Jekyll's data processing capabilities are often limited by sequential execution and memory constraints when handling large datasets. By building sophisticated Ruby data processing pipelines, you can transform, aggregate, and analyze data with exceptional performance while maintaining Jekyll's simplicity. This technical guide explores advanced Ruby techniques for building ETL (Extract, Transform, Load) pipelines that leverage parallel processing, streaming data, and memory optimization to handle massive datasets efficiently within Jekyll's build process.

In This Guide

Data Pipeline Architecture and Design Patterns

Effective data pipeline architecture separates extraction, transformation, and loading phases while providing fault tolerance and monitoring. The pipeline design uses the processor pattern with composable stages that can be reused across different data sources.

The architecture comprises source adapters for different data formats, processor chains for transformation logic, and sink adapters for output destinations. Each stage implements a common interface allowing flexible composition. Error handling, logging, and performance monitoring are built into the pipeline framework to ensure reliability and visibility.


module Jekyll
  module DataPipelines
    # Base pipeline architecture
    class Pipeline
      def initialize(stages = [])
        @stages = stages
        @metrics = PipelineMetrics.new
      end
      
      def process(data)
        @metrics.record_start
        
        result = @stages.reduce(data) do |current_data, stage|
          @metrics.record_stage_start(stage)
          processed_data = stage.process(current_data)
          @metrics.record_stage_complete(stage, processed_data)
          processed_data
        end
        
        @metrics.record_complete(result)
        result
      rescue => e
        @metrics.record_error(e)
        raise PipelineError.new("Pipeline processing failed", e)
      end
      
      def |(other_stage)
        self.class.new(@stages + [other_stage])
      end
    end
    
    # Base stage class
    class Stage
      def process(data)
        raise NotImplementedError, "Subclasses must implement process method"
      end
      
      def |(other_stage)
        Pipeline.new([self, other_stage])
      end
    end
    
    # Specific stage implementations
    class ExtractStage < Stage
      def initialize(source_adapter)
        @source = source_adapter
      end
      
      def process(_ = nil)
        @source.extract
      end
    end
    
    class TransformStage < Stage
      def initialize(transformer)
        @transformer = transformer
      end
      
      def process(data)
        @transformer.transform(data)
      end
    end
    
    class LoadStage < Stage
      def initialize(sink_adapter)
        @sink = sink_adapter
      end
      
      def process(data)
        @sink.load(data)
        data # Return data for potential further processing
      end
    end
    
    # Pipeline builder for fluent interface
    class PipelineBuilder
      def initialize
        @stages = []
      end
      
      def extract(source_adapter)
        @stages << ExtractStage.new(source_adapter)
        self
      end
      
      def transform(transformer)
        @stages << TransformStage.new(transformer)
        self
      end
      
      def load(sink_adapter)
        @stages << LoadStage.new(sink_adapter)
        self
      end
      
      def build
        Pipeline.new(@stages)
      end
    end
  end
end

# Usage example:
pipeline = Jekyll::DataPipelines::PipelineBuilder.new
  .extract(JsonFileSource.new('_data/products.json'))
  .transform(ProductNormalizer.new)
  .transform(ImageProcessor.new)
  .load(JekyllDataSink.new('products'))
  .build

pipeline.process

Parallel Data Processing with Ruby Threads and Fibers

Parallel processing dramatically improves performance for CPU-intensive data transformations. Ruby's threads and fibers enable concurrent execution while managing shared state and resource limitations.

Here's an implementation of parallel data processing for Jekyll:


module Jekyll
  module ParallelProcessing
    class ParallelProcessor
      def initialize(worker_count: Etc.nprocessors - 1)
        @worker_count = worker_count
        @queue = Queue.new
        @results = Queue.new
        @workers = []
      end
      
      def process_batch(data, &block)
        setup_workers(&block)
        enqueue_data(data)
        wait_for_completion
        collect_results
      ensure
        stop_workers
      end
      
      def process_stream(enum, &block)
        # Use fibers for streaming processing
        fiber_pool = FiberPool.new(@worker_count)
        
        enum.lazy.map do |item|
          fiber_pool.schedule { block.call(item) }
        end.each(&:resume)
      end
      
      private
      
      def setup_workers(&block)
        @worker_count.times do
          @workers << Thread.new do
            while item = @queue.pop
              break if item == :TERMINATE
              
              begin
                result = block.call(item)
                @results << [item, result, nil]
              rescue => e
                @results << [item, nil, e]
              end
            end
          end
        end
      end
      
      def enqueue_data(data)
        data.each { |item| @queue << item }
        @worker_count.times { @queue << :TERMINATE }
      end
      
      def wait_for_completion
        @workers.each(&:join)
      end
      
      def collect_results
        results = []
        errors = []
        
        until @results.empty?
          item, result, error = @results.pop(true) rescue nil
          if error
            errors << { item: item, error: error }
          elsif result
            results << result
          end
        end
        
