Class: Perpetuity::Postgres

Inherits:
Object
  • Object
show all
Defined in:
lib/perpetuity/postgres.rb,
lib/perpetuity/postgres/index.rb,
lib/perpetuity/postgres/query.rb,
lib/perpetuity/postgres/table.rb,
lib/perpetuity/postgres/version.rb,
lib/perpetuity/postgres/json_hash.rb,
lib/perpetuity/postgres/nil_query.rb,
lib/perpetuity/postgres/sql_value.rb,
lib/perpetuity/postgres/connection.rb,
lib/perpetuity/postgres/expression.rb,
lib/perpetuity/postgres/json_array.rb,
lib/perpetuity/postgres/null_value.rb,
lib/perpetuity/postgres/serializer.rb,
lib/perpetuity/postgres/sql_select.rb,
lib/perpetuity/postgres/sql_update.rb,
lib/perpetuity/postgres/table_name.rb,
lib/perpetuity/postgres/text_value.rb,
lib/perpetuity/postgres/query_union.rb,
lib/perpetuity/postgres/sql_function.rb,
lib/perpetuity/postgres/boolean_value.rb,
lib/perpetuity/postgres/negated_query.rb,
lib/perpetuity/postgres/numeric_value.rb,
lib/perpetuity/postgres/connection_pool.rb,
lib/perpetuity/postgres/query_attribute.rb,
lib/perpetuity/postgres/serialized_data.rb,
lib/perpetuity/postgres/table/attribute.rb,
lib/perpetuity/postgres/timestamp_value.rb,
lib/perpetuity/postgres/index_collection.rb,
lib/perpetuity/postgres/query_expression.rb,
lib/perpetuity/postgres/json_string_value.rb,
lib/perpetuity/postgres/query_intersection.rb,
lib/perpetuity/postgres/value_with_attribute.rb

Defined Under Namespace

Classes: BooleanValue, Connection, ConnectionPool, Expression, Index, IndexCollection, JSONArray, JSONHash, JSONStringValue, NegatedQuery, NilQuery, NullValue, NumericValue, Query, QueryAttribute, QueryExpression, QueryIntersection, QueryUnion, SQLFunction, SQLSelect, SQLUpdate, SQLValue, SerializedData, Serializer, Table, TableName, TextValue, TimestampValue, ValueWithAttribute

Constant Summary collapse

VERSION = 
"0.0.3"
InvalidTableName = 
Class.new(StandardError)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Postgres

Returns a new instance of Postgres.



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# File 'lib/perpetuity/postgres.rb', line 19

def initialize options
  @host      = options.fetch(:host) { 'localhost' }
  @port      = options.fetch(:port) { 5432 }
  @db        = options.fetch(:db)
  @pool_size = options.fetch(:pool_size) { 5 }
  @username  = options.fetch(:username) { ENV['USER'] }
  @password  = options.fetch(:password) {}

  @connection ||= ConnectionPool.new(
    db:       db,
    host:     host,
    port:     port,
    username: username,
    password: password,
    pool_size: pool_size
  )
end

Instance Attribute Details

#connection ⇒ Object (readonly)

Returns the value of attribute connection.



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# File 'lib/perpetuity/postgres.rb', line 16

def connection
  @connection
end

#db ⇒ Object (readonly)

Returns the value of attribute db.



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# File 'lib/perpetuity/postgres.rb', line 16

def db
  @db
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/perpetuity/postgres.rb', line 16

def host
  @host
end

#password ⇒ Object (readonly)

Returns the value of attribute password.



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# File 'lib/perpetuity/postgres.rb', line 16

def password
  @password
end

#pool_size ⇒ Object (readonly)

Returns the value of attribute pool_size.



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# File 'lib/perpetuity/postgres.rb', line 16

def pool_size
  @pool_size
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/perpetuity/postgres.rb', line 16

def port
  @port
end

#username ⇒ Object (readonly)

Returns the value of attribute username.



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# File 'lib/perpetuity/postgres.rb', line 16

def username
  @username
end

Instance Method Details

#activate_index!(index) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 148

def activate_index! index
  sql = "CREATE "
  sql << "UNIQUE " if index.unique?
  sql << "INDEX ON #{TableName.new(index.table)} (#{index.attribute_names.join(',')})"
  connection.execute(sql)
  index.activate!
rescue PG::UndefinedTable => e
  create_table_with_attributes index.table, index.attributes
  retry
end

#active_indexes(table) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 159

def active_indexes table
  sql = <<-SQL
  SELECT pg_class.relname AS name,
         ARRAY(
           SELECT pg_get_indexdef(pg_index.indexrelid, k + 1, true)
           FROM generate_subscripts(pg_index.indkey, 1) AS k
           ORDER BY k
         ) AS attributes,
         pg_index.indisunique AS unique,
         pg_index.indisready AS active
  FROM pg_class
  INNER JOIN pg_index ON pg_class.oid = pg_index.indexrelid
  WHERE pg_class.relname ~ '^#{table}.*idx$'
  SQL

  indexes = connection.execute(sql).map do |index|
    Index.from_sql(index)
  end
  IndexCollection.new(table, indexes)
end

#add_column(table_name, column_name, attributes) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 260

def add_column table_name, column_name, attributes
  attr = attributes.detect { |a| a.name.to_s == column_name.to_s }
  column = Table::Attribute.new(attr.name, attr.type, attr.options)

  sql = %Q(ALTER TABLE "#{table_name}" ADD #{column.sql_declaration})
  connection.execute sql
end

#cast_id(id, id_attribute) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 230

def cast_id id, id_attribute
  return id if id_attribute.nil?

