require 'benchmark'
require 'date'
# Method that requires a library, ensuring that rubygems is loaded
# This is used in the database adaptors to require DB drivers. Reasons:
# (1) database drivers are the only third-party library that Rails depend upon
# (2) they are often installed as gems
def require_library_or_gem(library_name)
begin
require library_name
rescue LoadError => cannot_require
# 1. Requiring the module is unsuccessful, maybe it's a gem and nobody required rubygems yet. Try.
begin
require 'rubygems'
rescue LoadError => rubygems_not_installed
raise cannot_require
end
# 2. Rubygems is installed and loaded. Try to load the library again
begin
require library_name
rescue LoadError => gem_not_installed
raise cannot_require
end
end
end
module ActiveRecord
class Base
class ConnectionSpecification #:nodoc:
attr_reader :config, :adapter_method
def initialize (config, adapter_method)
@config, @adapter_method = config, adapter_method
end
end
# The class -> [adapter_method, config] map
@@defined_connections = {}
# Establishes the connection to the database. Accepts a hash as input where
# the :adapter key must be specified with the name of a database adapter (in lower-case)
# example for regular databases (MySQL, Postgresql, etc):
#
# ActiveRecord::Base.establish_connection(
# :adapter => "mysql",
# :host => "localhost",
# :username => "myuser",
# :password => "mypass",
# :database => "somedatabase"
# )
#
# Example for SQLite database:
#
# ActiveRecord::Base.establish_connection(
# :adapter => "sqlite",
# :dbfile => "path/to/dbfile"
# )
#
# Also accepts keys as strings (for parsing from yaml for example):
# ActiveRecord::Base.establish_connection(
# "adapter" => "sqlite",
# "dbfile" => "path/to/dbfile"
# )
#
# The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError
# may be returned on an error.
#
# == Connecting to another database for a single model
#
# To support different connections for different classes, you can
# simply call establish_connection with the classes you wish to have
# different connections for:
#
# class Courses < ActiveRecord::Base
# ...
# end
#
# Courses.establish_connection( ... )
def self.establish_connection(spec = nil)
case spec
when nil
raise AdapterNotSpecified unless defined? RAILS_ENV
establish_connection(RAILS_ENV)
when ConnectionSpecification
@@defined_connections[self] = spec
when Symbol, String
establish_connection(configurations[spec.to_s])
else
spec = symbolize_strings_in_hash(spec)
unless spec.key?(:adapter) then raise AdapterNotSpecified end
adapter_method = "#{spec[:adapter]}_connection"
unless respond_to?(adapter_method) then raise AdapterNotFound end
remove_connection
establish_connection(ConnectionSpecification.new(spec, adapter_method))
end
end
# Locate the connection of the nearest super class. This can be an
# active or defined connections: if it is the latter, it will be
# opened and set as the active connection for the class it was defined
# for (not necessarily the current class).
def self.retrieve_connection #:nodoc:
klass = self
until klass == ActiveRecord::Base.superclass
Thread.current['active_connections'] ||= {}
if Thread.current['active_connections'][klass]
return Thread.current['active_connections'][klass]
elsif @@defined_connections[klass]
klass.connection = @@defined_connections[klass]
return self.connection
end
klass = klass.superclass
end
raise ConnectionNotEstablished
end
# Returns true if a connection that's accessible to this class have already been opened.
def self.connected?
klass = self
until klass == ActiveRecord::Base.superclass
if Thread.current['active_connections'].is_a?(Hash) && Thread.current['active_connections'][klass]
return true
else
klass = klass.superclass
end
end
return false
end
# Remove the connection for this class. This will close the active
# connection and the defined connection (if they exist). The result
# can be used as argument for establish_connection, for easy
# re-establishing of the connection.
def self.remove_connection(klass=self)
conn = @@defined_connections[klass]
@@defined_connections.delete(klass)
Thread.current['active_connections'] ||= {}
Thread.current['active_connections'][klass] = nil
conn.config if conn
end
# Set the connection for the class.
def self.connection=(spec)
raise ConnectionNotEstablished unless spec
conn = self.send(spec.adapter_method, spec.config)
Thread.current['active_connections'] ||= {}
Thread.current['active_connections'][self] = conn
end
# Converts all strings in a hash to symbols.
def self.symbolize_strings_in_hash(hash)
hash.inject({}) do |hash_with_symbolized_strings, pair|
hash_with_symbolized_strings[pair.first.to_sym] = pair.last
hash_with_symbolized_strings
end
end
end
module ConnectionAdapters # :nodoc:
class Column # :nodoc:
attr_reader :name, :default, :type, :limit
# The name should contain the name of the column, such as "name" in "name varchar(250)"
# The default should contain the type-casted default of the column, such as 1 in "count int(11) DEFAULT 1"
# The type parameter should either contain :integer, :float, :datetime, :date, :text, or :string
# The sql_type is just used for extracting the limit, such as 10 in "varchar(10)"
def initialize(name, default, sql_type = nil)
@name, @default, @type = name, default, simplified_type(sql_type)
@limit = extract_limit(sql_type) unless sql_type.nil?
