namespace, break into different classes

bloomfilter.gemspec

@@ -1,6 +1,6 @@
 # -*- encoding: utf-8 -*-
 $:.push File.expand_path("../lib", __FILE__)
-require "bloomfilter"
+require "bloomfilter/version"
 
 Gem::Specification.new do |s|
   s.name        = "bloomfilter"

lib/bloomfilter.rb

@@ -1,110 +1,8 @@
-require 'redisbloom'
-require 'cbloomfilter'
-
-class BloomFilter
-  VERSION = "1.3.1"
-
-  attr_reader :bf
-
-  def initialize(opts = {})
-    @opts = {
-      :size    => 100,
-      :hashes  => 4,
-      :seed    => Time.now.to_i,
-      :bucket  => 3,
-      :raise   => false,
-      :type    => :c,
-      :values  => false
-    }.merge(opts)
-
-    @values = {}
-    @bf = create_filter
-  end
-
-  def create_filter(bitmap = nil)
-    case @opts[:type]
-      # arg 1: m => size : number of buckets in a bloom filter
-      # arg 2: k => hashes : number of hash functions
-      # arg 3: s => seed : seed of hash functions
-      # arg 4: b => bucket : number of bits in a bloom filter bucket
-      # arg 5: r => raise : raise on bucket overflow?
-      when :c then
-        bf = CBloomFilter.new(@opts[:size], @opts[:hashes], @opts[:seed], @opts[:bucket], @opts[:raise])
-        bf.load(bitmap) if !bitmap.nil?
-        bf
-      when :redis then RedisBloom.new(@opts)
-      else
-        raise "invalid type"
-    end
-  end
-
-  def insert(key, value=nil, ttl=nil)
-    @bf.insert(key, ttl)
-    @values[key] = value if @opts[:values]
-  end
-  alias :[]= :insert
-
-  def include?(*keys)
-    if @opts[:values]
-      keys.collect do |key|
-        @values[key] if @bf.include?(key)
-      end.compact
-    else
-      @bf.include?(*keys)
-    end
-  end
-  alias :key? :include?
-
-  def [](key)
-    return nil if not (@opts[:values] and include?(key))
-    @values[key]
-  end
+require 'redis'
+require 'zlib'
 
-  def keys
-    return nil if not @opts[:values]
-    @values.keys
-  end
-
-  def delete(key); @bf.delete(key); end
-  def clear; @bf.clear; end
-  def size; @bf.num_set; end
-  def merge!(o); @bf.merge!(o.bf); end
-
-  def bitmap
-    case @opts[:type]
-    when :c then @bf.bitmap
-    else
-      raise "cannot export bitmap for this bloomfilter type"
-    end
-  end
-
-  def marshal_load(ary)
-    @opts, @values, bitmap = *ary
-    @bf = create_filter(bitmap)
-    @bf
-  end
-
-  def marshal_dump
-    [@opts, @values, @bf.bitmap]
-  end
-
-  def self.load(filename)
-    Marshal.load(File.open(filename, 'r'))
-  end
-
-  def save(filename)
-    File.open(filename, 'w') do |f|
-      f << Marshal.dump(self)
-    end
-  end
-
-  def stats
-    fp = ((1.0 - Math.exp(-(@opts[:hashes] * size).to_f / @opts[:size])) ** @opts[:hashes]) * 100
-    printf "Number of filter buckets (m): %d\n" % @opts[:size]
-    printf "Number of bits per buckets (b): %d\n" % @opts[:bucket]
-    printf "Number of filter elements (n): %d\n" % size
-    printf "Number of filter hashes (k) : %d\n" % @opts[:hashes]
-    printf "Raise on overflow? (r) : %s\n" % @opts[:raise].to_s
-    printf "Predicted false positive rate = %.2f%\n" % fp
-  end
-end
+require 'cbloomfilter'
+require 'bloomfilter/filter'
+require 'bloomfilter/native'
+require 'bloomfilter/redis'
+require 'bloomfilter/version'

lib/bloomfilter/filter.rb

@@ -0,0 +1,13 @@
+module BloomFilter
+  class Filter
+    def stats
+      fp = ((1.0 - Math.exp(-(@opts[:hashes] * size).to_f / @opts[:size])) ** @opts[:hashes]) * 100
+      printf "Number of filter buckets (m): %d\n" % @opts[:size]
+      printf "Number of bits per buckets (b): %d\n" % @opts[:bucket]
+      printf "Number of filter elements (n): %d\n" % size
+      printf "Number of filter hashes (k) : %d\n" % @opts[:hashes]
+      printf "Raise on overflow? (r) : %s\n" % @opts[:raise].to_s
+      printf "Predicted false positive rate = %.2f%\n" % fp
+    end
+  end
+end

