Class: Redis::SortedSet

Inherits:
BaseObject show all
Includes:
Helpers::CoreCommands, Helpers::Serialize
Defined in:
lib/redis/sorted_set.rb

Overview

Class representing a sorted set.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Helpers::Serialize

#from_redis, #to_redis

Methods included from Helpers::CoreCommands

#exists?, #expire, #expireat, #move, #persist, #rename, #renamenx, #sort, #ttl, #type

Methods inherited from BaseObject

#initialize, #redis

Constructor Details

This class inherits a constructor from Redis::BaseObject

Instance Attribute Details

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/redis/sorted_set.rb', line 15

def key
  @key
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/redis/sorted_set.rb', line 15

def options
  @options
end

Instance Method Details

#==(x) ⇒ Object 



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# File 'lib/redis/sorted_set.rb', line 258

def ==(x)
  members == x
end

#[](index, length = nil) ⇒ Object Also known as: slice

Same functionality as Ruby arrays. If a single number is given, return just the element at that index using Redis: ZRANGE. Otherwise, return a range of values using Redis: ZRANGE.



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# File 'lib/redis/sorted_set.rb', line 34

def [](index, length=nil)
  if index.is_a? Range
    range(index.first, index.last)
  elsif length
    case length <=> 0
    when 1  then range(index, index + length - 1)
    when 0  then []
    when -1 then nil  # Ruby does this (a bit weird)
    end
  else
    result = score(index) || 0 # handles a nil score
  end
end

#[]=(member, score) ⇒ Object

How to add values using a sorted set. The key is the member, eg, “Peter”, and the value is the score, eg, 163. So:

num_posts['Peter'] = 163



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# File 'lib/redis/sorted_set.rb', line 20

def []=(member, score)
  add(member, score)
end

#add(member, score) ⇒ Object

Add a member and its corresponding value to Redis. Note that the arguments to this are flipped; the member comes first rather than the score, since the member is the unique item (not the score).



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# File 'lib/redis/sorted_set.rb', line 27

def add(member, score)
  redis.zadd(key, score, to_redis(member))
end

#at(index) ⇒ Object

Return the value at the given index. Can also use familiar list syntax. Redis: ZRANGE



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# File 'lib/redis/sorted_set.rb', line 268

def at(index)
  range(index, index).first
end

#decrement(member, by = 1) ⇒ Object Also known as: decr, decrby

Convenience to calling increment() with a negative number.



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# File 'lib/redis/sorted_set.rb', line 175

def decrement(member, by=1)
  redis.zincrby(key, -by, to_redis(member)).to_i
end

#delete(value) ⇒ Object

Delete the value from the set. Redis: ZREM



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# File 'lib/redis/sorted_set.rb', line 150

def delete(value)
  redis.zrem(key, to_redis(value))
end

#delete_if(&block) ⇒ Object

Delete element if it matches block

Raises:

  • (ArgumentError) 


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# File 'lib/redis/sorted_set.rb', line 155

def delete_if(&block)
  raise ArgumentError, "Missing block to SortedSet#delete_if" unless block_given?
  res = false
  redis.zrange(key, 0, -1).each do |m|
    if block.call(from_redis(m))
      res = redis.zrem(key, m)
    end
  end
  res
end

#difference(*sets) ⇒ Object Also known as: diff, ^, -

Return the difference vs another set. Can pass it either another set object or set name. Also available as ^ or - which is a bit cleaner:

members_difference = set1 ^ set2
members_difference = set1 - set2

If you want to specify multiple sets, you must use difference:

members_difference = set1.difference(set2, set3, set4)
members_difference = set1.diff(set2, set3, set4)

Redis: SDIFF



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# File 'lib/redis/sorted_set.rb', line 240

def difference(*sets)
  from_redis redis.zdiff(key, *keys_from_objects(sets))
end

#diffstore(name, *sets) ⇒ Object

Calculate the diff and store it in Redis as name. Returns the number of elements in the stored union. Redis: SDIFFSTORE