        { results: results, errors: errors }
      end
      
      def stop_workers
        @workers.each do |worker|
          worker.kill if worker.alive?
        end
      end
    end
    
    # Fiber-based processing for I/O bound operations
    class FiberPool
      def initialize(size)
        @size = size
        @queue = Queue.new
        @fibers = size.times.map { create_worker_fiber }
      end
      
      def schedule(&job)
        fiber = @fibers.find(&:alive?) || create_worker_fiber
        fiber.transfer(job)
      end
      
      private
      
      def create_worker_fiber
        Fiber.new do |job|
          loop do
            result = job.call
            job = Fiber.yield(result)
          end
        end
      end
    end
    
    # Parallel data processing plugin for Jekyll
    class ParallelDataProcessor < Generator
      def generate(site)
        @site = site
        
        # Process large datasets in parallel
        process_large_collections
        process_external_data_sources
        generate_parallel_content
      end
      
      private
      
      def process_large_collections
        processor = ParallelProcessor.new
        
        @site.collections.each do |name, collection|
          next if collection.docs.size < 50 # Only parallelize large collections
          
          results = processor.process_batch(collection.docs) do |doc|
            process_document_parallel(doc)
          end
          
          handle_processing_results(results, name)
        end
      end
      
      def process_document_parallel(doc)
        {
          id: doc.id,
          enhanced_data: {
            semantic_analysis: analyze_semantics(doc.content),
            readability_score: calculate_readability(doc.content),
            related_content: find_related_content(doc),
            seo_optimization: generate_seo_suggestions(doc)
          },
          processing_time: Time.now
        }
      end
      
      def process_external_data_sources
        # Process external APIs and data sources in parallel
        data_sources = @site.config['external_data_sources'] || []
        
        processor = ParallelProcessor.new
        results = processor.process_batch(data_sources) do |source|
          fetch_and_process_external_data(source)
        end
        
        # Store processed external data
        results[:results].each do |data|
          @site.data[data[:source_name]] = data[:content]
        end
      end
      
      def fetch_and_process_external_data(source)
        require 'net/http'
        require 'json'
        
        uri = URI.parse(source['url'])
        response = Net::HTTP.get_response(uri)
        
        if response.is_a?(Net::HTTPSuccess)
          raw_data = JSON.parse(response.body)
          transform_external_data(raw_data, source['transformations'])
        else
          raise "Failed to fetch #{source['url']}: #{response.code}"
        end
      end
    end
  end
end

Streaming Data Processing and Memory Optimization

Streaming processing enables handling datasets larger than available memory by processing data in chunks. This approach is essential for large Jekyll sites with extensive content or external data sources.

Here's a streaming data processing implementation:


module Jekyll
  module StreamingProcessing
    class StreamProcessor
      def initialize(batch_size: 1000)
        @batch_size = batch_size
      end
      
      def process_large_dataset(enum, &processor)
        enum.each_slice(@batch_size).lazy.map do |batch|
          process_batch(batch, &processor)
        end
      end
      
      def process_file_stream(path, &processor)
        # Stream process large files line by line
        File.open(path, 'r') do |file|
          file.lazy.each_slice(@batch_size).map do |lines|
            process_batch(lines, &processor)
          end
        end
      end
      
      def transform_stream(input_enum, transformers)
        transformers.reduce(input_enum) do |stream, transformer|
          stream.lazy.flat_map { |item| transformer.transform(item) }
        end
      end
      
      private
      
      def process_batch(batch, &processor)
        batch.map { |item| processor.call(item) }
      end
    end
    
    # Memory-efficient data transformations
    class LazyTransformer
      def initialize(&transform_block)
        @transform_block = transform_block
      end
      
      def transform(data)
        data.lazy.map(&@transform_block)
      end
    end
    
    class LazyFilter
      def initialize(&filter_block)
        @filter_block = filter_block
      end
      
      def transform(data)
        data.lazy.select(&@filter_block)
      end
    end
    
    # Streaming file processor for large data files
    class StreamingFileProcessor
      def process_large_json_file(file_path)
        # Process JSON files that are too large to load into memory
        File.open(file_path, 'r') do |file|
          json_stream = JsonStreamParser.new(file)
          
          json_stream.each_object.lazy.map do |obj|
            process_json_object(obj)
          end.each do |processed|
            yield processed if block_given?
          end
        end
      end
      
      def process_large_csv_file(file_path, &processor)
        require 'csv'
        
