Default values for entries

lib/kredis/attributes.rb

@@ -2,56 +2,56 @@ module Kredis::Attributes
   extend ActiveSupport::Concern
 
   class_methods do
-    def kredis_proxy(name, key: nil, config: :shared, after_change: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change
+    def kredis_proxy(name, key: nil, default: nil, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change
     end
 
-    def kredis_string(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_string(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
-    def kredis_integer(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_integer(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
-    def kredis_decimal(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_decimal(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
-    def kredis_datetime(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_datetime(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
-    def kredis_flag(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_flag(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
 
       define_method("#{name}?") do
         send(name).marked?
       end
     end
 
-    def kredis_float(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_float(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
     def kredis_enum(name, key: nil, values:, default:, config: :shared, after_change: nil)
       kredis_connection_with __method__, name, key, values: values, default: default, config: config, after_change: after_change
     end
 
-    def kredis_json(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_json(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
-    def kredis_list(name, key: nil, typed: :string, config: :shared, after_change: nil)
-      kredis_connection_with __method__, name, key, typed: typed, config: config, after_change: after_change
+    def kredis_list(name, key: nil, default: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, default: default, typed: typed, config: config, after_change: after_change
     end
 
-    def kredis_unique_list(name, limit: nil, key: nil, typed: :string, config: :shared, after_change: nil)
-      kredis_connection_with __method__, name, key, limit: limit, typed: typed, config: config, after_change: after_change
+    def kredis_unique_list(name, limit: nil, key: nil, default: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, default: default, limit: limit, typed: typed, config: config, after_change: after_change
     end
 
-    def kredis_set(name, key: nil, typed: :string, config: :shared, after_change: nil)
-      kredis_connection_with __method__, name, key, typed: typed, config: config, after_change: after_change
+    def kredis_set(name, key: nil, default: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, default: default, typed: typed, config: config, after_change: after_change
     end
 
     def kredis_slot(name, key: nil, config: :shared, after_change: nil)
@@ -62,16 +62,16 @@ def kredis_slots(name, available:, key: nil, config: :shared, after_change: nil)
       kredis_connection_with __method__, name, key, available: available, config: config, after_change: after_change
     end
 
-    def kredis_counter(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_counter(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
-    def kredis_hash(name, key: nil, typed: :string, config: :shared, after_change: nil)
-      kredis_connection_with __method__, name, key, typed: typed, config: config, after_change: after_change
+    def kredis_hash(name, key: nil, default: nil, typed: :string, config: :shared, after_change: nil)
+      kredis_connection_with __method__, name, key, default: default, typed: typed, config: config, after_change: after_change
     end
 
-    def kredis_boolean(name, key: nil, config: :shared, after_change: nil, expires_in: nil)
-      kredis_connection_with __method__, name, key, config: config, after_change: after_change, expires_in: expires_in
+    def kredis_boolean(name, key: nil, default: nil, config: :shared, after_change: nil, expires_in: nil)
+      kredis_connection_with __method__, name, key, default: default, config: config, after_change: after_change, expires_in: expires_in
     end
 
     private
@@ -84,6 +84,7 @@ def kredis_connection_with(method, name, key, **options)
           if instance_variable_defined?(ivar_symbol)
             instance_variable_get(ivar_symbol)
           else
+            options.merge!(default: kredis_default_evaluated(options[:default])) if options[:default]
             new_type = Kredis.send(type, kredis_key_evaluated(key) || kredis_key_for_attribute(name), **options)
             instance_variable_set ivar_symbol,
               after_change ? enrich_after_change_with_record_access(new_type, after_change) : new_type
@@ -115,4 +116,12 @@ def enrich_after_change_with_record_access(type, original_after_change)
       when Symbol then Kredis::Types::CallbacksProxy.new(type, ->(_) { send(original_after_change) })
       end
     end
+
+    def kredis_default_evaluated(default)
+      case default
+      when Proc   then Proc.new { default.call(self) }
+      when Symbol then send(default)
+      else default
+      end
+    end
 end

lib/kredis/type/json.rb

@@ -8,7 +8,11 @@ def type
       end
 
       def cast_value(value)
-        JSON.load(value)
+        if value.is_a? Hash
+          value.stringify_keys
+        else
+          JSON.load(value)
+        end
       end
 
       def serialize(value)

lib/kredis/types.rb

@@ -1,8 +1,8 @@
 module Kredis::Types
   autoload :CallbacksProxy, "kredis/types/callbacks_proxy"
 