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# File 'lib/redis/sorted_set.rb', line 249

def diffstore(name, *sets)
  redis.zdiffstore(name, key, *keys_from_objects(sets))
end

#empty? ⇒ Boolean

Returns true if the set has no members. Redis: SCARD == 0

Returns:

  • (Boolean) 


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# File 'lib/redis/sorted_set.rb', line 254

def empty?
  length == 0
end

#first ⇒ Object

Return the first element in the list. Redis: ZRANGE(0)



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# File 'lib/redis/sorted_set.rb', line 273

def first
  at(0)
end

#increment(member, by = 1) ⇒ Object Also known as: incr, incrby

Increment the rank of that member atomically and return the new value. This method is aliased as incr() for brevity. Redis: ZINCRBY



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# File 'lib/redis/sorted_set.rb', line 168

def increment(member, by=1)
  redis.zincrby(key, by, to_redis(member)).to_i
end

#intersection(*sets) ⇒ Object Also known as: intersect, inter, &

Return the intersection with another set. Can pass it either another set object or set name. Also available as & which is a bit cleaner:

members_in_both = set1 & set2

If you want to specify multiple sets, you must use intersection:

members_in_all = set1.intersection(set2, set3, set4)
members_in_all = set1.inter(set2, set3, set4)  # alias

Redis: SINTER



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# File 'lib/redis/sorted_set.rb', line 192

def intersection(*sets)
  from_redis redis.zinter(key, *keys_from_objects(sets))
end

#interstore(name, *sets) ⇒ Object

Calculate the intersection and store it in Redis as name. Returns the number of elements in the stored intersection. Redis: SUNIONSTORE



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# File 'lib/redis/sorted_set.rb', line 201

def interstore(name, *sets)
  redis.zinterstore(name, keys_from_objects([self] + sets))
end

#last ⇒ Object

Return the last element in the list. Redis: ZRANGE(-1)



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# File 'lib/redis/sorted_set.rb', line 278

def last
  at(-1)
end

#length ⇒ Object Also known as: size

The number of members in the set. Aliased as size. Redis: ZCARD



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# File 'lib/redis/sorted_set.rb', line 283

def length
  redis.zcard(key)
end

#member?(value) ⇒ Boolean

Return a boolean indicating whether value is a member.

Returns:

  • (Boolean) 


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# File 'lib/redis/sorted_set.rb', line 294

def member?(value)
  !redis.zscore(key, to_redis(value)).nil?
end

#members(options = {}) ⇒ Object

Return all members of the sorted set with their scores. Extremely CPU-intensive. Better to use a range instead.



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# File 'lib/redis/sorted_set.rb', line 80

def members(options={})
  v = from_redis range(0, -1, options)
  v.nil? ? [] : v
end

#range(start_index, end_index, options = {}) ⇒ Object

Return a range of values from start_index to end_index. Can also use the familiar list Ruby syntax. Redis: ZRANGE



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# File 'lib/redis/sorted_set.rb', line 87

def range(start_index, end_index, options={})
  if options[:withscores] || options[:with_scores]
    from_redis redis.zrange(key, start_index, end_index, :with_scores => true)
  else
    from_redis redis.zrange(key, start_index, end_index)
  end
end

#range_size(min, max) ⇒ Object

The number of members within a range of scores. Redis: ZCOUNT



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# File 'lib/redis/sorted_set.rb', line 289

def range_size(min, max)
  redis.zcount(key, min, max)
end

#rangebyscore(min, max, options = {}) ⇒ Object

Return the all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). Options:

:count, :offset - passed to LIMIT
:withscores     - if true, scores are returned as well

Redis: ZRANGEBYSCORE



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# File 'lib/redis/sorted_set.rb', line 109

def rangebyscore(min, max, options={})
  args = {}
  args[:limit] = [options[:offset] || 0, options[:limit] || options[:count]] if
            options[:offset] || options[:limit] || options[:count]
  args[:with_scores] = true if options[:withscores] || options[:with_scores]

  from_redis redis.zrangebyscore(key, min, max, args)
end

#rank(member) ⇒ Object

Return the rank of the member in the sorted set, with scores ordered from low to high. revrank returns the rank with scores ordered from high to low. When the given member does not exist in the sorted set, nil is returned. The returned rank (or index) of the member is 0-based for both commands



