Add memoization groups (group: option) for v1.5.0

CHANGELOG.md

@@ -8,6 +8,18 @@ from v1.0.0 onwards. Prior 0.x releases may include breaking changes between min
 
 ## [Unreleased]
 
+## [1.5.0] - 2026-06-02
+
+### Added
+
+- `group:` option on `memoize` — assigns a method to a named invalidation group (`memoize :find, group: :database`). Groups are stored on the class and survive re-memoization; a method can belong to at most one group at a time (re-memoizing with a different group moves it). Accepts any non-empty Symbol or String. Can be set as a class default via `safe_memoize_options group: :my_group`.
+- `reset_memo_group(group_name)` instance method — clears all per-instance cached entries for every method in the named group in a single call; each evicted entry fires the `:on_evict` hook. A no-op for unknown groups.
+- `reset_shared_memo_group(group_name)` class method — the shared-cache equivalent of `reset_memo_group`; clears all shared-cache entries for every method in the group that was memoized with `shared: true`.
+- `memo_group_methods(group_name)` instance method — returns the array of method names belonging to the given group on the instance's class (empty array for unknown groups).
+- `memo_groups` instance method — returns all group names registered on the instance's class.
+- `safe_memo_group_methods(group_name)` class method — class-level equivalent of `memo_group_methods`.
+- `safe_memo_groups` class method — class-level equivalent of `memo_groups`.
+
 ## [1.4.0] - 2026-06-02
 
 ### Added

README.md

@@ -79,6 +79,7 @@ SafeMemoize uses Ruby's `prepend` mechanism. When you call `memoize :method_name
 - [Plugin / extension architecture — `SafeMemoize::Extension` DSL for adding custom `memoize` options and global lifecycle handlers without monkey-patching](#plugin--extension-architecture)
 - [Per-class default options via `safe_memoize_options` — set TTL, max size, copy-on-read, and other defaults for every `memoize` call on the class without repeating them](#per-class-default-options-safe_memoize_options)
 - [Copy-on-read via `copy_on_read: true` — returns a `dup`/`deep_dup` on every cache read to protect shared cached state from caller mutation](#copy-on-read)
+- [Cache invalidation groups via `group:` — tag related methods with a group name and bust them all with a single `reset_memo_group` call](#cache-invalidation-groups)
 
 ## Installation
 
@@ -194,6 +195,79 @@ obj.reset_all_memos                             # Clears all memoized values
 
 [↑ Back to features](#features)
 
+### Cache invalidation groups
+
+Tag related methods with `group:` and bust them all at once with a single `reset_memo_group` call:
+
+```ruby
+class RepoService
+  prepend SafeMemoize
+
+  def find_user(id) = db.query("SELECT * FROM users WHERE id=?", id)
+  def find_post(id) = db.query("SELECT * FROM posts WHERE id=?", id)
+  def site_config    = db.query("SELECT * FROM config LIMIT 1")
+
+  memoize :find_user,  group: :database
+  memoize :find_post,  group: :database
+  memoize :site_config                    # no group — unaffected by group reset
+end
+
+svc = RepoService.new
+svc.find_user(1)
+svc.find_post(42)
+svc.site_config
+
+svc.reset_memo_group(:database)          # invalidates find_user and find_post only
+svc.memoized?(:site_config)              # => true — unaffected
+```
+
+For `shared: true` methods, use the class method:
+
+```ruby
+class CatalogService
+  prepend SafeMemoize
+
+  def products = fetch_all_products
+  def categories = fetch_all_categories
+
+  memoize :products,   shared: true, group: :catalog
+  memoize :categories, shared: true, group: :catalog
+end
+
+CatalogService.reset_shared_memo_group(:catalog)    # clears shared cache for both methods
+```
+
+#### Introspection
+
+```ruby
+svc.memo_groups                              # => [:database]  — all groups on the class
+svc.memo_group_methods(:database)            # => [:find_user, :find_post]
+CatalogService.safe_memo_groups              # => [:catalog]
+CatalogService.safe_memo_group_methods(:catalog)  # => [:products, :categories]
+```
+
+#### Class-wide group default
+
+Use `safe_memoize_options` to assign all subsequently memoized methods to the same group:
+
+```ruby
+class ApiClient
+  prepend SafeMemoize
+  safe_memoize_options group: :api
+
+  def users  = http.get("/users")
+  def orders = http.get("/orders")
+
+  memoize :users               # group: :api
+  memoize :orders              # group: :api
+  memoize :health, group: nil  # override — no group
+end
+```
+
+A method belongs to at most one group at a time; re-memoizing with a different `group:` moves it.
+
+[↑ Back to features](#features)
+
 ### Lifecycle hooks
 
