From 2818307e93c6e73837ca08c4f37864adb56651df Mon Sep 17 00:00:00 2001
From: Joao Gante <joaofranciscocardosogante@gmail.com>
Date: Thu, 16 Jan 2025 17:04:54 +0000
Subject: [PATCH] [generate] can instantiate
 `GenerationConfig(cache_implementation="static")` (#35679)

fix failing instantiation
---
 .../generation/configuration_utils.py          | 18 ++++++++----------
 tests/generation/test_configuration_utils.py   |  6 ++++++
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/transformers/generation/configuration_utils.py b/src/transformers/generation/configuration_utils.py
index 18cf26b8b73415..3f142ce772984b 100644
--- a/src/transformers/generation/configuration_utils.py
+++ b/src/transformers/generation/configuration_utils.py
@@ -43,7 +43,7 @@
 
 logger = logging.get_logger(__name__)
 METADATA_FIELDS = ("_from_model_config", "_commit_hash", "_original_object_hash", "transformers_version")
-NEEDS_CACHE_CONFIG = {}
+CACHE_CONFIG_MAPPING = {}
 NEED_SETUP_CACHE_CLASSES_MAPPING = {}
 QUANT_BACKEND_CLASSES_MAPPING = {}
 ALL_CACHE_IMPLEMENTATIONS = []
@@ -62,8 +62,8 @@
     )
     from .logits_process import SynthIDTextWatermarkLogitsProcessor, WatermarkLogitsProcessor
 
-    NEEDS_CACHE_CONFIG["quantized"] = QuantizedCacheConfig
-    NEEDS_CACHE_CONFIG["static"] = StaticCacheConfig
+    CACHE_CONFIG_MAPPING["quantized"] = QuantizedCacheConfig
+    CACHE_CONFIG_MAPPING["static"] = StaticCacheConfig
     NEED_SETUP_CACHE_CLASSES_MAPPING = {
         "static": StaticCache,
         "offloaded_static": OffloadedStaticCache,
@@ -73,7 +73,7 @@
     }
     QUANT_BACKEND_CLASSES_MAPPING = {"quanto": QuantoQuantizedCache, "HQQ": HQQQuantizedCache}
     ALL_CACHE_IMPLEMENTATIONS = (
-        list(NEED_SETUP_CACHE_CLASSES_MAPPING.keys()) + list(NEEDS_CACHE_CONFIG.keys()) + ["offloaded"]
+        list(NEED_SETUP_CACHE_CLASSES_MAPPING.keys()) + list(CACHE_CONFIG_MAPPING.keys()) + ["offloaded"]
     )
 
 
@@ -409,11 +409,9 @@ def __init__(self, **kwargs):
         self.use_cache = kwargs.pop("use_cache", True)
         self.cache_implementation = kwargs.pop("cache_implementation", None)
         self.cache_config = kwargs.pop("cache_config", None)
-        if self.cache_implementation is not None and self.cache_implementation in NEEDS_CACHE_CONFIG:
-            cache_config_class = NEEDS_CACHE_CONFIG[self.cache_implementation]
-            if self.cache_config is None:
-                self.cache_config = cache_config_class()
-            elif isinstance(self.cache_config, dict):
+        if self.cache_implementation is not None and self.cache_implementation in CACHE_CONFIG_MAPPING:
+            cache_config_class = CACHE_CONFIG_MAPPING[self.cache_implementation]
+            if isinstance(self.cache_config, dict):
                 self.cache_config = cache_config_class.from_dict(self.cache_config)
         self.return_legacy_cache = kwargs.pop("return_legacy_cache", None)
 
@@ -766,7 +764,7 @@ def validate(self, is_init=False):
                 f"{ALL_CACHE_IMPLEMENTATIONS}"
             )
         if self.cache_config is not None:
-            cache_class = NEEDS_CACHE_CONFIG.get(self.cache_implementation)
+            cache_class = CACHE_CONFIG_MAPPING.get(self.cache_implementation)
             if cache_class is None:
                 raise ValueError(
                     "You provided a `cache_config` but the cache implementation you are using "
diff --git a/tests/generation/test_configuration_utils.py b/tests/generation/test_configuration_utils.py
index 24fea85a900d67..ef30599581ffae 100644
--- a/tests/generation/test_configuration_utils.py
+++ b/tests/generation/test_configuration_utils.py
@@ -259,6 +259,12 @@ def test_generation_mode(self):
         config = GenerationConfig()
         self.assertEqual(config.get_generation_mode(assistant_model="foo"), GenerationMode.ASSISTED_GENERATION)
 
+    def test_static_cache_without_cache_config(self):
+        """Regression test for #35026 -- static cache should work without a cache config."""
+        config = GenerationConfig(cache_implementation="static")
+        self.assertEqual(config.cache_implementation, "static")
+        self.assertEqual(config.cache_config, None)
+
 
 class GenerationConfigSerializationTest(unittest.TestCase):
     def test_serialize_generation_sequence_bias(self):