feat: add strategies as an adapter type

.github/workflows/coverage.yml

@@ -28,8 +28,8 @@ jobs:
       - name: Set up Elixir
         uses: erlef/setup-beam@v1
         with:
-          elixir-version: '1.14.1' # Define the elixir version [required]
-          otp-version: '25.1.2' # Define the OTP version [required]
+          version-type: strict
+          version-file: .tool-versions
 
       - name: Restore dependencies cache
         uses: actions/cache@v3
@@ -49,5 +49,8 @@ jobs:
       - name: Run Coveralls
         run: mix coveralls.json
 
-      - name: Upload to codecov.io
-        uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: true
+          verbose: true

.github/workflows/credo.yml

@@ -15,8 +15,8 @@ jobs:
       - name: Set up Elixir
         uses: erlef/setup-beam@v1
         with:
-          elixir-version: '1.14.1' # Define the elixir version [required]
-          otp-version: '25.1.2' # Define the OTP version [required]
+          version-type: strict
+          version-file: .tool-versions
 
       - name: Restore dependencies cache
         uses: actions/cache@v3

.github/workflows/dialyzer.yml

@@ -15,8 +15,8 @@ jobs:
       - name: Set up Elixir
         uses: erlef/setup-beam@v1
         with:
-          elixir-version: '1.14.1' # Define the elixir version [required]
-          otp-version: '25.1.2' # Define the OTP version [required]
+          version-type: strict
+          version-file: .tool-versions
 
       - name: Restore dependencies cache
         uses: actions/cache@v3

.github/workflows/test.yml

@@ -28,8 +28,8 @@ jobs:
       - name: Set up Elixir
         uses: erlef/setup-beam@v1
         with:
-          elixir-version: '1.14.1' # Define the elixir version [required]
-          otp-version: '25.1.2' # Define the OTP version [required]
+          version-type: strict
+          version-file: .tool-versions
 
       - name: Restore dependencies cache
         uses: actions/cache@v3

guides/explanation/architecture.md

@@ -8,9 +8,10 @@ ElixirCache is designed around a simple principle: provide a consistent interfac
 
 1. **Core Interface**: Defined by the `Cache` module
 2. **Adapters**: Backend-specific implementations
-3. **Term Encoder**: Handles serialization and compression
-4. **Telemetry Integration**: For observability and metrics
-5. **Sandbox System**: For isolated testing
+3. **Strategy Adapters**: Higher-level patterns that compose over adapters
+4. **Term Encoder**: Handles serialization and compression
+5. **Telemetry Integration**: For observability and metrics
+6. **Sandbox System**: For isolated testing
 
 ## The Cache Behaviour
 
@@ -82,6 +83,31 @@ A simple implementation using Elixir's Agent for lightweight in-memory storage.
 
 Wraps the ConCache library to provide its expiration and callback capabilities.
 
+## Strategy Adapters
+
+Strategy adapters implement the `Cache.Strategy` behaviour and compose over
+regular adapters to provide higher-level caching patterns. They are specified
+using a tuple format: `adapter: {StrategyModule, UnderlyingAdapterOrConfig}`.
+
+### Cache.HashRing
+
+Distributes cache keys across Erlang cluster nodes using a consistent hash ring
+powered by `libring`. Operations are forwarded to the owning node via
+`:erpc.call/4`. The ring monitors node membership automatically.
+
+### Cache.MultiLayer
+
+Chains multiple cache modules together. Reads cascade fastest → slowest with
+automatic backfill on slower-layer hits. Writes go slowest → fastest to ensure
+durability before populating fast layers.
+
+### Cache.RefreshAhead
+
+Proactively refreshes values in the background before they expire. When a `get`
+detects a value is within the refresh window, it returns the current value
+immediately and spawns an async task to fetch a fresh one. Uses per-node ETS
+deduplication and cross-node `:global` locking to prevent redundant refreshes.
+
 ## Telemetry Integration
 
 ElixirCache provides telemetry events for all cache operations:

guides/how-to/choosing_adapter.md

@@ -51,7 +51,7 @@ defmodule MyApp.PersistentCache do
     adapter: Cache.DETS,
     name: :my_app_persistent_cache,
     opts: [
-      file: "cache_data.dets"
+      file_path: "/tmp/cache_data"
     ]
 end
 ```
@@ -71,9 +71,9 @@ defmodule MyApp.DistributedCache do
     adapter: Cache.Redis,
     name: :my_app_redis_cache,
     opts: [
-      host: "localhost",
-      port: 6379,
-      pool_size: 5
+      uri: "redis://localhost:6379",
+      size: 10,
+      max_overflow: 5
     ]
 end
 ```
@@ -143,24 +143,12 @@ defmodule MyApp.Cache do
     name: :my_app_cache,
     opts: get_opts()
 