        CSV.foreach(file_path, headers: true).lazy.each_slice(1000) do |batch|
          processed_batch = batch.map(&processor)
          yield processed_batch if block_given?
        end
      end
    end
    
    # JSON stream parser for large files
    class JsonStreamParser
      def initialize(io)
        @io = io
        @buffer = ""
      end
      
      def each_object
        return enum_for(:each_object) unless block_given?
        
        in_object = false
        depth = 0
        object_start = 0
        
        @io.each_char do |char|
          @buffer << char
          
          case char
          when '{'
            depth += 1
            in_object = true if depth == 1
            object_start = @buffer.length - 1 if depth == 1
          when '}'
            depth -= 1
            if depth == 0 && in_object
              object_json = @buffer[object_start..-1]
              yield JSON.parse(object_json) rescue nil
              @buffer.clear
              in_object = false
            end
          end
        end
      end
    end
    
    # Memory-optimized Jekyll generator
    class StreamingDataGenerator < Generator
      def generate(site)
        @site = site
        @stream_processor = StreamProcessor.new
        
        process_large_data_files
        generate_streaming_content
        optimize_memory_usage
      end
      
      private
      
      def process_large_data_files
        # Process large data files without loading into memory
        data_dir = File.join(@site.source, '_data')
        
        Dir.glob(File.join(data_dir, '*.json')).each do |json_file|
          next if File.size(json_file) < 10_000_000 # Only stream large files
          
          stream_processor = StreamingFileProcessor.new
          collection_name = File.basename(json_file, '.json')
          
          stream_processor.process_large_json_file(json_file) do |obj|
            process_streaming_data_object(obj, collection_name)
          end
        end
      end
      
      def process_streaming_data_object(obj, collection_name)
        # Process individual objects from stream
        enhanced_obj = enhance_data_object(obj)
        
        # Create Jekyll documents from streamed objects
        create_document_from_stream(enhanced_obj, collection_name)
      end
      
      def create_document_from_stream(data, collection_name)
        doc = Document.new(
          data['content'] || '',
          {
            site: @site,
            collection: @site.collections[collection_name]
          }
        )
        
        doc.data = data
        doc.data['layout'] ||= 'default'
        
        @site.collections[collection_name].docs << doc
      end
      
      def optimize_memory_usage
        # Force garbage collection after memory-intensive operations
        GC.start
        
        # Monitor memory usage
        memory_usage = `ps -o rss= -p #{Process.pid}`.to_i / 1024
        Jekyll.logger.info "Memory usage: #{memory_usage}MB"
        
        if memory_usage > 500 # 500MB threshold
          Jekyll.logger.warn "High memory usage detected, optimizing..."
          optimize_large_collections
        end
      end
      
      def optimize_large_collections
        @site.collections.each do |name, collection|
          next if collection.docs.size < 1000
          
          # Convert to lazy enumeration for memory efficiency
          collection.define_singleton_method(:docs) do
            @lazy_docs ||= @docs.lazy
            @lazy_docs
          end
        end
      end
    end
  end
end

Advanced Data Transformation and Enumerable Techniques

Ruby's Enumerable module provides powerful data transformation capabilities. Advanced techniques like lazy evaluation, method chaining, and custom enumerators enable complex data processing with clean, efficient code.


module Jekyll
  module DataTransformation
    # Advanced enumerable utilities for data processing
    module EnumerableUtils
      def self.grouped_transformation(enum, group_size, &transform)
        enum.each_slice(group_size).lazy.flat_map(&transform)
      end
      
      def self.pipelined_transformation(enum, *transformers)
        transformers.reduce(enum) do |current, transformer|
          current.lazy.map { |item| transformer.call(item) }
        end
      end
      
      def self.memoized_transformation(enum, &transform)
        cache = {}
        
        enum.lazy.map do |item|
          cache[item] ||= transform.call(item)
        end
      end
    end
    
    # Data transformation DSL
    class TransformationBuilder
      def initialize
        @transformations = []
      end
      
      def map(&block)
        @transformations << ->(enum) { enum.lazy.map(&block) }
        self
      end
      
      def select(&block)
        @transformations << ->(enum) { enum.lazy.select(&block) }
        self
      end
      
      def reject(&block)
        @transformations << ->(enum) { enum.lazy.reject(&block) }
        self
      end
      
      def flat_map(&block)
        @transformations << ->(enum) { enum.lazy.flat_map(&block) }
        self
      end
      
      def group_by(&block)
        @transformations << ->(enum) { enum.lazy.group_by(&block) }
        self
      end
      
      def sort_by(&block)
        @transformations << ->(enum) { enum.lazy.sort_by(&block) }
        self
      end
      
      def apply_to(enum)
        @transformations.reduce(enum.lazy) do |current, transformation|
          transformation.call(current)
        end
      end
    end
    
