module Sequel::Timezones

Sequel doesn't pay much attention to timezones by default, but you can set it handle timezones if you want. There are three separate timezone settings, application_timezone, database_timezone, and typecast_timezone. All three timezones have getter and setter methods. You can set all three timezones to the same value at once via Sequel.default_timezone=.

The only timezone values that are supported by default are :utc (convert to UTC), :local (convert to local time), and nil (don't convert). If you need to convert to a specific timezone, or need the timezones being used to change based on the environment (e.g. current user), you need to use the named_timezones extension (and use DateTime as the datetime_class). Sequel also ships with a thread_local_timezones extensions which allows each thread to have its own timezone values for each of the timezones.

Attributes

application_timezone[R]

The timezone you want the application to use. This is the timezone that incoming times from the database and typecasting are converted to.

convert_two_digit_years[RW]

Sequel converts two digit years in Dates and DateTimes by default, so 01/02/03 is interpreted at January 2nd, 2003, and 12/13/99 is interpreted as December 13, 1999. You can override this to treat those dates as January 2nd, 0003 and December 13, 0099, respectively, by:

Sequel.convert_two_digit_years = false
database_timezone[R]

The timezone for storage in the database. This is the timezone to which Sequel will convert timestamps before literalizing them for storage in the database. It is also the timezone that Sequel will assume database timestamp values are already in (if they don't include an offset).

datetime_class[RW]

Sequel can use either Time or DateTime for times returned from the database. It defaults to Time. To change it to DateTime:

Sequel.datetime_class = DateTime

Note that Time and DateTime objects have a different API, and in cases where they implement the same methods, they often implement them differently (e.g. + using seconds on Time and days on DateTime).

single_threaded[RW]

Set whether Sequel is being used in single threaded mode. by default, Sequel uses a thread-safe connection pool, which isn't as fast as the single threaded connection pool, and also has some additional thread safety checks. If your program will only have one thread, and speed is a priority, you should set this to true:

Sequel.single_threaded = true
typecast_timezone[R]

The timezone that incoming data that Sequel needs to typecast is assumed to be already in (if they don't include an offset).

Public Instance Methods

application_to_database_timestamp(v) click to toggle source

Convert the given Time/DateTime object into the database timezone, used when literalizing objects in an SQL string.

   # File lib/sequel/timezones.rb
45 def application_to_database_timestamp(v)
46   convert_output_timestamp(v, Sequel.database_timezone)
47 end
condition_specifier?(obj) click to toggle source

Returns true if the passed object could be a specifier of conditions, false otherwise. Currently, Sequel considers hashes and arrays of two element arrays as condition specifiers.

Sequel.condition_specifier?({}) # => true
Sequel.condition_specifier?([[1, 2]]) # => true
Sequel.condition_specifier?([]) # => false
Sequel.condition_specifier?([1]) # => false
Sequel.condition_specifier?(1) # => false
   # File lib/sequel/core.rb
84 def condition_specifier?(obj)
85   case obj
86   when Hash
87     true
88   when Array
89     !obj.empty? && !obj.is_a?(SQL::ValueList) && obj.all?{|i| i.is_a?(Array) && (i.length == 2)}
90   else
91     false
92   end
93 end
connect(*args, &block) click to toggle source

Creates a new database object based on the supplied connection string and optional arguments. The specified scheme determines the database class used, and the rest of the string specifies the connection options. For example:

DB = Sequel.connect('sqlite:/') # Memory database
DB = Sequel.connect('sqlite://blog.db') # ./blog.db
DB = Sequel.connect('sqlite:///blog.db') # /blog.db
DB = Sequel.connect('postgres://user:password@host:port/database_name')
DB = Sequel.connect('sqlite:///blog.db', max_connections: 10)

You can also pass a single options hash:

DB = Sequel.connect(adapter: 'sqlite', database: './blog.db')

If a block is given, it is passed the opened Database object, which is closed when the block exits. For example:

Sequel.connect('sqlite://blog.db'){|db| puts db[:users].count}

If a block is not given, a reference to this database will be held in Sequel::DATABASES until it is removed manually. This is by design, and used by Sequel::Model to pick the default database. It is recommended to pass a block if you do not want the resulting Database object to remain in memory until the process terminates, or use the keep_reference: false Database option.

