⚡️ Speed up method Item.get_transaction_event by 23%

[codeflash-ai]

📄 23% (0.23x) speedup for Item.get_transaction_event in sentry_sdk/envelope.py

⏱️ Runtime : 275 microseconds → 223 microseconds (best of 214 runs)

📝 Explanation and details

The optimization replaces a property access self.type with a direct dictionary lookup self.headers.get("type") and adds a type property for API compatibility.

Key changes:

• In get_transaction_event(), self.type is replaced with item_type = self.headers.get("type") to cache the lookup
• Added a @property type method that returns self.headers.get("type")

Why this is faster:
The original code accessed self.type, which triggers Python's attribute resolution mechanism. Since type isn't a direct instance attribute, Python searches the class hierarchy and potentially calls descriptors. The optimized version directly accesses the headers dictionary where the type is actually stored, avoiding the overhead of attribute resolution.

The cached lookup (item_type = ...) also ensures the dictionary is only accessed once per method call rather than potentially multiple times during the conditional evaluation.

Performance characteristics:
Based on the test results, this optimization provides consistent 20-30% speedups across all test cases, with particularly strong performance gains (30%+) for non-transaction types and edge cases. The optimization is most effective for workloads with frequent get_transaction_event() calls, which is common in monitoring/telemetry systems where envelope items are processed at high volume.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 1295 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	✅ 2 Passed
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

from typing import Any, Dict, Optional, Union

# imports
import pytest  # used for our unit tests
from sentry_sdk.envelope import Item


# Helper class to simulate payload references
class PayloadRef:
    def __init__(self, bytes: bytes):
        self.bytes = bytes
        # Try to decode as UTF-8 and parse as JSON if possible
        try:
            import json
            self.text = bytes.decode("utf-8")
            self.json = json.loads(self.text)
        except Exception:
            self.text = None
            self.json = None
        # Infer content type
        if self.json is not None:
            self.inferred_content_type = "application/json"
        else:
            self.inferred_content_type = "application/octet-stream"

    def __repr__(self):
        return f"<PayloadRef bytes={self.bytes!r} json={self.json!r}>"
from sentry_sdk.envelope import Item

# unit tests

# -----------------
# Basic Test Cases
# -----------------

def test_transaction_event_with_valid_json():
    # Test: Valid transaction type and valid JSON payload
    data = {"event_id": "123", "type": "transaction", "amount": 100}
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 883ns -> 677ns (30.4% faster)

def test_non_transaction_type_returns_none():
    # Test: Non-transaction type should return None even if payload is valid JSON
    data = {"event_id": "123", "type": "transaction", "amount": 100}
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="error")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 714ns -> 554ns (28.9% faster)

def test_transaction_type_with_invalid_json():
    # Test: Transaction type but payload is not valid JSON
    payload = b"not a json"
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 876ns -> 683ns (28.3% faster)

def test_transaction_type_with_str_payload():
    # Test: Transaction type with payload as string (valid JSON)
    data = {"foo": "bar", "baz": 42}
    import json
    payload = json.dumps(data)
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 841ns -> 653ns (28.8% faster)

def test_transaction_type_with_payloadref_direct():
    # Test: Transaction type with a direct PayloadRef instance
    data = {"x": 1}
    import json
    payload_ref = PayloadRef(json.dumps(data).encode("utf-8"))
    item = Item(payload_ref, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 943ns -> 724ns (30.2% faster)

# -----------------
# Edge Test Cases
# -----------------

def test_transaction_type_with_empty_payload():
    # Test: Empty payload should return None
    item = Item(b"", type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 825ns -> 656ns (25.8% faster)

def test_transaction_type_with_none_payload():
    # Test: None as payload (should raise)
    with pytest.raises(AttributeError):
        Item(None, type="transaction").get_transaction_event()

def test_transaction_type_with_non_utf8_bytes():
    # Test: Non-UTF8 bytes payload
    payload = b"\xff\xfe\xfd"  # Invalid UTF-8
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 900ns -> 727ns (23.8% faster)

