Class: Redis::Counter
- Inherits:
-
BaseObject
- Object
- BaseObject
- Redis::Counter
- Includes:
- Helpers::CoreCommands
- Defined in:
- lib/redis/counter.rb
Overview
Class representing a Redis counter. This functions like a proxy class, in that you can say @object.counter_name to get the value and then directly, or you can use the counter :foo class method in your class to define a counter.
Instance Attribute Summary collapse
-
#key ⇒ Object
readonly
Returns the value of attribute key.
-
#options ⇒ Object
readonly
Returns the value of attribute options.
-
#redis ⇒ Object
readonly
Returns the value of attribute redis.
Instance Method Summary collapse
-
#decrement(by = 1, &block) ⇒ Object
(also: #decr)
Decrement the counter atomically and return the new value.
-
#getset(to = ) ⇒ Object
Reset the counter to its starting value, and return previous value.
-
#increment(by = 1, &block) ⇒ Object
(also: #incr)
Increment the counter atomically and return the new value.
-
#initialize(key, *args) ⇒ Counter
constructor
A new instance of Counter.
- #nil? ⇒ Boolean
-
#reset(to = ) ⇒ Object
Reset the counter to its starting value.
-
#to_s ⇒ Object
Proxy methods to help make @object.counter == 10 work.
-
#value ⇒ Object
(also: #get, #to_i)
Returns the current value of the counter.
Methods included from Helpers::CoreCommands
#delete, #exists?, #expire, #expireat, #move, #rename, #renamenx, #sort, #ttl, #type
Constructor Details
#initialize(key, *args) ⇒ Counter
Returns a new instance of Counter.
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# File 'lib/redis/counter.rb', line 16 def initialize(key, *args) super(key, *args) @options[:start] ||= 0 @redis.setnx(key, @options[:start]) unless @options[:start] == 0 || @options[:init] === false end |
Instance Attribute Details
#key ⇒ Object (readonly)
Returns the value of attribute key.
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# File 'lib/redis/counter.rb', line 15 def key @key end |
#options ⇒ Object (readonly)
Returns the value of attribute options.
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# File 'lib/redis/counter.rb', line 15 def @options end |
#redis ⇒ Object (readonly)
Returns the value of attribute redis.
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# File 'lib/redis/counter.rb', line 15 def redis @redis end |
Instance Method Details
#decrement(by = 1, &block) ⇒ Object Also known as: decr
Decrement the counter atomically and return the new value. If passed a block, that block will be evaluated with the new value of the counter as an argument. If the block returns nil or throws an exception, the counter will automatically be incremented to its previous value. This method is aliased as incr() for brevity.
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# File 'lib/redis/counter.rb', line 64 def decrement(by=1, &block) val = redis.decrby(key, by).to_i block_given? ? rewindable_block(:increment, val, &block) : val end |
#getset(to = ) ⇒ Object
Reset the counter to its starting value, and return previous value. Use this to “reap” the counter and save it somewhere else. This is atomic in that no increments or decrements are lost if you process the returned value.
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# File 'lib/redis/counter.rb', line 35 def getset(to=[:start]) redis.getset(key, to.to_i).to_i end |
#increment(by = 1, &block) ⇒ Object Also known as: incr
Increment the counter atomically and return the new value. If passed a block, that block will be evaluated with the new value of the counter as an argument. If the block returns nil or throws an exception, the counter will automatically be decremented to its previous value. This method is aliased as incr() for brevity.
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# File 'lib/redis/counter.rb', line 53 def increment(by=1, &block) val = redis.incrby(key, by).to_i block_given? ? rewindable_block(:decrement, val, &block) : val end |
#nil? ⇒ Boolean
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# File 'lib/redis/counter.rb', line 74 def nil?; value.nil? end |
#reset(to = ) ⇒ Object
Reset the counter to its starting value. Not atomic, so use with care. Normally only useful if you’re discarding all sub-records associated with a parent and starting over (for example, restarting a game and disconnecting all players).
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# File 'lib/redis/counter.rb', line 26 def reset(to=[:start]) redis.set key, to.to_i true # hack for redis-rb regression end |
#to_s ⇒ Object
Proxy methods to help make @object.counter == 10 work
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# File 'lib/redis/counter.rb', line 72 def to_s; value.to_s; end |
#value ⇒ Object Also known as: get, to_i
Returns the current value of the counter. Normally just calling the counter will lazily fetch the value, and only update it if increment or decrement is called. This forces a network call to redis-server to get the current value.
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# File 'lib/redis/counter.rb', line 43 def value redis.get(key).to_i end |