feat: Add micro-benchmarks for writes comparing standard (regional) vs rapid (zonal) buckets. (#1707)

* Add performance microbenchmarking suite for Writes
* This compares Regional (Standard Storage) with Zonal (Rapid Storage)
buckets.
* Regional uses JSON wheres Zonal uses gRPC bidi

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: chandra-siri

tests/perf/microbenchmarks/README.md

@@ -15,10 +15,13 @@ pytest --benchmark-json=output.json -vv -s tests/perf/microbenchmarks/reads/test
 
 To run a single test, append `::` followed by the test name to the file path.
 
-Example:
+Examples:
 ```bash
 pytest --benchmark-json=output.json -vv -s tests/perf/microbenchmarks/reads/test_reads.py::test_downloads_single_proc_single_coro
 ```
+```bash
+pytest --benchmark-json=output.json -vv -s tests/perf/microbenchmarks/writes/test_writes.py::test_uploads_single_proc_single_coro
+```
 
 ## Configuration
 

tests/perf/microbenchmarks/conftest.py

@@ -26,6 +26,7 @@
     AsyncAppendableObjectWriter,
 )
 from google.cloud.storage._experimental.asyncio.async_grpc_client import AsyncGrpcClient
+from tests.perf.microbenchmarks.writes.parameters import WriteParameters
 
 _OBJECT_NAME_PREFIX = "micro-benchmark"
 
@@ -135,10 +136,16 @@ def _create_files(num_files, bucket_name, bucket_type, object_size, chunk_size=1
 @pytest.fixture
 def workload_params(request):
     params = request.param
-    files_names = _create_files(
-        params.num_files,
-        params.bucket_name,
-        params.bucket_type,
-        params.file_size_bytes,
-    )
+    if isinstance(params, WriteParameters):
+        files_names = [
+            f"{_OBJECT_NAME_PREFIX}-{uuid.uuid4().hex[:5]}"
+            for _ in range(params.num_files)
+        ]
+    else:
+        files_names = _create_files(
+            params.num_files,
+            params.bucket_name,
+            params.bucket_type,
+            params.file_size_bytes,
+        )
     return params, files_names

tests/perf/microbenchmarks/writes/__init__.py

@@ -0,0 +1,100 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agre