Class: CassandraObject::Adapters::CassandraAdapter

Inherits:
AbstractAdapter show all
Defined in:
lib/cassandra_object/adapters/cassandra_adapter.rb

Defined Under Namespace

Classes: QueryBuilder

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#config

Instance Method Summary collapse

Methods inherited from AbstractAdapter

#batch, #batching?, #execute_batchable, #initialize, #statement_with_options

Constructor Details

This class inherits a constructor from CassandraObject::Adapters::AbstractAdapter

Instance Method Details

#cassandra_cluster_options ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 51

def cassandra_cluster_options
  cluster_options = config.slice(*[
      :auth_provider,
      :client_cert,
      :compression,
      :compressor,
      :connect_timeout,
      :connections_per_local_node,
      :connections_per_remote_node,
      :consistency,
      :credentials,
      :futures_factory,
      :hosts,
      :load_balancing_policy,
      :logger,
      :page_size,
      :passphrase,
      :password,
      :port,
      :private_key,
      :protocol_version,
      :reconnection_policy,
      :retry_policy,
      :schema_refresh_delay,
      :schema_refresh_timeout,
      :server_cert,
      :ssl,
      :timeout,
      :trace,
      :username
  ])

  {
      load_balancing_policy: 'Cassandra::LoadBalancing::Policies::%s',
      reconnection_policy: 'Cassandra::Reconnection::Policies::%s',
      retry_policy: 'Cassandra::Retry::Policies::%s'
  }.each do |policy_key, class_template|
    if cluster_options[policy_key]
      cluster_options[policy_key] = (class_template % [policy_key.classify]).constantize
    end
  end

  # Setting defaults
  cluster_options.merge!({
                             consistency: cluster_options[:consistency] || :quorum,
                             protocol_version: cluster_options[:protocol_version] || 3,
                             page_size: cluster_options[:page_size] || 10000
                         })
  return cluster_options
end

#cassandra_version ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 215

def cassandra_version
  @cassandra_version ||= execute('select release_version from system.local').rows.first['release_version'].to_f
end

#connection ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 103

def connection
  @connection ||= begin
    cluster = Cassandra.cluster cassandra_cluster_options
    cluster.connect config[:keyspace]
  end
end

#consistency ⇒ Object

/SCHEMA



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 221

def consistency
  defined?(@consistency) ? @consistency : nil
end

#consistency=(val) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 225

def consistency=(val)
  @consistency = val
end

#create_table(table_name, params = {}) ⇒ Object

SCHEMA



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 187

def create_table(table_name, params = {})
  stmt = "CREATE TABLE #{table_name} "
  if params.any? && !params[:attributes].present?
    raise 'No attributes for the table'
  elsif !params[:attributes].include? 'PRIMARY KEY'
    raise 'No PRIMARY KEY defined'
  end

  stmt += "(#{params[:attributes]})"
  # WITH COMPACT STORAGE
  schema_execute statement_create_with_options(stmt, params[:options]), config[:keyspace]
end

#delete(table, key, ids) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 170

def delete(table, key, ids)
  ids = [ids] if !ids.is_a?(Array)
  statement = "DELETE FROM #{table} WHERE #{key} IN (#{ids.map{|id| "'#{id}'"}.join(',')})"
  execute(statement, nil)
end

#drop_table(table_name, confirm = false) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 200

def drop_table(table_name, confirm = false)
  count = (schema_execute "SELECT count(*) FROM #{table_name}", config[:keyspace]).rows.first['count']
  if confirm || count == 0
    schema_execute "DROP TABLE #{table_name}", config[:keyspace]
  else
    raise "The table #{table_name} is not empty! If you want to drop it add the option confirm = true"
  end
end

#execute(statement, arguments = []) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 110

def execute(statement, arguments = [])
  ActiveSupport::Notifications.instrument('cql.cassandra_object', cql: statement) do
    type_hints = []
    arguments.each { |a| type_hints << CassandraObject::Types::TypeHelper.guess_type(a) } unless arguments.nil?
    connection.execute statement, arguments: arguments, type_hints: type_hints, consistency: consistency, page_size: config[:page_size]
  end
end

