Class: StoredHash

Inherits:
Object
  • Object
show all
Defined in:
lib/stored_hash.rb

Overview

This is a drop in replacement for Hash. It does act just the same but reads/writes from a yaml file whenever the hash or the file changes. This is much slower than a hash, as you might guess. A StoredHash is thread-safe.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(file, *args, &block) ⇒ StoredHash

Returns a new instance of StoredHash.



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# File 'lib/stored_hash.rb', line 17

def initialize file, *args, &block
  @data  = Hash.new(*args, &block)
  @file  = file
  @mutex = Mutex.new
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*args, &blk) ⇒ Object

Here is where the magic happens. Before any method is called on the hash we’ll check the file for changes (of course only reading the file if it has been changed). After the method terminated we check whether the hash has been changed and if so, we write it to the file.



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# File 'lib/stored_hash.rb', line 49

def method_missing(*args, &blk)
  synchronize do |file|
    update file if should_update? file
    @old_data ||= duplicate_data
    result = @data.send(*args, &blk)
    write if should_write?
    return self if result == @data
    result
  end
end

Instance Attribute Details

#file ⇒ Object (readonly)

Returns the value of attribute file.



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# File 'lib/stored_hash.rb', line 11

def file
  @file
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/stored_hash.rb', line 23

def == other
  super or @data == other
end

#is_a?(whatever) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/stored_hash.rb', line 64

def is_a? whatever
  super whatever or @data.is_a? whatever
end

#to_hash ⇒ Object 



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# File 'lib/stored_hash.rb', line 60

def to_hash
  @data.dup
end