-  defp get_adapter do
-    case Mix.env() do
-      :test -> Cache.Sandbox
-      :dev -> Cache.ETS
-      :prod -> Cache.Redis
-    end
-  end
-
-  defp get_opts do
-    case Mix.env() do
-      :test -> []
-      :dev -> [read_concurrency: true]
-      :prod -> [
-        host: System.get_env("REDIS_HOST", "localhost"),
-        port: String.to_integer(System.get_env("REDIS_PORT", "6379")),
-        pool_size: 10
-      ]
-    end
+  if Mix.env() === :test do
+    defp get_adapter, do: Cache.ETS
+    defp get_opts, do: []
+  else
+    defp get_adapter, do: Cache.Redis
+    defp get_opts, do: [uri: "redis://localhost:6379", size: 10]
   end
 end
 ```

guides/how-to/redis_setup.md

@@ -21,9 +21,9 @@ defmodule MyApp.RedisCache do
     adapter: Cache.Redis,
     name: :my_app_redis,
     opts: [
-      host: "localhost",
-      port: 6379,
-      pool_size: 5
+      uri: "redis://localhost:6379",
+      size: 10,
+      max_overflow: 5
     ]
 end
 ```
@@ -46,38 +46,26 @@ end
 
 ## Redis Configuration Options
 
-The Redis adapter supports various configuration options:
+The Redis adapter accepts the following options:
+
+| Option | Type | Required | Description |
+|---|---|---|---|
+| `uri` | `string` | Yes | Redis connection URI (e.g. `"redis://localhost:6379"`, `"redis://:password@host:6379/0"`) |
+| `size` | `pos_integer` | No | Number of workers in the connection pool (default: 50) |
+| `max_overflow` | `pos_integer` | No | Maximum overflow workers the pool can create (default: 20) |
+| `strategy` | `:fifo` or `:lifo` | No | Queue strategy for the Poolboy connection pool |
+
+Authentication, database selection, and SSL are configured via the URI string:
 
 ```elixir
 defmodule MyApp.RedisCache do
   use Cache,
     adapter: Cache.Redis,
     name: :my_app_redis,
     opts: [
-      # Connection settings
-      host: "redis.example.com",
-      port: 6379,
-      password: "your_password",  # Optional
-      database: 0,                # Optional, default is 0
-
-      # Connection pool settings
-      pool_size: 10,              # Number of connections in the pool
-      max_overflow: 5,            # Maximum number of overflow workers
-
-      # Timeout settings
-      timeout: 5000,              # Connection timeout in milliseconds
-
-      # SSL options
-      ssl: true,                  # Enable SSL
-      ssl_opts: [                 # SSL options
-        verify: :verify_peer,
-        cacertfile: "/path/to/ca_certificate.pem",
-        certfile: "/path/to/client_certificate.pem",
-        keyfile: "/path/to/client_key.pem"
-      ],
-
-      # Encoding options
-      compression_level: 1        # Level of compression (0-9, higher = more compression)
+      uri: "redis://:my_password@redis.example.com:6379/2",
+      size: 10,
+      max_overflow: 5
     ]
 end
 ```
@@ -92,10 +80,9 @@ defmodule MyApp.RedisCache do
     adapter: Cache.Redis,
     name: :my_app_redis,
     opts: [
-      host: System.get_env("REDIS_HOST", "localhost"),
-      port: String.to_integer(System.get_env("REDIS_PORT", "6379")),
-      password: System.get_env("REDIS_PASSWORD"),
-      pool_size: String.to_integer(System.get_env("REDIS_POOL_SIZE", "10"))
+      uri: System.get_env("REDIS_URL", "redis://localhost:6379"),
+      size: String.to_integer(System.get_env("REDIS_POOL_SIZE", "10")),
+      max_overflow: 5
     ]
 end
 ```

guides/how-to/testing_with_cache.md

@@ -4,105 +4,71 @@ This guide explains how to effectively test applications that use ElixirCache, f
 
 ## Using the Sandbox Mode
 
-ElixirCache provides a sandbox mode specifically designed for testing. This ensures that your tests:
+ElixirCache provides a sandbox mode that gives each test its own isolated cache
+namespace. This ensures your tests:
 
 1. Are isolated from each other
 2. Don't leave lingering cache data between test runs
 3. Can run in parallel without conflicts
 
-### Configuring Your Cache for Testing
+### Configuring Your Cache
 
-In your test environment, you can wrap any cache adapter with the sandbox functionality:
+Use `sandbox?: Mix.env() === :test` on your cache module. The adapter stays the
+same in every environment — the sandbox wraps whatever adapter you choose:
 