#execute_async(queries, arguments = []) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 118

def execute_async(queries, arguments = [])
  futures = queries.map do |q|
    ActiveSupport::Notifications.instrument('cql.cassandra_object', cql: q) do
      connection.execute_async q, arguments: arguments, consistency: consistency, page_size: config[:page_size]
    end
  end
  futures.map do |future|
    rows = future.get
    rows
  end
end

#execute_batch(statements) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 176

def execute_batch(statements)
  raise 'No can do' if statements.empty?
  batch = connection.batch do |b|
    statements.each do |statement|
      b.add(statement[:query], arguments: statement[:arguments])
    end
  end
  connection.execute(batch, page_size: config[:page_size])
end

#insert(table, id, attributes, ttl = nil) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 141

def insert(table, id, attributes, ttl = nil)
  write(table, id, attributes, ttl)
end

#schema_execute(cql, keyspace) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 209

def schema_execute(cql, keyspace)
  schema_db = Cassandra.cluster cassandra_cluster_options
  connection = schema_db.connect keyspace
  connection.execute cql, consistency: consistency
end

#select(scope) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 130

def select(scope)
  queries = QueryBuilder.new(self, scope).to_query_async
  # todo paginate
  cql_rows = execute_async(queries).map{|item| item.rows.map{|x| x}}.flatten!
  cql_rows.each do |cql_row|
    attributes = cql_row.to_hash
    key = attributes.delete(scope._key)
    yield(key, attributes) unless attributes.empty?
  end
end

#statement_create_with_options(stmt, options = '') ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 229

def statement_create_with_options(stmt, options = '')
  if !options.nil?
    statement_with_options stmt, options
  else
    # standard
    if cassandra_version < 3
      "#{stmt} WITH bloom_filter_fp_chance = 0.001
        AND caching = '{\"keys\":\"ALL\", \"rows_per_partition\":\"NONE\"}'
        AND comment = ''
        AND compaction = {'min_sstable_size': '52428800', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'}
        AND compression = {'chunk_length_kb': '64', 'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
        AND dclocal_read_repair_chance = 0.0
        AND default_time_to_live = 0
        AND gc_grace_seconds = 864000
        AND max_index_interval = 2048
        AND memtable_flush_period_in_ms = 0
        AND min_index_interval = 128
        AND read_repair_chance = 1.0
        AND speculative_retry = 'NONE';"
    else
      "#{stmt} WITH read_repair_chance = 0.0
        AND dclocal_read_repair_chance = 0.1
        AND gc_grace_seconds = 864000
        AND bloom_filter_fp_chance = 0.01
        AND caching = { 'keys' : 'ALL', 'rows_per_partition' : 'NONE' }
        AND comment = ''
        AND compaction = { 'class' : 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold' : 32, 'min_threshold' : 4 }
        AND compression = { 'chunk_length_in_kb' : 64, 'class' : 'org.apache.cassandra.io.compress.LZ4Compressor' }
        AND default_time_to_live = 0
        AND speculative_retry = '99PERCENTILE'
        AND min_index_interval = 128
        AND max_index_interval = 2048
        AND crc_check_chance = 1.0;
      "
    end
  end
end

#update(table, id, attributes, ttl = nil) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 145

def update(table, id, attributes, ttl = nil)
  write_update(table, id, attributes)
end

#write(table, id, attributes, ttl = nil) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 149

def write(table, id, attributes, ttl = nil)
  statement = "INSERT INTO #{table} (#{(attributes.keys).join(',')}) VALUES (#{(['?'] * attributes.size).join(',')})"
  statement += " USING TTL #{ttl.to_s}" if ttl.present?
  arguments = attributes.values
  execute(statement, arguments)
end

#write_update(table, id, attributes) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_adapter.rb', line 156

def write_update(table, id, attributes)
  queries =[]
  # id here is the name of the key of the model
  id_value = attributes[id]
  if (not_nil_attributes = attributes.reject { |key, value| value.nil? }).any?
    statement = "INSERT INTO #{table} (#{(not_nil_attributes.keys).join(',')}) VALUES (#{(['?'] * not_nil_attributes.size).join(',')})"
    queries << {query: statement, arguments: not_nil_attributes.values}
  end
  if (nil_attributes = attributes.select { |key, value| value.nil? }).any?
    queries << {query: "DELETE #{nil_attributes.keys.join(',')} FROM #{table} WHERE #{id} = ?", arguments: [id_value.to_s]}
  end
  execute_batchable(queries)
end