Merge pull request #31 from nats-io/nuid

Adopt NUID for inboxes generation

Gemfile

@@ -5,4 +5,5 @@ gemspec
 group :test do
   gem 'rake'
   gem 'rspec'
+  gem 'benchmark-ips'
 end

Gemfile.lock

@@ -1,11 +1,12 @@
 PATH
   remote: .
   specs:
-    nats-pure (0.5.0)
+    nats-pure (0.6.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
+    benchmark-ips (2.7.2)
     diff-lcs (1.3)
     rake (12.3.0)
     rspec (3.7.0)
@@ -26,6 +27,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  benchmark-ips
   nats-pure!
   rake
   rspec

benchmark/nuid_perf.rb

@@ -0,0 +1,20 @@
+require 'securerandom'
+require 'nats/nuid'
+require 'benchmark/ips'
+
+Benchmark.ips do |x|
+  x.report "NUID based inboxes with locked instance" do |t|
+    t.times { "_INBOX.#{NATS::NUID.next}" }
+  end
+
+  x.report "NUID based inboxes with owned instance" do |t|
+    nuid = NATS::NUID.new
+    t.times { "_INBOX.#{nuid.next}" }
+  end
+
+  x.report "SecureRandom based inboxes" do |t|
+    t.times { "_INBOX.#{::SecureRandom.hex(11)}" }
+  end
+
+  x.compare!
+end

lib/nats/io/client.rb

@@ -14,6 +14,7 @@
 
 require 'nats/io/parser'
 require 'nats/io/version'
+require 'nats/nuid'
 require 'thread'
 require 'socket'
 require 'json'
@@ -178,6 +179,7 @@ def initialize
         @resp_sub = nil
         @resp_map = nil
         @resp_sub_prefix = nil
+        @nuid = NATS::NUID.new
       end
 
       # Establishes connection to NATS.
@@ -390,7 +392,7 @@ def request(subject, payload, opts={}, &blk)
           start_resp_mux_sub! unless @resp_sub_prefix
 
           # Create token for this request.
-          token = SecureRandom.hex(11)
+          token = @nuid.next
           inbox = "#{@resp_sub_prefix}.#{token}"
 
           # Create the a future for the request that will
@@ -1169,7 +1171,7 @@ def start_threads!
       # Prepares requests subscription that handles the responses
       # for the new style request response.
       def start_resp_mux_sub!
-        @resp_sub_prefix = "_INBOX.#{SecureRandom.hex(11)}"
+        @resp_sub_prefix = "_INBOX.#{@nuid.next}"
         @resp_map = Hash.new { |h,k| h[k] = { }}
 
         @resp_sub = Subscription.new

lib/nats/io/version.rb

@@ -15,7 +15,7 @@
 module NATS
   module IO
     # NOTE: These are all announced to the server on CONNECT
-    VERSION  = "0.5.0"
+    VERSION  = "0.6.0"
     LANG     = "#{RUBY_ENGINE}2".freeze
     PROTOCOL = 1
   end

lib/nats/nuid.rb

@@ -0,0 +1,81 @@
+# Copyright 2016-2018 The NATS Authors
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+require 'securerandom'
+
+module NATS
+  class NUID
+    DIGITS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('')
+    BASE          = 62
+    PREFIX_LENGTH = 12
+    SEQ_LENGTH    = 10
+    TOTAL_LENGTH  = PREFIX_LENGTH + SEQ_LENGTH
+    MAX_SEQ       = BASE**10
+    MIN_INC       = 33
+    MAX_INC       = 333
+    INC = MAX_INC - MIN_INC
+
+    def initialize
+      @prand    = Random.new
+      @seq      = @prand.rand(MAX_SEQ)
+      @inc      = MIN_INC + @prand.rand(INC)
+      @prefix   = ''
+      randomize_prefix!
+    end
+
+    def next
+      @seq += @inc
+      if @seq >= MAX_SEQ
+        randomize_prefix!
+        reset_sequential!
+      end
+      l = @seq
+
+      # Do this inline 10 times to avoid even more extra allocs,
+      # then use string interpolation of everything which works
+      # faster for doing concat.
+      s_10 = DIGITS[l % BASE];
+
+      # Ugly, but parallel assignment is slightly faster here...
+      s_09, s_08, s_07, s_06, s_05, s_04, s_03, s_02, s_01 = \
+      (l /= BASE; DIGITS[l % BASE]), (l /= BASE; DIGITS[l % BASE]), (l /= BASE; DIGITS[l % BASE]),\
+      (l /= BASE; DIGITS[l % BASE]), (l /= BASE; DIGITS[l % BASE]), (l /= BASE; DIGITS[l % BASE]),\
+      (l /= BASE; DIGITS[l % BASE]), (l /= BASE; DIGITS[l % BASE]), (l /= BASE; DIGITS[l % BASE])
+      "#{@prefix}#{s_01}#{s_02}#{s_03}#{s_04}#{s_05}#{s_06}#{s_07}#{s_08}#{s_09}#{s_10}"
+    end
+
+    def randomize_prefix!
+      @prefix = \
+      SecureRandom.random_bytes(PREFIX_LENGTH).each_byte
+        .reduce('') do |prefix, n|
+        prefix << DIGITS[n % BASE]
+      end
+    end
+
+    private
+
+    def reset_sequential!
+      @seq = @prand.rand(MAX_SEQ)
+      @inc = MIN_INC + @prand.rand(INC)
+    end
+
+    class << self
+      @@nuid = NUID.new.extend(MonitorMixin)
+      def next
+        @@nuid.synchronize do
+          @@nuid.next
+        end
+      end
+    end
+  end
+end

