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) explain = if Gitlab::Database.postgresql? "EXPLAIN ANALYZE #{query};" else "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