def test_transaction_type_with_large_json_payload():
    # Test: Large but valid JSON payload
    data = {"numbers": list(range(1000))}
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 879ns -> 706ns (24.5% faster)

def test_transaction_type_with_headers_and_content_type_override():
    # Test: Content type in headers should be respected
    data = {"foo": "bar"}
    import json
    payload = json.dumps(data).encode("utf-8")
    headers = {"content_type": "application/custom"}
    item = Item(payload, headers=headers, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 841ns -> 686ns (22.6% faster)

def test_transaction_type_with_filename_and_other_headers():
    # Test: Filename and other headers are set
    data = {"foo": "bar"}
    import json
    payload = json.dumps(data).encode("utf-8")
    headers = {"data_category": "test"}
    item = Item(payload, headers=headers, type="transaction", filename="file.txt")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 855ns -> 687ns (24.5% faster)

def test_type_none_returns_none():
    # Test: Type is None, should return None
    data = {"foo": "bar"}
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type=None)
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 767ns -> 625ns (22.7% faster)

def test_transaction_type_with_json_array_payload():
    # Test: Payload is a JSON array (valid JSON)
    import json
    data = [{"a": 1}, {"b": 2}]
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 860ns -> 678ns (26.8% faster)

def test_transaction_type_with_json_null_payload():
    # Test: Payload is a JSON null
    payload = b"null"
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 829ns -> 675ns (22.8% faster)

def test_transaction_type_with_json_number_payload():
    # Test: Payload is a JSON number
    payload = b"12345"
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 807ns -> 634ns (27.3% faster)

def test_transaction_type_with_json_string_payload():
    # Test: Payload is a JSON string
    payload = b'"hello"'
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 749ns -> 601ns (24.6% faster)

# -----------------
# Large Scale Test Cases
# -----------------

def test_transaction_type_with_very_large_json_object():
    # Test: Very large JSON object (dict with 1000 keys)
    data = {str(i): i for i in range(1000)}
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 946ns -> 743ns (27.3% faster)

def test_transaction_type_with_very_large_json_array():
    # Test: Very large JSON array (1000 elements)
    data = list(range(1000))
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 849ns -> 696ns (22.0% faster)

def test_many_items_in_sequence():
    # Test: Creating and checking many Items in sequence for memory/performance
    import json
    for i in range(100):
        data = {"event_id": str(i), "type": "transaction", "amount": i}
        payload = json.dumps(data).encode("utf-8")
        item = Item(payload, type="transaction")
        codeflash_output = item.get_transaction_event(); result = codeflash_output # 38.3μs -> 30.2μs (26.8% faster)

def test_large_payload_with_non_transaction_type():
    # Test: Large payload but non-transaction type, should always return None
    data = {"numbers": list(range(1000))}
    import json
    payload = json.dumps(data).encode("utf-8")
    item = Item(payload, type="event")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 720ns -> 544ns (32.4% faster)

def test_large_payload_with_invalid_json():
    # Test: Large invalid JSON payload, should return None
    payload = b"[" + b"1," * 999 + b"]"
    item = Item(payload, type="transaction")
    # This is invalid JSON due to trailing comma
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 813ns -> 657ns (23.7% faster)
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
import json

# imports
import pytest  # used for our unit tests
from sentry_sdk.envelope import Item


# Helper class to simulate payload reference
class PayloadRef:
    def __init__(self, bytes=None, json=None):
        self.bytes = bytes
        self._json = json

    @property
    def inferred_content_type(self):
        # Infer content type based on bytes
        if self.bytes is None:
            return None
        try:
            decoded = self.bytes.decode("utf-8")
            json.loads(decoded)
            return "application/json"
        except Exception:
            return "application/octet-stream"

    @property
    def json(self):
        # Return the JSON object if possible
        if self._json is not None:
            return self._json
        if self.bytes is None:
            return None
        try:
            return json.loads(self.bytes.decode("utf-8"))
        except Exception:
            return None
from sentry_sdk.envelope import Item

