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Module: Redis::Commands::Bless

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In:
::Redis, ::Redis::Commands, ::Redis::MultiConnection, ::Redis::PipelinedConnection
Defined in: lib/redis/commands/bless.rb

Overview

The BLESS command family (Redis 8.12): per-key protection flags that shield a key from memory-pressure actions. The only flag so far is NO-EVICT, which excludes the key from the eviction policy.

Flags are passed to the server verbatim: no client-side validation or normalization is done, so spell them the way the server does ("NO-EVICT"). An unknown flag is rejected by the server with a ::Redis::CommandError.

Instance Method Summary

Instance Method Details

#bless_clear(key, flag) ⇒ Boolean

Remove a protection flag from a key.

Examples:

redis.bless_clear("foo", "NO-EVICT")
  # => true
redis.bless_clear("foo", "NO-EVICT")
  # => false

Parameters:

  • key (String)
  • flag (String) —

    the protection flag, e.g. "NO-EVICT"

Returns:

  • (Boolean) —

    whether the key's flag set changed (false if the flag was already clear)

[ GitHub ] 

  


# File 'lib/redis/commands/bless.rb', line 57



def bless_clear(key, flag)
  send_command([:bless, "CLEAR", key, flag], &Boolify)
end


  








  

    #bless_get(key)  ⇒ Array<String> 
  



  

    
Return the active protection flags of a key.

  





    

    
Examples:

      
redis.set("foo", "bar")
redis.bless_set("foo", "NO-EVICT")
redis.bless_get("foo")
  # => ["NO-EVICT"]

  


Parameters:


    
  
  • 
    key
    (String)
  
    • 



Returns:


    
  
  • 
    (Array<String>)
—    
    the key's active flags (e.g. "NO-EVICT");
empty when none are set
    
  
    • 





  [ GitHub ]


  

  


# File 'lib/redis/commands/bless.rb', line 25



def bless_get(key)
  send_command([:bless, "GET", key])
end


  








  

    #bless_scan(cursor, flag, count: nil)  ⇒ Array(String, Array<String>) 
  



  

    
  

    Note:
    
On Redis::Cluster the driver walks the nodes one by one, as it
does for SCAN, encoding the node index into the returned cursor, so
a full iteration covers every shard. Inside pipelined/multi the
command is sent to a single node instead and only that node's keys
are returned.

  



Incrementally iterate the keys of the current database that carry the
given protection flag. Like SCAN, a full iteration is complete when
the returned cursor is "0".

  





    

    
Examples:

        
Retrieve the first batch of keys blessed with NO-EVICT

      
redis.bless_scan(0, "NO-EVICT")
  # => ["17", ["key:1", "key:2"]]

        
Hint the batch size

      
redis.bless_scan(17, "NO-EVICT", count: 100)
  # => ["0", ["key:3"]]

  


Parameters:


    
  
  • 
    cursor
    (String, Integer)
—    
    the cursor of the iteration
    
  
    • 
  
  • 
    flag
    (String)
—    
    the protection flag, e.g. "NO-EVICT"
    
  
    • 
  
  • 
    options
    (Hash)
  
    • 



Returns:


    
  
  • 
    (Array(String, Array<String>))
—    
    the next cursor and the keys found
    
  
    • 





  [ GitHub ]


  

  


# File 'lib/redis/commands/bless.rb', line 83



def bless_scan(cursor, flag, count: nil)
  args = [:bless, "SCAN", cursor, flag]
  args << "COUNT" << Integer(count) if count

  send_command(args)
end


  








  

    #bless_scan_each(flag, **options, &block)  ⇒ Enumerator 
  



  

    
Iterate every key of the current database that carries the given
protection flag, driving #bless_scan until the cursor wraps around.

  





    

    
Examples:

        
Collect all keys blessed with NO-EVICT (with possible duplicates)

      
redis.bless_scan_each("NO-EVICT").to_a
  # => ["key:1", "key:2", "key:3"]

        
Execute a block for each blessed key

      
redis.bless_scan_each("NO-EVICT", count: 100) { |key| puts key }

  


Parameters:


    
  
  • 
    flag
    (String)
—    
    the protection flag, e.g. "NO-EVICT"
    
  
    • 
  
  • 
    options
    (Hash)
  
    • 


    
Options Hash (**options):

    
    
        
  • 
          :count
          (Integer)
            — 
    return about this many keys per call
            
    • 
    


Returns:


    
  
  • 
    (Enumerator)
—    
    an enumerator over all found keys when no block is given
    
  
    • 





  [ GitHub ]


  

  


# File 'lib/redis/commands/bless.rb', line 103



def bless_scan_each(flag, **options, &block)
  return to_enum(:bless_scan_each, flag, **options) unless block_given?

  cursor = 0
  loop do
    cursor, keys = bless_scan(cursor, flag, **options)
    keys.each(&block)
    break if cursor == "0"
  end
end


  








  

    #bless_set(key, flag)  ⇒ Boolean 
  



  

    
Add a protection flag to a key.

  





    

    
Examples:

      
redis.bless_set("foo", "NO-EVICT")
  # => true
redis.bless_set("foo", "NO-EVICT")
  # => false

  


Parameters:


    
  
  • 
    key
    (String)
  
    • 
  
  • 
    flag
    (String)
—    
    the protection flag, e.g. "NO-EVICT"
    
  
    • 



Returns:


    
  
  • 
    (Boolean)
—    
    whether the key's flag set changed (false if the
flag was already set)
    
  
    • 





  [ GitHub ]


  

  


# File 'lib/redis/commands/bless.rb', line 41



def bless_set(key, flag)
  send_command([:bless, "SET", key, flag], &Boolify)
end