Class: MemStore::HashStore

Inherits:
ObjectStore show all
Defined in:
lib/memstore/hashstore.rb,
lib/memstore/json.rb,
lib/memstore/yaml.rb,
lib/memstore/msgpack.rb

Overview

A HashStore accesses item attributes through item.

Instance Attribute Summary

Attributes inherited from ObjectStore

#items

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ObjectStore

#[], #all, #count_all, #count_any, #count_none, #count_not_all, #count_one, #delete_items, #delete_keys, #find_all, #find_any, #find_none, #find_not_all, #find_one, #first_all, #first_any, #first_none, #first_not_all, #first_one, from_file, #insert, #length, #to_binary, #to_file, with_file

Constructor Details

#initialize(key = nil, items = {}) ⇒ HashStore

Initializes a HashStore.

key - Optional Object used as an item’s key attribute (default: nil).

When no key is specified, Object#hash will be used for uniquely identifying items.

items - Optional Hash of items to initialize the data store with (default: empty Hash).

Examples

store = HashStore.new
store = HashStore.new(:id)
store = HashStore.new(nil, { a.hash => a, b.hash => b, c.hash => c })
store = HashStore.new(:id, { 1 => a, 2 => b, 3 => c })

Returns initialized ObjectStore.



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# File 'lib/memstore/hashstore.rb', line 22

def initialize(key=nil, items={})
  @key, @items = key, items
end

Class Method Details

.from_binary(binary) ⇒ Object

Restores a data store from binary format.

binary - Binary data containing a serialized instance of HashStore.

Examples

store = HashStore.from_binary(IO.read(file))

Returns instance of HashStore

or nil if marshalling failed or marshalled object isn

Raises whatever Marshal::load raises.



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# File 'lib/memstore/hashstore.rb', line 42

def self.from_binary(binary)
  restored = Marshal.load(binary) rescue nil
  if restored.instance_of?(HashStore) then restored else nil end
end

.from_hash(hash) ⇒ Object

Restores a data store from a Hash.

hash - Hash that contains a serialized HashStore.

It must have the fields :key/"key" and :items/"items".

Examples

store = HashStore.from_hash(hash)

Returns instance of HashStore

or nil if hash isn


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# File 'lib/memstore/hashstore.rb', line 58

def self.from_hash(hash)
  begin
    if hash.has_key?(:key) then key = hash[:key]
    elsif hash.has_key? "key" then key = hash["key"]
    else return nil end

    if hash.has_key?(:items) then items = hash[:items]
    elsif hash.has_key? "items" then items = hash["items"]
    else return nil end

    if items.is_a?(Hash) then self.new(key, items) else self.new(key) end
  rescue
    nil
  end
end

.from_json(json) ⇒ Object 



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# File 'lib/memstore/json.rb', line 17

def self.from_json(json)
  self.from_hash(JSON.parse(json)) rescue nil
end

.from_json_file(file) ⇒ Object 



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# File 'lib/memstore/json.rb', line 21

def self.from_json_file(file)
  self.from_json(IO.read(file)) rescue nil
end

.from_msgpack(msgpack) ⇒ Object 



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# File 'lib/memstore/msgpack.rb', line 17

def self.from_msgpack(msgpack)
  self.from_hash(MessagePack.unpack(msgpack)) rescue nil
end

.from_msgpack_file(file) ⇒ Object 



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# File 'lib/memstore/msgpack.rb', line 21

def self.from_msgpack_file(file)
  self.from_msgpack(IO.read(file)) rescue nil
end

.from_yaml(yaml) ⇒ Object 



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# File 'lib/memstore/yaml.rb', line 17

def self.from_yaml(yaml)
  begin
    self.from_hash(YAML.load(yaml))
  rescue StandardError, Psych::SyntaxError
    nil
  end
end

.from_yaml_file(file) ⇒ Object 



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# File 'lib/memstore/yaml.rb', line 25

def self.from_yaml_file(file)
  self.from_yaml(IO.read(file)) rescue nil
end

.with_json_file(file, key = nil, items = {}, &block) ⇒ Object 



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# File 'lib/memstore/json.rb', line 25

def self.with_json_file(file, key=nil, items={}, &block)
  self.execute_with_file(:from_json_file, :to_json_file, file, key, items, &block)
end

.with_msgpack_file(file, key = nil, items = {}, &block) ⇒ Object 



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# File 'lib/memstore/msgpack.rb', line 25

def self.with_msgpack_file(file, key=nil, items={}, &block)
  self.execute_with_file(:from_msgpack_file, :to_msgpack_file, file, key, items, &block)
end

.with_yaml_file(file, key = nil, items = {}, &block) ⇒ Object 



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# File 'lib/memstore/yaml.rb', line 29

def self.with_yaml_file(file, key=nil, items={}, &block)
  self.execute_with_file(:from_yaml_file, :to_yaml_file, file, key, items, &block)
end

Instance Method Details

#to_hash ⇒ Object

Returns data store as a Hash with the fields :key and :items.



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# File 'lib/memstore/hashstore.rb', line 27

def to_hash
  { key: @key, items: @items }
end

#to_json ⇒ Object 



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# File 'lib/memstore/json.rb', line 9

def to_json
  self.to_hash.to_json
end

#to_json_file(file) ⇒ Object 



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# File 'lib/memstore/json.rb', line 13

def to_json_file(file)
  IO.write(file, self.to_json)
end

#to_msgpack ⇒ Object 



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# File 'lib/memstore/msgpack.rb', line 9

def to_msgpack
  self.to_hash.to_msgpack
end

#to_msgpack_file(file) ⇒ Object 



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# File 'lib/memstore/msgpack.rb', line 13

def to_msgpack_file(file)
  IO.write(file, self.to_msgpack)
end

#to_yaml ⇒ Object 



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# File 'lib/memstore/yaml.rb', line 9

def to_yaml
  self.to_hash.to_yaml
end

#to_yaml_file(file) ⇒ Object 



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# File 'lib/memstore/yaml.rb', line 13

def to_yaml_file(file)
  IO.write(file, self.to_yaml)
end