For details, see the “Connecting to a Database” guide. To set up a primary/replica or sharded database connection, see the “Primary/Replica Database Configurations and Sharding” guide.

    # File lib/sequel/core.rb
124 def connect(*args, &block)
125   Database.connect(*args, &block)
126 end
convert_exception_class(exception, klass) click to toggle source

Convert the exception to the given class. The given class should be Sequel::Error or a subclass. Returns an instance of klass with the message and backtrace of exception.

    # File lib/sequel/core.rb
137 def convert_exception_class(exception, klass)
138   return exception if exception.is_a?(klass)
139   e = klass.new("#{exception.class}: #{exception.message}")
140   e.wrapped_exception = exception
141   e.set_backtrace(exception.backtrace)
142   e
143 end
convert_output_timestamp(v, output_timezone) click to toggle source

Converts the object to the given output_timezone.

   # File lib/sequel/timezones.rb
50 def convert_output_timestamp(v, output_timezone)
51   if output_timezone
52     if v.is_a?(DateTime)
53       case output_timezone
54       when :utc
55         v.new_offset(0)
56       when :local
57         v.new_offset(local_offset_for_datetime(v))
58       else
59         convert_output_datetime_other(v, output_timezone)
60       end
61     else
62       case output_timezone
63       when :utc
64         v.getutc
65       when :local
66         v.getlocal
67       else
68         convert_output_time_other(v, output_timezone)
69       end
70     end
71   else
72     v
73   end
74 end
convert_timestamp(v, input_timezone) click to toggle source

Converts the given object from the given input timezone to the application_timezone using convert_input_timestamp and convert_output_timestamp.

   # File lib/sequel/timezones.rb
79 def convert_timestamp(v, input_timezone)
80   begin
81     if v.is_a?(Date) && !v.is_a?(DateTime)
82       # Dates handled specially as they are assumed to already be in the application_timezone
83       if datetime_class == DateTime
84         DateTime.civil(v.year, v.month, v.day, 0, 0, 0, application_timezone == :local ? Rational(Time.local(v.year, v.month, v.day).utc_offset, 86400) : 0)
85       else
86         Time.public_send(application_timezone == :utc ? :utc : :local, v.year, v.month, v.day)
87       end
88     else
89       convert_output_timestamp(convert_input_timestamp(v, input_timezone), application_timezone)
90     end
91   rescue InvalidValue
92     raise
93   rescue => e
94     raise convert_exception_class(e, InvalidValue)
95   end
96 end
core_extensions?() click to toggle source

Assume the core extensions are not loaded by default, if the core_extensions extension is loaded, this will be overridden.

    # File lib/sequel/core.rb
130 def core_extensions?
131   false
132 end
current() click to toggle source

The current concurrency primitive, Thread.current by default.

    # File lib/sequel/core.rb
146 def current
147   Thread.current
148 end
database_to_application_timestamp(v) click to toggle source

Convert the given object into an object of Sequel.datetime_class in the application_timezone. Used when converting datetime/timestamp columns returned by the database.

    # File lib/sequel/timezones.rb
101 def database_to_application_timestamp(v)
102   convert_timestamp(v, Sequel.database_timezone)
103 end
default_timezone=(tz) click to toggle source

Sets the database, application, and typecasting timezones to the given timezone.

    # File lib/sequel/timezones.rb
106 def default_timezone=(tz)
107   self.database_timezone = tz
108   self.application_timezone = tz
109   self.typecast_timezone = tz
110 end
elapsed_seconds_since(timer) click to toggle source

The elapsed seconds since the given timer object was created. The timer object should have been created via Sequel.start_timer.

