(*proxy)
       proxy_hash = build_proxy_hash(proxy)
@@ -254,7 +140,7 @@ def via(*proxy)
     #   HTTP.follow.get("http://example.com")
     #
     # @param [Hash] options redirect options
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @see Redirector#initialize
     # @api public
     def follow(options = {})
@@ -267,7 +153,7 @@ def follow(options = {})
     #   HTTP.headers("Accept" => "text/plain").get("http://example.com")
     #
     # @param [Hash] headers request headers
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def headers(headers)
       branch default_options.with_headers(headers)
@@ -279,7 +165,7 @@ def headers(headers)
     #   HTTP.cookies(session: "abc123").get("http://example.com")
     #
     # @param [Hash] cookies cookies to set
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def cookies(cookies)
       branch default_options.with_cookies(cookies)
@@ -291,7 +177,7 @@ def cookies(cookies)
     #   HTTP.encoding("UTF-8").get("http://example.com")
     #
     # @param [String, Encoding] encoding encoding to use
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def encoding(encoding)
       branch default_options.with_encoding(encoding)
@@ -303,7 +189,7 @@ def encoding(encoding)
     #   HTTP.accept("application/json").get("http://example.com")
     #
     # @param [String, Symbol] type MIME type to accept
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def accept(type)
       headers Headers::ACCEPT => MimeType.normalize(type)
@@ -315,7 +201,7 @@ def accept(type)
     #   HTTP.auth("Bearer token123").get("http://example.com")
     #
     # @param [#to_s] value Authorization header value
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def auth(value)
       headers Headers::AUTHORIZATION => value.to_s
@@ -330,7 +216,7 @@ def auth(value)
     # @param [#fetch] opts
     # @option opts [#to_s] :user
     # @option opts [#to_s] :pass
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def basic_auth(opts)
       user  = opts.fetch(:user)
@@ -368,7 +254,7 @@ def default_options=(opts)
     # @example
     #   HTTP.nodelay.get("http://example.com")
     #
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def nodelay
       branch default_options.with_nodelay(true)
@@ -380,13 +266,13 @@ def nodelay
     #   HTTP.use(:auto_inflate).get("http://example.com")
     #
     # @param [Array<Symbol, Hash>] features features to enable
-    # @return [HTTP::Client]
+    # @return [HTTP::Session]
     # @api public
     def use(*features)
       branch default_options.with_features(features)
     end
 
-    # Return a retriable client that retries on failure
+    # Return a retriable session that retries on failure
     #
     # @example Usage
     #
@@ -403,20 +289,29 @@ def use(*features)
     #   HTTP.retriable(tries: 3, delay: proc { |i| 1 + i*i }).get(url)
     #
     # @param (see Performer#initialize)
-    # @return [HTTP::Retriable::Client]
+    # @return [HTTP::Retriable::Session]
     # @api public
     def retriable(**options)
-      Retriable::Client.new(Retriable::Performer.new(options), default_options)
+      Retriable::Session.new(Retriable::Performer.new(options), default_options)
     end
 
     private
 
-    # Create a new client with the given options
+    # Create a new session with the given options
+    #
+    # @param [HTTP::Options] options options for the session
+    # @return [HTTP::Session]
+    # @api private
+    def branch(options)
+      HTTP::Session.new(options)
+    end
+
+    # Create a new client for executing a request
     #
     # @param [HTTP::Options] options options for the client
     # @return [HTTP::Client]
     # @api private
-    def branch(options)
+    def make_client(options)
       HTTP::Client.new(options)
     end
   end