module PgHero::Methods::Basic

Public Instance Methods

current_user() click to toggle source
# File lib/pghero/methods/basic.rb, line 21
def current_user
  select_one("SELECT current_user")
end
database_name() click to toggle source
# File lib/pghero/methods/basic.rb, line 17
def database_name
  select_one("SELECT current_database()")
end
quote_ident(value) click to toggle source
# File lib/pghero/methods/basic.rb, line 33
def quote_ident(value)
  with_connection { |c| c.quote_column_name(value) }
end
server_version() click to toggle source
# File lib/pghero/methods/basic.rb, line 25
def server_version
  @server_version ||= select_one("SHOW server_version")
end
server_version_num() click to toggle source
# File lib/pghero/methods/basic.rb, line 29
def server_version_num
  @server_version_num ||= select_one("SHOW server_version_num").to_i
end
ssl_used?() click to toggle source
# File lib/pghero/methods/basic.rb, line 4
def ssl_used?
  ssl_used = nil
  with_transaction(rollback: true) do
    begin
      execute("CREATE EXTENSION IF NOT EXISTS sslinfo")
    rescue ActiveRecord::StatementInvalid
      # not superuser
    end
    ssl_used = select_one("SELECT ssl_is_used()")
  end
  ssl_used
end

Private Instance Methods

add_source(sql) click to toggle source
# File lib/pghero/methods/basic.rb, line 117
def add_source(sql)
  "#{sql} /*pghero*/"
end
execute(sql) click to toggle source
# File lib/pghero/methods/basic.rb, line 104
def execute(sql)
  with_connection { |c| c.execute(add_source(sql)) }
end
quote(value) click to toggle source
# File lib/pghero/methods/basic.rb, line 121
def quote(value)
  with_connection { |c| c.quote(value) }
end
quote_column_name(value) click to toggle source
# File lib/pghero/methods/basic.rb, line 129
def quote_column_name(value)
  with_connection { |c| c.quote_column_name(value) }
end
quote_table_name(value) click to toggle source
# File lib/pghero/methods/basic.rb, line 125
def quote_table_name(value)
  with_connection { |c| c.quote_table_name(value) }
end
select_all(sql, stats: false, query_columns: []) click to toggle source
# File lib/pghero/methods/basic.rb, line 39
def select_all(sql, stats: false, query_columns: [])
  with_connection(stats: stats) do |conn|
    select_all_leased(sql, conn: conn, query_columns: query_columns)
  end
end
select_all_leased(sql, conn:, query_columns:) click to toggle source
# File lib/pghero/methods/basic.rb, line 45
def select_all_leased(sql, conn:, query_columns:)
  # squish for logs
  retries = 0
  begin
    result = conn.select_all(add_source(squish(sql)))
    if ActiveRecord::VERSION::MAJOR >= 8
      result = result.to_a.map(&:symbolize_keys)
    else
      result = result.map(&:symbolize_keys)
    end
    if filter_data
      query_columns.each do |column|
        result.each do |row|
          begin
            row[column] = PgQuery.normalize(row[column])
          rescue PgQuery::ParseError
            # try replacing "interval $1" with "$1::interval"
            # see https://github.com/lfittl/pg_query/issues/169 for more info
            # this is not ideal since it changes the query slightly
            # we could skip normalization
            # but this has a very small chance of data leakage
            begin
              row[column] = PgQuery.normalize(row[column].gsub(/\binterval\s+(\$\d+)\b/i, "\\1::interval"))
            rescue PgQuery::ParseError
              row[column] = "<unable to filter data>"
            end
          end
        end
      end
    end
    result
  rescue ActiveRecord::StatementInvalid => e
    # fix for random internal errors
    if e.message.include?("PG::InternalError") && retries < 2
      retries += 1
      sleep(0.1)
      retry
    else
      raise e
    end
  end
end
select_all_size(sql) click to toggle source
# File lib/pghero/methods/basic.rb, line 92
def select_all_size(sql)
  result = select_all(sql)
  result.each do |row|
    row[:size] = PgHero.pretty_size(row[:size_bytes])
  end
  result
end
select_all_stats(sql, **options) click to toggle source
# File lib/pghero/methods/basic.rb, line 88
def select_all_stats(sql, **options)
  select_all(sql, **options, stats: true)
end
select_one(sql) click to toggle source
# File lib/pghero/methods/basic.rb, line 100
def select_one(sql)
  select_all(sql).first.values.first
end
squish(str) click to toggle source
# File lib/pghero/methods/basic.rb, line 113
def squish(str)
  str.to_s.squish
end
table_exists?(table) click to toggle source
# File lib/pghero/methods/basic.rb, line 150
def table_exists?(table)
  with_connection(stats: true) { |c| c.table_exists?(table) }
end
unquote(part) click to toggle source
# File lib/pghero/methods/basic.rb, line 133
def unquote(part)
  if part && part.start_with?('"')
    part[1..-2]
  else
    part
  end
end
with_connection(stats: false, &block) click to toggle source
# File lib/pghero/methods/basic.rb, line 108
def with_connection(stats: false, &block)
  model = stats ? ::PgHero::Stats : connection_model
  model.connection_pool.with_connection(&block)
end
with_transaction(lock_timeout: nil, statement_timeout: nil, rollback: false) { || ... } click to toggle source
# File lib/pghero/methods/basic.rb, line 141
def with_transaction(lock_timeout: nil, statement_timeout: nil, rollback: false)
  connection_model.transaction do
    select_all "SET LOCAL statement_timeout = #{statement_timeout.to_i}" if statement_timeout
    select_all "SET LOCAL lock_timeout = #{lock_timeout.to_i}" if lock_timeout
    yield
    raise ActiveRecord::Rollback if rollback
  end
end