    # File lib/sequel/core.rb
331 def elapsed_seconds_since(timer)
332   start_timer - timer
333 end
extension(*extensions) click to toggle source

Load all Sequel extensions given. Extensions are just files that exist under sequel/extensions in the load path, and are just required.

In some cases, requiring an extension modifies classes directly, and in others, it just loads a module that you can extend other classes with. Consult the documentation for each extension you plan on using for usage.

Sequel.extension(:blank)
Sequel.extension(:core_extensions, :named_timezones)
    # File lib/sequel/core.rb
158 def extension(*extensions)
159   extensions.each{|e| orig_require("sequel/extensions/#{e}")}
160 end
json_parser_error_class() click to toggle source

The exception classed raised if there is an error parsing JSON. This can be overridden to use an alternative json implementation.

    # File lib/sequel/core.rb
164 def json_parser_error_class
165   JSON::ParserError
166 end
object_to_json(obj, *args, &block) click to toggle source

Convert given object to json and return the result. This can be overridden to use an alternative json implementation.

    # File lib/sequel/core.rb
170 def object_to_json(obj, *args, &block)
171   obj.to_json(*args, &block)
172 end
orig_require(files, subdir=nil)

Alias of original require method, as Sequel.require is does a relative require for backwards compatibility.

Alias for: require
parse_json(json) click to toggle source

Parse the string as JSON and return the result. This can be overridden to use an alternative json implementation.

    # File lib/sequel/core.rb
176 def parse_json(json)
177   JSON.parse(json, :create_additions=>false)
178 end
recursive_map(array, converter) click to toggle source

Convert each item in the array to the correct type, handling multi-dimensional arrays. For each element in the array or subarrays, call the converter, unless the value is nil.

    # File lib/sequel/core.rb
183 def recursive_map(array, converter)
184   array.map do |i|
185     if i.is_a?(Array)
186       recursive_map(i, converter)
187     elsif !i.nil?
188       converter.call(i)
189     end
190   end
191 end
require(files, subdir=nil) click to toggle source

For backwards compatibility only. require_relative should be used instead.

    # File lib/sequel/core.rb
194 def require(files, subdir=nil)
195   # Use Kernel.require_relative to work around JRuby 9.0 bug
196   Array(files).each{|f| Kernel.require_relative "#{"#{subdir}/" if subdir}#{f}"}
197 end
Also aliased as: orig_require
split_symbol(sym) click to toggle source

Splits the symbol into three parts, if symbol splitting is enabled (not the default). Each part will either be a string or nil. If symbol splitting is disabled, returns an array with the first and third parts being nil, and the second part beind a string version of the symbol.

For columns, these parts are the table, column, and alias. For tables, these parts are the schema, table, and alias.

    # File lib/sequel/core.rb
206 def split_symbol(sym)
207   unless v = Sequel.synchronize{SPLIT_SYMBOL_CACHE[sym]}
208     if split_symbols?
209       v = case s = sym.to_s
210       when /\A((?:(?!__).)+)__((?:(?!___).)+)___(.+)\z/
211         [$1.freeze, $2.freeze, $3.freeze].freeze
212       when /\A((?:(?!___).)+)___(.+)\z/
213         [nil, $1.freeze, $2.freeze].freeze
214       when /\A((?:(?!__).)+)__(.+)\z/
215         [$1.freeze, $2.freeze, nil].freeze
216       else
217         [nil, s.freeze, nil].freeze
218       end
219     else
220       v = [nil,sym.to_s.freeze,nil].freeze
221     end
222     Sequel.synchronize{SPLIT_SYMBOL_CACHE[sym] = v}
223   end
224   v
225 end
split_symbols=(v) click to toggle source

Setting this to true enables Sequel's historical behavior of splitting symbols on double or triple underscores:

