instance method `decrement`

Ruby on Rails 8.1.2

Since v5.2.8.1

Available in: v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

decrement(name, amount = 1, options = nil)

Decrement a cached integer value using the Redis decrby atomic operator. Returns the updated value.

If the key is unset or has expired, it will be set to -amount:

cache.decrement("foo") # => -1

To set a specific value, call #write passing raw: true:

cache.write("baz", 5, raw: true)
cache.decrement("baz") # => 4

Decrementing a non-numeric value, or a value written without raw: true, will fail and return nil.

To read the value later, call #read_counter:

cache.decrement("baz") # => 3
cache.read_counter("baz") # 3

Failsafe: Raises errors.

Parameters

name req
amount opt = 1
options opt = nil

Source

# File activesupport/lib/active_support/cache/redis_cache_store.rb, line 286
      def decrement(name, amount = 1, options = nil)
        options = merged_options(options)
        key = normalize_key(name, options)

        instrument :decrement, key, amount: amount do
          failsafe :decrement do
            change_counter(key, -amount, options)
          end
        end
      end

Defined in activesupport/lib/active_support/cache/redis_cache_store.rb line 286 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveSupport::Cache::RedisCacheStore

Signature

Parameters