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# File 'lib/redis/sorted_set.rb', line 62

def rank(member)
  if n = redis.zrank(key, to_redis(member))
    n.to_i
  else
    nil
  end
end

#remrangebyrank(min, max) ⇒ Object

Remove all elements in the sorted set at key with rank between start and end. Start and end are 0-based with rank 0 being the element with the lowest score. Both start and end can be negative numbers, where they indicate offsets starting at the element with the highest rank. For example: -1 is the element with the highest score, -2 the element with the second highest score and so forth. Redis: ZREMRANGEBYRANK



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# File 'lib/redis/sorted_set.rb', line 139

def remrangebyrank(min, max)
  redis.zremrangebyrank(key, min, max)
end

#remrangebyscore(min, max) ⇒ Object

Remove all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). Redis: ZREMRANGEBYSCORE



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# File 'lib/redis/sorted_set.rb', line 145

def remrangebyscore(min, max)
  redis.zremrangebyscore(key, min, max)
end

#revrange(start_index, end_index, options = {}) ⇒ Object

Return a range of values from start_index to end_index in reverse order. Redis: ZREVRANGE



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# File 'lib/redis/sorted_set.rb', line 96

def revrange(start_index, end_index, options={})
  if options[:withscores] || options[:with_scores]
    from_redis redis.zrevrange(key, start_index, end_index, :with_scores => true)
  else
    from_redis redis.zrevrange(key, start_index, end_index)
  end
end

#revrangebyscore(max, min, options = {}) ⇒ Object

Returns all the elements in the sorted set at key with a score between max and min (including elements with score equal to max or min). In contrary to the default ordering of sorted sets, for this command the elements are considered to be ordered from high to low scores. Options:

:count, :offset - passed to LIMIT
:withscores     - if true, scores are returned as well

Redis: ZREVRANGEBYSCORE



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# File 'lib/redis/sorted_set.rb', line 125

def revrangebyscore(max, min, options={})
  args = {}
  args[:limit] = [options[:offset] || 0, options[:limit] || options[:count]] if
            options[:offset] || options[:limit] || options[:count]
  args[:with_scores] = true if options[:withscores] || options[:with_scores]

  from_redis redis.zrevrangebyscore(key, max, min, args)
end

#revrank(member) ⇒ Object 



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# File 'lib/redis/sorted_set.rb', line 70

def revrank(member)
  if n = redis.zrevrank(key, to_redis(member))
    n.to_i
  else
    nil
  end
end

#score(member) ⇒ Object

Return the score of the specified element of the sorted set at key. If the specified element does not exist in the sorted set, or the key does not exist at all, nil is returned. Redis: ZSCORE.



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# File 'lib/redis/sorted_set.rb', line 52

def score(member)
  result = redis.zscore(key, to_redis(member))

  result.to_f unless result.nil?
end

#to_s ⇒ Object 



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# File 'lib/redis/sorted_set.rb', line 262

def to_s
  members.join(', ')
end

#union(*sets) ⇒ Object Also known as: |, +

Return the union with another set. Can pass it either another set object or set name. Also available as | and + which are a bit cleaner:

members_in_either = set1 | set2
members_in_either = set1 + set2

If you want to specify multiple sets, you must use union:

members_in_all = set1.union(set2, set3, set4)

Redis: SUNION



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# File 'lib/redis/sorted_set.rb', line 216

def union(*sets)
  from_redis redis.zunion(key, *keys_from_objects(sets))
end

#unionstore(name, *sets) ⇒ Object

Calculate the union and store it in Redis as name. Returns the number of elements in the stored union. Redis: SUNIONSTORE



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# File 'lib/redis/sorted_set.rb', line 224

def unionstore(name, *sets)
  redis.zunionstore(name, keys_from_objects([self] + sets))
end