Class: CassandraObject::Adapters::CassandraDriver::Client

Inherits:
ActiveRecord::ConnectionAdapters::AbstractAdapter
  • Object
show all
Defined in:
lib/cassandra_object/adapters/cassandra_driver.rb

Overview

The client class acts like the old cassandra gem

Constant Summary collapse

KEY_FIELD = 
'key'
NAME_FIELD = 
'column1'
VALUE_FIELD = 
'value'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(session, cluster) ⇒ Client

Returns a new instance of Client.



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 75

def initialize(session, cluster)
  @session = session
  @cluster = cluster
end

Instance Attribute Details

#cluster ⇒ Object (readonly)

Returns the value of attribute cluster.



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 69

def cluster
  @cluster
end

#session ⇒ Object (readonly)

Returns the value of attribute session.



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 69

def session
  @session
end

Instance Method Details

#add(column_family, key, by, fields, opts = nil) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 169

def add(column_family, key, by, fields, opts=nil)
  async = opts.try(:[], :async)
  fields = [fields] unless fields.is_a?(Array)

  fields.each do |field|
    query = "UPDATE \"#{column_family}\" SET #{VALUE_FIELD} = #{VALUE_FIELD} + #{by} WHERE #{KEY_FIELD} = #{escape(key, key_type(column_family))} AND #{NAME_FIELD} = #{escape(field, name_type(column_family))};"
    async ? self.execute_async(query, execute_options(opts)) : self.execute(query, execute_options(opts))
  end
end

#add_column_family(column_family) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 265

def add_column_family(column_family)
  value_type = column_family.default_validation_class == 'CounterColumnType' ? 'counter' : 'text'

  query = "CREATE TABLE \"\#{column_family.name}\" (\n  key blob,\n  column1 text,\n  value \#{value_type},\n  PRIMARY KEY (key, column1)\n) WITH COMPACT STORAGE\n  AND CLUSTERING ORDER BY (column1 ASC)\n  AND bloom_filter_fp_chance = 0.1\n  AND caching = '{\"keys\":\"ALL\", \"rows_per_partition\":\"NONE\"}'\n  AND comment = ''\n  AND compaction = {'sstable_size_in_mb': '160', 'class': 'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'}\n  AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.SnappyCompressor'}\n  AND dclocal_read_repair_chance = 0.1\n  AND default_time_to_live = 0\n  AND gc_grace_seconds = 864000\n  AND max_index_interval = 2048\n  AND memtable_flush_period_in_ms = 0\n  AND min_index_interval = 128\n  AND read_repair_chance = 0.0\n  AND speculative_retry = 'NONE';\n"

  self.execute(query)

  self.column_families[column_family.name.to_s] = column_family
end

#batch ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 254

def batch
  yield
end

#close ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 80

def close
  session.close
end

#column_families ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 250

def column_families
  @column_families ||= self.cluster.keyspace(session.keyspace).tables.inject({}) { |hsh, table| hsh[table.name] = table; hsh }
end

#convert_str_to_hex(str) ⇒ Object

insert a blob



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 338

def convert_str_to_hex(str)
  '0x' << str.unpack('H*').first
end

#convert_str_to_timeuuid(str) ⇒ Object

when the column names are timeuuid



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 333

def convert_str_to_timeuuid(str)
  SimpleUUID::UUID.new(str).to_guid
end

#decode(val, type) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 323

def decode(val, type)
  case type
  when :timeuuid
    SimpleUUID::UUID.new(val.to_s).to_s # binary version
  else
    val
  end
end

#escape(str, type) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 312

def escape(str, type)
  case type
  when :timeuuid
    convert_str_to_timeuuid str
  when :blob
    convert_str_to_hex str
  else
    "'#{str}'"
  end
end

#execute(query, options = {}) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 84

def execute(query, options={})
  ActiveSupport::Notifications.instrument('query.cassandra', query: query, options: options, async: false) do
    session.execute query, options
  end
end

#execute_async(query, options = {}) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 90

def execute_async(query, options={})
  ActiveSupport::Notifications.instrument('query.cassandra', query: query, options: options, async: true) do
    session.execute_async query, options
  end
end

