Class: Merb::Cache::FileStore

Inherits:
AbstractStore show all
Defined in:
lib/merb-cache/stores/fundamental/file_store.rb

Overview

Cache store that uses files. Usually this is good for fragment and page caching but not object caching.

By default cached files are stored in tmp/cache under Merb.root directory. To use other location pass :dir option to constructor.

File caching does not support expiration time.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from AbstractStore

#delete_all!, #write_all

Constructor Details

#initialize(config = {}) ⇒ FileStore

Creates directory for cached files unless it exists.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 13

def initialize(config = {})
  @dir = config[:dir] || Merb.root_path(:tmp / :cache)

  create_path(@dir)
end

Instance Attribute Details

#dirObject

Returns the value of attribute dir



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 10

def dir
  @dir
end

Instance Method Details

#delete(key, parameters = {}) ⇒ Object

Deletes cached template by key using FileUtils#rm.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 60

def delete(key, parameters = {})
  if File.file?(path = pathify(key, parameters))
    FileUtils.rm(path)
  end
end

#delete_allObject

Raises:



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 66

def delete_all
  raise NotSupportedError
end

#exists?(key, parameters = {}) ⇒ Boolean

Checks if cached template with given key exists.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 55

def exists?(key, parameters = {})
  File.file?(pathify(key, parameters))
end

#fetch(key, parameters = {}, conditions = {}, &blk) ⇒ Object

Fetches cached data by key if it exists. If it does not, uses passed block to get new cached value and writes it using given key.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 50

def fetch(key, parameters = {}, conditions = {}, &blk)
  read(key, parameters) || (writable?(key, parameters, conditions) && write(key, value = blk.call, parameters, conditions) && value)
end

#pathify(key, parameters = {}) ⇒ Object



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 70

def pathify(key, parameters = {})
  if key.to_s =~ /^\//
    path = "#{@dir}#{key}"
  else
    path = "#{@dir}/#{key}"
  end

  path << "--#{parameters.to_sha2}" unless parameters.empty?
  path
end

#read(key, parameters = {}) ⇒ Object

Reads cached template from disk if it exists.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 29

def read(key, parameters = {})
  if exists?(key, parameters)
    read_file(pathify(key, parameters))
  end
end

#writable?(key, parameters = {}, conditions = {}) ⇒ Boolean

File caching does not support expiration time.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 20

def writable?(key, parameters = {}, conditions = {})
  case key
  when String, Numeric, Symbol
    !conditions.has_key?(:expire_in)
  else nil
  end
end

#write(key, data = nil, parameters = {}, conditions = {}) ⇒ Object

Writes cached template to disk, creating cache directory if it does not exist.



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# File 'lib/merb-cache/stores/fundamental/file_store.rb', line 37

def write(key, data = nil, parameters = {}, conditions = {})
  if writable?(key, parameters, conditions)
    if File.file?(path = pathify(key, parameters))
      write_file(path, data)
    else
      create_path(path) && write_file(path, data)
    end
  end
end