⚡️ Speed up method GitHubSourceReader.can_read by 63%

[codeflash-ai]

📄 63% (0.63x) speedup for GitHubSourceReader.can_read in marimo/_cli/file_path.py

⏱️ Runtime : 65.4 milliseconds → 40.0 milliseconds (best of 34 runs)

📝 Explanation and details

The optimization achieves a 63% speedup by eliminating redundant URL parsing operations through two key changes:

1. Reduced URL parsing in is_github_src
The original code called urllib.parse.urlparse(url) twice - once for hostname and once for path. The optimized version parses the URL only once and reuses the parsed object, reducing parsing overhead by ~50% within this function.

2. Eliminated duplicate function calls in can_read
The original can_read method called is_github_src twice (once for ".py" and once for ".md"), resulting in 4 total URL parsing operations per call. The optimized version inlines the logic and performs URL parsing just once, then checks both extensions against the same parsed path.

Performance impact analysis:

• Best gains on invalid URLs: Tests with non-GitHub domains show 40-72% speedups because the optimization short-circuits after hostname validation
• Significant gains on valid GitHub URLs: 14-55% speedups depending on extension type
• Excellent scaling: Large-scale tests (1000+ URLs) show consistent 25-120% improvements, with invalid URL batches performing exceptionally well

The optimization is particularly effective for workloads that process many URLs since urllib.parse.urlparse() is computationally expensive, and eliminating 3 out of 4 parsing operations provides substantial performance benefits across all test scenarios.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	✅ 56 Passed
🌀 Generated Regression Tests	✅ 8072 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	✅ 2 Passed
📊 Tests Coverage	100.0%

⚙️ Existing Unit Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
_cli/test_file_path.py::test_github_source_reader	37.0μs	25.6μs	44.9%✅
_cli/test_file_path.py::test_github_source_reader_different_extensions	47.7μs	35.7μs	33.7%✅

🌀 Generated Regression Tests and Runtime

import re
import urllib.parse

# imports
import pytest  # used for our unit tests
from marimo._cli.file_path import GitHubSourceReader

# --- Unit tests for GitHubSourceReader.can_read ---

@pytest.fixture
def reader():
    """Fixture for GitHubSourceReader instance."""
    return GitHubSourceReader()

# 1. Basic Test Cases

def test_github_py_url(reader):
    """Basic: Valid github.com .py URL should be readable."""
    url = "https://github.com/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 20.4μs -> 17.8μs (14.4% faster)

def test_github_md_url(reader):
    """Basic: Valid github.com .md URL should be readable."""
    url = "https://github.com/user/repo/blob/main/README.md"
    codeflash_output = reader.can_read(url) # 26.3μs -> 17.0μs (55.0% faster)

def test_raw_github_py_url(reader):
    """Basic: Valid raw.githubusercontent.com .py URL should be readable."""
    url = "https://raw.githubusercontent.com/user/repo/main/script.py"
    codeflash_output = reader.can_read(url) # 20.8μs -> 18.3μs (13.8% faster)

def test_raw_github_md_url(reader):
    """Basic: Valid raw.githubusercontent.com .md URL should be readable."""
    url = "https://raw.githubusercontent.com/user/repo/main/README.md"
    codeflash_output = reader.can_read(url) # 28.0μs -> 18.1μs (54.7% faster)

def test_github_py_url_with_query(reader):
    """Basic: Valid github.com .py URL with query params should be readable."""
    url = "https://github.com/user/repo/blob/main/script.py?foo=bar"
    codeflash_output = reader.can_read(url) # 19.2μs -> 18.1μs (5.87% faster)

def test_github_md_url_with_fragment(reader):
    """Basic: Valid github.com .md URL with fragment should be readable."""
    url = "https://github.com/user/repo/blob/main/README.md#section"
    codeflash_output = reader.can_read(url) # 26.0μs -> 17.4μs (49.6% faster)

def test_github_url_other_extension(reader):
    """Basic: github.com URL with unsupported extension should not be readable."""
    url = "https://github.com/user/repo/blob/main/image.png"
    codeflash_output = reader.can_read(url) # 25.8μs -> 16.4μs (56.9% faster)

def test_raw_github_url_other_extension(reader):
    """Basic: raw.githubusercontent.com URL with unsupported extension should not be readable."""
    url = "https://raw.githubusercontent.com/user/repo/main/data.csv"
    codeflash_output = reader.can_read(url) # 27.7μs -> 18.1μs (53.4% faster)

def test_non_github_url(reader):
    """Basic: Non-GitHub URL should not be readable."""
    url = "https://gitlab.com/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 22.0μs -> 15.7μs (40.1% faster)

def test_non_url_string(reader):
    """Basic: Non-URL string should not be readable."""
    name = "script.py"
    codeflash_output = reader.can_read(name) # 1.75μs -> 1.19μs (46.8% faster)

def test_empty_string(reader):
    """Basic: Empty string should not be readable."""
    name = ""
    codeflash_output = reader.can_read(name) # 1.70μs -> 1.13μs (50.6% faster)

