Use content addressed storage file when available.

app/controllers/file_controller.rb

@@ -24,7 +24,7 @@ def show
       ip: request.remote_ip
     )
 
-    send_file current_file.path, disposition:
+    send_file current_file.path, filename: current_file.file_name, disposition:
   end
   # rubocop:enable Metrics/AbcSize
 

app/models/cocina.rb

@@ -52,6 +52,13 @@ def find_file(file_name)
              .find { |file| file['filename'] == file_name } || raise(ActionController::MissingFile, "File not found '#{file_name}'")
   end
 
+  def find_file_md5(file_name)
+    file_node = find_file(file_name)
+    file_node.fetch('hasMessageDigests')
+             .find { |digest_node| digest_node.fetch('type') == 'md5' }
+             .fetch('digest')
+  end
+
   def thumbnail_file
     data.dig('structural', 'contains')
         .lazy.flat_map { |file_set| file_set.dig('structural', 'contains') }

app/models/stacks_file.rb

@@ -9,6 +9,7 @@ class StacksFile
   def initialize(file_name:, cocina:)
     @file_name = file_name
     @cocina = cocina
+    validate!
   end
 
   attr_reader :file_name, :cocina
@@ -17,7 +18,7 @@ def id
     cocina.druid
   end
 
-  validates :id, format: { with: StorageRoot::DRUID_PARTS_PATTERN }
+  validates :file_name, presence: true
 
   # Some files exist but have unreadable permissions, treat these as non-existent
   def readable?
@@ -40,6 +41,7 @@ def path
     @path ||= storage_root.absolute_path
   end
 
+  # Used as the IIIF identifier for retrieving this file from the image server
   def treeified_path
     storage_root.relative_path
   end

app/models/storage_root.rb

@@ -13,21 +13,9 @@ def initialize(file_name:, cocina:)
 
   delegate :druid, to: :cocina
 
-  def druid_parts
-    @druid_parts ||= druid.match(DRUID_PARTS_PATTERN)
-  end
-
-  def absolute_path
-    return unless relative_path
+  delegate :absolute_path, to: :path_finder
 
-    path_finder.absolute_path.to_s
-  end
-
-  def relative_path
-    return unless druid_parts && file_name
-
-    path_finder.relative_path.to_s
-  end
+  delegate :relative_path, to: :path_finder
 
   def treeified_id
     File.join(druid_parts[1..4])
@@ -38,26 +26,41 @@ def treeified_id
   attr_reader :cocina, :file_name
 
   def path_finder
-    @path_finder ||= path_finder_class.new(treeified_id:, druid:, file_name:)
+    @path_finder ||= path_finder_class.new(treeified_id:, file_name:, cocina:)
   end
 
   def path_finder_class
     LegacyPathFinder
   end
 
+  def druid_parts
+    @druid_parts ||= druid.match(DRUID_PARTS_PATTERN)
+  end
+
   # Calculate file paths in the legacy Stacks structure
   class LegacyPathFinder
-    def initialize(treeified_id:, file_name:, druid:) # rubocop:disable Lint/UnusedMethodArgument
+    def initialize(treeified_id:, file_name:, cocina:)
       @treeified_id = treeified_id
       @file_name = file_name
+      @cocina = cocina
     end
 
+    # As this is used for external service URLs (Canteloupe image server), we don't want to put content addressable path here.'
     def relative_path
       File.join(@treeified_id, @file_name)
     end
 
     def absolute_path
+      return content_addressable_path if File.exist?(content_addressable_path)
+
       File.join(Settings.stacks.storage_root, relative_path)
     end
+
+    def content_addressable_path
+      @content_addressable_path ||= begin
+        md5 = @cocina.find_file_md5(@file_name)
+        File.join(Settings.stacks.storage_root, @treeified_id, @cocina.druid, 'content', md5)
+      end
+    end
   end
 end

