Class: DBQueryMatchers::QueryCounter

Inherits:
Object
  • Object
show all
Defined in:
lib/db_query_matchers/query_counter.rb

Overview

Counter to keep track of the number of queries caused by running a piece of code. Closely tied to the `:make_database_queries` matcher, this class is designed to be a consumer of `sql.active_record` events.

Examples:

counter = DBQueryMatchers::QueryCounter.new
ActiveSupport::Notifications.subscribed(counter.to_proc,
                                       'sql.active_record') do
  # run code here
end
puts counter.count          # prints the number of queries made
puts counter.log.join(', ') # prints all queries made

See Also:

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ QueryCounter


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# File 'lib/db_query_matchers/query_counter.rb', line 19

def initialize(options = {})
  @matches = options[:matches]
  @count = 0
  @log   = []
end

Instance Attribute Details

#countObject (readonly)

Returns the value of attribute count


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# File 'lib/db_query_matchers/query_counter.rb', line 17

def count
  @count
end

#logObject (readonly)

Returns the value of attribute log


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# File 'lib/db_query_matchers/query_counter.rb', line 17

def log
  @log
end

Instance Method Details

#callback(_name, _start, _finish, _message_id, payload) ⇒ Object

Method called from the ActiveSupport::Notifications module (through the lambda created by `to_proc`) when an SQL query is made.


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# File 'lib/db_query_matchers/query_counter.rb', line 41

def callback(_name, _start,  _finish, _message_id, payload)
  return if @matches && !any_match?(@matches, payload[:sql])
  return if any_match?(DBQueryMatchers.configuration.ignores, payload[:sql])
  return if DBQueryMatchers.configuration.schemaless && payload[:name] == "SCHEMA"

  count_query
  log_query(payload[:sql])

  DBQueryMatchers.configuration.on_query_counted.call(payload)
end

#to_procProc

Turns a QueryCounter instance into a lambda. Designed to be used when subscribing to events through the ActiveSupport::Notifications module.


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# File 'lib/db_query_matchers/query_counter.rb', line 29

def to_proc
  lambda(&method(:callback))
end