:table__column         # table.column
:column___alias        # column AS alias
:table__column___alias # table.column AS alias

It is only recommended to turn this on for backwards compatibility until such symbols have been converted to use newer Sequel APIs such as:

Sequel[:table][:column]            # table.column
Sequel[:column].as(:alias)         # column AS alias
Sequel[:table][:column].as(:alias) # table.column AS alias

Sequel::Database instances do their own caching of literalized symbols, and changing this setting does not affect those caches. It is recommended that if you want to change this setting, you do so directly after requiring Sequel, before creating any Sequel::Database instances.

Disabling symbol splitting will also disable the handling of double underscores in virtual row methods, causing such methods to yield regular identifers instead of qualified identifiers:

# Sequel.split_symbols = true
Sequel.expr{table__column}  # table.column
Sequel.expr{table[:column]} # table.column

# Sequel.split_symbols = false
Sequel.expr{table__column}  # table__column
Sequel.expr{table[:column]} # table.column
    # File lib/sequel/core.rb
257 def split_symbols=(v)
258   Sequel.synchronize{SPLIT_SYMBOL_CACHE.clear}
259   @split_symbols = v
260 end
split_symbols?() click to toggle source

Whether Sequel currently splits symbols into qualified/aliased identifiers.

    # File lib/sequel/core.rb
263 def split_symbols?
264   @split_symbols
265 end
start_timer() click to toggle source

A timer object that can be passed to Sequel.elapsed_seconds_since to return the number of seconds elapsed.

    # File lib/sequel/core.rb
318 def start_timer
319   Process.clock_gettime(Process::CLOCK_MONOTONIC)
320 end
string_to_date(string) click to toggle source

Converts the given string into a Date object.

Sequel.string_to_date('2010-09-10') # Date.civil(2010, 09, 10)
    # File lib/sequel/core.rb
270 def string_to_date(string)
271   begin
272     Date.parse(string, Sequel.convert_two_digit_years)
273   rescue => e
274     raise convert_exception_class(e, InvalidValue)
275   end
276 end
string_to_datetime(string) click to toggle source

Converts the given string into a Time or DateTime object, depending on the value of Sequel.datetime_class.

Sequel.string_to_datetime('2010-09-10 10:20:30') # Time.local(2010, 09, 10, 10, 20, 30)
    # File lib/sequel/core.rb
282 def string_to_datetime(string)
283   begin
284     if datetime_class == DateTime
285       DateTime.parse(string, convert_two_digit_years)
286     else
287       datetime_class.parse(string)
288     end
289   rescue => e
290     raise convert_exception_class(e, InvalidValue)
291   end
292 end
string_to_time(string) click to toggle source

Converts the given string into a Sequel::SQLTime object.

v = Sequel.string_to_time('10:20:30') # Sequel::SQLTime.parse('10:20:30')
DB.literal(v) # => '10:20:30'
    # File lib/sequel/core.rb
298 def string_to_time(string)
299   begin
300     SQLTime.parse(string)
301   rescue => e
302     raise convert_exception_class(e, InvalidValue)
303   end
304 end
synchronize() { |: synchronize(&block)| ... } click to toggle source

Unless in single threaded mode, protects access to any mutable global data structure in Sequel. Uses a non-reentrant mutex, so calling code should be careful. In general, this should only be used around the minimal possible code such as Hash#[], Hash#[]=, Hash#delete, Array#<<, and Array#delete.

    # File lib/sequel/core.rb
311 def synchronize(&block)
312   @single_threaded ? yield : @data_mutex.synchronize(&block)
313 end
transaction(dbs, opts=OPTS, &block) click to toggle source

Uses a transaction on all given databases with the given options. This:

Sequel.transaction([DB1, DB2, DB3]){}

is equivalent to:

DB1.transaction do
  DB2.transaction do
    DB3.transaction do
    end
  end
end

except that if Sequel::Rollback is raised by the block, the transaction is rolled back on all databases instead of just the last one.

