Module: Switchman::ActiveRecord::QueryMethods

Defined in:
lib/switchman/active_record/query_methods.rb

Instance Method Summary collapse

Instance Method Details

#all_shards ⇒ Object

the shard value as an array or a relation



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# File 'lib/switchman/active_record/query_methods.rb', line 75

def all_shards
  case shard_value
  when Shard, DefaultShard
    [shard_value]
  when ::ActiveRecord::Base
    shard_value.respond_to?(:associated_shards) ? shard_value.associated_shards : [shard_value.shard]
  when nil
    [Shard.current(klass.connection_class_for_self)]
  else
    shard_value
  end
end

#or(other) ⇒ Object 



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# File 'lib/switchman/active_record/query_methods.rb', line 88

def or(other)
  super(other.shard(primary_shard))
end

#primary_shard ⇒ Object

the shard that where_values are relative to. if it’s multiple shards, they’re stored relative to the first shard



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# File 'lib/switchman/active_record/query_methods.rb', line 56

def primary_shard
  case shard_value
  when Shard, DefaultShard
    shard_value
  # associated_shards
  when ::ActiveRecord::Base
    shard_value.shard
  when Array
    shard_value.first
  when ::ActiveRecord::Relation
    Shard.default
  when nil
    Shard.current(klass.connection_class_for_self)
  else
    raise ArgumentError, "invalid shard value #{shard_value}"
  end
end

#shard(value, source = :explicit) ⇒ Object 



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# File 'lib/switchman/active_record/query_methods.rb', line 37

def shard(value, source = :explicit)
  spawn.shard!(value, source)
end

#shard!(value, source = :explicit) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/switchman/active_record/query_methods.rb', line 41

def shard!(value, source = :explicit)
  raise ArgumentError, "shard can't be nil" unless value

  old_primary_shard = primary_shard
  self.shard_value = value
  self.shard_source_value = source
  if old_primary_shard != primary_shard || source == :to_a
    transpose_clauses(old_primary_shard, primary_shard,
                      remove_nonlocal_primary_keys: source == :to_a)
  end
  self
end

#shard_source_value ⇒ Object 



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# File 'lib/switchman/active_record/query_methods.rb', line 21

def shard_source_value
  @values[:shard_source]
end

#shard_source_value=(value) ⇒ Object

Raises:

  • (::ActiveRecord::ImmutableRelation) 


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# File 'lib/switchman/active_record/query_methods.rb', line 31

def shard_source_value=(value)
  raise ::ActiveRecord::ImmutableRelation if @loaded

  @values[:shard_source] = value
end

#shard_value ⇒ Object

shard_value is one of:

A shard
An array or relation of shards
An AR object (query runs against that object's associated_shards)

shard_source_value is one of:

:implicit    - inferred from current shard when relation was created, or primary key where clause
:explicit    - explicit set on the relation
:association - a special value that scopes from associations use to use slightly different logic
               for foreign key transposition
:to_a        - a special value that Relation#to_a uses when querying multiple shards to
               remove primary keys from conditions that aren't applicable to the current shard



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# File 'lib/switchman/active_record/query_methods.rb', line 17

def shard_value
  @values[:shard]
end

#shard_value=(value) ⇒ Object

Raises:

  • (::ActiveRecord::ImmutableRelation) 


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# File 'lib/switchman/active_record/query_methods.rb', line 25

def shard_value=(value)
  raise ::ActiveRecord::ImmutableRelation if @loaded

  @values[:shard] = value
end