 Register callbacks that fire when cached entries are evicted or expire.
@@ -1611,6 +1685,7 @@ Anything **not** listed here — internal modules, private methods, `@__safe_mem
 | `shared_cache:` | `String \| nil` | `nil` | Name of a globally-registered shared store; incompatible with `shared:`, `store:`, `fiber_local:`, `ractor_safe:`, and `max_size:` |
 | `cache_bust:` | `Proc \| Symbol \| nil` | `nil` | Version-token callable; invoked on the instance at each lookup; token is folded into the key; incompatible with `key:` |
 | `copy_on_read:` | `Boolean` | `false` | Return a `dup`/`deep_dup` of the cached value on every read; protects shared state from caller mutation; nil and frozen values pass through; incompatible with `ractor_safe:` |
+| `group:` | `Symbol \| String \| nil` | `nil` | Assigns the method to a named invalidation group; call `reset_memo_group` / `reset_shared_memo_group` to bust all methods in the group at once; a method belongs to at most one group |
 | *(extension options)* | any | — | Unknown kwargs are validated against registered extensions; raise `ArgumentError` if unclaimed |
 
 ### `memoize_all` options (class method)
@@ -1628,7 +1703,7 @@ All `memoize` option keys above, plus:
 
 | Option key | Type | Default | Notes |
 |---|---|---|---|
-| any `memoize` key except mode-switches | — | — | Accepts `ttl:`, `max_size:`, `ttl_refresh:`, `if:`, `unless:`, `key:`, `cache_bust:`, `copy_on_read:`, `namespace:`, `store:`; raises `ArgumentError` for `shared:`, `fiber_local:`, `ractor_safe:`, `shared_cache:` |
+| any `memoize` key except mode-switches | — | — | Accepts `ttl:`, `max_size:`, `ttl_refresh:`, `if:`, `unless:`, `key:`, `cache_bust:`, `copy_on_read:`, `namespace:`, `store:`, `group:`; raises `ArgumentError` for `shared:`, `fiber_local:`, `ractor_safe:`, `shared_cache:` |
 
 ### Instance methods (public)
 
@@ -1650,10 +1725,18 @@ All `memoize` option keys above, plus:
 | Method | Returns |
 |---|---|
 | `reset_memo(method_name, *args, **kwargs)` | `nil` |
+| `reset_memo_group(group_name)` | `nil` |
 | `reset_all_memos` | `nil` |
 | `memo_touch(method_name, *args, ttl: nil, **kwargs)` | `Boolean` |
 | `memo_refresh(method_name, *args, **kwargs)` | cached value |
 
+**Group introspection**
+
+| Method | Returns |
+|---|---|
+| `memo_groups` | `Array<Symbol>` — all group names on the class |
+| `memo_group_methods(group_name)` | `Array<Symbol>` — methods in the group |
+
 **Warm-up and persistence**
 
 | Method | Returns |
@@ -1705,11 +1788,19 @@ All `memoize` option keys above, plus:
 |---|---|
 | `reset_shared_memo(method_name, *args, **kwargs)` | `nil` |
 | `reset_all_shared_memos` | `nil` |
+| `reset_shared_memo_group(group_name)` | `nil` |
 | `shared_memoized?(method_name, *args, **kwargs)` | `Boolean` |
 | `shared_memo_count(method_name = nil)` | `Integer` |
 | `shared_memo_age(method_name, *args, **kwargs)` | `Numeric \| nil` |
 | `shared_memo_stale?(method_name, *args, **kwargs)` | `Boolean` |
 