spec/controllers/file_controller_spec.rb

@@ -8,26 +8,7 @@
   end
 
   let(:public_json) do
-    {
-      'externalIdentifier' => druid,
-      'structural' => {
-        'contains' => [
-          {
-            'structural' => {
-              'contains' => [
-                {
-                  'filename' => 'image.jp2',
-                  'access' => {
-                    'view' => 'world',
-                    'download' => 'world'
-                  }
-                }
-              ]
-            }
-          }
-        ]
-      }
-    }
+    Factories.cocina_with_file
   end
 
   describe '#show' do
@@ -37,14 +18,40 @@
     subject { get :show, params: { id: druid, file_name: 'image.jp2' } }
 
     it 'sends the file to the user' do
-      expect(controller).to receive(:send_file).with(path, disposition: :inline).and_call_original
+      expect(controller).to receive(:send_file).with(path, filename: 'image.jp2', disposition: :inline).and_call_original
       subject
     end
 
-    it 'sends headers for content' do
-      expect(controller).to receive(:send_file).with(path, disposition: :attachment).and_call_original
-      get :show, params: { id: druid, file_name: 'image.jp2', download: 'any' }
-      expect(response.headers.to_h).to include 'content-length' => 11_043, 'accept-ranges' => 'bytes'
+    context 'when file is not in a content addressable path' do
+      it 'returns legacy file' do
+        expect(controller).to receive(:send_file).with(path, filename: 'image.jp2', disposition: :attachment).and_call_original
+        get :show, params: { id: druid, file_name: 'image.jp2', download: 'any' }
+        expect(response.headers.to_h).to include(
+          'content-length' => 11_043,
+          'accept-ranges' => 'bytes',
+          "content-disposition" => "attachment; filename=\"image.jp2\"; filename*=UTF-8''image.jp2"
+        )
+      end
+    end
+
+    context 'when file is in a content addressable path' do
+      let(:path) { 'spec/fixtures/nr/349/ct/7889/nr349ct7889/content/02f77c96c40ad3c7c843baa9c7b2ff2c' }
+      around do |ex|
+        FileUtils.mkdir_p('spec/fixtures/nr/349/ct/7889/nr349ct7889/content/')
+        File.link('spec/fixtures/nr/349/ct/7889/image.jp2', path)
+        ex.run
+        File.unlink(path)
+      end
+
+      it 'sends headers for content' do
+        expect(controller).to receive(:send_file).with(path, filename: 'image.jp2', disposition: :attachment).and_call_original
+        get :show, params: { id: druid, file_name: 'image.jp2', download: 'any' }
+        expect(response.headers.to_h).to include(
+          'content-length' => 11_043,
+          'accept-ranges' => 'bytes',
+          "content-disposition" => "attachment; filename=\"image.jp2\"; filename*=UTF-8''image.jp2"
+        )
+      end
     end
 
     it 'missing file returns 404 Not Found' do

spec/controllers/legacy_image_service_controller_spec.rb

@@ -9,6 +9,7 @@
 
   let(:public_json) do
     {
+      'externalIdentifier' => 'druid:nr349ct7889',
       'structural' => {
         'contains' => [
           {

spec/factories/cocina.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Factories
+  def self.cocina(id: "druid:nr349ct7889")
+    { "externalIdentifier" => id }
+  end
+
+  def self.cocina_with_file(id: "druid:nr349ct7889", file_name: 'image.jp2', access: {},
+                            file_access: { 'view' => 'world', 'download' => 'world' },
+                            mime_type: 'image/jp2')
+    cocina(id:).merge(
+      'access' => access,
+      'structural' => {
+        'contains' => [
+          {
+            'structural' => {
+              'contains' => [
+                {
+                  'filename' => file_name,
+                  'hasMessageDigests' => [
+                    { 'type' => 'sha1', 'digest' => 'b1a2922356709cc53b85f1b8027982d23b573f80' },
+                    { 'type' => 'md5', 'digest' => '02f77c96c40ad3c7c843baa9c7b2ff2c' }
+                  ],
+                  'hasMimeType' => mime_type,
+                  'access' => file_access
+                }
+              ]
+            }
+          }
+        ]
+      }
+    )
+  end
+end