nats-pure.gemspec

@@ -20,17 +20,18 @@ spec = Gem::Specification.new do |s|
   s.summary = 'NATS is an open-source, high-performance, lightweight cloud messaging system.'
   s.homepage = 'https://nats.io'
   s.description = 'NATS is an open-source, high-performance, lightweight cloud messaging system.'
-  s.licenses = ['MIT']
+  s.licenses = ['Apache-2.0']
   s.has_rdoc = false
 
   s.authors = ['Waldemar Quevedo']
-  s.email = ['wally@apcera.com']
+  s.email = ['wally@synadia.com']
 
   s.require_paths = ['lib']
 
   s.files = %w[
     lib/nats/io/client.rb
     lib/nats/io/parser.rb
     lib/nats/io/version.rb
+    lib/nats/nuid.rb
   ]
 end

spec/nuid_spec.rb

@@ -0,0 +1,86 @@
+# Copyright 2016-2018 The NATS Authors
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'spec_helper'
+
+describe 'NUID' do
+  it "should have a fixed length and be unique" do
+    nuid = NATS::NUID.new
+    entries = []
+    total = 500_000
+    total.times do
+      entry = nuid.next
+      expect(entry.size).to eql(NATS::NUID::TOTAL_LENGTH)
+      entries << entry
+    end
+    entries.uniq!
+    expect(entries.count).to eql(total)
+  end
+
+  it "should be unique after 1M entries" do
+    total = 1_000_000
+    entries = []
+    nuid = NATS::NUID.new
+    total.times do
+      entries << nuid.next
+    end
+    entries.uniq!
+    expect(entries.count).to eql(total)
+  end
+
+  it "should randomize the prefix after sequence is done" do
+    nuid = NATS::NUID.new
+    seq_a = nuid.instance_variable_get('@seq')
+    inc_a = nuid.instance_variable_get('@inc')
+    a = nuid.next
+
+    seq_b = nuid.instance_variable_get('@seq')
+    inc_b = nuid.instance_variable_get('@inc')
+    expect(seq_a < seq_b).to eql(true)
+    expect(seq_b).to eql(seq_a + inc_a)
+    b = nuid.next
+
+    nuid.instance_variable_set('@seq', NATS::NUID::MAX_SEQ+1)
+    c = nuid.next
+    l = NATS::NUID::PREFIX_LENGTH
+    expect(a[0..l]).to eql(b[0..l])
+    expect(a[0..l]).to_not eql(c[0..l])
+  end
+
+  context "when using the NUID.next" do
+    it "should be thread safe" do
+      ts = Hash.new { |h,k| h[k] = { }}
+      total = 100_000
+      10.times do |n|
+        ts[n][:thread] = Thread.new do
+          sleep 0.01
+          total.times do
+            ts[n][:entries] ||= []
+            ts[n][:entries] << NATS::NUID.next
+          end
+        end
+      end
+
+      total_entries = []
+      ts.each do |k, t|
+        t[:thread].join
+        expect(t[:entries].count).to eql(total)
+        total_entries << t[:entries]
+      end
+      total_entries.flatten!
+      total_entries.uniq!
+      expect(total_entries.count).to eql(total * 10)
+    end
+  end
+end

spec/spec_helper.rb

@@ -14,6 +14,7 @@
 
 $:.unshift('./lib')
 require 'nats/io/client'
+require 'nats/nuid'
 require 'tempfile'
 require 'monitor'