`module Generic`

Provides generic Redis commands for cluster environments. These methods distribute operations across cluster nodes based on key slots.

Definitions

`def del(*keys, role: :master, **options)`

Delete one or more keys from the cluster. Uses the appropriate client(s) for each key's slot.

Signature

parameter　keys　Array(String): The keys to delete.
parameter　role　Symbol: The role of node to use (:master or :slave).
parameter　options　Hash: Additional options passed to the client.
returns　Integer: The number of keys deleted.

Implementation

def del(*keys, role: :master, **options)
	return 0 if keys.empty?
	
	count = 0
	
	clients_for(*keys, role: role) do |client, grouped_keys|
		count += client.call("DEL", *grouped_keys)
	end
	
	return count
end

`def exists(*keys, role: :master, **options)`

Check existence of one or more keys in the cluster.

Signature

parameter　keys　Array(String): The keys to check.
parameter　role　Symbol: The role of node to use (:master or :slave).
parameter　options　Hash: Additional options passed to the client.
returns　Integer: The number of keys existing.

Implementation

def exists(*keys, role: :master, **options)
	return 0 if keys.empty?
	
	count = 0
	
	clients_for(*keys, role: role) do |client, grouped_keys|
		count += client.call("EXISTS", *grouped_keys)
	end
	
	return count
end

`def mget(*keys, role: :master, **options)`

Get the values of multiple keys from the cluster.

Signature

parameter　keys　Array(String): The keys to fetch.
parameter　role　Symbol: The role of node to use (:master or :slave).
parameter　options　Hash: Additional options passed to the client.
returns　Array: The values for the given keys, in order.

Implementation

def mget(*keys, role: :master, **options)
	return [] if keys.empty?
	
	results = Array.new(keys.size)
	key_to_index = keys.each_with_index.to_h
	
	clients_for(*keys, role: role) do |client, grouped_keys|
		values = client.call("MGET", *grouped_keys)
		grouped_keys.each_with_index do |key, i|
			results[key_to_index[key]] = values[i]
		end
	end
	
	return results
end

`def get(key, role: :master, **options)`

Get the value of a single key from the cluster.

Signature

parameter　key　String: The key to fetch.
parameter　role　Symbol: The role of node to use (:master or :slave).
parameter　options　Hash: Additional options passed to the client.
returns　Object: The value for the given key.

Implementation

def get(key, role: :master, **options)
	slot = slot_for(key)
	client = client_for(slot, role)
	
	return client.call("GET", key)
end

`def set(key, value, role: :master, **options)`

Set the value of a single key in the cluster.

Signature

parameter　key　String: The key to set.
parameter　value　Object: The value to set.
parameter　role　Symbol: The role of node to use (:master or :slave).
parameter　options　Hash: Additional options passed to the client.
returns　String | Boolean: Status reply or true/false depending on client implementation.

Implementation

def set(key, value, role: :master, **options)
	slot = slot_for(key)
	client = client_for(slot, role)
	
	return client.call("SET", key, value)
end