⚡️ Speed up method AwsEnvironment.get_partition by 86%

[codeflash-ai]

📄 86% (0.86x) speedup for AwsEnvironment.get_partition in wandb/sdk/launch/environment/aws_environment.py

⏱️ Runtime : 2.21 seconds → 1.19 seconds (best of 60 runs)

📝 Explanation and details

The optimization reduces unnecessary thread executor overhead by eliminating redundant async wrapping for lightweight, non-blocking operations.

Key Changes:

1. Removed thread offloading for boto3.Session constructor - This is a lightweight object creation that doesn't perform network I/O, so calling it synchronously eliminates executor overhead
2. Removed thread offloading for session.client() creation - Client creation just builds a service client object without network calls, so it can run synchronously
3. Kept thread offloading only for client.get_caller_identity() - This is the actual network-bound AWS API call that benefits from being run in an executor thread

Why This Is Faster:
The original code wrapped every boto3 operation in event_loop_thread_exec, creating unnecessary async executor tasks. Each executor call adds overhead: thread pool scheduling, context switching, and future/task creation. The line profiler shows the most time was spent in client = await event_loop_thread_exec(session.client)("sts") (75.9% of total time), which was purely overhead since session.client() is non-blocking.

Performance Results:

• 86% runtime improvement (2.21s → 1.19s) by eliminating two expensive executor calls per operation
• 5.3% throughput improvement (24,339 → 25,620 ops/sec) showing better resource utilization
• The optimization is most effective for high-concurrency scenarios as shown in the test cases with 50-200 concurrent operations, where executor overhead compounds significantly

The optimization maintains identical functionality while dramatically reducing async executor overhead for operations that don't need it.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 845 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	86.7%

🌀 Generated Regression Tests and Runtime

import asyncio  # used to run async functions
import re

import pytest  # used for our unit tests
from wandb.sdk.launch.environment.aws_environment import AwsEnvironment


# Minimal LaunchError for raising
class LaunchError(Exception):
    pass

# Minimal botocore.exceptions.ClientError stub
class ClientError(Exception):
    pass

class BotocoreExceptions:
    ClientError = ClientError

class Botocore:
    exceptions = BotocoreExceptions()

botocore = Botocore()

# --- Test helpers ---

class DummySTSClient:
    def __init__(self, arn=None, raise_client_error=False):
        self._arn = arn
        self._raise_client_error = raise_client_error

    def get_caller_identity(self):
        if self._raise_client_error:
            raise botocore.exceptions.ClientError("Simulated ClientError")
        if self._arn is None:
            return {}
        return {"Arn": self._arn}

class DummySession:
    def __init__(self, arn=None, raise_client_error=False):
        self._arn = arn
        self._raise_client_error = raise_client_error

    def client(self, service_name):
        return DummySTSClient(arn=self._arn, raise_client_error=self._raise_client_error)

# --- Unit Tests ---

@pytest.mark.asyncio
async def test_get_partition_basic_aws_partition():
    """Basic: Should return 'aws' partition for standard AWS ARN."""
    env = AwsEnvironment("us-east-1", "key", "secret", "token")
    # Patch get_session to return DummySession with standard AWS ARN
    async def dummy_get_session():
        return DummySession(arn="arn:aws:iam::123456789012:user/test")
    env.get_session = dummy_get_session
    result = await env.get_partition()

@pytest.mark.asyncio
async def test_get_partition_basic_aws_cn_partition():
    """Basic: Should return 'aws-cn' partition for China AWS ARN."""
    env = AwsEnvironment("cn-north-1", "key", "secret", "token")
    async def dummy_get_session():
        return DummySession(arn="arn:aws-cn:iam::123456789012:user/test")
    env.get_session = dummy_get_session
    result = await env.get_partition()

@pytest.mark.asyncio
async def test_get_partition_basic_aws_us_gov_partition():
    """Basic: Should return 'aws-us-gov' partition for GovCloud AWS ARN."""
    env = AwsEnvironment("us-gov-west-1", "key", "secret", "token")
    async def dummy_get_session():
        return DummySession(arn="arn:aws-us-gov:iam::123456789012:user/test")
    env.get_session = dummy_get_session
    result = await env.get_partition()

