gitlab-org--gitlab-foss/lib/gitlab/sherlock/query.rb
2015-11-09 14:29:10 +01:00

114 lines
3.4 KiB
Ruby

module Gitlab
module Sherlock
class Query
attr_reader :id, :query, :started_at, :finished_at, :backtrace
# SQL identifiers that should be prefixed with newlines.
PREFIX_NEWLINE = /
\s+(FROM
|(LEFT|RIGHT)?INNER\s+JOIN
|(LEFT|RIGHT)?OUTER\s+JOIN
|WHERE
|AND
|GROUP\s+BY
|ORDER\s+BY
|LIMIT
|OFFSET)\s+/ix # Vim indent breaks when this is on a newline :<
# Creates a new Query using a String and a separate Array of bindings.
#
# query - A String containing a SQL query, optionally with numeric
# placeholders (`$1`, `$2`, etc).
#
# bindings - An Array of ActiveRecord columns and their values.
# started_at - The start time of the query as a Time-like object.
# finished_at - The completion time of the query as a Time-like object.
#
# Returns a new Query object.
def self.new_with_bindings(query, bindings, started_at, finished_at)
bindings.each_with_index do |(_, value), index|
quoted_value = ActiveRecord::Base.connection.quote(value)
query = query.gsub("$#{index + 1}", quoted_value)
end
new(query, started_at, finished_at)
end
# query - The SQL query as a String (without placeholders).
# started_at - The start time of the query as a Time-like object.
# finished_at - The completion time of the query as a Time-like object.
def initialize(query, started_at, finished_at)
@id = SecureRandom.uuid
@query = query
@started_at = started_at
@finished_at = finished_at
@backtrace = caller_locations.map do |loc|
Location.from_ruby_location(loc)
end
unless @query.end_with?(';')
@query += ';'
end
end
# Returns the query duration in milliseconds.
def duration
@duration ||= (@finished_at - @started_at) * 1000.0
end
def to_param
@id
end
# Returns a human readable version of the query.
def formatted_query
@formatted_query ||= format_sql(@query)
end
# Returns the last application frame of the backtrace.
def last_application_frame
@last_application_frame ||= @backtrace.find(&:application?)
end
# Returns an Array of application frames (excluding Gems and the likes).
def application_backtrace
@application_backtrace ||= @backtrace.select(&:application?)
end
# Returns the query plan as a String.
def explain
unless @explain
ActiveRecord::Base.connection.transaction do
@explain = raw_explain(@query).values.flatten.join("\n")
# Roll back any queries that mutate data so we don't mess up
# anything when running explain on an INSERT, UPDATE, DELETE, etc.
raise ActiveRecord::Rollback
end
end
@explain
end
private
def raw_explain(query)
if Gitlab::Database.postgresql?
explain = "EXPLAIN ANALYZE #{query};"
else
explain = "EXPLAIN #{query};"
end
ActiveRecord::Base.connection.execute(explain)
end
def format_sql(query)
query.each_line.
map { |line| line.strip }.
join("\n").
gsub(PREFIX_NEWLINE) { "\n#{$1} " }
end
end
end
end