+### Group class methods (available on any class that uses `group:`)
+
+| Method | Returns |
+|---|---|
+| `safe_memo_groups` | `Array<Symbol>` — all group names on the class |
+| `safe_memo_group_methods(group_name)` | `Array<Symbol>` — methods belonging to the group |
+
 **Ractor-safe shared cache (added when any method uses `ractor_safe: true`)**
 
 | Method | Returns |

ROADMAP.md

@@ -10,7 +10,7 @@ This document tracks the planned evolution of SafeMemoize through v1.0.0 and bey
 
 | Feature | Description | Status |
 |---|---|---|
-| Memoization groups | `memoize :find, group: :database` then `reset_memo_group(:database)` to invalidate all methods tagged with the same group at once; groups can span multiple methods on the same class | Planned |
+| Memoization groups | `memoize :find, group: :database` then `reset_memo_group(:database)` to invalidate all methods tagged with the same group at once; groups can span multiple methods on the same class | Shipped |
 
 ---
 

lib/safe_memoize/class_methods.rb

@@ -64,6 +64,11 @@ module ClassMethods
     #   itself. Prevents callers from mutating shared cached state. Frozen and +nil+
     #   values are returned as-is. Incompatible with +ractor_safe:+ (ractor values are
     #   always frozen; use that guarantee instead).
+    # @param group [Symbol, String, nil] assigns the method to a named invalidation
+    #   group. Call {PublicMethods#reset_memo_group} on an instance (or
+    #   {.reset_shared_memo_group} for shared-mode methods) to bust every method in the
+    #   group at once. A method may belong to at most one group; re-memoizing with a
+    #   different group moves it. Must be a non-empty Symbol or String.
     # @return [void]
     # @raise [ArgumentError] if the method does not exist, or option values are invalid
     #
@@ -84,7 +89,7 @@ module ClassMethods
     # @example With a custom store
     #   STORE = SafeMemoize::Stores::Memory.new
     #   memoize :fetch, store: STORE, ttl: 300
-    def memoize(method_name, ttl: UNSET, max_size: UNSET, ttl_refresh: UNSET, if: UNSET, unless: UNSET, shared: UNSET, key: UNSET, store: UNSET, fiber_local: UNSET, ractor_safe: UNSET, namespace: UNSET, shared_cache: UNSET, cache_bust: UNSET, copy_on_read: UNSET, **extension_options)
+    def memoize(method_name, ttl: UNSET, max_size: UNSET, ttl_refresh: UNSET, if: UNSET, unless: UNSET, shared: UNSET, key: UNSET, store: UNSET, fiber_local: UNSET, ractor_safe: UNSET, namespace: UNSET, shared_cache: UNSET, cache_bust: UNSET, copy_on_read: UNSET, group: UNSET, **extension_options)
       method_name = method_name.to_sym
 
       unless method_defined?(method_name) || private_method_defined?(method_name) || protected_method_defined?(method_name)
@@ -126,6 +131,7 @@ def memoize(method_name, ttl: UNSET, max_size: UNSET, ttl_refresh: UNSET, if: UN
         copy_on_read = cls_defaults[:copy_on_read] if copy_on_read.equal?(UNSET) && cls_defaults.key?(:copy_on_read)
         namespace = cls_defaults[:namespace] if namespace.equal?(UNSET) && cls_defaults.key?(:namespace)
         store = cls_defaults[:store] if store.equal?(UNSET) && cls_defaults.key?(:store)
+        group = cls_defaults[:group] if group.equal?(UNSET) && cls_defaults.key?(:group)
       end
 
       # Normalize remaining UNSET to original per-call defaults
@@ -141,6 +147,7 @@ def memoize(method_name, ttl: UNSET, max_size: UNSET, ttl_refresh: UNSET, if: UN
       shared_cache = nil if shared_cache.equal?(UNSET)
       cache_bust = nil if cache_bust.equal?(UNSET)
       copy_on_read = false if copy_on_read.equal?(UNSET)
+      group = nil if group.equal?(UNSET)
       cond_if = nil if cond_if.equal?(UNSET)
       cond_unless = nil if cond_unless.equal?(UNSET)
 
