From 2f9fbaf421d462bc75f6df0b55c2e009618ce2f3 Mon Sep 17 00:00:00 2001
From: Krrish Dholakia <krrishdholakia@gmail.com>
Date: Thu, 12 Dec 2024 15:36:23 -0800
Subject: [PATCH] fix(pattern_match_deployments.py): match to more specific
 pattern

match to more specific pattern

allows setting generic wildcard model access group and excluding specific models more easily
---
 .../router_utils/pattern_match_deployments.py | 43 ++++++++++++++++++-
 .../test_router_pattern_matching.py           | 28 +++++++++++-
 2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/litellm/router_utils/pattern_match_deployments.py b/litellm/router_utils/pattern_match_deployments.py
index 3b10dcdb769..63e8a0c42ea 100644
--- a/litellm/router_utils/pattern_match_deployments.py
+++ b/litellm/router_utils/pattern_match_deployments.py
@@ -4,13 +4,51 @@ Class to handle llm wildcard routing and regex pattern matching
 
 import copy
 import re
+from functools import cached_property
 from re import Match
-from typing import Dict, List, Optional
+from typing import Dict, List, Optional, Tuple
 
 from litellm import get_llm_provider
 from litellm._logging import verbose_router_logger
 
 
+class PatternUtils:
+    @staticmethod
+    def calculate_pattern_specificity(pattern: str) -> Tuple[int, int]:
+        """
+        Calculate pattern specificity based on length and complexity.
+
+        Args:
+            pattern: Regex pattern to analyze
+
+        Returns:
+            Tuple of (length, complexity) for sorting
+        """
+        complexity_chars = ["*", "+", "?", "\\", "^", "$", "|", "(", ")"]
+        return (
+            len(pattern),  # Longer patterns more specific
+            sum(
+                pattern.count(char) for char in complexity_chars
+            ),  # More regex complexity
+        )
+
+    @staticmethod
+    def sorted_patterns(
+        patterns: Dict[str, List[Dict]]
+    ) -> List[Tuple[str, List[Dict]]]:
+        """
+        Cached property for patterns sorted by specificity.
+
+        Returns:
+            Sorted list of pattern-deployment tuples
+        """
+        return sorted(
+            patterns.items(),
+            key=lambda x: PatternUtils.calculate_pattern_specificity(x[0]),
+            reverse=True,
+        )
+
+
 class PatternMatchRouter:
     """
     Class to handle llm wildcard routing and regex pattern matching
@@ -99,12 +137,13 @@ class PatternMatchRouter:
             if request is None:
                 return None
 
+            sorted_patterns = PatternUtils.sorted_patterns(self.patterns)
             regex_filtered_model_names = (
                 [self._pattern_to_regex(m) for m in filtered_model_names]
                 if filtered_model_names is not None
                 else []
             )
-            for pattern, llm_deployments in self.patterns.items():
+            for pattern, llm_deployments in sorted_patterns:
                 if (
                     filtered_model_names is not None
                     and pattern not in regex_filtered_model_names
diff --git a/tests/local_testing/test_router_pattern_matching.py b/tests/local_testing/test_router_pattern_matching.py
index 35e4d2c3d84..619c594421c 100644
--- a/tests/local_testing/test_router_pattern_matching.py
+++ b/tests/local_testing/test_router_pattern_matching.py
@@ -133,7 +133,7 @@ def test_route_with_multiple_matching_patterns():
     router.add_pattern("openai/*", deployment1.to_json(exclude_none=True))
     router.add_pattern("openai/gpt-*", deployment2.to_json(exclude_none=True))
     assert router.route("openai/gpt-3.5-turbo") == [
-        deployment1.to_json(exclude_none=True)
+        deployment2.to_json(exclude_none=True)
     ]
 
 
@@ -265,3 +265,29 @@ def test_pattern_matching_router_with_default_wildcard():
         model="gpt-3.5-turbo",
         messages=[{"role": "user", "content": "Hello, how are you?"}],
     )
+
+
+def test_pattern_matching_router_with_default_wildcard_and_model_wildcard():
+    """
+    Match to more specific pattern first.
+    """
+    router = Router(
+        model_list=[
+            {
+                "model_name": "*",
+                "litellm_params": {"model": "*"},
+                "model_info": {"access_groups": ["default"]},
+            },
+            {
+                "model_name": "llmengine/*",
+                "litellm_params": {"model": "openai/*"},
+            },
+        ]
+    )
+
+    assert len(router.pattern_router.patterns) > 0
+
+    pattern_router = router.pattern_router
+    deployments = pattern_router.route("llmengine/gpt-3.5-turbo")
+    assert len(deployments) == 1
+    assert deployments[0]["model_name"] == "llmengine/*"