Class: Sack::Database

Inherits:
Object
  • Object
show all
Defined in:
lib/sack/database.rb,
lib/sack/database/data.rb,
lib/sack/database/model.rb,
lib/sack/database/ftypes.rb,
lib/sack/database/schema.rb,
lib/sack/database/generator.rb,
lib/sack/database/sanitizer.rb,
lib/sack/database/statement.rb,
lib/sack/database/model/data.rb,
lib/sack/database/model/validation.rb,
lib/sack/database/model/relationships.rb,
lib/sack/database/model/relationships/has_many.rb,
lib/sack/database/model/relationships/belongs_to.rb

Overview

Database Class

Defined Under Namespace

Modules: Generator, Model, Sanitizer, Schema, Statement Classes: Data

Constant Summary collapse

ACTIONS =

Actions: Allowed data methods

[
  :create_table,
  :count,
  :find,
  :find_by,
  :fetch,
  :fetch_by,
  :fetch_all,
  :create,
  :update,
  :update_by,
  :save,
  :delete,
    :delete_by
]
FTYPES =

Field Types: Available field types to be used when defining schemas.

{
  str: 'VARCHAR(255)',
  txt: 'TEXT',
  int: 'INTEGER',
  flo: 'REAL',
  uniq: 'UNIQUE',
  pk: 'PRIMARY KEY',
  ai: 'AUTOINCREMENT'
}
FTYPES_CLASSES =

Ruby Type Conversions: Maps Field Types to Ruby Classes.

{
  str: String,
    txt: String,
    int: Fixnum,
    flo: Float
}

Instance Method Summary collapse

Constructor Details

#initialize(connector, connstring, schema) ⇒ Database

Construct: Builds a Database on top of a backend connector and connstring, set to operate on schema.

Parameters:

  • connector (Object) —

    Generic database backend connector

  • connstring (String) —

    Connector-specific connection string

  • schema (Hash) —

    Schema definition - see README



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# File 'lib/sack/database.rb', line 40

def initialize connector, connstring, schema

  # Set Connector & Connstring
  @connector = connector
  @connstring = connstring

  # Set Schema
  @schema = schema

  # Create Lock
  @lock = Mutex.new

  # Verify Schema
  verify_schema
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object

Method Missing: Catches and routes database actions through data access interface.



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# File 'lib/sack/database.rb', line 98

def method_missing name, *args

  # Check Action
  raise "Unknown action [#{name}]" unless ACTIONS.include? name

  # Open Database { Perform Action }
  open { |db| return db.send name, *args }
end

Instance Method Details

#check_schema(data) ⇒ Object

Check Schema: Verifies the supplied schema against the actual database.

Parameters:

  • data (Data) —

    Data access interface

Returns:

  • (Object) —

    True if schema is valid, False otherwise



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# File 'lib/sack/database.rb', line 84

def check_schema data
  @schema.keys.inject(true) { |a, table| a && (data.exec "select count(*) from #{table};" rescue nil) }
end

#open ⇒ Object

Open: Opens a session on the database for yielding.



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# File 'lib/sack/database.rb', line 58

def open

  # Lock DB
  @lock.synchronize do

    # Open Database
    db = @connector.open @connstring

    # Yield Block
    yield Data.new(@connector, db, @schema) if block_given?

    # Close Database
    db.close
  end
end

#rebuild_schema(data) ⇒ Object

Rebuild Schema: Re-creates the database according to the supplied schema.

Parameters:

  • data (Data) —

    Data access interface



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# File 'lib/sack/database.rb', line 91

def rebuild_schema data
  @schema.each { |table, fields| data.create_table table, fields rescue data.alter_table table, fields }
  raise "Rebuilding Schema Failed - Check Database & Access Permissions" unless check_schema data
end

#verify_schema ⇒ Object

Verify Schema: Verifies the supplied schema against the actual database & re-creates it if necessary.



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# File 'lib/sack/database.rb', line 76

def verify_schema
  open { |data| rebuild_schema data unless check_schema data }
end