@@ -213,6 +220,15 @@ def memoize(method_name, ttl: UNSET, max_size: UNSET, ttl_refresh: UNSET, if: UN
         __safe_memo_method_namespaces__[method_name] = namespace
       end
 
+      if group
+        unless group.is_a?(Symbol) || group.is_a?(String)
+          raise ArgumentError, "group: must be a Symbol or String (got #{group.class})"
+        end
+        group = group.to_sym
+        raise ArgumentError, "group: must not be empty" if group.empty?
+        __safe_memo_register_group__(method_name, group)
+      end
+
       if shared_cache
         raise ArgumentError, "shared_cache: must be a String (got #{shared_cache.class})" unless shared_cache.is_a?(String)
         raise ArgumentError, "shared_cache: must not be empty" if shared_cache.empty?
@@ -763,6 +779,35 @@ def shared_memo_stale?(method_name, *args, **kwargs)
       end
     end
 
+    # Clears all shared-cache entries for every method in the given group.
+    #
+    # Only affects methods memoized with +shared: true+. For per-instance cache
+    # invalidation use {PublicMethods#reset_memo_group} on the instance.
+    #
+    # @param group_name [Symbol, String]
+    # @return [void]
+    def reset_shared_memo_group(group_name)
+      group_name = group_name.to_sym
+      (__safe_memo_groups__[group_name] || []).each { |m| reset_shared_memo(m) }
+    end
+
+    # Returns the method names belonging to the given invalidation group, or an
+    # empty array when the group is unknown.
+    #
+    # @param group_name [Symbol, String]
+    # @return [Array<Symbol>]
+    def safe_memo_group_methods(group_name)
+      group_name = group_name.to_sym
+      (__safe_memo_groups__[group_name] || []).dup
+    end
+
+    # Returns all group names registered on this class.
+    #
+    # @return [Array<Symbol>]
+    def safe_memo_groups
+      __safe_memo_groups__.keys
+    end
+
     private
 
     def __safe_memo_shared_cache__
@@ -793,6 +838,17 @@ def __safe_memoize_defaults__
       @__safe_memoize_defaults__
     end
 
+    def __safe_memo_groups__
+      @__safe_memo_groups__ ||= {}
+    end
+
+    def __safe_memo_register_group__(method_name, group)
+      groups = __safe_memo_groups__
+      # Remove method from any prior group it belonged to
+      groups.each_value { |methods| methods.delete(method_name) }
+      (groups[group] ||= []) << method_name
+    end
+
     # Resolves the effective first-element key sym for a given bare method name,
     # applying the active namespace. Used by class-level cache operations where
     # instance methods (compute_cache_key) are unavailable.

lib/safe_memoize/public_methods.rb

@@ -359,6 +359,37 @@ def reset_memo(method_name, *args, **kwargs)
       end
     end
 
+    # Clears all per-instance cached entries for every method belonging to the
+    # given invalidation group (declared via +memoize :method, group: :name+).
+    #
+    # A no-op when the group is unknown or has no members. Each evicted entry
+    # fires the +:on_evict+ hook. For shared-mode methods use the class-level
+    # {ClassMethods.reset_shared_memo_group} instead.
+    #
+    # @param group_name [Symbol, String]
+    # @return [void]
+    def reset_memo_group(group_name)
+      group_name = group_name.to_sym
+      (self.class.send(:__safe_memo_groups__)[group_name] || []).each { |m| reset_memo(m) }
+    end
+
+    # Returns the method names belonging to the given invalidation group on
+    # this instance's class, or an empty array when the group is unknown.
+    #
+    # @param group_name [Symbol, String]
+    # @return [Array<Symbol>]
+    def memo_group_methods(group_name)
+      group_name = group_name.to_sym
+      (self.class.send(:__safe_memo_groups__)[group_name] || []).dup
+    end
+
+    # Returns all invalidation group names registered on this instance's class.
+    #
+    # @return [Array<Symbol>]
+    def memo_groups
+      self.class.send(:__safe_memo_groups__).keys
+    end
+
     # Clears all cached entries for every method on this instance.
     # Each evicted entry fires the +:on_evict+ hook.
     #

sig/safe_memoize.rbs

@@ -17,6 +17,7 @@ module SafeMemoize
   @__safe_memo_shared_cache__: Hash[memo_key, memo_record]?
   @__safe_memo_shared_mutex__: Mutex?
   @__safe_memo_shared_lru_order__: Hash[Symbol, Hash[memo_key, true]]?
+  @__safe_memo_groups__: Hash[Symbol, Array[Symbol]]?
 