-  def proxy(key, config: :shared, after_change: nil)
-    type_from(Proxy, config, key, after_change: after_change)
+  def proxy(key, default: nil, config: :shared, after_change: nil)
+    type_from(Proxy, config, key, after_change: after_change, default: default)
   end
 
 
@@ -39,36 +39,36 @@ def json(key, default: nil, config: :shared, after_change: nil, expires_in: nil)
   end
 
 
-  def counter(key, expires_in: nil, config: :shared, after_change: nil)
-    type_from(Counter, config, key, after_change: after_change, expires_in: expires_in)
+  def counter(key, expires_in: nil, default: nil, config: :shared, after_change: nil)
+    type_from(Counter, config, key, after_change: after_change, default: default, expires_in: expires_in)
   end
 
   def cycle(key, values:, expires_in: nil, config: :shared, after_change: nil)
     type_from(Cycle, config, key, after_change: after_change, values: values, expires_in: expires_in)
   end
 
-  def flag(key, config: :shared, after_change: nil, expires_in: nil)
-    type_from(Flag, config, key, after_change: after_change, expires_in: expires_in)
+  def flag(key, default: nil, config: :shared, after_change: nil, expires_in: nil)
+    type_from(Flag, config, key, after_change: after_change, default: default, expires_in: expires_in)
   end
 
   def enum(key, values:, default:, config: :shared, after_change: nil)
     type_from(Enum, config, key, after_change: after_change, values: values, default: default)
   end
 
-  def hash(key, typed: :string, config: :shared, after_change: nil)
-    type_from(Hash, config, key, after_change: after_change, typed: typed)
+  def hash(key, typed: :string, default: nil, config: :shared, after_change: nil)
+    type_from(Hash, config, key, after_change: after_change, default: default, typed: typed)
   end
 
-  def list(key, typed: :string, config: :shared, after_change: nil)
-    type_from(List, config, key, after_change: after_change, typed: typed)
+  def list(key, default: nil, typed: :string, config: :shared, after_change: nil)
+    type_from(List, config, key, after_change: after_change, default: default, typed: typed)
   end
 
-  def unique_list(key, typed: :string, limit: nil, config: :shared, after_change: nil)
-    type_from(UniqueList, config, key, after_change: after_change, typed: typed, limit: limit)
+  def unique_list(key, default: nil, typed: :string, limit: nil, config: :shared, after_change: nil)
+    type_from(UniqueList, config, key, after_change: after_change, default: default, typed: typed, limit: limit)
   end
 
-  def set(key, typed: :string, config: :shared, after_change: nil)
-    type_from(Set, config, key, after_change: after_change, typed: typed)
+  def set(key, default: nil, typed: :string, config: :shared, after_change: nil)
+    type_from(Set, config, key, after_change: after_change, default: default, typed: typed)
   end
 
   def slot(key, config: :shared, after_change: nil)

lib/kredis/types/counter.rb

@@ -4,24 +4,27 @@ class Kredis::Types::Counter < Kredis::Types::Proxying
   attr_accessor :expires_in
 
   def increment(by: 1)
-    multi do
-      set 0, ex: expires_in, nx: true
-      incrby by
-    end[-1]
+    init_default_in_multi { incrby by }
   end
 
   def decrement(by: 1)
-    multi do
-      set 0, ex: expires_in, nx: true
-      decrby by
-    end[-1]
+    init_default_in_multi { decrby by }
   end
 
   def value
-    get.to_i
+    (get || default).to_i
   end
 
   def reset
     del
   end
+
+  private
+    def set_default(value)
+      set value.to_i, ex: expires_in, nx: true
+    end
+
+    def default
+      super.to_i
+    end
 end

lib/kredis/types/enum.rb

@@ -3,7 +3,7 @@
 class Kredis::Types::Enum < Kredis::Types::Proxying
   proxying :set, :get, :del, :exists?
 
