dramatically simpify interface by forcing key at initialization

lib/suo/client/base.rb

@@ -4,96 +4,101 @@ module Suo
       DEFAULT_OPTIONS = {
         acquisition_timeout: 0.1,
         acquisition_delay: 0.01,
-        stale_lock_expiration: 3600
+        stale_lock_expiration: 3600,
+        resources: 1
       }.freeze
 
-      attr_accessor :client
+      attr_accessor :client, :key, :resources, :options
 
       include MonitorMixin
 
-      def initialize(options = {})
+      def initialize(key, options = {})
         fail "Client required" unless options[:client]
         @options = DEFAULT_OPTIONS.merge(options)
         @retry_count = (@options[:acquisition_timeout] / @options[:acquisition_delay].to_f).ceil
         @client = @options[:client]
-        super()
+        @resources = @options[:resources].to_i
+        @key = key
+        super() # initialize Monitor mixin for thread safety
       end
 
-      def lock(key, resources = 1)
+      def lock
-        token = acquire_lock(key, resources)
+        token = acquire_lock
 
         if block_given? && token
           begin
-            yield(token)
+            yield
           ensure
-            unlock(key, token)
+            unlock(token)
           end
         else
           token
         end
       end
 
-      def locked?(key, resources = 1)
+      def locked?
-        locks(key).size >= resources
+        locks.size >= resources
       end
 
-      def locks(key)
+      def locks
-        val, _ = get(key)
+        val, _ = get
         cleared_locks = deserialize_and_clear_locks(val)
 
         cleared_locks
       end
 
-      def refresh(key, acquisition_token)
+      def refresh(token)
-        retry_with_timeout(key) do
+        retry_with_timeout do
-          val, cas = get(key)
+          val, cas = get
 
           if val.nil?
-            initial_set(key)
+            initial_set
             next
           end
 
           cleared_locks = deserialize_and_clear_locks(val)
 
-          refresh_lock(cleared_locks, acquisition_token)
+          refresh_lock(cleared_locks, token)
 
-          break if set(key, serialize_locks(cleared_locks), cas)
+          break if set(serialize_locks(cleared_locks), cas)
         end
       end
 
-      def unlock(key, acquisition_token)
+      def unlock(token)
-        return unless acquisition_token
+        return unless token
 
-        retry_with_timeout(key) do
+        retry_with_timeout do
-          val, cas = get(key)
+          val, cas = get
 
           break if val.nil?
 
           cleared_locks = deserialize_and_clear_locks(val)
 
-          acquisition_lock = remove_lock(cleared_locks, acquisition_token)
+          acquisition_lock = remove_lock(cleared_locks, token)
 
           break unless acquisition_lock
-          break if set(key, serialize_locks(cleared_locks), cas)
+          break if set(serialize_locks(cleared_locks), cas)
         end
       rescue LockClientError => _ # rubocop:disable Lint/HandleExceptions
         # ignore - assume success due to optimistic locking
       end
 
-      def clear(key) # rubocop:disable Lint/UnusedMethodArgument
+      def clear
         fail NotImplementedError
       end
 
       private
 
-      def acquire_lock(key, resources = 1)
+      attr_accessor :retry_count
+
+      def acquire_lock
         token = SecureRandom.base64(16)
 
-        retry_with_timeout(key) do
+        retry_with_timeout do
-          val, cas = get(key)
+          val, cas = get
 
           if val.nil?
-            initial_set(key)
+            initial_set
             next
           end
 
@@ -104,41 +109,41 @@ module Suo
 
             newval = serialize_locks(cleared_locks)
 
-            return token if set(key, newval, cas)
+            return token if set(newval, cas)
           end
         end
 
         nil
       end
 
-      def get(key) # rubocop:disable Lint/UnusedMethodArgument
+      def get
         fail NotImplementedError
       end
 
-      def set(key, newval, cas) # rubocop:disable Lint/UnusedMethodArgument
+      def set(newval, cas) # rubocop:disable Lint/UnusedMethodArgument
         fail NotImplementedError
       end
 
-      def initial_set(key, val = "") # rubocop:disable Lint/UnusedMethodArgument
+      def initial_set(val = "") # rubocop:disable Lint/UnusedMethodArgument
         fail NotImplementedError
       end
 
-      def synchronize(key) # rubocop:disable Lint/UnusedMethodArgument
+      def synchronize
         mon_synchronize { yield }
       end
 
-      def retry_with_timeout(key)
+      def retry_with_timeout
         start = Time.now.to_f
 
-        @retry_count.times do
+        retry_count.times do
           elapsed = Time.now.to_f - start
-          break if elapsed >= @options[:acquisition_timeout]
+          break if elapsed >= options[:acquisition_timeout]
 
-          synchronize(key) do
+          synchronize do
             yield
           end
 
-          sleep(rand(@options[:acquisition_delay] * 1000).to_f / 1000)
+          sleep(rand(options[:acquisition_delay] * 1000).to_f / 1000)
         end
       rescue => _
         raise LockClientError
@@ -163,7 +168,7 @@ module Suo
       end
 
       def clear_expired_locks(locks)
-        expired = Time.now - @options[:stale_lock_expiration]
+        expired = Time.now - options[:stale_lock_expiration]
         locks.reject { |time, _| time < expired }
       end
 

lib/suo/client/memcached.rb

@@ -1,27 +1,27 @@
 module Suo
   module Client
     class Memcached < Base
-      def initialize(options = {})
+      def initialize(key, options = {})
         options[:client] ||= Dalli::Client.new(options[:connection] || ENV["MEMCACHE_SERVERS"] || "127.0.0.1:11211")
         super
       end
 
-      def clear(key)
+      def clear
-        @client.delete(key)
+        @client.delete(@key)
       end
 
       private
 
-      def get(key)
+      def get
-        @client.get_cas(key)
+        @client.get_cas(@key)
       end
 
-      def set(key, newval, cas)
+      def set(newval, cas)
-        @client.set_cas(key, newval, cas)
+        @client.set_cas(@key, newval, cas)
       end
 
-      def initial_set(key, val = "")
+      def initial_set(val = "")
-        @client.set(key, val)
+        @client.set(@key, val)
       end
     end
   end

lib/suo/client/redis.rb

@@ -1,39 +1,39 @@
 module Suo
   module Client
     class Redis < Base
-      def initialize(options = {})
+      def initialize(key, options = {})
         options[:client] ||= ::Redis.new(options[:connection] || {})
         super
       end
 
-      def clear(key)
+      def clear
-        @client.del(key)
+        @client.del(@key)
       end
 
       private
 
-      def get(key)
+      def get
-        [@client.get(key), nil]
+        [@client.get(@key), nil]
       end
 
-      def set(key, newval, _)
+      def set(newval, _)
         ret = @client.multi do |multi|
-          multi.set(key, newval)
+          multi.set(@key, newval)
         end
 
         ret && ret[0] == "OK"
       end
 
-      def synchronize(key)
+      def synchronize
-        @client.watch(key) do
+        @client.watch(@key) do
           yield
         end
       ensure
         @client.unwatch
       end
 
-      def initial_set(key, val = "")
+      def initial_set(val = "")
-        @client.set(key, val)
+        @client.set(@key, val)
       end
     end
   end