# unit tests

# ----------------
# BASIC TEST CASES
# ----------------

def test_transaction_type_valid_json_payload():
    # Test with type "transaction" and valid JSON payload
    payload = {"event_id": "123", "type": "transaction"}
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 803ns -> 659ns (21.9% faster)

def test_transaction_type_bytes_payload():
    # Test with type "transaction" and valid JSON payload as bytes
    payload = {"event_id": "abc", "foo": 1}
    item = Item(payload=json.dumps(payload).encode("utf-8"), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 765ns -> 680ns (12.5% faster)

def test_transaction_type_payloadref_payload():
    # Test with type "transaction" and PayloadRef object
    payload = {"event_id": "xyz", "bar": 2}
    item = Item(payload=PayloadRef(bytes=json.dumps(payload).encode("utf-8")), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 6.79μs -> 6.47μs (4.88% faster)

def test_non_transaction_type_returns_none():
    # Test with type other than "transaction"
    payload = {"event_id": "123", "type": "transaction"}
    item = Item(payload=json.dumps(payload), type="event")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 740ns -> 549ns (34.8% faster)

def test_transaction_type_invalid_json_payload():
    # Test with type "transaction" and invalid JSON payload
    item = Item(payload=b"not a json", type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 784ns -> 640ns (22.5% faster)

def test_transaction_type_empty_payload():
    # Test with type "transaction" and empty payload
    item = Item(payload=b"", type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 823ns -> 608ns (35.4% faster)

# ----------------
# EDGE TEST CASES
# ----------------

def test_transaction_type_payload_is_none():
    # Test with type "transaction" and payload is None
    item = Item(payload=PayloadRef(bytes=None), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 1.22μs -> 1.04μs (17.6% faster)

def test_transaction_type_payload_json_is_none():
    # Test with type "transaction" and PayloadRef with json=None
    item = Item(payload=PayloadRef(bytes=b'{}', json=None), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 5.86μs -> 5.49μs (6.72% faster)

def test_transaction_type_payload_json_is_explicitly_none():
    # Test with type "transaction" and PayloadRef with bytes=None, json=None
    item = Item(payload=PayloadRef(bytes=None, json=None), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 1.17μs -> 902ns (29.2% faster)

def test_transaction_type_payload_str_with_unicode():
    # Test with type "transaction" and payload as unicode string
    payload = {"event_id": "üñîçødë", "type": "transaction"}
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 806ns -> 689ns (17.0% faster)

def test_transaction_type_payload_with_headers():
    # Test with type "transaction" and custom headers
    payload = {"event_id": "header", "type": "transaction"}
    headers = {"x-test": "yes"}
    item = Item(payload=json.dumps(payload), type="transaction", headers=headers)
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 855ns -> 663ns (29.0% faster)

def test_transaction_type_payload_with_filename_and_content_type():
    # Test with filename and explicit content_type
    payload = {"event_id": "file", "type": "transaction"}
    item = Item(payload=json.dumps(payload), type="transaction", filename="test.json", content_type="application/json")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 814ns -> 625ns (30.2% faster)

def test_transaction_type_payload_with_non_json_content_type():
    # Test with content_type set to something non-json
    payload = {"event_id": "file", "type": "transaction"}
    item = Item(payload=json.dumps(payload), type="transaction", content_type="text/plain")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 789ns -> 632ns (24.8% faster)

def test_transaction_type_payload_with_missing_type_field():
    # Test with type "transaction" but payload does not have "type" field
    payload = {"event_id": "no_type"}
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 820ns -> 659ns (24.4% faster)

def test_transaction_type_payload_is_empty_dict():
    # Test with type "transaction" and payload is empty dict
    payload = {}
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 765ns -> 629ns (21.6% faster)

def test_transaction_type_payload_is_list():
    # Test with type "transaction" and payload is a JSON list
    payload = [{"event_id": 1}, {"event_id": 2}]
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 797ns -> 637ns (25.1% faster)

