Allow Response::Body#each to take a buffer_size

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- `HTTP::Response::Body#each` now accepts a `buffer_size:` keyword argument
+  to control the chunk size used when streaming the body, instead of always
+  using `HTTP::Connection::BUFFER_SIZE` (16KB). ([#782])
+
 ### Fixed
 
 - Building a default `Host` header now raises `HTTP::RequestError` when the
@@ -293,6 +299,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `Request` and `Response`. Use `request.headers["..."]` and
   `response.headers["..."]` instead ([#537])
 
+[#782]: https://github.com/httprb/http/issues/782
 [#270]: https://github.com/httprb/http/issues/270
 [#223]: https://github.com/httprb/http/issues/223
 [#358]: https://github.com/httprb/http/issues/358

lib/http/response/body.rb

@@ -67,13 +67,17 @@ def readpartial(*)
       # @example
       #   body.each { |chunk| puts chunk }
       #
+      # @example
+      #   body.each(buffer_size: 1.megabyte) { |chunk| puts chunk }
+      #
+      # @param buffer_size [Integer] the maximum size of each yielded chunk
       # @yield [chunk] Passes each chunk to the block
       # @yieldparam chunk [String]
       # @return [void]
       # @api public
-      def each
+      def each(buffer_size: Connection::BUFFER_SIZE)
         loop do
-          yield readpartial
+          yield readpartial(buffer_size)
         end
       rescue EOFError # rubocop:disable Lint/SuppressedException
       end

sig/http.rbs

@@ -1034,8 +1034,8 @@ module HTTP
 
       def initialize: (untyped stream, ?encoding: String | Encoding) -> void
       def readpartial: (?Integer size, ?String? outbuf) -> String
-      def each: () { (String) -> void } -> void
-             | () -> Enumerator[String, void]
+      def each: (?buffer_size: Integer) { (String) -> void } -> void
+             | (?buffer_size: Integer) -> Enumerator[String, void]
       def to_s: () -> untyped
       alias to_str to_s
       def stream!: () -> untyped

test/http/response/body_test.rb

@@ -95,6 +95,34 @@ def test_each_yields_each_chunk
     assert_equal "Hello, World!", collected.join
   end
 
+  def test_each_passes_buffer_size_to_underlying_readpartial
+    received_sizes = []
+    conn = Object.new
+    conn.define_singleton_method(:readpartial) do |size = nil|
+      received_sizes << size
+      raise EOFError if received_sizes.size > 1
+
+      "data"
+    end
+    body = HTTP::Response::Body.new(conn, encoding: Encoding::UTF_8)
+    body.each(buffer_size: 1_048_576) { |chunk| chunk }
+
+    assert_equal [1_048_576, 1_048_576], received_sizes
+  end
+
+  def test_each_defaults_buffer_size_to_connection_buffer_size
+    received_sizes = []
+    conn = Object.new
+    conn.define_singleton_method(:readpartial) do |size = nil|
+      received_sizes << size
+      raise EOFError
+    end
+    body = HTTP::Response::Body.new(conn, encoding: Encoding::UTF_8)
+    body.each { |chunk| chunk }
+
+    assert_equal [HTTP::Connection::BUFFER_SIZE], received_sizes
+  end
+
   # ---------------------------------------------------------------------------
   # #to_s when streaming
   # ---------------------------------------------------------------------------