    # Specific data transformers for common Jekyll tasks
    class ContentEnhancer
      def initialize(site)
        @site = site
      end
      
      def enhance_documents(documents)
        TransformationBuilder.new
          .map { |doc| add_reading_metrics(doc) }
          .map { |doc| add_related_content(doc) }
          .map { |doc| add_seo_data(doc) }
          .apply_to(documents)
      end
      
      private
      
      def add_reading_metrics(doc)
        doc.data['word_count'] = doc.content.split(/\s+/).size
        doc.data['reading_time'] = (doc.data['word_count'] / 200.0).ceil
        doc.data['complexity_score'] = calculate_complexity(doc.content)
        doc
      end
      
      def add_related_content(doc)
        related = find_related_documents(doc)
        doc.data['related_content'] = related.take(5).to_a
        doc
      end
      
      def find_related_documents(doc)
        @site.documents.lazy
          .reject { |other| other.id == doc.id }
          .sort_by { |other| calculate_similarity(doc, other) }
          .reverse
      end
      
      def calculate_similarity(doc1, doc2)
        # Simple content-based similarity
        words1 = doc1.content.downcase.split(/\W+/).uniq
        words2 = doc2.content.downcase.split(/\W+/).uniq
        
        common_words = words1 & words2
        total_words = words1 | words2
        
        common_words.size.to_f / total_words.size
      end
    end
    
    class DataNormalizer
      def normalize_collection(collection)
        TransformationBuilder.new
          .map { |doc| normalize_document(doc) }
          .select { |doc| doc.data['published'] != false }
          .map { |doc| add_default_values(doc) }
          .apply_to(collection.docs)
      end
      
      private
      
      def normalize_document(doc)
        # Normalize common data fields
        doc.data['title'] = doc.data['title'].to_s.strip
        doc.data['date'] = parse_date(doc.data['date'])
        doc.data['tags'] = Array(doc.data['tags']).map(&:to_s).map(&:strip)
        doc.data['categories'] = Array(doc.data['categories']).map(&:to_s).map(&:strip)
        doc
      end
      
      def add_default_values(doc)
        doc.data['layout'] ||= 'default'
        doc.data['author'] ||= 'Unknown'
        doc.data['excerpt'] ||= generate_excerpt(doc.content)
        doc
      end
    end
    
    # Jekyll generator using advanced data transformation
    class DataTransformationGenerator < Generator
      def generate(site)
        @site = site
        @enhancer = ContentEnhancer.new(site)
        @normalizer = DataNormalizer.new
        
        transform_site_data
        enhance_content_collections
        generate_derived_data
      end
      
      private
      
      def transform_site_data
        # Transform site data using advanced enumerable techniques
        @site.data.transform_values! do |value|
          if value.is_a?(Array)
            process_array_data(value)
          elsif value.is_a?(Hash)
            process_hash_data(value)
          else
            value
          end
        end
      end
      
      def process_array_data(array)
        array.lazy
          .map { |item| deep_transform_values(item) }
          .select { |item| filter_data_item(item) }
          .to_a
      end
      
      def process_hash_data(hash)
        hash.transform_values { |v| deep_transform_values(v) }
          .select { |k, v| filter_data_item(v) }
      end
      
      def deep_transform_values(obj)
        case obj
        when Array
          obj.map { |item| deep_transform_values(item) }
        when Hash
          obj.transform_values { |v| deep_transform_values(v) }
        when String
          obj.strip
        else
          obj
        end
      end
      
      def enhance_content_collections
        @site.collections.each do |name, collection|
          next if collection.docs.empty?
          
          # Apply transformations to collection
          enhanced_docs = @enhancer.enhance_documents(collection.docs)
          normalized_docs = @normalizer.normalize_collection(collection)
          
          # Update collection with transformed docs
          collection.docs.replace(normalized_docs.to_a)
        end
      end
    end
  end
end

These high-performance Ruby data processing techniques transform Jekyll's capabilities for handling large datasets and complex transformations. By leveraging parallel processing, streaming data, and advanced enumerable patterns, you can build Jekyll sites that process millions of data points efficiently while maintaining the simplicity and reliability of static site generation.