#execute_options(opts) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 228

def execute_options(opts)
  opts.try(:slice,
           :consistency,
           :page_size,
           :trace,
           :timeout,
           :serial_consistency
          ) || {}
end

#get(column_family, key, *columns_options) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 111

def get(column_family, key, *columns_options)
  opts = columns_options.pop if columns_options.last.is_a?(Hash)
  async = opts.try(:[], :async)

  columns = columns_options.flatten.compact

  query =
    if columns.size == 1
      "SELECT #{VALUE_FIELD} FROM \"#{column_family}\" WHERE #{KEY_FIELD} = #{escape(key, key_type(column_family))} AND #{NAME_FIELD} = #{escape(columns.first, name_type(column_family))}"
    else
      "SELECT #{NAME_FIELD}, #{VALUE_FIELD} FROM \"#{column_family}\" WHERE #{KEY_FIELD} = #{escape(key, key_type(column_family))}"
    end

  result = async ? self.execute_async(query, execute_options(opts)) : self.execute(query, execute_options(opts))
  return result if async

  if columns.size == 1
    result.size > 0 ? result.first[VALUE_FIELD] : nil
  else
    data = result.inject({}) { |hsh, row| hsh[row[NAME_FIELD]] = row[VALUE_FIELD]; hsh }
    columns.size > 0 ? data.slice(*columns.map(&:to_s)) : data
  end
end

#get_columns(column_family, key, columns, opts) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 135

def get_columns(column_family, key, columns, opts)
  async = opts.try(:[], :async)

  name_fields = columns.map { |c| escape(c, name_type(column_family)) }.join(', ')

  query = "SELECT #{NAME_FIELD}, #{VALUE_FIELD} FROM \"#{column_family}\" WHERE #{NAME_FIELD} IN(#{name_fields}) AND #{KEY_FIELD} = #{escape(key, key_type(column_family))}"

  result = async ? self.execute_async(query, execute_options(opts)) : self.execute(query, execute_options(opts))
  return result if async

  data = result
         .inject({}) { |hsh, row| hsh[row[NAME_FIELD]] = row[VALUE_FIELD]; hsh }

  columns.map { |column| data[column.to_s] }
end

#get_columns_as_hash(column_family, key, columns, opts) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 151

def get_columns_as_hash(column_family, key, columns, opts)
  async = opts.try(:[], :async)

  name_fields = columns.map { |c| "'#{c}'" }.join(', ')

  query = "SELECT #{NAME_FIELD}, #{VALUE_FIELD} FROM \"#{column_family}\" WHERE #{NAME_FIELD} IN(#{name_fields}) AND #{KEY_FIELD} = #{escape(key, key_type(column_family))}"

  result = async ? self.execute_async(query, execute_options(opts)) : self.execute(query, execute_options(opts))
  return result if async

  result
    .inject({}) { |hsh, row| hsh[row[NAME_FIELD]] = row[VALUE_FIELD]; hsh }
end

#get_range(column_family, opts = {}, &blk) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 193

def get_range(column_family, opts={}, &blk)
  key_count = opts[:key_count] || 100
  query = "SELECT #{KEY_FIELD} FROM \"#{column_family}\" LIMIT #{key_count}"
  keys = self.execute(query, execute_options(opts)).map { |result| result[KEY_FIELD] }
  keys.size > 0 ? multi_get(column_family, keys) : {}
end

#get_slice(column_family, key, column, start, finish, count, reversed, consistency, opts = {}) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 212

def get_slice(column_family, key, column, start, finish, count, reversed, consistency, opts={})
  opts[:consistency] = consistency

  query = "SELECT * FROM \"#{column_family}\" WHERE #{KEY_FIELD} = #{escape(key, key_type(column_family))}"
  query << " AND #{NAME_FIELD} = #{escape(column, name_type(column_family))}" if column
  query << " AND #{NAME_FIELD} >= #{escape(start, name_type(column_family))}" unless start.empty?
  query << " AND #{NAME_FIELD} <= #{escape(finish, name_type(column_family))}" unless finish.empty?
  query << " ORDER BY #{NAME_FIELD} #{reverse_comparator(column_family) ? 'ASC' : 'DESC'}" if reversed
  query << " LIMIT #{count}"

  self.execute(query, execute_options(opts)).inject({}) do |results, row|
    results[decode(row[NAME_FIELD], name_type(column_family))] = decode(row[VALUE_FIELD], value_type(column_family))
    results
  end
end

