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Optimize array! DSL #14

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Merged
moberegger merged 9 commits into from
Jun 16, 2025
Merged

Optimize array! DSL #14

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9dcf3f7
Optimize array! DSL
moberegger Jun 3, 2025
dd20ab1
Better array! optimization
moberegger Jun 12, 2025
77d740a
Default collections args to nil
moberegger Jun 12, 2025
957d044
Stop allocating memory for empty collections
moberegger Jun 12, 2025
9fb0b81
Save memory allocations for internal array calls
moberegger Jun 12, 2025
2aa6f20
Make constants private
moberegger Jun 12, 2025
c7c88ff
Add support for present?
moberegger Jun 13, 2025
e380da0
More frozen empty arrays
moberegger Jun 16, 2025
0cdb1b6
Add benchmark code
moberegger Jun 16, 2025
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39 changes: 23 additions & 16 deletions lib/jbuilder.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
require 'jbuilder/version'
require 'json'
require 'active_support/core_ext/hash/deep_merge'
require 'active_support/core_ext/object/blank'

class Jbuilder
@@key_formatter = nil
Expand All @@ -33,14 +34,16 @@ def self.encode(*args, &block)
new(*args, &block).target!
end

BLANK = Blank.new
BLANK = Blank.new.freeze
EMPTY_ARRAY = [].freeze
private_constant :BLANK, :EMPTY_ARRAY

def set!(key, value = BLANK, *args, &block)
result = if ::Kernel.block_given?
if !_blank?(value)
# json.comments @post.comments { |comment| ... }
# { "comments": [ { ... }, { ... } ] }
_scope{ array! value, &block }
_scope{ _array value, &block }
Comment on lines -43 to +46
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@moberegger moberegger Jun 13, 2025

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json.set! :posts, posts do |post|
  json.extract! post, :id, :body
end
ruby 3.4.4 (2025-05-14 revision a38531fd3f) +YJIT +PRISM [arm64-darwin24]
Warming up --------------------------------------
              before    74.247k i/100ms
               after    77.990k i/100ms
Calculating -------------------------------------
              before    755.086k (± 1.2%) i/s    (1.32 μs/i) -      3.787M in   5.015504s
               after    802.630k (± 1.4%) i/s    (1.25 μs/i) -      4.055M in   5.053783s

Comparison:
               after:   802630.0 i/s
              before:   755086.0 i/s - 1.06x  slower

Calculating -------------------------------------
              before   800.000  memsize (   520.000  retained)
                        11.000  objects (     4.000  retained)
                         0.000  strings (     0.000  retained)
               after   760.000  memsize (   520.000  retained)
                        10.000  objects (     4.000  retained)
                         0.000  strings (     0.000  retained)

Comparison:
               after:        760 allocated
              before:        800 allocated - 1.05x more

else
# json.comments { ... }
# { "comments": ... }
Expand All @@ -60,7 +63,7 @@ def set!(key, value = BLANK, *args, &block)
elsif _is_collection?(value)
# json.comments @post.comments, :content, :created_at
# { "comments": [ { "content": "hello", "created_at": "..." }, { "content": "world", "created_at": "..." } ] }
_scope{ array! value, *args }
_scope{ _array value, args }
Comment on lines -63 to +66
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@moberegger moberegger Jun 13, 2025

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json.set! :posts, posts, :id, :body
ruby 3.4.4 (2025-05-14 revision a38531fd3f) +YJIT +PRISM [arm64-darwin24]
Warming up --------------------------------------
              before    69.118k i/100ms
               after    80.906k i/100ms
Calculating -------------------------------------
              before    718.268k (± 1.5%) i/s    (1.39 μs/i) -      3.594M in   5.005122s
               after    837.174k (± 1.5%) i/s    (1.19 μs/i) -      4.207M in   5.026501s

Comparison:
               after:   837173.8 i/s
              before:   718267.7 i/s - 1.17x  slower

Calculating -------------------------------------
              before   832.000  memsize (   520.000  retained)
                         8.000  objects (     4.000  retained)
                         0.000  strings (     0.000  retained)
               after   640.000  memsize (   520.000  retained)
                         7.000  objects (     4.000  retained)
                         0.000  strings (     0.000  retained)

Comparison:
               after:        640 allocated
              before:        832 allocated - 1.30x more

else
# json.author @post.creator, :name, :email_address
# { "author": { "name": "David", "email_address": "[email protected]" } }
Expand Down Expand Up @@ -207,18 +210,8 @@ def child!
# json.array! [1, 2, 3]
#
# [1,2,3]
def array!(collection = [], *attributes, &block)
array = if collection.nil?
[]
elsif ::Kernel.block_given?
_map_collection(collection, &block)
elsif attributes.any?
_map_collection(collection) { |element| _extract element, attributes }
else
_format_keys(collection.to_a)
end

@attributes = _merge_values(@attributes, array)
def array!(collection = EMPTY_ARRAY, *attributes, &block)
_array(collection, attributes, &block)
end

# Extracts the mentioned attributes or hash elements from the passed object and turns them into attributes of the JSON.
Expand All @@ -244,7 +237,7 @@ def extract!(object, *attributes)

def call(object, *attributes, &block)
if ::Kernel.block_given?
array! object, &block
_array object, &block
else
_extract object, attributes
end
Expand Down Expand Up @@ -277,6 +270,20 @@ def target!

alias_method :method_missing, :set!

def _array(collection = EMPTY_ARRAY, attributes = nil, &block)
array = if collection.nil?
EMPTY_ARRAY
elsif block
_map_collection(collection, &block)
elsif attributes.present?
_map_collection(collection) { |element| _extract element, attributes }
else
_format_keys(collection.to_a)
end

@attributes = _merge_values(@attributes, array)
end

def _extract(object, attributes)
if ::Hash === object
_extract_hash_values(object, attributes)
Expand Down
10 changes: 5 additions & 5 deletions lib/jbuilder/jbuilder_template.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -118,14 +118,14 @@ def target!
@cached_root || super
end

def array!(collection = [], *args)
def array!(collection = EMPTY_ARRAY, *args, &block)
options = args.first

if args.one? && _partial_options?(options)
if _partial_options?(options)
options[:collection] = collection
_render_partial_with_options options
else
super
_array collection, args, &block
end
end

Expand Down Expand Up @@ -167,9 +167,9 @@ def _render_partial_with_options(options)
.new(@context.lookup_context, options) { |&block| _scope(&block) }
.render_collection_with_partial(collection, partial, @context, nil)

array! if results.respond_to?(:body) && results.body.nil?
_array if results.respond_to?(:body) && results.body.nil?
else
array!
_array
end
else
_render_partial options
Expand Down