 ```elixir
-# In lib/my_app/cache.ex
 defmodule MyApp.Cache do
   use Cache,
-    adapter: get_cache_adapter(),
+    adapter: Cache.Redis,
     name: :my_app_cache,
-    opts: get_cache_opts(),
-    # Enable sandbox mode in test environment
-    sandbox?: Mix.env() == :test
-
-  defp get_cache_adapter do
-    case Mix.env() do
-      :test -> Cache.ETS
-      :dev -> Cache.ETS
-      :prod -> Cache.Redis
-    end
-  end
-
-  defp get_cache_opts do
-    case Mix.env() do
-      :test -> []
-      :dev -> []
-      :prod -> [host: "redis.example.com", port: 6379]
-    end
-  end
+    opts: [uri: "redis://localhost:6379"],
+    sandbox?: Mix.env() === :test
 end
 ```
 
+When `sandbox?` is `true`, `Cache.Sandbox` is used as the adapter automatically.
+You do not need to switch adapters between environments.
+
 ### Setting Up the Sandbox Registry
 
-To use the sandbox functionality in your tests, you need to start the `Cache.SandboxRegistry` in your test setup:
+Add `Cache.SandboxRegistry.start_link()` to your `test/test_helper.exs`:
 
 ```elixir
 # In test/test_helper.exs
+Cache.SandboxRegistry.start_link()
 ExUnit.start()
-
-# Start the sandbox registry for your tests
-{:ok, _pid} = Cache.SandboxRegistry.start_link()
-
-# Start your application's supervision tree
-Application.ensure_all_started(:my_app)
 ```
 
 ### Using the Sandbox in Tests
 
-Using the sandbox in your tests is very simple. All you need to do is start the sandbox registry in your setup block:
+Register your cache in each test's `setup` block with
+`Cache.SandboxRegistry.start/1`. This starts the cache supervisor and
+registers the current test process for isolation:
 
 ```elixir
 defmodule MyApp.CacheTest do
   use ExUnit.Case, async: true
 
-  defmodule TestCache do
-    use Cache,
-      adapter: Cache.Redis,  # The actual adapter doesn't matter in sandbox mode
-      name: :test_cache,
-      opts: [],
-      sandbox?: Mix.env() === :test
-  end
-
   setup do
-    # This single line is all you need to set up sandbox isolation
-    Cache.SandboxRegistry.start(TestCache)
+    Cache.SandboxRegistry.start(MyApp.Cache)
     :ok
   end
-
-  test "can store and retrieve values" do
-    assert :ok = TestCache.put("test-key", "test-value")
-    assert {:ok, "test-value"} = TestCache.get("test-key")
-  end
-
-  test "can handle complex data structures" do
-    data = %{users: [%{name: "Alice"}, %{name: "Bob"}]}
-    assert :ok = TestCache.put("complex-key", data)
-    assert {:ok, ^data} = TestCache.get("complex-key")
+
+  test "stores and retrieves values" do
+    assert :ok === MyApp.Cache.put("key", "value")
+    assert {:ok, "value"} === MyApp.Cache.get("key")
   end
 
-  test "provides isolation between tests" do
-    # This will return nil because each test has an isolated cache
-    assert {:ok, nil} = TestCache.get("test-key")
+  test "each test is isolated" do
+    assert {:ok, nil} === MyApp.Cache.get("key")
   end
 end
 ```
 
-
 ## Tips for Testing with ElixirCache
 
-1. **Always use the sandbox in tests**: This prevents interference between tests.
-2. **Clean up after each test**: Use `on_exit` to unregister from the sandbox.
-3. **Use unique keys**: Even with sandboxing, using descriptive, unique keys makes debugging easier.
-4. **Test edge cases**: Including cache misses, errors, and TTL expiration.
-5. **Consider using fixtures**: For commonly cached data structures.
-6. **Verify telemetry events**: If your application relies on cache metrics.
+1. **Always use `sandbox?: Mix.env() === :test`**: Keep the same adapter everywhere — the sandbox handles isolation.
+2. **Use `Cache.SandboxRegistry.start/1` in setup**: This is the only line needed per test.
+3. **Tests can be `async: true`**: Each test gets its own sandbox namespace.
+4. **Test edge cases**: Cache misses, errors, and TTL expiration.
+5. **Verify telemetry events**: If your application relies on cache metrics.