Class: Kaal::Internal::Sequel::MySQLBackend
Overview
MySQL named-lock engine backed by Sequel.
Constant Summary
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- MAX_LOCK_NAME_LENGTH =
64
- UNSET_SKIP_LOCKED_SUPPORT =
Object.new.freeze
Class Method Summary
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Instance Method Summary
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#dispatch_attempt_logger, #log_dispatch_attempt, #parse_lock_key, parse_lock_key
#disconnect_for_fork, #with_lock
Constructor Details
#initialize(database, namespace: nil, use_skip_locked: UNSET_SKIP_LOCKED_SUPPORT) ⇒ MySQLBackend
Returns a new instance of MySQLBackend.
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 22
def initialize(database, namespace: nil, use_skip_locked: UNSET_SKIP_LOCKED_SUPPORT)
super()
@database = Kaal::Persistence::Database.new(database)
@namespace = namespace
@use_skip_locked = use_skip_locked
end
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Class Method Details
.normalize_lock_name(key) ⇒ Kaal::rbs_any, ::String
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 55
def self.normalize_lock_name(key)
return key if key.length <= MAX_LOCK_NAME_LENGTH
digest = Digest::SHA256.hexdigest(key)
prefix_length = MAX_LOCK_NAME_LENGTH - 17
"#{key[0...prefix_length]}:#{digest[0...16]}"
end
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Instance Method Details
#acquire(key, _ttl) ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 41
def acquire(key, _ttl)
acquired = scalar('SELECT GET_LOCK(?, 0) AS lock_result', self.class.normalize_lock_name(key)) == 1
log_dispatch_attempt(key) if acquired
acquired
rescue StandardError => e
raise Kaal::Backend::LockAdapterError, "MySQL acquire failed for #{key}: #{e.message}"
end
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#definition_registry ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 33
def definition_registry
@definition_registry ||= Kaal::Definition::DatabaseEngine.new(database: @database.connection)
end
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#delayed_store ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 37
def delayed_store
@delayed_store ||= Kaal::DelayedJob::DatabaseEngine.new(database: @database.connection, use_skip_locked: supports_skip_locked?)
end
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#dispatch_registry ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 29
def dispatch_registry
@dispatch_registry ||= Kaal::Dispatch::DatabaseEngine.new(database: @database.connection, namespace: resolved_namespace)
end
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#release(key) ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 49
def release(key)
scalar('SELECT RELEASE_LOCK(?) AS lock_result', self.class.normalize_lock_name(key)) == 1
rescue StandardError => e
raise Kaal::Backend::LockAdapterError, "MySQL release failed for #{key}: #{e.message}"
end
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#resolved_namespace ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 70
def resolved_namespace
@namespace || Kaal.configuration.namespace
end
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#scalar(sql, *binds) ⇒ Kaal::rbs_any
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 65
def scalar(sql, *binds)
row = @database.connection.fetch(sql, *binds).first
row.values.first
end
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#supports_skip_locked? ⇒ Boolean
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# File 'lib/kaal/internal/sequel/mysql_backend.rb', line 74
def supports_skip_locked?
return @use_skip_locked unless @use_skip_locked.equal?(UNSET_SKIP_LOCKED_SUPPORT)
version_string = scalar('SELECT VERSION() AS version')
Kaal::DelayedJob::MySQLVersionSupport.skip_locked_supported?(version_string)
end
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