Add HyperLogLog commands (#431)

Author: maxd

lib/redis.rb

@@ -2415,6 +2415,39 @@ def sscan_each(key, options={}, &block)
     end
   end
 
+  # Add one or more members to a HyperLogLog structure.
+  #
+  # @param [String] key
+  # @param [String, Array<String>] member one member, or array of members
+  # @return [Boolean] true if at least 1 HyperLogLog internal register was altered. false otherwise.
+  def pfadd(key, member)
+    synchronize do |client|
+      client.call([:pfadd, key, member], &_boolify)
+    end
+  end
+
+  # Get the approximate cardinality of members added to HyperLogLog structure.
+  #
+  # @param [String] key
+  # @return [Fixnum]
+  def pfcount(key)
+    synchronize do |client|
+      client.call([:pfcount, key])
+    end
+  end
+
+  # Merge multiple HyperLogLog values into an unique value that will approximate the cardinality of the union of
+  # the observed Sets of the source HyperLogLog structures.
+  #
+  # @param [String] dest_key destination key
+  # @param [String, Array<String>] source_key source key, or array of keys
+  # @return [Boolean]
+  def pfmerge(dest_key, *source_key)
+    synchronize do |client|
+      client.call([:pfmerge, dest_key, *source_key], &_boolify_set)
+    end
+  end
+
   def id
     @original_client.id
   end

lib/redis/distributed.rb

@@ -781,6 +781,24 @@ def script(subcommand, *args)
       on_each_node(:script, subcommand, *args)
     end
 
+    # Add one or more members to a HyperLogLog structure.
+    def pfadd(key, member)
+      node_for(key).pfadd(key, member)
+    end
+
+    # Get the approximate cardinality of members added to HyperLogLog structure.
+    def pfcount(key)
+      node_for(key).pfcount(key)
+    end
+
+    # Merge multiple HyperLogLog values into an unique value that will approximate the cardinality of the union of
+    # the observed Sets of the source HyperLogLog structures.
+    def pfmerge(dest_key, *source_key)
+      ensure_same_node(:pfmerge, [dest_key, *source_key]) do |node|
+        node.pfmerge(dest_key, *source_key)
+      end
+    end
+
     def _eval(cmd, args)
       script = args.shift
       options = args.pop if args.last.is_a?(Hash)

test/commands_on_hyper_log_log_test.rb

@@ -0,0 +1,21 @@
+# encoding: UTF-8
+
+require File.expand_path("helper", File.dirname(__FILE__))
+require "lint/hyper_log_log"
+
+class TestCommandsOnHyperLogLog < Test::Unit::TestCase
+
+  include Helper::Client
+  include Lint::HyperLogLog
+
+  def test_pfmerge
+    target_version "2.8.9" do
+      r.pfadd "foo", "s1"
+      r.pfadd "bar", "s2"
+
+      assert_equal true, r.pfmerge("res", "foo", "bar")
+      assert_equal 2, r.pfcount("res")
+    end
+  end
+
+end

test/distributed_commands_on_hyper_log_log_test.rb

@@ -0,0 +1,22 @@
+# encoding: UTF-8
+
+require File.expand_path("helper", File.dirname(__FILE__))
+require "lint/hyper_log_log"
+
+class TestDistributedCommandsOnHyperLogLog < Test::Unit::TestCase
+
+  include Helper::Distributed
+  include Lint::HyperLogLog
+
+  def test_pfmerge
+    target_version "2.8.9" do
+      assert_raise Redis::Distributed::CannotDistribute do
+        r.pfadd "foo", "s1"
+        r.pfadd "bar", "s2"
+
+        assert r.pfmerge("res", "foo", "bar")
+      end
+    end
+  end
+
+end

test/lint/hyper_log_log.rb

@@ -0,0 +1,48 @@
+module Lint
+
+  module HyperLogLog
+
+    def test_pfadd
+      target_version "2.8.9" do
+        assert_equal true, r.pfadd("foo", "s1")
+        assert_equal true, r.pfadd("foo", "s2")
+        assert_equal false, r.pfadd("foo", "s1")
+
+        assert_equal 2, r.pfcount("foo")
+      end
+    end
+
+    def test_variadic_pfadd
+      target_version "2.8.9" do
+        assert_equal true, r.pfadd("foo", ["s1", "s2"])
+        assert_equal true, r.pfadd("foo", ["s1", "s2", "s3"])
+
+        assert_equal 3, r.pfcount("foo")
+      end
+    end
+
+    def test_pfcount
+      target_version "2.8.9" do
+        assert_equal 0, r.pfcount("foo")
+
+        assert_equal true, r.pfadd("foo", "s1")
+
+        assert_equal 1, r.pfcount("foo")
+      end
+    end
+
+    def test_variadic_pfcount
+      target_version "2.8.9" do
+        assert_equal 0, r.pfcount(["foo", "bar"])
+
+        assert_equal true, r.pfadd("foo", "s1")
+        assert_equal true, r.pfadd("bar", "s1")
+        assert_equal true, r.pfadd("bar", "s2")
+
+        assert_equal 2, r.pfcount(["foo", "bar"])
+      end
+    end
+
+  end
+
+end