Create swf_assets:manifests:load task to save all manifest files

Doing that sweet, sweet backfill!! It's not exactly *fast*, since
there's about 570k records to work through, but it's pretty good all
things considered! Thanks, surprisingly-reusable async code!

app/models/swf_asset.rb

@@ -117,10 +117,12 @@ class SwfAsset < ApplicationRecord
   end
 
   def manifest
+    raise "manifest_url is blank" if manifest_url.blank?
     NeopetsMediaArchive.load_json(manifest_url)
   end
 
   def preload_manifest
+    raise "manifest_url is blank" if manifest_url.blank?
     NeopetsMediaArchive.preload_file(manifest_url)
   end
 
@@ -251,7 +253,14 @@ class SwfAsset < ApplicationRecord
       # NeopetsMediaArchive will share a pool of persistent connections for
       # them.
       swf_assets.map do |swf_asset|
-        semaphore.async { swf_asset.preload_manifest }
+        semaphore.async do
+          begin
+            swf_asset.preload_manifest
+          rescue StandardError => error
+            Rails.logger.error "Could not preload manifest for asset " + 
+              "#{swf_asset.id} (#{swf_asset.manifest_url}): #{error.message}"
+          end
+        end
       end
 
       # Wait until all tasks are done.

lib/tasks/swf_assets.rake

@@ -35,15 +35,43 @@ namespace :swf_assets do
 		end
 	end
 
+	namespace :manifests do
+		desc "Save all known manifests to the Neopets Media Archive"
+		task load: [:environment] do
+			# Log errors to STDOUT, but we don't need the info messages about
+			# successful saves.
+			Rails.logger = Logger.new(STDOUT, level: :error)
+
+			# Find all the manifests with known URLs. (We don't have a database
+			# filter for "do we already have the manifest downloaded", but that's
+			# okay, the preload method will quickly check that for us!)
+			swf_assets = SwfAsset.where.not(manifest_url: nil)
+			total_count = swf_assets.count
+			puts "Found #{total_count} assets with manifests"
+
+			# For each batch of 1000 assets, load their manifests concurrently.
+			# Wrap everything in a top-level sync, so keyboard interrupts will
+			# propagate all the way up to here, instead of just cancelling the
+			# current batch.
+			Sync do
+				saved_count = 0
+				swf_assets.find_in_batches(batch_size: 1000) do |swf_assets|
+					SwfAsset.preload_manifests(swf_assets)
+					saved_count += swf_assets.size
+					puts "Loaded #{saved_count} of #{total_count} manifests"
+				end
+			end
+		end
+
 		desc "Backfill manifest_url for SwfAsset models"
-	task manifests: [:environment] do
+		task urls: [:environment] do
 			timeout = ENV.fetch("TIMEOUT", "5").to_i
 
 			assets = SwfAsset.where(manifest_url: nil)
 			count = assets.count
 			puts "Found #{count} assets without manifests"
 
-		Async do
+			Sync do
 				# Share a pool of persistent connections, rather than reconnecting on
 				# each request. (This library does that automatically!)
 				internet = Async::HTTP::Internet.instance
@@ -109,6 +137,7 @@ namespace :swf_assets do
 			end
 		end
 	end
+end
 
 SWF_URL_PATTERN = %r{^(?:https?:)?//images\.neopets\.com/cp/(bio|items)/swf/(.+?)_([a-z0-9]+)\.swf$}
 def infer_manifest_url(swf_url, internet)