Cache module tests. Gems added. Settings updated.

app/controllers/media_controller.rb

@@ -11,7 +11,14 @@ def item
     # use params to get query string or parsed route parameters
 
     # get the path for the file matching the request
-    @file_path = Cache::calculate_target_path(params)
+    file_name = Cache::cached_spectrogram_file(params)
+    #file_name = Cache::cached_audio_file(params)
+    #file_name = Cache::original_audio_file({ :id => '21EC2020-3AEA-1069-A2DD-08002B30309D', :date => '20121026', :time => '132600', :format => 'wav'})
+
+    #@file_path = Cache::possible_paths(file_name)
+    #@file_path = Cache::existing_paths(Cache::cached_spectrogram_storage_paths,file_name)
+    #@file_path = QubarSite::Application.config.media_file_config.cached_spectrogram_paths
+    @file_path = Cache::possible_paths(Cache::cached_spectrogram_storage_paths,file_name)
 
     # see if the requested file exists
 

lib/modules/cache.rb

@@ -1,17 +1,119 @@
+require 'String'
+
+# Determines file names for cached and original files.
 module Cache
 
+  @parameter_file_name_separator = '_'
+
   public
 
-  # calculate the target file name and path based on the modification parameters
-  def self.calculate_target_path(modify_parameters = {})
-    #Mime::Type.lookup_by_extension(
-    #QubarSite::Application.config.media_file_config
+  #original audio
+
+  # get the file name for an original audio file
+  def self.original_audio_file(modify_parameters = {})
+    file_name = self.build_parameters [ :id, :date, :time, :format ], modify_parameters
+    file_name
+  end
+
+  # get all the storage paths for original audio
+  def self.original_audio_storage_paths()
+    storage_paths = QubarSite::Application.config.media_file_config.original_audio_paths
+    storage_paths
+  end
+
+  # cached audio
+
+  # get the file name for a cached audio file
+  def self.cached_audio_file(modify_parameters = {})
+    file_name = self.build_parameters [ :id, :start_offset, :end_offset, :channel, :sample_rate, :format ], modify_parameters
+    file_name
+  end
+
+  # get all the storage paths for cached audio
+  def self.cached_audio_storage_paths()
+    storage_paths = QubarSite::Application.config.media_file_config.cached_audio_paths
+    storage_paths
+  end
+
+  def self. cached_audio_defaults()
+    cache_defaults = QubarSite::Application.config.media_file_config.cached_audio_defaults
+    cache_defaults
+  end
+
+   def self. cached_spectrogram_defaults()
+    cache_defaults = QubarSite::Application.config.media_file_config.cached_spectrogram_defaults
+    cache_defaults
   end
 
-  # check to see if a target file exists
-  def self.exists(source, modify_parameters = {})
-    File.exists? calculate_target_path(source, modify_parameters)
+  # cached spectrograms
+
+  # get the file name for a cached spectrogram
+  def self.cached_spectrogram_file(modify_parameters = {})
+    file_name = self.build_parameters [ :id, :start_offset, :end_offset, :channel, :sample_rate, :window, :colour, :format ], modify_parameters
+    file_name
+  end
+
+  # get all the storage paths for cached spectrograms
+  def self.cached_spectrogram_storage_paths()
+    storage_paths = QubarSite::Application.config.media_file_config.cached_spectrogram_paths
+    storage_paths
+  end
+
+  # get all possible full paths for a file
+  def self.possible_paths(storage_paths, file_name)
+    possible_paths = storage_paths.collect { |path| File.join(path,file_name) }
+    possible_paths
+  end
+
+  # get the full paths for all existing files that match a file name
+  def self.existing_paths(storage_paths, file_name)
+    existing_paths = possible_paths(storage_paths, file_name).find_all {|file| File.exists? file }
+    existing_paths
   end
 
   private
+
+  def self.build_parameters(parameter_names = {}, modify_parameters = {})
+    file_name = ''
+
+    parameter_names.each do |param| 
+      if param == :id
+        file_name += get_parameter(:id, modify_parameters, false)
+      elsif param == :format
+        file_name += '.'+get_parameter(:format, modify_parameters, false)
+      else 
+        file_name += get_parameter(param, modify_parameters)
+      end
+    end
+
+    file_name
+  end
+
+  def self.get_parameter(parameter, modify_parameters, include_separator = true)
+    # need to cater for the situation where modify_parameters contains strings (we want symbols)
+    modify_parameters.keys.each do |key|
+      modify_parameters[(key.to_sym rescue key) || key] = modify_parameters.delete(key)
+    end
+
+    # need to cater for the situation where parameter is a string (we want a symbol)
+    parameter = parameter.to_s.to_sym
+
+    raise ArgumentError, "Parameters must include #{parameter}." unless modify_parameters.include? parameter
+    result_name = ''
+
+    if modify_parameters.include? parameter
+      result_name = modify_parameters[parameter]
+
+      if parameter == :format
+        result_name = result_name.trim '.', ''
+      end
+
+      if include_separator
+        result_name = @parameter_file_name_separator+result_name
+      end
+    end
+
+    result_name
+  end
+
 end

lib/modules/string.rb

@@ -1,5 +1,5 @@
 class String
-  def trim(replace_chars, substitute_chars)
-    "#{self}".gsub(/^[#{substitute_chars}]+|[#{substitute_chars}]+$/, replace_chars)
+  def trim(chars_to_replace, char_to_insert)
+    "#{self}".gsub(/^[#{chars_to_replace}]+|[#{chars_to_replace}]+$/, char_to_insert)
   end
 end