auto-refresh config's boutiques descriptor #1174

BrainPortal/app/models/tool_config.rb

@@ -625,9 +625,13 @@ def self.register_descriptor(descriptor, tool_name, tool_version) #:nodoc:
   def self.registered_boutiques_descriptor(tool_name, tool_version) #:nodoc:
     @_descriptors_ ||= {}
     key = [ tool_name, tool_version ] # two strings
+    @_descriptors_[key] = @_descriptors_[key]&.reload_if_file_timestamp_changed
     @_descriptors_[key]
   end
 
+  # This method returns a +BoutiquesDescriptor+ object associated with the
+  # with tool config either from cache, or if a specific path given from the corresponding file
+  # is specified from that file
   def boutiques_descriptor
     path = boutiques_descriptor_path.presence
     if ! path

BrainPortal/lib/boutiques_support.rb

@@ -151,6 +151,7 @@ class ContainerImage      < RestrictedHash ; end
   class BoutiquesDescriptor
 
     attr_accessor :from_file    # not a hash attribute; a file name, for info
+    attr_accessor :mtime_of_file # not a hash attribute, a file timestamp, for caching
 
 
     def initialize(hash={})
@@ -175,18 +176,31 @@ def self.new_from_string(text)
 
     def self.new_from_file(path)
       obj = self.new_from_string(File.read(path))
-      obj.from_file = path
+      obj.from_file     = path
+      obj.mtime_of_file = File.mtime(path)
       obj
     end
 
+    # Refreshes the descriptor from the file if the file has changed.
+    # Returns self if the file has not changed, or a new descriptor
+    # if the file has changed. This is useful for quickly updating the descriptor(s)
+    # for small corrections or updates. Presently it is used only for the
+    # boutiques present in boutiques-descriptor subdirectories.
+    def reload_if_file_timestamp_changed
+      filepath = self.from_file
+      return self if filepath.blank? || (File.mtime(filepath) - self.mtime_of_file ).abs < 1
+      self.class.new_from_file(filepath)
+    end
+
     def validate
       BoutiquesSupport.validate(self) # amazingly, the JSON validator also work with our descriptor class
     end
 
     # When dup'ing, also copy the from_file attribute
     def dup #:nodoc:
       copy = super
-      copy.from_file = self.from_file
+      copy.from_file     = self.from_file
+      copy.mtime_of_file = self.mtime_of_file
       copy
     end