   UNSET: untyped
   SHARED_CACHE_REGISTRY: Hash[String, Stores::Base]
@@ -65,7 +66,7 @@ module SafeMemoize
   end
 
   module ClassMethods
-    def memoize: (Symbol | String method_name, ?ttl: Numeric?, ?max_size: Integer?, ?ttl_refresh: bool, ?if: (^(untyped result) -> boolish)?, ?unless: (^(untyped result) -> boolish)?, ?shared: bool, ?key: (^(*untyped args, **untyped kwargs) -> untyped)?, ?store: Stores::Base?, ?fiber_local: bool, ?ractor_safe: bool, ?namespace: String?, ?shared_cache: String?, ?cache_bust: (^() -> untyped) | Symbol | nil, ?copy_on_read: bool, **untyped extension_options) -> void
+    def memoize: (Symbol | String method_name, ?ttl: Numeric?, ?max_size: Integer?, ?ttl_refresh: bool, ?if: (^(untyped result) -> boolish)?, ?unless: (^(untyped result) -> boolish)?, ?shared: bool, ?key: (^(*untyped args, **untyped kwargs) -> untyped)?, ?store: Stores::Base?, ?fiber_local: bool, ?ractor_safe: bool, ?namespace: String?, ?shared_cache: String?, ?cache_bust: (^() -> untyped) | Symbol | nil, ?copy_on_read: bool, ?group: Symbol | String | nil, **untyped extension_options) -> void
     def safe_memoize_store: () -> Stores::Base?
     def safe_memoize_store=: (Stores::Base?) -> Stores::Base?
     def safe_memoize_namespace: () -> String?
@@ -78,6 +79,9 @@ module SafeMemoize
     def shared_memo_count: (?Symbol | String method_name) -> Integer
     def shared_memo_age: (Symbol | String method_name, *untyped args, **untyped kwargs) -> Float?
     def shared_memo_stale?: (Symbol | String method_name, *untyped args, **untyped kwargs) -> bool
+    def reset_shared_memo_group: (Symbol | String group_name) -> void
+    def safe_memo_group_methods: (Symbol | String group_name) -> Array[Symbol]
+    def safe_memo_groups: () -> Array[Symbol]
 
     private
 
@@ -88,6 +92,8 @@ module SafeMemoize
     def __safe_memo_method_namespaces__: () -> Hash[Symbol, String]
     def __safe_memo_class_cache_bust_generators__: () -> Hash[Symbol, Proc | Symbol]
     def __safe_memoize_defaults__: () -> Hash[Symbol, untyped]?
+    def __safe_memo_groups__: () -> Hash[Symbol, Array[Symbol]]
+    def __safe_memo_register_group__: (Symbol method_name, Symbol group) -> void
     def memoized_method_visibility: (Symbol method_name) -> Symbol
   end
 
@@ -114,6 +120,9 @@ module SafeMemoize
     def memo_age: (Symbol | String method_name, *untyped args, **untyped kwargs) -> Float?
     def memo_stale?: (Symbol | String method_name, *untyped args, **untyped kwargs) -> bool
     def reset_memo: (Symbol | String method_name, *untyped args, **untyped kwargs) -> void
+    def reset_memo_group: (Symbol | String group_name) -> void
+    def memo_group_methods: (Symbol | String group_name) -> Array[Symbol]
+    def memo_groups: () -> Array[Symbol]
     def reset_all_memos: () -> void
     def memo_inspect: (Symbol | String method_name, *untyped args, **untyped kwargs) -> { cached: bool, value: untyped, hits: Integer, misses: Integer, ttl_remaining: Float?, age: Float?, custom_key: untyped, lru_position: Integer? }?
   end