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Forked from kpumuk/mysql_adapter_extensions.rb
Created April 15, 2011 19:30
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if Rails.env.development?
ActiveRecord::ConnectionAdapters::Mysql2Adapter.send(:include, QueryTracer::MysqlAdapterExtensions)
Object.send(:include, QueryTracer::ObjectExtensions)
end
module QueryTracer
# Helper methods for `ActiveRecord::ConnectionAdapters::Mysql2Adapter` to enable SQL queries
# tracing functionality. There are two goals:
#
# * Add source line into the query itself so it would be possible to understand where
# the query was issues from:
#
# SELECT * FROM `admins` WHERE
# ((`admins`.`user_id` = 1)) LIMIT 1
# /*OOPS:app/models/user.rb:72:in `admin?'*/
#
# * Add SQL tracing ability: record all SQL queries along with full stack traces:
#
# with_sql_trace do
# Document.first.published?
# end
# ActiveRecord::ConnectionAdapters::MysqlAdapter.tap do |a|
# pp a.sql_trace
# pp a.sql_trace_analyzed
# end
#
module MysqlAdapterExtensions
# A list of code points, where most specific ones are at the top, and generic are in the bottom.
# Do not merge them into a single regular expression, so we will get more precise information
# on where query was invoked from.
INCLUDE_CODEPOINTS = [
%r{^#{Rails.root}/(app/presenters/.*)},
%r{^#{Rails.root}/(app/views/.*)},
%r{^#{Rails.root}/(app/controllers/.*)},
%r{^#{Rails.root}/(app/models/.*)},
%r{^#{Rails.root}/(lib/.*)},
%r{^#{Rails.root}/(spec/.*)},
%r{^#{Rails.root}/(app/.*)},
%r{^#{Rails.root}/(vendor/(?:gems|plugins)/.*)},
%r{^#{Rails.root}/(.*)},
%r{in `(irb)_binding'}
]
# A regular expression used to skip certain code points (gems that do nothing
# but add noice to the result).
EXCLUDE_CODEPOINT = %r{^#{Rails.root}/(?:vendor/(?:rails|gems/(?:composite_primary_keys|db-charmer)|plugins/(?:paginating_find|acts_as_sluggable))|config/initializers/mysql_adapter_extensions\.rb|tmp/gems)}
# A regular expression to exclude certain SQL queries from processing (who cares
# where SHOW TABLES was issues from).
EXCLUDE_SQL = %r{^(SET|SHOW)}
def self.included(base)
base.alias_method_chain :execute, :code_line_reporting
base.extend ClassMethods
# Cache current code revision on start
base.current_code_revision
end
# Append codepoint info to every SQL query.
def execute_with_code_line_reporting(sql, *args)
# Skip noisy queries
unless sql =~ EXCLUDE_SQL
# Skip noisy codepoints
stack = caller.reject { |line| line =~ EXCLUDE_CODEPOINT }
# Save SQL and stack trace if SQL tracing enabled
if self.class.sql_trace_enabled?
self.class.sql_trace << { :sql => sql, :stack => stack }
end
# Find the best codepoint in stack trace and append it with current
# code revision to SQL query as a comment
INCLUDE_CODEPOINTS.each do |codepoint|
if line = stack.grep(codepoint).first
rev = self.class.current_code_revision ? "#{self.class.current_code_revision}:" : ''
sql = "#{sql} /*QueryTrace:#{rev}#{line[codepoint, 1]}*/"
break
end
end
end
# We're done
execute_without_code_line_reporting(sql, *args)
end
module ClassMethods
# Detect the current code revision and memoize it for the future.
def current_code_revision
# Do we have the code revision memoized?
return @@current_code_revision if defined?(@@current_code_revision)
@@current_code_revision = if Rails.env.test? || Rails.env.development?
# Do not add noise in development or test environment
nil
elsif File.exists?("#{Rails.root}/REVISION")
# Capistrano-deployed application, we know where to get current revision
File.read("#{Rails.root}/REVISION").chomp.strip
else
# Try to use git
rev = `git rev-parse HEAD 2>/dev/null`.chomp.strip
rev.empty? ? nil : rev
end
end
# Enable SQL tracing.
def sql_trace_enable!
# Do nothing, if it was enabled before.
unless sql_trace_enabled?
# Clear old trace.
@sql_trace = []
@sql_trace_enabled = true
end
end
# Disable SQL tracing.
def sql_trace_disable!
@sql_trace_enabled = false
end
# Check if SQL tracing enabled.
def sql_trace_enabled?
!!@sql_trace_enabled
end
# Get the latest SQL trace information. `Array` of `Hash`es, each contains
# to keys:
#
# * `:sql` - an actual SQL query;
# * `:trace` - a Ruby stack trace.
def sql_trace
@sql_trace ||= []
end
# Get the latest SQL trace information in the same format as `sql_trace`,
# but filter out all non-`SELECT` queries, and remove `Rails.root` from
# all file paths in stack traces.
def sql_trace_analyzed
trace = sql_trace.reject { |row| !(row[:sql] =~ /^\s*SELECT/) }
trace.each do |row|
row[:stack].each { |line| line.sub!("#{Rails.root}/", '') }
row[:stack].reject! { |row| row =~ %r{^/} }
end
trace
end
# Execute a block of code with SQL queries tracing enabled.
def with_sql_trace
sql_trace_enable!
yield
ensure
sql_trace_disable!
end
end
end
# Helper method for `Object` to simplify SQL tracing.
module ObjectExtensions
# Execute a block of code with SQL queries tracing enabled.
def with_sql_trace(&block)
ActiveRecord::ConnectionAdapters::Mysql2Adapter.with_sql_trace(&block)
end
end
end
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