Class: HashIndex

Inherits:
Object
  • Object
show all
Defined in:
lib/ObjectModel/Indexes/HashIndex.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, &hasher) ⇒ HashIndex

Returns a new instance of HashIndex.



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 4

def initialize name, &hasher
  name.should! :be_a, Symbol
  @name, @hasher = name, hasher
end

Instance Attribute Details

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 2

def name
  @name
end

#repository ⇒ Object

Returns the value of attribute repository.



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 2

def repository
  @repository
end

#storage ⇒ Object

Returns the value of attribute storage.



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 2

def storage
  @storage
end

Instance Method Details

#[](hash) ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 14

def [] hash
  entity_id = get_entity_id hash   
  return entity_id != nil ? @repository.by_id(entity_id) : nil
end

#add(entity) ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 32

def add entity
  hash = @hasher.call(entity)
  #    hash.should! :be_a, String
  storage[@name].insert :hash => hash.to_s, :entity_id => entity.entity_id if hash != nil
end

#create_index ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 45

def create_index
  if storage.db.table_exists? @name
    return true
  else     
    storage.db.create_table @name do      
      column :hash, :text
      column :entity_id, :text
      primary_key :hash
      
#       index :hash
#       index :entity_id
    end
    return false
  end
end

#delete_index ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 61

def delete_index
  storage.db.drop_table @name if storage.db.table_exists? @name
end

#get_entity_id(hash) ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 19

def get_entity_id hash
  row = storage[@name][:hash => hash.to_s]
  return row ? row[:entity_id] : nil
end

#include?(hash) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 9

def include? hash
  hash.should! :be_a, String
  return storage[@name][:hash => hash] != nil
end

#print_storage(i_name) ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 38

def print_storage i_name
  return unless i_name == nil or i_name == @name
  puts "\nHashIndex #{@name}:"
  storage[@name].print
  @storage
end

#update(entity, copy) ⇒ Object 



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# File 'lib/ObjectModel/Indexes/HashIndex.rb', line 24

def update entity, copy   
  storage[@name].filter(:entity_id => entity.entity_id).delete
  unless copy.deleted?
    hash = @hasher.call(entity)     
    storage[@name].insert :hash => hash.to_s, :entity_id => entity.entity_id if hash != nil 
  end
end