optimize gapic #2531

ohmayr · 2026-01-21T23:25:54Z

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Fixes #<issue_number_goes_here> 🦕

gemini-code-assist · 2026-01-21T23:26:11Z

Summary of Changes

Hello @ohmayr, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request implements a significant performance optimization by introducing a caching mechanism for context-aware schema objects. By passing a shared context_cache through the with_context methods, the system can avoid recomputing identical object derivatives, especially those involved in resolving naming collisions. This change aims to reduce processing time and improve the overall efficiency of the GAPIC generator.

Highlights

Introduced Context Caching: A context_cache dictionary is now passed through various with_context methods across api.py, metadata.py, and wrappers.py to store and reuse previously computed context-aware objects, preventing redundant calculations.
Optimized with_context Calls: The with_context methods in Address, Metadata, Field, MessageType, EnumType, ExtendedOperationInfo, OperationInfo, Method, and Service now check the context_cache before performing computations, returning cached results if available.
Early Exit for MessageType: An optimization was added to MessageType.with_context to return the current instance early if the collisions set has not changed, further reducing redundant processing.
Global Collisions as Frozenset: In api.py, naive.names is now converted to a frozenset (global_collisions) once and reused, improving efficiency when passed to multiple with_context calls.

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Code Review

This pull request introduces a caching mechanism to optimize with_context calls, which is a good idea for performance. However, the implementation has a few issues that need to be addressed: a critical bug in api.py that will cause a runtime error, and several issues with the caching implementation itself regarding type safety, potential cache corruption, and code duplication. My detailed comments point out these issues with suggestions for fixes.

gemini-code-assist · 2026-01-21T23:28:34Z

gapic/schema/api.py

-                        collisions=v.names,
-                        visited_messages=visited_messages,
+                        collisions=global_collisions,
+                        visited_messages=frozenset(v.names),


There's a type mismatch here. The visited_messages parameter in with_context expects a Set[wrappers.MessageType], but you are passing frozenset(v.names), which is a frozenset[str]. This will likely lead to a TypeError at runtime inside MessageType.with_context when set operations are performed. The original code passed an empty set of MessageType. To fix this, you should pass an empty set.

Suggested change

visited_messages=frozenset(v.names),

visited_messages=set(),

gemini-code-assist · 2026-01-21T23:28:34Z

gapic/schema/metadata.py

        return selector

-    def with_context(self, *, collisions: Set[str]) -> "Address":
+    def with_context(self, *, collisions: Set[str], context_cache: Optional[Dict[tuple, "MessageType"]] = None,) -> "Address":


The type hint for context_cache is incorrect. It's specified as Optional[Dict[tuple, "MessageType"]], but this method caches and returns an Address object. This same issue exists across all the modified with_context methods in this pull request (in both metadata.py and wrappers.py), where each method caches objects of its own class type. This can lead to type confusion and bugs.

A more accurate type hint would be Optional[Dict[tuple, Any]] to reflect that the cache holds various types. Note that this would require importing Any from typing on line 31.

Suggested change

def with_context(self, *, collisions: Set[str], context_cache: Optional[Dict[tuple, "MessageType"]] = None,) -> "Address":

def with_context(self, *, collisions: Set[str], context_cache: Optional[Dict[tuple, Any]] = None,) -> "Address":

gemini-code-assist · 2026-01-21T23:28:34Z

gapic/schema/metadata.py

        """
-        return (
+        context_cache = context_cache if context_cache is not None else {}
+        cache_key = (id(self), id(collisions))


Using id(collisions) as part of the cache key is unsafe because collisions is a mutable Set. If the set is modified elsewhere, its ID remains the same, but its contents change. This can lead to incorrect cache hits, as the logic of with_context depends on the contents of the collisions set. To make caching robust, the cache key should be based on the content of the set, for example by using a frozenset. This issue is present in all with_context methods that have been modified in this PR.

Suggested change

cache_key = (id(self), id(collisions))

cache_key = (id(self), frozenset(collisions))

gemini-code-assist · 2026-01-21T23:28:34Z

gapic/schema/metadata.py

+        context_cache = context_cache if context_cache is not None else {}
+        cache_key = (id(self), id(collisions))
+        if cache_key in context_cache:
+            return context_cache[cache_key]
+
+        updated_msg = (
            dataclasses.replace(self, collisions=collisions)
            if collisions and collisions != self.collisions
            else self
        )

+        context_cache[cache_key] = updated_msg
+        return updated_msg


The caching logic here is repeated in many with_context methods across metadata.py and wrappers.py. To improve maintainability and adhere to the DRY (Don't Repeat Yourself) principle, consider refactoring this logic into a reusable decorator. A decorator could encapsulate the caching mechanism, making the with_context methods cleaner and less prone to copy-paste errors.

product-auto-label bot added the size: m Pull request size is medium. label Jan 21, 2026

gemini-code-assist bot reviewed Jan 21, 2026

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optimize gapic

8e7e903

ohmayr force-pushed the cache-api-context branch from 68e453e to 8e7e903 Compare January 22, 2026 01:36

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optimize gapic #2531

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	def with_context(self, *, collisions: Set[str], context_cache: Optional[Dict[tuple, "MessageType"]] = None,) -> "Address":
	def with_context(self, *, collisions: Set[str], context_cache: Optional[Dict[tuple, Any]] = None,) -> "Address":

	cache_key = (id(self), id(collisions))
	cache_key = (id(self), frozenset(collisions))

optimize gapic #2531

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