Setup the config setter for lock timeout options + update README.md

Author: CharlesDelannoy

README.md

@@ -329,6 +329,8 @@ SafePgMigrations.config.safe_timeout = 5.seconds # Statement timeout used for al
 
 SafePgMigrations.config.lock_timeout = nil # Lock timeout used for all DDL operations except from CREATE / DROP INDEX. If not set, safe_timeout will be used with a deduction of 1% to ensure that the lock timeout is raised in priority
 
+SafePgMigrations.config.max_lock_timeout_for_retry = 1.second # Max lock timeout for the retries for all DDL operations except from CREATE / DROP INDEX. Each retry will increase the lock_timeout by (max_lock_timeout_for_retry - lock_timeout) / max_tries
+
 SafePgMigrations.config.blocking_activity_logger_verbose = true # Outputs the raw blocking queries on timeout. When false, outputs information about the lock instead
 
 SafePgMigrations.config.sensitive_logger = nil # When given, sensitive data will be sent to this logger instead of the standard output. Must implement method `info`.

lib/safe-pg-migrations/configuration.rb

@@ -10,13 +10,11 @@ class Configuration
                     blocking_activity_logger_margin
                     blocking_activity_logger_verbose
                     default_value_backfill_threshold
-                    lock_timeout
                     max_tries
-                    max_lock_timeout
                     retry_delay
                     sensitive_logger
                   ])
-    attr_reader :safe_timeout
+    attr_reader :lock_timeout, :safe_timeout, :max_lock_timeout_for_retry
 
     def initialize
       self.default_value_backfill_threshold = nil
@@ -28,30 +26,38 @@ def initialize
       self.backfill_pause = 0.5.second
       self.retry_delay = 1.minute
       self.max_tries = 5
-      self.max_lock_timeout = 1.second
+      self.max_lock_timeout_for_retry = 1.second
       self.sensitive_logger = nil
     end
 
     def lock_timeout=(value)
       raise 'Setting lock timeout to 0 disables the lock timeout and is dangerous' if value == 0.seconds
 
-      unless value.nil? || value < safe_timeout
-        raise ArgumentError, "Lock timeout (#{value}) cannot be greater than safe timeout (#{safe_timeout})"
+      unless value.nil? || (value < safe_timeout && value < max_lock_timeout_on_retry)
+        raise ArgumentError, "Lock timeout (#{value}) cannot be greater than the safe timeout (#{safe_timeout}) or the max lock timeout for retry (#{max_lock_timeout_for_retry})"
       end
 
       @lock_timeout = value
     end
 
     def safe_timeout=(value)
-      raise 'Setting safe timeout to 0 disables the safe timeout and is dangerous' unless value
+      raise 'Setting safe timeout to 0 or nil disables the safe timeout and is dangerous' unless value && value > 0.seconds
 
-      unless lock_timeout.nil? || value > lock_timeout || value > max_lock_timeout
-        raise ArgumentError, "Safe timeout (#{value}) cannot be less than lock timeout (#{lock_timeout})"
+      unless lock_timeout.nil? || (value > lock_timeout && value > max_lock_timeout_for_retry)
+        raise ArgumentError, "Safe timeout (#{value}) cannot be lower than the lock timeout (#{lock_timeout}) or the max lock timeout for retry (#{max_lock_timeout_for_retry})"
       end
 
       @safe_timeout = value
     end
 
+    def max_lock_timeout_for_retry(value)
+      unless lock_timeout.nil? || (value > lock_timeout && value < safe_timeout)
+        raise ArgumentError, "Max lock timeout for retry (#{value}) cannot be lower than the lock timeout (#{lock_timeout}) and greater than the safe timeout (#{safe_timeout})"
+      end
+
+      @max_lock_timeout_for_retry = value
+    end
+
     def pg_statement_timeout
       pg_duration safe_timeout
     end