Class: Alephant::Sequencer::SequenceTable

Inherits:
Object
  • Object
show all
Defined in:
lib/alephant/models/sequence_table.rb

Constant Summary collapse

TIMEOUT = 
120
DEFAULT_CONFIG = 
{
  :write_units => 5,
  :read_units => 10,
}
SCHEMA = 
{
  :hash_key => {
    :key => :string,
    :value => :string
  }
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(table_name, config = DEFAULT_CONFIG) ⇒ SequenceTable

Returns a new instance of SequenceTable.



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# File 'lib/alephant/models/sequence_table.rb', line 22

def initialize(table_name, config = DEFAULT_CONFIG)
  @mutex = Mutex.new
  @dynamo_db = AWS::DynamoDB.new
  @table_name = table_name
  @config = config
end

Instance Attribute Details

#table_name ⇒ Object (readonly)

Returns the value of attribute table_name.



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# File 'lib/alephant/models/sequence_table.rb', line 8

def table_name
  @table_name
end

Instance Method Details

#create ⇒ Object 



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# File 'lib/alephant/models/sequence_table.rb', line 29

def create
  @mutex.synchronize do
    ensure_table_exists
    ensure_table_active
  end
end

#delete_item!(ident) ⇒ Object 



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# File 'lib/alephant/models/sequence_table.rb', line 56

def delete_item!(ident)
  table.items[ident].delete
end

#sequence_for(ident) ⇒ Object 



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# File 'lib/alephant/models/sequence_table.rb', line 40

def sequence_for(ident)
  rows = batch_get_value_for(ident)
  rows.count >= 1 ? rows.first['value'].to_i : 0
end

#set_sequence_for(ident, value) ⇒ Object 



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# File 'lib/alephant/models/sequence_table.rb', line 45

def set_sequence_for(ident,value)
  @mutex.synchronize do
    AWS::DynamoDB::BatchWrite.new.tap { |batch|
      batch.put(
        table_name,
        [:key => ident,:value => value]
      )
    }.process!
  end
end

#table ⇒ Object 



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# File 'lib/alephant/models/sequence_table.rb', line 36

def table
  @table ||= @dynamo_db.tables[@table_name]
end