Class: Kaal::Internal::Sequel::MySQLBackend

Inherits:
Backend::Adapter show all
Includes:
Backend::DispatchLogging
Defined in:
lib/kaal/internal/sequel/mysql_backend.rb

Overview

MySQL named-lock engine backed by Sequel.

Constant Summary collapse

MAX_LOCK_NAME_LENGTH = 
64
UNSET_SKIP_LOCKED_SUPPORT = 
Object.new.freeze

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Backend::DispatchLogging

#log_dispatch_attempt, #parse_lock_key, parse_lock_key

Methods inherited from Backend::Adapter

#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

Class Method Details

.normalize_lock_name(key) ⇒ Object 



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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

Instance Method Details

#acquire(key, _ttl) ⇒ Object 



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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

#definition_registry ⇒ Object 



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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

#delayed_store ⇒ Object 



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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

#dispatch_registry ⇒ Object 



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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

#release(key) ⇒ Object 



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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