Note that this method cannot guarantee that all databases will commit or rollback. For example, if DB3 commits but attempting to commit on DB2 fails (maybe because foreign key checks are deferred), there is no way to uncommit the changes on DB3. For that kind of support, you need to have two-phase commit/prepared transactions (which Sequel supports on some databases).

    # File lib/sequel/core.rb
357 def transaction(dbs, opts=OPTS, &block)
358   unless opts[:rollback]
359     rescue_rollback = true
360     opts = Hash[opts].merge!(:rollback=>:reraise)
361   end
362   pr = dbs.reverse.inject(block){|bl, db| proc{db.transaction(opts, &bl)}}
363   if rescue_rollback
364     begin
365       pr.call
366     rescue Sequel::Rollback
367       nil
368     end
369   else
370     pr.call
371   end
372 end
typecast_to_application_timestamp(v) click to toggle source

Convert the given object into an object of Sequel.datetime_class in the application_timezone. Used when typecasting values when assigning them to model datetime attributes.

    # File lib/sequel/timezones.rb
115 def typecast_to_application_timestamp(v)
116   convert_timestamp(v, Sequel.typecast_timezone)
117 end
virtual_row(&block) click to toggle source

If the supplied block takes a single argument, yield an SQL::VirtualRow instance to the block argument. Otherwise, evaluate the block in the context of a SQL::VirtualRow instance.

Sequel.virtual_row{a} # Sequel::SQL::Identifier.new(:a)
Sequel.virtual_row{|o| o.a} # Sequel::SQL::Function.new(:a)
    # File lib/sequel/core.rb
381 def virtual_row(&block)
382   vr = VIRTUAL_ROW
383   case block.arity
384   when -1, 0
385     vr.instance_exec(&block)
386   else
387     block.call(vr)
388   end  
389 end

Private Instance Methods

adapter_method(adapter, *args, &block) click to toggle source

Helper method that the database adapter class methods that are added to Sequel via metaprogramming use to parse arguments.

    # File lib/sequel/core.rb
395 def adapter_method(adapter, *args, &block)
396   options = args.last.is_a?(Hash) ? args.pop : OPTS
397   opts = {:adapter => adapter.to_sym}
398   opts[:database] = args.shift if args.first.is_a?(String)
399   if args.any?
400     raise ::Sequel::Error, "Wrong format of arguments, either use (), (String), (Hash), or (String, Hash)"
401   end
402 
403   connect(opts.merge(options), &block)
404 end
convert_input_datetime_no_offset(v, input_timezone) click to toggle source

Convert the given DateTime to the given input_timezone, keeping the same time and just modifying the timezone.

    # File lib/sequel/timezones.rb
123 def convert_input_datetime_no_offset(v, input_timezone)
124   case input_timezone
125   when nil, :utc
126     v # DateTime assumes UTC if no offset is given
127   when :local
128     offset = local_offset_for_datetime(v)
129     v.new_offset(offset) - offset
130   else
131     convert_input_datetime_other(v, input_timezone)
132   end
133 end
convert_input_datetime_other(v, input_timezone) click to toggle source

Convert the given DateTime to the given input_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

    # File lib/sequel/timezones.rb
138 def convert_input_datetime_other(v, input_timezone)
139   raise InvalidValue, "Invalid input_timezone: #{input_timezone.inspect}"
140 end
convert_input_time_other(v, input_timezone) click to toggle source

Convert the given Time to the given input_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

    # File lib/sequel/timezones.rb
145 def convert_input_time_other(v, input_timezone)
146   raise InvalidValue, "Invalid input_timezone: #{input_timezone.inspect}"
147 end
convert_input_timestamp(v, input_timezone) click to toggle source

Converts the object from a String, Array, Date, DateTime, or Time into an instance of Sequel.datetime_class. If given an array or a string that doesn't contain an offset, assume that the array/string is already in the given input_timezone.

