Class: Schemas::Descriptor

Inherits:
Object
  • Object
show all
Includes:
RedisStore
Defined in:
lib/schemas/descriptor.rb

Constant Summary collapse

SCHEMA_REFRESH_INTERVAL = 
APP_CONFIG['schema_refresh_interval'] || 1.day
LOWERCASE_DB_IDENTIFIERS = 
APP_CONFIG['lowercase_db_identifiers'] || false
INFORMATION_SCHEMA_QUERY = 
<<-SQL
  SELECT
    #{LOWERCASE_DB_IDENTIFIERS ? 'LOWER(table_schema) AS ': ''}table_schema,
    #{LOWERCASE_DB_IDENTIFIERS ? 'LOWER(table_name) AS ': ''}table_name,
    #{LOWERCASE_DB_IDENTIFIERS ? 'LOWER(column_name) AS ': ''}column_name,
    udt_name,
    character_maximum_length
  FROM information_schema.columns
  WHERE table_schema NOT IN ('INFORMATION_SCHEMA', 'information_schema', 'pg_catalog', 'public')
  ORDER BY table_schema, table_name, ordinal_position;
SQL

Constants included from RedisStore

RedisStore::EXPIRE

Instance Method Summary collapse

Methods included from RedisStore

#redis_retrieve, #redis_store!

Constructor Details

#initialize(role) ⇒ Descriptor

Returns a new instance of Descriptor.



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# File 'lib/schemas/descriptor.rb', line 20

def initialize(role)
  @role = role
  @cache = []

  Rails.logger.info("Start schema refresher thread for #{@role}")
  @refresher_thread = Thread.new{ schema_refresher }
end

Instance Method Details

#columns ⇒ Object 



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# File 'lib/schemas/descriptor.rb', line 36

def columns
  retrieve.map do |column|
    HashWithIndifferentAccess.new(
      column: column['column_name'],
      table: column['table_name'],
      schema: column['table_schema'],
      type: column['udt_name']
    )
  end
end

#key ⇒ Object 



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# File 'lib/schemas/descriptor.rb', line 47

def key
  @key ||= "#{@role}_schema_descriptor"
end

#schemas ⇒ Object 



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# File 'lib/schemas/descriptor.rb', line 28

def schemas
  retrieve.map { |row| row['table_schema'] }.uniq
end

#table_columns(schema) ⇒ Object 



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# File 'lib/schemas/descriptor.rb', line 32

def table_columns(schema)
  retrieve.select { |row| row['table_schema'] == schema }.group_by { |row| row['table_name'] }
end