lib/bloomfilter/native.rb

@@ -0,0 +1,98 @@
+module BloomFilter
+  class Native < Filter
+    attr_reader :bf
+
+    def initialize(opts = {})
+      @opts = {
+        :size    => 100,
+        :hashes  => 4,
+        :seed    => Time.now.to_i,
+        :bucket  => 3,
+        :raise   => false,
+        :type    => :c,
+        :values  => false
+      }.merge(opts)
+
+      @values = {}
+      @bf = create_filter
+    end
+
+    def create_filter(bitmap = nil)
+      case @opts[:type]
+        # arg 1: m => size : number of buckets in a bloom filter
+        # arg 2: k => hashes : number of hash functions
+        # arg 3: s => seed : seed of hash functions
+        # arg 4: b => bucket : number of bits in a bloom filter bucket
+        # arg 5: r => raise : raise on bucket overflow?
+        when :c then
+          bf = CBloomFilter.new(@opts[:size], @opts[:hashes], @opts[:seed], @opts[:bucket], @opts[:raise])
+          bf.load(bitmap) if !bitmap.nil?
+          bf
+        when :redis then RedisBloom.new(@opts)
+        else
+          raise "invalid type"
+      end
+    end
+
+    def insert(key, value=nil, ttl=nil)
+      @bf.insert(key, ttl)
+      @values[key] = value if @opts[:values]
+    end
+    alias :[]= :insert
+
+    def include?(*keys)
+      if @opts[:values]
+        keys.collect do |key|
+          @values[key] if @bf.include?(key)
+        end.compact
+      else
+        @bf.include?(*keys)
+      end
+    end
+    alias :key? :include?
+
+    def [](key)
+      return nil if not (@opts[:values] and include?(key))
+      @values[key]
+    end
+
+    def keys
+      return nil if not @opts[:values]
+      @values.keys
+    end
+
+    def delete(key); @bf.delete(key); end
+    def clear; @bf.clear; end
+    def size; @bf.num_set; end
+    def merge!(o); @bf.merge!(o.bf); end
+
+    def bitmap
+      case @opts[:type]
+        when :c then @bf.bitmap
+        else
+          raise "cannot export bitmap for this bloomfilter type"
+      end
+    end
+
+    def marshal_load(ary)
+      @opts, @values, bitmap = *ary
+      @bf = create_filter(bitmap)
+      @bf
+    end
+
+    def marshal_dump
+      [@opts, @values, @bf.bitmap]
+    end
+
+    def self.load(filename)
+      Marshal.load(File.open(filename, 'r'))
+    end
+
+    def save(filename)
+      File.open(filename, 'w') do |f|
+        f << Marshal.dump(self)
+      end
+    end
+
+  end
+end

lib/bloomfilter/redis.rb

@@ -0,0 +1,64 @@
+module BloomFilter
+  class Redis < Filter
+
+    def initialize(opts)
+      @opts = {
+        :size    => 100,
+        :hashes  => 4,
+        :seed    => Time.now.to_i,
+        :bucket  => 3,
+        :raise   => false,
+        :values  => false,
+
+        :ttl => false,
+        :server => {}
+      }.merge opts
+      @db = ::Redis.new(@opts[:server])
+    end
+
+    def insert(key, ttl=nil)
+      ttl = @opts[:ttl] if ttl.nil?
+
+      indexes_for(key).each do |idx|
+        @db.incr idx
+        @db.expire(idx, ttl) if ttl
+      end
+    end
+    alias :[]= :insert
+
+    def delete(key)
+      indexes_for(key).each do |idx|
+        if @db.decr(idx).to_i <= 0
+          @db.del(idx)
+        end
+      end
+    end
+
+    def include?(*keys)
+      indexes = keys.collect { |key| indexes_for(key) }
+      not @db.mget(*indexes.flatten).include? nil
+    end
+    alias :key? :include?
+
+    def num_set
+      @db.keys("rbloom:*").size
+    end
+    alias :size :num_set
+
+    def clear
+      @db.flushdb
+    end
+
+    private
+
+      # compute index offsets for provided key
+      def indexes_for(key)
+        indexes = []
+        @opts[:hashes].times do |i|
+          indexes.push "rbloom:" + (Zlib.crc32("#{key}:#{i+@opts[:seed]}") % @opts[:size]).to_s
+        end
+
+        indexes
+      end
+  end
+end

lib/bloomfilter/version.rb

@@ -0,0 +1,3 @@
+module BloomFilter
+  VERSION = "1.3.1"
+end