Parent

Object

Hiera::Filecache

Public Class Methods

new() click to toggle source 
# File lib/hiera/filecache.rb, line 3
def initialize
  @cache = {}
end

Public Instance Methods

path_metadata(path) click to toggle source

This is based on the old caching in the YAML backend and has a resolution of 1 second, changes made within the same second of a previous read will be ignored

# File lib/hiera/filecache.rb, line 69
def path_metadata(path)
  stat = File.stat(path)
  {:inode => stat.ino, :mtime => stat.mtime, :size => stat.size}
end
read(path, expected_type=nil, default=nil) click to toggle source

Reads a file, optionally parse it in some way check the output type and set a default

Simply invoking it this way will return the file contents

data = read("/some/file")

But as most cases of file reading in hiera involves some kind of parsing through a serializer there's some help for those cases:

data = read("/some/file", Hash, {}) do |data|
   JSON.parse(data)
end

In this case it will read the file, parse it using JSON then check that the end result is a Hash, if it's not a hash or if reading/parsing fails it will return {} instead

Prior to calling this method you should be sure the file exist

# File lib/hiera/filecache.rb, line 27
def read(path, expected_type=nil, default=nil)
  @cache[path] ||= {:data => nil, :meta => path_metadata(path)}

  if File.exist?(path) && !@cache[path][:data] || stale?(path)
    if block_given?
      begin
        @cache[path][:data] = yield(File.read(path))
      rescue => e
        Hiera.debug("Reading data from %s failed: %s: %S" % [path, e.class, e.to_s])
        @cache[path][:data] = default
      end
    else
      @cache[path][:data] = File.read(path)
    end
  end

  if block_given? && !expected_type.nil?
    unless @cache[path][:data].is_a?(expected_type)
      Hiera.debug("Data retrieved from %s is not a %s, setting defaults" % [path, expected_type])
      @cache[path][:data] = default
    end
  end

  @cache[path][:data]
end
stale?(path) click to toggle source 
# File lib/hiera/filecache.rb, line 53
def stale?(path)
  meta = path_metadata(path)

  @cache[path] ||= {:data => nil, :meta => nil}

  if @cache[path][:meta] == meta
    return false
  else
    @cache[path][:meta] = meta
    return true
  end
end

[Validate]

Generated with the Darkfish Rdoc Generator 2.