  if [Bignum, Fixnum, Integer].include? id_attribute.type
    id.to_i
  else
    id
  end
end

#count(klass, query = 'TRUE', options = {}, &block) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 80

def count klass, query='TRUE', options={}, &block
  where = if block_given?
            query(&block)
          else
            query
          end
  options = translate_options(options).merge(from: klass, where: where)
  table = table_name(klass)
  sql = select 'COUNT(*)', options
  connection.execute(sql).to_a.first['count'].to_i
rescue PG::UndefinedTable
  # Table does not exist, so there are 0 records
  0
end

#create_table(name, attributes) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 210

def create_table name, attributes
  connection.execute Table.new(name, attributes).create_table_sql
end

#create_table_with_attributes(klass, attributes) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 250

def create_table_with_attributes klass, attributes
  table_attributes = attributes.map do |attr|
    name = attr.name
    type = attr.type
    options = attr.options
    Table::Attribute.new name, type, options
  end
  create_table klass.to_s, table_attributes
end

#delete(id, klass) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 73

def delete id, klass
  table = TableName.new(klass)
  id_string = TextValue.new(id)
  sql = "DELETE FROM #{table} WHERE id = #{id_string}"
  connection.execute(sql).to_a
end

#delete_all(klass) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 103

def delete_all klass
  table = table_name(klass)
  sql = "DELETE FROM #{table}"
  connection.execute(sql)
rescue PG::UndefinedTable
  # Do nothing. There is already nothing here.
end

#drop_table(name) ⇒ Object Also known as: drop_collection 



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# File 'lib/perpetuity/postgres.rb', line 205

def drop_table name
  connection.execute "DROP TABLE IF EXISTS #{table_name(name)}"
end

#find(klass, id) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 95

def find klass, id
  retrieve(klass, query { |o| o.id == id }.to_db).first
end

#has_table?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/perpetuity/postgres.rb', line 214

def has_table? name
  connection.tables.include? name
end

#increment(klass, id, attribute, count = 1) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 244

def increment klass, id, attribute, count=1
  table = TableName.new(klass)
  sql = %Q{UPDATE #{table} SET #{attribute} = #{attribute} + #{count} WHERE id = #{SQLValue.new(id)} RETURNING #{attribute}}
  connection.execute(sql).to_a
end

#index(klass, attributes, options = {}) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 133

def index klass, attributes, options={}
  name = "#{klass}_#{Array(attributes).map(&:name).join('_')}_idx"
  index = Index.new(name: name,
                    attributes: Array(attributes),
                    unique: !!options[:unique],
                    active: false)
  indexes(klass) << index
  index
end

#indexes(klass) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 143

def indexes klass
  @indexes ||= {}
  @indexes[klass] ||= IndexCollection.new(klass)
end

#insert(klass, serialized_objects, attributes) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 37

def insert klass, serialized_objects, attributes
  table = TableName.new(klass)
  data = serialized_objects.reduce(:+)
  sql = "INSERT INTO #{table} #{data} RETURNING id"

  results = connection.execute(sql).to_a
  ids = results.map { |result| cast_id(result['id'], attributes[:id]) }

  ids
rescue PG::UndefinedTable => e # Table doesn't exist, so we create it.
  retries ||= 0
  retries += 1
  create_table_with_attributes klass, attributes
  retry unless retries > 1
  raise e
rescue PG::UndefinedColumn => e
  retries ||= 0
  retries += 1
  error ||= nil

  if retries > 1 && e.message == error
    # We've retried more than once and we're getting the same error
    raise
  end

  error = e.message
  if error =~ /column "(.+)" of relation "(.+)" does not exist/
    column_name = $1
    table_name = $2
    add_column table_name, column_name, attributes
    retry
  end

  raise
end

#negate_query(&block) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 115

def negate_query &block
  NegatedQuery.new(&block)
end

#postgresify(value) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 218

def postgresify value
  Serializer.new(nil).serialize_attribute value
end

#query(&block) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 111

def query &block
  Query.new(&block)
end

#remove_index(index) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 180

def remove_index index
  sql = %Q{DROP INDEX IF EXISTS #{TableName.new(index.name)}}
  connection.execute(sql)
end

#retrieve(klass, criteria, options = {}) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 119

def retrieve klass, criteria, options={}
  options = translate_options(options).merge from: klass, where: criteria

  sql = select options
  connection.execute(sql).to_a
rescue PG::UndefinedTable
  []
end

#select(*args) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 201

def select *args
  SQLSelect.new(*args).to_s
end

#serialize(object, mapper) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 222

def serialize object, mapper
  Serializer.new(mapper).serialize object
end

#serialize_changed_attributes(object, original, mapper) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 226

def serialize_changed_attributes object, original, mapper
  Serializer.new(mapper).serialize_changes object, original
end

#table_name(klass) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 99

def table_name klass
  TableName.new(klass)
end

#translate_options(options) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 185

def translate_options options
  options = options.dup
  if options[:attribute]
    options[:order] = options.delete(:attribute)
    if direction = options.delete(:direction)
      direction = direction.to_s[/(asc|desc)/i]
      options[:order] = { options[:order] => direction }
    end
  end
  if options[:skip]
    options[:offset] = options.delete(:skip)
  end

  options
end

#unserialize(data, mapper) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 240

def unserialize data, mapper
  Serializer.new(mapper).unserialize data
end

#update(klass, id, attributes) ⇒ Object 



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# File 'lib/perpetuity/postgres.rb', line 128

def update klass, id, attributes
  sql = SQLUpdate.new(klass, id, attributes).to_s
  connection.execute(sql).to_a
end