@pytest.mark.asyncio



async def test_get_partition_concurrent_different_partitions():
    """Edge: Run multiple get_partition calls concurrently with different partitions."""
    env1 = AwsEnvironment("us-east-1", "key", "secret", "token")
    env2 = AwsEnvironment("cn-north-1", "key", "secret", "token")
    env3 = AwsEnvironment("us-gov-west-1", "key", "secret", "token")

    async def dummy_get_session_aws():
        return DummySession(arn="arn:aws:iam::123:user/test")
    async def dummy_get_session_cn():
        return DummySession(arn="arn:aws-cn:iam::123:user/test")
    async def dummy_get_session_gov():
        return DummySession(arn="arn:aws-us-gov:iam::123:user/test")

    env1.get_session = dummy_get_session_aws
    env2.get_session = dummy_get_session_cn
    env3.get_session = dummy_get_session_gov

    # Run all three concurrently
    results = await asyncio.gather(
        env1.get_partition(),
        env2.get_partition(),
        env3.get_partition(),
    )

@pytest.mark.asyncio
async def test_get_partition_concurrent_same_partition():
    """Edge: Run multiple get_partition calls concurrently with the same partition."""
    envs = []
    for _ in range(5):
        env = AwsEnvironment("us-east-1", "key", "secret", "token")
        async def dummy_get_session():
            return DummySession(arn="arn:aws:iam::123:user/test")
        env.get_session = dummy_get_session
        envs.append(env)
    results = await asyncio.gather(*(env.get_partition() for env in envs))

@pytest.mark.asyncio
async def test_get_partition_large_scale_concurrent_100():
    """Large Scale: Run 100 concurrent get_partition calls with valid ARNs."""
    envs = []
    for i in range(100):
        env = AwsEnvironment("us-east-1", "key", "secret", "token")
        # Alternate between aws and aws-cn partitions
        arn = "arn:aws:iam::123:user/test" if i % 2 == 0 else "arn:aws-cn:iam::123:user/test"
        async def make_dummy_get_session(arn=arn):
            return DummySession(arn=arn)
        env.get_session = make_dummy_get_session
        envs.append(env)
    results = await asyncio.gather(*(env.get_partition() for env in envs))
    # Check correct alternation
    for i, result in enumerate(results):
        expected = "aws" if i % 2 == 0 else "aws-cn"

@pytest.mark.asyncio
async def test_get_partition_large_scale_concurrent_mixed_errors():
    """Large Scale: Run 50 concurrent calls, half with errors, half valid."""
    envs = []
    for i in range(50):
        env = AwsEnvironment("us-east-1", "key", "secret", "token")
        if i % 2 == 0:
            # Valid
            async def dummy_get_session():
                return DummySession(arn="arn:aws:iam::123:user/test")
            env.get_session = dummy_get_session
        else:
            # Will raise ClientError
            async def dummy_get_session():
                return DummySession(arn="arn:aws:iam::123:user/test", raise_client_error=True)
            env.get_session = dummy_get_session
        envs.append(env)
    # Gather, catching exceptions
    results = await asyncio.gather(
        *(env.get_partition() for env in envs), return_exceptions=True
    )
    for i, result in enumerate(results):
        if i % 2 == 0:
            pass
        else:
            pass

@pytest.mark.asyncio


async def test_get_partition_throughput_high_load():
    """Throughput: Run 200 concurrent get_partition calls (high load, but < 1000)."""
    envs = []
    for _ in range(200):
        env = AwsEnvironment("us-east-1", "key", "secret", "token")
        async def dummy_get_session():
            return DummySession(arn="arn:aws:iam::123:user/test")
        env.get_session = dummy_get_session
        envs.append(env)
    results = await asyncio.gather(*(env.get_partition() for env in envs))
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
import asyncio  # used to run async functions
import re
import types

import pytest  # used for our unit tests
from wandb.sdk.launch.environment.aws_environment import AwsEnvironment


# Simulate LaunchError
class LaunchError(Exception):
    pass

# Simulate botocore.exceptions.ClientError
class BotocoreClientError(Exception):
    pass

# --- Test helpers ---

class DummySTSClient:
    """Dummy STS client to simulate get_caller_identity."""
    def __init__(self, arn=None, raise_exc=None):
        self._arn = arn
        self._raise_exc = raise_exc

    def get_caller_identity(self):
        if self._raise_exc:
            raise self._raise_exc
        if self._arn is None:
            return {}
        return {"Arn": self._arn}

class DummySession:
    """Dummy session to simulate boto3.Session().client()."""
    def __init__(self, arn=None, raise_exc=None):
        self._arn = arn
        self._raise_exc = raise_exc

    def client(self, service_name):
        return DummySTSClient(arn=self._arn, raise_exc=self._raise_exc)

# --- Test cases ---

@pytest.mark.asyncio

To edit these changes git checkout codeflash/optimize-AwsEnvironment.get_partition-mhe48zzn and push.