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 memcached decr atomic operator. Returns the updated value.

If the key is unset or has expired, it will be set to 0. Memcached does not support negative counters.

cache.decrement("foo") # => 0

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

Parameters

name req
amount opt = 1
options opt = nil

Source

# File activesupport/lib/active_support/cache/mem_cache_store.rb, line 165
      def decrement(name, amount = 1, options = nil)
        options = merged_options(options)
        key = normalize_key(name, options)

        instrument(:decrement, key, amount: amount) do
          rescue_error_with nil do
            @data.with { |c| c.decr(key, amount, options[:expires_in], 0) }
          end
        end
      end

Defined in activesupport/lib/active_support/cache/mem_cache_store.rb line 165 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveSupport::Cache::MemCacheStore

Signature

Parameters