Add support for threaded/parallel generation of webp

Author: Aaron Purnomo Murniadi

jekyll-webp.gemspec

@@ -1,4 +1,5 @@
 # coding: utf-8
+require 'date'
 require_relative 'lib/jekyll-webp/version'
 
 Gem::Specification.new do |spec|

lib/jekyll-webp/defaults.rb

@@ -43,7 +43,11 @@ module Webp
 
       # List of files or directories to explicitly include
       # e.g. single files outside of the main image directories
-      'include'   => []
+      'include'   => [],
+
+      # Number of threads to use for parallel generation. 
+      # 0 or 1 means sequential (no parallelism).
+      'threads' => 0
     }
 
   end # module Webp

lib/jekyll-webp/version.rb

@@ -1,8 +1,8 @@
 module Jekyll
   module Webp
-    VERSION = "1.0.0"
+    VERSION = "1.0.1"
     # When modifying remember to issue a new tag command in git before committing, then push the new tag
-    # git tag -a v1.0.0 -m "Gem v1.0.0"
+    # git tag -a v1.0.1 -m "Gem v1.0.1"
     # git push origin --tags
   end #module Webp
 end #module Jekyll

lib/jekyll-webp/webpGenerator.rb

@@ -53,8 +53,11 @@ def generate(site)
         # Counting the number of files generated
         file_count = 0
 
-        # Iterate through every image in each of the image folders and create a webp image
-        # if one has not been created already for that image.
+        # Collection of tasks to be processed
+        # Each task is a hash with all necessary info to process the file
+        tasks = []
+
+        # Iterate through every image in each of the image folders and collect files to process
         for imgdir in @config['img_dir']
           imgdir_source = File.join(site.source, imgdir)
           imgdir_destination = File.join(site.dest, imgdir)
@@ -83,28 +86,88 @@ def generate(site)
               FileUtils::mkdir_p(imgdir_destination + imgfile_relative_path)
               outfile_fullpath_webp = File.join(imgdir_destination + imgfile_relative_path, outfile_filename)
 
-              # Check if the file already has a webp alternative?
-              # If we're force rebuilding all webp files then ignore the check
-              # also check the modified time on the files to ensure that the webp file
-              # is newer than the source file, if not then regenerate
-              if @config['regenerate'] || !File.file?(outfile_fullpath_webp) ||
-                 File.mtime(outfile_fullpath_webp) <= File.mtime(imgfile)
-                Jekyll.logger.info "WebP:", "Change to source image file #{imgfile} detected, regenerating WebP"
-
-                # Generate the file
-                WebpExec.run(@config['quality'], @config['flags'], imgfile, outfile_fullpath_webp, @config['webp_path'])
-                file_count += 1
-              end
-              if File.file?(outfile_fullpath_webp)
-                # Keep the webp file from being cleaned by Jekyll
-                site.static_files << WebpFile.new(site,
-                                                  site.dest,
-                                                  File.join(imgdir, imgfile_relative_path),
-                                                  outfile_filename)
-              end
+              # Add to tasks list
+              tasks << {
+                'imgfile' => imgfile,
+                'outfile_fullpath_webp' => outfile_fullpath_webp,
+                'imgdir' => imgdir,
+                'imgfile_relative_path' => imgfile_relative_path,
+                'outfile_filename' => outfile_filename
+              }
           end # dir.foreach
         end # img_dir
 
+        
+        # Define the work block
+        mutex = Mutex.new
+        
+        process_file = Proc.new do |task|
+          imgfile = task['imgfile']
+          outfile_fullpath_webp = task['outfile_fullpath_webp']
+          imgdir = task['imgdir']
+          imgfile_relative_path = task['imgfile_relative_path']
+          outfile_filename = task['outfile_filename']
+
+          # Check if the file already has a webp alternative?
+          # If we're force rebuilding all webp files then ignore the check
+          # also check the modified time on the files to ensure that the webp file
+          # is newer than the source file, if not then regenerate
+          if @config['regenerate'] || !File.file?(outfile_fullpath_webp) ||
+             File.mtime(outfile_fullpath_webp) <= File.mtime(imgfile)
+            Jekyll.logger.info "WebP:", "Change to source image file #{imgfile} detected, regenerating WebP"
+
+            # Generate the file
+            WebpExec.run(@config['quality'], @config['flags'], imgfile, outfile_fullpath_webp, @config['webp_path'])
+            
+            # Thread-safe increment
+            if @config['threads'] && @config['threads'] > 1
+               mutex.synchronize { file_count += 1 }
+            else
+               file_count += 1
+            end
+          end
+          
+          if File.file?(outfile_fullpath_webp)
+            # Keep the webp file from being cleaned by Jekyll
+            if @config['threads'] && @config['threads'] > 1
+              mutex.synchronize do
+                site.static_files << WebpFile.new(site, site.dest, File.join(imgdir, imgfile_relative_path), outfile_filename)
+              end
+            else
+              site.static_files << WebpFile.new(site, site.dest, File.join(imgdir, imgfile_relative_path), outfile_filename)
+            end
+          end
+        end
+
+        # Execute tasks
+        thread_count = @config['threads'].to_i
+        
+        if thread_count > 1
+          Jekyll.logger.info "WebP:", "Parallel processing enabled with #{thread_count} threads"
+          queue = Queue.new
+          tasks.each { |t| queue << t }
+          
+          workers = (1..thread_count).map do
+            Thread.new do
+              begin
+                while !queue.empty?
+                  # Non-blocking pop; rescue if empty
+                  task = queue.pop(true) rescue nil
+                  process_file.call(task) if task
+                end
+              rescue ThreadError
+                # Queue empty
+              end
+            end
+          end
+          workers.each(&:join)
+        else
+          # Sequential execution
+          tasks.each do |task|
+             process_file.call(task)
+          end
+        end
+
         Jekyll.logger.info "WebP:","Generator Complete: #{file_count} file(s) generated"
 
       end #function generate