#get_value(column_family, key, column, consistency) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 165

def get_value(column_family, key, column, consistency)
  get column_family, key, [column], :consistency => consistency
end

#has_table?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 242

def has_table?(name)
  self.cluster.keyspace(session.keyspace).has_table? name
end

#insert(column_family, key, values, opts = nil) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 96

def insert(column_family, key, values, opts=nil)
  ttl = opts.try(:[], :ttl)
  async = opts.try(:[], :async)

  insert_into_options = ttl ? " USING TTL #{ttl}" : ''

  query = "BEGIN BATCH\n"
  query << values.map do |name, value|
    "  INSERT INTO \"#{column_family}\" (#{KEY_FIELD}, #{NAME_FIELD}, #{VALUE_FIELD}) VALUES (#{escape(key, key_type(column_family))}, #{escape(name, name_type(column_family))}, #{escape(value, value_type(column_family))})#{insert_into_options}"
  end.join("\n")
  query << "\nAPPLY BATCH;"

  async ? self.execute_async(query, execute_options(opts)) : self.execute(query, execute_options(opts))
end

#key_type(column_family) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 296

def key_type(column_family)
  self.cluster.keyspace(keyspace).table(column_family).column(KEY_FIELD).type.kind
end

#keyspace ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 238

def keyspace
  session.keyspace
end

#multi_get(column_family, keys, *args) ⇒ Object 



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

def multi_get(column_family, keys, *args)
  opts = args.pop if args.last.is_a?(Hash)
  keys = keys.map { |key| escape(key, key_type(column_family)) }.join(',')
  results = {}
  query = "SELECT * FROM \"#{column_family}\" WHERE #{KEY_FIELD} IN(#{keys})"
  self.execute(query, execute_options(opts)).each do |row|
    results[row[KEY_FIELD]] ||= {}
    results[row[KEY_FIELD]][row[NAME_FIELD]] = row[VALUE_FIELD]
  end
  results
end

#name_type(column_family) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 300

def name_type(column_family)
  self.cluster.keyspace(keyspace).table(column_family).column(NAME_FIELD).type.kind
end

#remove(column_family, key, *args) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 179

def remove(column_family, key, *args)
  opts = args.pop if args.last.is_a?(Hash)
  async = opts.try(:[], :async)

  query =
    if args.first.nil? || args.first.is_a?(Hash)
      "DELETE FROM \"#{column_family}\" WHERE #{KEY_FIELD} = #{escape(key, key_type(column_family))};"
    else
      "DELETE \"#{column_family}\" WHERE #{KEY_FIELD} = #{escape(key, key_type(column_family))} AND #{NAME_FIELD} = #{escape(args.first, name_type(column_family))};"
    end

  async ? self.execute_async(query, execute_options(opts)) : self.execute(query, execute_options(opts))
end

#reverse_comparator(column_family) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 308

def reverse_comparator(column_family)
  self.cluster.keyspace(keyspace).table(column_family).send(:clustering_order).first == :desc
end

#schema(reload = false) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 258

def schema(reload=false)
  if reload
    remove_instance_variable(:@schema_cache) if instance_variable_defined?(:@schema_cache)
    remove_instance_variable(:@column_families) if instance_variable_defined?(:@column_families)
  end
end

#schema_cache ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 246

def schema_cache
  @schema_cache ||= SchemaCache.new(self)
end

#value_type(column_family) ⇒ Object 



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# File 'lib/cassandra_object/adapters/cassandra_driver.rb', line 304

def value_type(column_family)
  self.cluster.keyspace(keyspace).table(column_family).column(VALUE_FIELD).type.kind
end