def test_transaction_type_payload_is_json_null():
    # Test with type "transaction" and payload is JSON null
    item = Item(payload="null", type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 791ns -> 652ns (21.3% faster)

def test_transaction_type_payload_is_boolean_json():
    # Test with type "transaction" and payload is JSON boolean
    item = Item(payload="true", type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 807ns -> 620ns (30.2% faster)

def test_transaction_type_payload_is_number_json():
    # Test with type "transaction" and payload is JSON number
    item = Item(payload="42", type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 782ns -> 632ns (23.7% faster)

def test_transaction_type_payload_is_nested_json():
    # Test with type "transaction" and deeply nested JSON
    payload = {"a": {"b": {"c": {"d": [1,2,3]}}}}
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 788ns -> 666ns (18.3% faster)

def test_transaction_type_payload_with_extra_headers():
    # Test with type "transaction" and headers containing extra keys
    payload = {"event_id": "extra"}
    headers = {"foo": "bar", "baz": "qux"}
    item = Item(payload=json.dumps(payload), type="transaction", headers=headers)
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 823ns -> 629ns (30.8% faster)

def test_transaction_type_payload_with_header_overrides():
    # Test header override for content_type
    payload = {"event_id": "override"}
    headers = {"content_type": "text/plain"}
    item = Item(payload=json.dumps(payload), type="transaction", headers=headers, content_type="application/json")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 777ns -> 665ns (16.8% faster)

def test_transaction_type_payload_with_header_type_override():
    # Test header override for type
    payload = {"event_id": "override"}
    headers = {"type": "not_transaction"}
    item = Item(payload=json.dumps(payload), type="transaction", headers=headers)
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 774ns -> 657ns (17.8% faster)

# -------------------------
# LARGE SCALE TEST CASES
# -------------------------

def test_large_json_payload():
    # Test with a large JSON object (under 1000 elements)
    payload = {"event_id": "large", "numbers": list(range(1000))}
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 785ns -> 702ns (11.8% faster)

def test_large_list_json_payload():
    # Test with a large JSON list (under 1000 elements)
    payload = [{"id": i, "value": str(i)} for i in range(999)]
    item = Item(payload=json.dumps(payload), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 1.10μs -> 906ns (21.3% faster)

def test_many_items_performance():
    # Test performance with many Item instances (under 1000)
    payload = {"event_id": "bulk", "foo": "bar"}
    items = [Item(payload=json.dumps(payload), type="transaction") for _ in range(500)]
    for item in items:
        codeflash_output = item.get_transaction_event() # 185μs -> 149μs (23.7% faster)

def test_large_nested_json_payload():
    # Test with a deeply nested, large JSON object
    nested = curr = {}
    for i in range(100):
        curr["level"] = {}
        curr = curr["level"]
    curr["end"] = "done"
    item = Item(payload=json.dumps(nested), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 907ns -> 664ns (36.6% faster)

def test_large_payload_bytes():
    # Test with a large payload as bytes (under 1000 elements)
    payload = {"data": ["x" * 100 for _ in range(100)]}
    item = Item(payload=json.dumps(payload).encode("utf-8"), type="transaction")
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 825ns -> 653ns (26.3% faster)

def test_large_payload_with_headers():
    # Test with a large payload and many headers
    payload = {"event_id": "headers"}
    headers = {f"header_{i}": str(i) for i in range(200)}
    item = Item(payload=json.dumps(payload), type="transaction", headers=headers)
    codeflash_output = item.get_transaction_event(); result = codeflash_output # 806ns -> 708ns (13.8% faster)
    for i in range(200):
        pass
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
from sentry_sdk.envelope import Item

def test_Item_get_transaction_event():
    Item.get_transaction_event(Item('', headers={}, type='transaction', content_type=0, filename=0))

🔎 Concolic Coverage Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
codeflash_concolic_j2vbhl1v/tmpda5ev0zf/test_concolic_coverage.py::test_Item_get_transaction_event	904ns	709ns	27.5%✅

To edit these changes git checkout codeflash/optimize-Item.get_transaction_event-mg9u9rq8 and push.