-  attr_accessor :values, :default
+  attr_accessor :values
 
   def initialize(...)
     super
@@ -17,7 +17,7 @@ def value=(value)
   end
 
   def value
-    get || default
+    get || default.presence_in(values)
   end
 
   def reset

lib/kredis/types/hash.rb

@@ -1,28 +1,37 @@
 require "active_support/core_ext/hash"
 
 class Kredis::Types::Hash < Kredis::Types::Proxying
-  proxying :hget, :hset, :hmget, :hdel, :hgetall, :hkeys, :hvals, :del, :exists?
+  ZERO_FIELDS_ADDED = 0
+
+  proxying :hset, :hdel, :hgetall, :del, :exists?, :multi, :callnx
 
   attr_accessor :typed
 
   def [](key)
-    string_to_type(hget(key), typed)
+    string_to_type(entries[key], typed)
   end
 
   def []=(key, value)
     update key => value
   end
 
+
   def update(**entries)
-    hset entries.transform_values{ |val| type_to_string(val, typed) } if entries.flatten.any?
+    return ZERO_FIELDS_ADDED if entries.flatten.blank?
+
+    init_default_in_multi do
+      hset entries.transform_values{ |val| type_to_string(val, typed) }
+    end
   end
 
   def values_at(*keys)
-    strings_to_types(hmget(keys) || [], typed)
+    strings_to_types(entries.values_at(*keys) || [], typed)
   end
 
   def delete(*keys)
-    hdel keys if keys.flatten.any?
+    return ZERO_FIELDS_ADDED if keys.flatten.blank?
+
+    init_default_in_multi { hdel keys }
   end
 
   def remove
@@ -31,15 +40,20 @@ def remove
   alias clear remove
 
   def entries
-    (hgetall || {}).transform_values { |val| string_to_type(val, typed) }.with_indifferent_access
+    (hgetall.presence || default || {}).transform_values { |val| string_to_type(val, typed) }.with_indifferent_access
   end
   alias to_h entries
 
   def keys
-    hkeys || []
+    entries.keys || []
   end
 
   def values
-    strings_to_types(hvals || [], typed)
+    strings_to_types(entries.values || [], typed)
   end
+
+  private
+    def set_default(entries)
+      callnx(:hset, entries.transform_values{ |val| type_to_string(val, typed) })
+    end
 end

lib/kredis/types/list.rb

@@ -1,27 +1,45 @@
 class Kredis::Types::List < Kredis::Types::Proxying
-  proxying :lrange, :lrem, :lpush, :rpush, :exists?, :del
+  proxying :lrange, :lrem, :lpush, :rpush, :exists?, :del, :callnx
 
   attr_accessor :typed
 
   def elements
-    strings_to_types(lrange(0, -1) || [], typed)
+    values = init_default_in_multi { lrange(0, -1) }
+    strings_to_types(values || [], typed)
   end
   alias to_a elements
 
   def remove(*elements)
-    types_to_strings(elements, typed).each { |element| lrem 0, element }
+    return [] if elements.flatten.blank?
+
+    init_default_in_multi do
+      types_to_strings(elements, typed).each { |element| lrem 0, element }
+    end
   end
 
   def prepend(*elements)
-    lpush types_to_strings(elements, typed) if elements.flatten.any?
+    return self.elements.count if elements.flatten.blank?
+
+    init_default_in_multi do
+      lpush types_to_strings(elements, typed)
+    end
   end
 
   def append(*elements)
-    rpush types_to_strings(elements, typed) if elements.flatten.any?
+    return self.elements.count if elements.flatten.blank?
+
+    init_default_in_multi do
+      rpush types_to_strings(elements, typed)
+    end
   end
   alias << append
 
   def clear
     del
   end
+
+  private
+    def set_default(elements)
+      callnx(:rpush, types_to_strings(Array(elements), typed))
+    end
 end

lib/kredis/types/proxy.rb

@@ -12,6 +12,8 @@ def initialize(redis, key, **options)
   end
 
   def multi(*args, **kwargs, &block)
+    return block.call if self.pipeline # return and execute block for nested multi pipeline
+
     redis.multi(*args, **kwargs) do |pipeline|
       self.pipeline = pipeline
       block.call
@@ -28,6 +30,21 @@ def method_missing(method, *args, **kwargs)
     end
   end
 
+  CALLNX = <<~LUA
+    if redis.call("exists", KEYS[1]) == 0 then
+      redis.call("%{method}", KEYS[1], unpack(ARGV))
+    end
+  LUA
+  def callnx(method, values)
+    safe_method_name = method.to_s.gsub(/[^a-z_]/, '_')
+    cmd = format(CALLNX, method: safe_method_name)
+    Kredis.instrument :proxy, **log_message(:callnx, *([safe_method_name] + Array(values))) do
+      failsafe do
+        redis.eval cmd, Array(key), Array(values).flatten
+      end
+    end
+  end
+
   private
     def redis
       pipeline || @redis