spec/models/stacks_file_spec.rb

@@ -5,29 +5,26 @@
 RSpec.describe StacksFile do
   let(:druid) { 'nr349ct7889' }
   let(:file_name) { 'image.jp2' }
-  let(:cocina) {  Cocina.new({ 'externalIdentifier' => druid }) }
+  let(:cocina) { Cocina.new(public_json) }
   let(:instance) { described_class.new(file_name:, cocina:) }
   let(:path) { storage_root.absolute_path }
   let(:storage_root) { StorageRoot.new(cocina:, file_name:) }
+  let(:public_json) { Factories.cocina_with_file }
+
+  context 'with a missing file name' do
+    let(:file_name) { nil }
+
+    it 'raises an error' do
+      expect { instance }.to raise_error ActiveModel::ValidationError
+    end
+  end
 
   describe '#path' do
     subject { instance.path }
 
     it 'is the druid tree path to the file' do
       expect(subject).to eq(path)
     end
-
-    context 'with a malformed druid' do
-      let(:druid) { 'abcdef' }
-
-      it { is_expected.to be_nil }
-    end
-
-    context 'with a missing file name' do
-      let(:file_name) { nil }
-
-      it { is_expected.to be_nil }
-    end
   end
 
   describe '#readable?' do

spec/rails_helper.rb

@@ -11,6 +11,8 @@
 require 'spec_helper'
 require 'rspec/rails'
 require 'capybara/rails'
+
+require_relative 'factories/cocina'
 # Add additional requires below this line. Rails is not loaded until this point!
 
 # Requires supporting ruby files with custom matchers and macros, etc, in

spec/requests/file_auth_request_spec.rb

@@ -25,32 +25,14 @@
     # NOTE:  stanford only + location rights tested under location context
     context 'stanford only (no location qualifications)' do
       let(:public_json) do
-        {
-          'externalIdentifier' => druid,
-          'structural' => {
-            'contains' => [
-              {
-                'structural' => {
-                  'contains' => [
-                    {
-                      'filename' => file_name,
-                      'access' => {
-                        'view' => 'stanford',
-                        'download' => 'stanford'
-                      }
-                    }
-                  ]
-                }
-              }
-            ]
-          }
-        }
+        Factories.cocina_with_file(file_access: { 'view' => 'stanford', 'download' => 'stanford' })
       end
 
       context 'webauthed user' do
         it 'allows when user webauthed and authorized' do
           allow_any_instance_of(FileController).to receive(:current_user).and_return(user_webauth_stanford_no_loc)
-          expect_any_instance_of(FileController).to receive(:send_file).with(stacks_file.path, disposition: :inline).and_call_original
+          expect_any_instance_of(FileController).to receive(:send_file).with(stacks_file.path, filename: 'image.jp2',
+                                                                                               disposition: :inline).and_call_original
           get "/file/#{druid}/#{file_name}"
         end
 
@@ -69,32 +51,14 @@
     context 'location' do
       context 'not stanford qualified in any way' do
         let(:public_json) do
-          {
-            'externalIdentifier' => druid,
-            'structural' => {
-              'contains' => [
-                {
-                  'structural' => {
-                    'contains' => [
-                      {
-                        'filename' => file_name,
-                        'access' => {
-                          'view' => 'location-based',
-                          'download' => 'location-based',
-                          'location' => 'location1'
-                        }
-                      }
-                    ]
-                  }
-                }
-              ]
-            }
-          }
+          Factories.cocina_with_file(file_access: { 'view' => 'location-based', 'download' => 'location-based',
+                                                    'location' => 'location1' })
         end
 
         it 'allows when user in location' do
           allow_any_instance_of(FileController).to receive(:current_user).and_return(user_loc_no_webauth)
-          expect_any_instance_of(FileController).to receive(:send_file).with(stacks_file.path, disposition: :inline).and_call_original
+          expect_any_instance_of(FileController).to receive(:send_file).with(stacks_file.path, filename: 'image.jp2',
+                                                                                               disposition: :inline).and_call_original
           get "/file/#{druid}/#{file_name}"
         end