1 files changed, 162 insertions, 0 deletions
diff --git a/activestorage/lib/active_storage/service/disk_service.rb b/activestorage/lib/active_storage/service/disk_service.rb
new file mode 100644
index 0000000000..52f3a3df16
--- /dev/null
+++ b/activestorage/lib/active_storage/service/disk_service.rb
@@ -0,0 +1,162 @@
+# frozen_string_literal: true
+
+require "fileutils"
+require "pathname"
+require "digest/md5"
+require "active_support/core_ext/numeric/bytes"
+
+module ActiveStorage
+  # Wraps a local disk path as an Active Storage service. See ActiveStorage::Service for the generic API
+  # documentation that applies to all services.
+  class Service::DiskService < Service
+    attr_reader :root
+
+    def initialize(root:)
+      @root = root
+    end
+
+    def upload(key, io, checksum: nil)
+      instrument :upload, key: key, checksum: checksum do
+        IO.copy_stream(io, make_path_for(key))
+        ensure_integrity_of(key, checksum) if checksum
+      end
+    end
+
+    def download(key, &block)
+      if block_given?
+        instrument :streaming_download, key: key do
+          stream key, &block
+        end
+      else
+        instrument :download, key: key do
+          begin
+            File.binread path_for(key)
+          rescue Errno::ENOENT
+            raise ActiveStorage::FileNotFoundError
+          end
+        end
+      end
+    end
+
+    def download_chunk(key, range)
+      instrument :download_chunk, key: key, range: range do
+        begin
+          File.open(path_for(key), "rb") do |file|
+            file.seek range.begin
+            file.read range.size
+          end
+        rescue Errno::ENOENT
+          raise ActiveStorage::FileNotFoundError
+        end
+      end
+    end
+
+    def delete(key)
+      instrument :delete, key: key do
+        begin
+          File.delete path_for(key)
+        rescue Errno::ENOENT
+          # Ignore files already deleted
+        end
+      end
+    end
+
+    def delete_prefixed(prefix)
+      instrument :delete_prefixed, prefix: prefix do
+        Dir.glob(path_for("#{prefix}*")).each do |path|
+          FileUtils.rm_rf(path)
+        end
+      end
+    end
+
+    def exist?(key)
+      instrument :exist, key: key do |payload|
+        answer = File.exist? path_for(key)
+        payload[:exist] = answer
+        answer
+      end
+    end
+
+    def url(key, expires_in:, filename:, disposition:, content_type:)
+      instrument :url, key: key do |payload|
+        verified_key_with_expiration = ActiveStorage.verifier.generate(key, expires_in: expires_in, purpose: :blob_key)
+
+        generated_url =
+          url_helpers.rails_disk_service_url(
+            verified_key_with_expiration,
+            host: current_host,
+            filename: filename,
+            disposition: content_disposition_with(type: disposition, filename: filename),
+            content_type: content_type
+          )
+
+        payload[:url] = generated_url
+
+        generated_url
+      end
+    end
+
+    def url_for_direct_upload(key, expires_in:, content_type:, content_length:, checksum:)
+      instrument :url, key: key do |payload|
+        verified_token_with_expiration = ActiveStorage.verifier.generate(
+          {
+            key: key,
+            content_type: content_type,
+            content_length: content_length,
+            checksum: checksum
+          },
+          { expires_in: expires_in,
+          purpose: :blob_token }
+        )
+
+        generated_url = url_helpers.update_rails_disk_service_url(verified_token_with_expiration, host: current_host)
+
+        payload[:url] = generated_url
+
+        generated_url
+      end
+    end
+
+    def headers_for_direct_upload(key, content_type:, **)
+      { "Content-Type" => content_type }
+    end
+
+    def path_for(key) #:nodoc:
+      File.join root, folder_for(key), key
+    end
+
+    private
+      def stream(key)
+        File.open(path_for(key), "rb") do |file|
+          while data = file.read(5.megabytes)
+            yield data
+          end
+        end
+      rescue Errno::ENOENT
+        raise ActiveStorage::FileNotFoundError
+      end
+
+      def folder_for(key)
+        [ key[0..1], key[2..3] ].join("/")
+      end
+
+      def make_path_for(key)
+        path_for(key).tap { |path| FileUtils.mkdir_p File.dirname(path) }
+      end
+
+      def ensure_integrity_of(key, checksum)
+        unless Digest::MD5.file(path_for(key)).base64digest == checksum
+          delete key
+          raise ActiveStorage::IntegrityError
+        end
+      end
+
+      def url_helpers
+        @url_helpers ||= Rails.application.routes.url_helpers
+      end
+
+      def current_host
+        ActiveStorage::Current.host
+      end
+  end
+end