    # File lib/sequel/timezones.rb
152 def convert_input_timestamp(v, input_timezone)
153   case v
154   when String
155     v2 = Sequel.string_to_datetime(v)
156     if !input_timezone || Date._parse(v).has_key?(:offset)
157       v2
158     else
159       # Correct for potentially wrong offset if string doesn't include offset
160       if v2.is_a?(DateTime)
161         convert_input_datetime_no_offset(v2, input_timezone)
162       else
163         case input_timezone
164         when nil, :local
165           v2
166         when :utc
167           (v2 + v2.utc_offset).utc
168         else
169           convert_input_time_other((v2 + v2.utc_offset).utc, input_timezone)
170         end
171       end
172     end
173   when Array
174     y, mo, d, h, mi, s, ns, off = v
175     if datetime_class == DateTime
176       s += Rational(ns, 1000000000) if ns
177       if off
178         DateTime.civil(y, mo, d, h, mi, s, off)
179       else
180         convert_input_datetime_no_offset(DateTime.civil(y, mo, d, h, mi, s), input_timezone)
181       end
182     elsif off
183       s += Rational(ns, 1000000000) if ns
184       Time.new(y, mo, d, h, mi, s, (off*86400).to_i)
185     else
186       case input_timezone
187       when nil, :local
188         Time.local(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0))
189       when :utc
190         Time.utc(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0))
191       else
192         convert_input_time_other(Time.utc(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0)), input_timezone)
193       end
194     end
195   when Hash
196     ary = [:year, :month, :day, :hour, :minute, :second, :nanos].map{|x| (v[x] || v[x.to_s]).to_i}
197     if (offset = (v[:offset] || v['offset']))
198       ary << offset
199     end
200     convert_input_timestamp(ary, input_timezone)
201   when Time
202     if datetime_class == DateTime
203       v.to_datetime
204     else
205       v
206     end
207   when DateTime
208     if datetime_class == DateTime
209       v
210     else
211       v.to_time
212     end
213   else
214     raise InvalidValue, "Invalid convert_input_timestamp type: #{v.inspect}"
215   end
216 end
convert_output_datetime_other(v, output_timezone) click to toggle source

Convert the given DateTime to the given output_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

    # File lib/sequel/timezones.rb
221 def convert_output_datetime_other(v, output_timezone)
222   raise InvalidValue, "Invalid output_timezone: #{output_timezone.inspect}"
223 end
convert_output_time_other(v, output_timezone) click to toggle source

Convert the given Time to the given output_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

    # File lib/sequel/timezones.rb
228 def convert_output_time_other(v, output_timezone)
229   raise InvalidValue, "Invalid output_timezone: #{output_timezone.inspect}"
230 end
convert_timezone_setter_arg(tz) click to toggle source

Convert the timezone setter argument. Returns argument given by default, exists for easier overriding in extensions.

    # File lib/sequel/timezones.rb
234 def convert_timezone_setter_arg(tz)
235   tz
236 end
local_offset_for_datetime(dt) click to toggle source

Takes a DateTime dt, and returns the correct local offset for that dt, daylight savings included, in fraction of a day.

    # File lib/sequel/timezones.rb
239 def local_offset_for_datetime(dt)
240   time_offset_to_datetime_offset Time.local(dt.year, dt.month, dt.day, dt.hour, dt.min, dt.sec).utc_offset
241 end
time_offset_to_datetime_offset(offset_secs) click to toggle source

Caches offset conversions to avoid excess Rational math.

    # File lib/sequel/timezones.rb
244 def time_offset_to_datetime_offset(offset_secs)
245   if offset = Sequel.synchronize{@local_offsets[offset_secs]}
246     return offset
247   end
248   Sequel.synchronize{@local_offsets[offset_secs] = Rational(offset_secs, 86400)}
249 end