end
def default
type_cast(@default)
end
def klass
case type
when :integer then Fixnum
when :float then Float
when :datetime then Time
when :date then Date
when :text, :string then String
when :boolean then Object
end
end
def type_cast(value)
if value.nil? then return nil end
case type
when :string then value
when :text then value
when :integer then value.to_i
when :float then value.to_f
when :datetime then string_to_time(value)
when :date then string_to_date(value)
when :boolean then (value == "t" or value == true ? true : false)
else value
end
end
def human_name
Base.human_attribute_name(@name)
end
private
def string_to_date(string)
return string if Date === string
date_array = ParseDate.parsedate(string)
# treat 0000-00-00 as nil
Date.new(date_array[0], date_array[1], date_array[2]) rescue nil
end
def string_to_time(string)
return string if Time === string
time_array = ParseDate.parsedate(string).compact
# treat 0000-00-00 00:00:00 as nil
Time.local(*time_array) rescue nil
end
def extract_limit(sql_type)
$1.to_i if sql_type =~ /\((.*)\)/
end
def simplified_type(field_type)
case field_type
when /int/i
:integer
when /float|double|decimal|numeric/i
:float
when /time/i
:datetime
when /date/i
:date
when /(c|b)lob/i, /text/i
:text
when /char/i, /string/i
:string
when /boolean/i
:boolean
end
end
end
# All the concrete database adapters follow the interface laid down in this class.
# You can use this interface directly by borrowing the database connection from the Base with
# Base.connection.
class AbstractAdapter
@@row_even = true
include Benchmark
def initialize(connection, logger = nil) # :nodoc:
@connection, @logger = connection, logger
@runtime = 0
end
# Returns an array of record hashes with the column names as a keys and fields as values.
def select_all(sql, name = nil) end
# Returns a record hash with the column names as a keys and fields as values.
def select_one(sql, name = nil) end
# Returns an array of column objects for the table specified by +table_name+.
def columns(table_name, name = nil) end
# Returns the last auto-generated ID from the affected table.
def insert(sql, name = nil, pk = nil, id_value = nil) end
# Executes the update statement.
def update(sql, name = nil) end
# Executes the delete statement.
def delete(sql, name = nil) end
def reset_runtime # :nodoc:
rt = @runtime
@runtime = 0
return rt
end
# Wrap a block in a transaction. Returns result of block.
def transaction
begin
if block_given?
begin_db_transaction
result = yield
commit_db_transaction
result
end
rescue Exception => database_transaction_rollback
rollback_db_transaction
raise
end
end
# Begins the transaction (and turns off auto-committing).
def begin_db_transaction() end
# Commits the transaction (and turns on auto-committing).
def commit_db_transaction() end
# Rollsback the transaction (and turns on auto-committing). Must be done if the transaction block
# raises an exception or returns false.
def rollback_db_transaction() end
def quote(value, column = nil)
case value
when String then "'#{quote_string(value)}'" # ' (for ruby-mode)
when NilClass then "NULL"
when TrueClass then (column && column.type == :boolean ? "'t'" : "1")
when FalseClass then (column && column.type == :boolean ? "'f'" : "0")
when Float, Fixnum, Bignum, Date then "'#{value.to_s}'"
when Time, DateTime then "'#{value.strftime("%Y-%m-%d %H:%M:%S")}'"
else "'#{quote_string(value.to_yaml)}'"
end
end
def quote_string(s)
s.gsub(/\\/, '\&\&').gsub(/'/, "''") # ' (for ruby-mode)
end
def quote_column_name(name)
return name
end
# Returns a string of the CREATE TABLE SQL statements for recreating the entire structure of the database.
def structure_dump() end
protected
def log(sql, name, connection, &action)
begin
if @logger.nil?
action.call(connection)
else
result = nil
bm = measure { result = action.call(connection) }
@runtime += bm.real
log_info(sql, name, bm.real)
result
end
rescue => e
log_info("#{e.message}: #{sql}", name, 0)
raise ActiveRecord::StatementInvalid, "#{e.message}: #{sql}"
end
end
def log_info(sql, name, runtime)
if @logger.nil? then return end
@logger.info(
format_log_entry(
"#{name.nil? ? "SQL" : name} (#{sprintf("%f", runtime)})",
sql.gsub(/ +/, " ")
)
)
end
def format_log_entry(message, dump = nil)
if @@row_even then
@@row_even = false; caller_color = "1;32"; message_color = "4;33"; dump_color = "1;37"
else
@@row_even = true; caller_color = "1;36"; message_color = "4;35"; dump_color = "0;37"
end
log_entry = " \e[#{message_color}m#{message}\e[m"
log_entry << " \e[#{dump_color}m%s\e[m" % dump if dump.kind_of?(String) && !dump.nil?
log_entry << " \e[#{dump_color}m%p\e[m" % dump if !dump.kind_of?(String) && !dump.nil?
log_entry
end
end
end
end