class Webgen::Cache

A cache object provides access to various caches to speed up rendering of a website:

permanent: The permanent cache should be used for data that should be available between webgen runs.
volatile: The volatile cache is used for data that can easily be regenerated but might be expensive to do so. This cache is not stored between passes when writing nodes to the destination.
standard: The standard cache saves data between webgen runs and returns the cached data (not the newly set data) if it is available. This is useful, for example, to store file modifcation times and check if a file has been changed between runs.

The standard cache should be accessed through the [] method which returns the correct value and the []= method should be used for setting the new value. However, if you really need to access a particular value of the old or new standard cache, you can use the accessors old_data and new_data.

Attributes

new_data[R]

The cache data stored in the current webgen run.

old_data[R]

The cache data stored in the previous webgen run.

permanent[R]

The permanent cache hash.

volatile[R]

The volatile cache hash.

Public Class Methods

new() click to toggle source

Create a new cache object.

# File lib/webgen/cache.rb, line 38
def initialize()
  @old_data = {}
  @new_data = {}
  @volatile = {}
  @permanent = {}
end

Public Instance Methods

[](key) click to toggle source

Return the cached data (or, if it is not available, the new data) identified by key from the standard cache.

# File lib/webgen/cache.rb, line 47
def [](key)
  if @old_data.has_key?(key)
    @old_data[key]
  else
    @new_data[key]
  end
end

[]=(key, value) click to toggle source

Store value identified by key in the standard cache.

# File lib/webgen/cache.rb, line 56
def []=(key, value)
  @new_data[key] = value
end

dump() click to toggle source

Return all caches that should be available between webgen runs.

# File lib/webgen/cache.rb, line 66
def dump
  [@old_data.merge(@new_data), @permanent]
end

reset_volatile_cache() click to toggle source

Reset the volatile cache.

# File lib/webgen/cache.rb, line 71
def reset_volatile_cache
  @volatile = {}
end

restore(data) click to toggle source

Restore the cache from data.

# File lib/webgen/cache.rb, line 61
def restore(data)
  @old_data, @permanent = *data
end