feat(orm): extend model with destroy and touch

lib/prism/orm/model.rb

@@ -319,9 +319,77 @@ module Prism
         save!
       end
 
-      def destroy
-        self.class.store.delete(self.class.table_name, id) if persisted?
+      # Cascaded dependent destroys run inside the same transaction as the
+      # parent's own delete, so a failure partway through the cascade (or
+      # in after_destroy) rolls back every row it already removed - not
+      # just the parent - instead of leaving orphaned deletes behind.
+      # `force: true` (from Paranoia#really_destroy!) always removes the row
+      # for real even on a paranoid model, running the full callback/cascade/
+      # locking sequence again even if the record was already soft-deleted -
+      # matches Rails paranoia's really_destroy!, which re-runs the destroy
+      # callbacks rather than assuming a soft-deleted record is untouchable.
+      def destroy(force: false)
+        return self if destroyed? && !force
+        # Set before before_destroy runs (not after the paranoid-delete
+        # branch below decides) so a before_destroy hook can tell #soft_deleting?
+        # apart from a real delete - e.g. a hook that removes an uploaded
+        # file from disk should only do that on a hard delete, not one a
+        # paranoid model will still let #restore bring back.
+        @destroy_force = force
+        if !new_record?
+          self.class.transaction do
+            enlist_in_transaction(:destroy)
+            return self unless run_callbacks(:before_destroy)
+            cascade_dependent_associations
+            if paranoid_delete? && !force
+              soft_delete_row
+            elsif self.class.locking_enabled?
+              begin
+                self.class.store.delete(self.class.table_name, id, [self.class.locking_column, lock_version.to_i])
+              rescue Store::StaleRowError
+                raise StaleObjectError.new(self, :destroy)
+              end
+            else
+              self.class.store.delete(self.class.table_name, id)
+            end
             @destroyed = true
+            run_callbacks(:after_destroy)
+          end
+        else
+          @destroyed = true
+        end
+        self
+      end
+
+      # ActiveRecord::Persistence#touch-lite: bumps updated_at (plus any
+      # named extra attributes, e.g. `post.touch(:published_at)`) straight
+      # on the stored row and skips validations and the save callback chain
+      # entirely - only after_touch runs. This is what belongs_to ...,
+      # touch: true rides on (see Associable#define_touch): touching a
+      # comment's post whenever the comment is saved or destroyed changes
+      # the post's #cache_key, which is exactly what busts a `cache post do
+      # ... end` fragment that embeds the comment list.
+      def touch(*names)
+        raise RecordNotFound, "cannot touch a new record" if new_record?
+        raise RecordNotFound, "cannot touch a destroyed record" if destroyed?
+        now = Time.now.utc
+        attributes = {}
+        attributes['updated_at'] = now if self.class.columns.include?('updated_at')
+        names.each { |name| attributes[name.to_s] = now }
+        return self if attributes.empty?
+        if self.class.locking_enabled?
+          begin
+            row = self.class.store.update(self.class.table_name, id, attributes,
+                                           [self.class.locking_column, lock_version.to_i])
+          rescue Store::StaleRowError
+            raise StaleObjectError.new(self, :touch)
+          end
+          attributes[self.class.locking_column] = row[self.class.locking_column]
+        else
+          self.class.store.update(self.class.table_name, id, attributes)
+        end
+        attributes.each { |key, value| @attributes[key] = value }
+        run_callbacks(:after_touch)
         self
       end
 
@@ -336,6 +404,16 @@ module Prism
         @attributes.dup
       end
 
+      # Fragment-cache key: changes whenever the record is touched, so a
+      # `cache post do ... end` view fragment (Prism::CacheHelpers) keyed on
+      # this automatically busts on update without anyone deleting the old
+      # entry by hand.
+      def cache_key
+        base = "#{self.class.table_name}/#{id}"
+        timestamp = self['updated_at'] || self['created_at']
+        timestamp ? "#{base}-#{timestamp.to_i}" : base
+      end
+
       def ==(other)
         other.is_a?(self.class) && !id.nil? && id == other.id
       end
@@ -351,14 +429,34 @@ module Prism
         @attributes = row.dup
         @new_record = false
         @destroyed = false
+        clear_changes_information
         self
       end
 
       def touch_timestamps
         now = Time.now.utc
         columns = self.class.columns
-        @attributes['created_at'] ||= now if columns.include?('created_at') && new_record?
-        @attributes['updated_at'] = now if columns.include?('updated_at')
+        self['created_at'] = now if columns.include?('created_at') && new_record? && self['created_at'].nil?
+        self['updated_at'] = now if columns.include?('updated_at')
+      end
+
+      def initialize_lock_version
+        return unless self.class.locking_enabled?
+        @attributes[self.class.locking_column] = 0 if self[self.class.locking_column].nil?
+      end
+
+      # Only the columns this instance actually changed since it was
+      # loaded/created, never the full @attributes hash - an UPDATE that
+      # sends every column (including ones this instance never touched)
+      # would overwrite any value another code path mutated directly on
+      # the stored row in the meantime, such as a counter_cache bump
+      # (Store#increment_counter) from a cascade_dependent_associations
+      # step that runs on this very record earlier in the same #destroy,
+      # or simply this instance's attributes being stale relative to a
+      # concurrent write. Matches real UPDATE semantics (only SET the
+      # columns that changed) instead of a full-row REPLACE.
+      def dirty_attributes
+        @attributes.slice(*changed)
       end
     end
   end