# 2. Edge Test Cases

def test_github_url_with_uppercase_extension(reader):
    """Edge: .PY and .MD extensions should not be readable (case-sensitive)."""
    url = "https://github.com/user/repo/blob/main/SCRIPT.PY"
    codeflash_output = reader.can_read(url) # 28.3μs -> 18.6μs (51.6% faster)
    url2 = "https://github.com/user/repo/blob/main/README.MD"
    codeflash_output = reader.can_read(url2) # 14.1μs -> 9.28μs (52.1% faster)

def test_github_url_with_multiple_extensions(reader):
    """Edge: .py.md should not be readable (must end with .py or .md only)."""
    url = "https://github.com/user/repo/blob/main/script.py.md"
    codeflash_output = reader.can_read(url) # 25.5μs -> 16.0μs (59.6% faster)
    url2 = "https://github.com/user/repo/blob/main/script.md.py"
    codeflash_output = reader.can_read(url2) # 9.04μs -> 9.04μs (0.000% faster)

def test_github_url_with_dot_in_path(reader):
    """Edge: Path with dots but valid extension should be readable."""
    url = "https://github.com/user/repo/blob/main/v1.0.script.py"
    codeflash_output = reader.can_read(url) # 18.5μs -> 15.5μs (19.6% faster)

def test_github_url_with_subdomain(reader):
    """Edge: Subdomain github URLs should not be readable."""
    url = "https://subdomain.github.com/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 24.3μs -> 16.9μs (44.3% faster)

def test_github_url_with_port(reader):
    """Edge: github.com URL with port should be readable."""
    url = "https://github.com:443/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 18.4μs -> 16.8μs (9.42% faster)

def test_github_url_with_auth(reader):
    """Edge: github.com URL with user:pass auth should be readable."""
    url = "https://user:[email protected]/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 18.5μs -> 16.0μs (15.7% faster)

def test_github_url_with_ipv6(reader):
    """Edge: github.com URL with IPv6 should not be readable (hostname mismatch)."""
    url = "https://[::1]/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 37.2μs -> 30.4μs (22.2% faster)

def test_github_url_with_invalid_protocol(reader):
    """Edge: github.com URL with invalid protocol should not be readable."""
    url = "ftp://github.com/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 18.2μs -> 16.6μs (9.66% faster)

def test_github_url_with_trailing_slash(reader):
    """Edge: github.com URL with trailing slash after extension should not be readable."""
    url = "https://github.com/user/repo/blob/main/script.py/"
    codeflash_output = reader.can_read(url) # 25.4μs -> 16.6μs (53.1% faster)

def test_github_url_with_query_and_fragment(reader):
    """Edge: github.com .md URL with query and fragment should be readable."""
    url = "https://github.com/user/repo/blob/main/README.md?foo=bar#section"
    codeflash_output = reader.can_read(url) # 26.0μs -> 17.5μs (48.5% faster)

def test_github_url_with_path_ending(reader):
    """Edge: github.com URL with extension in middle of path should not be readable."""
    url = "https://github.com/user/repo/blob/main.py/script"
    codeflash_output = reader.can_read(url) # 24.2μs -> 16.4μs (47.7% faster)

def test_github_url_with_no_extension(reader):
    """Edge: github.com URL with no extension should not be readable."""
    url = "https://github.com/user/repo/blob/main/README"
    codeflash_output = reader.can_read(url) # 24.7μs -> 16.2μs (52.1% faster)

def test_github_url_with_fake_extension(reader):
    """Edge: github.com URL with .py in query string but not in path should not be readable."""
    url = "https://github.com/user/repo/blob/main/README?file=script.py"
    codeflash_output = reader.can_read(url) # 26.6μs -> 17.4μs (52.7% faster)

def test_github_url_with_fragment_extension(reader):
    """Edge: github.com URL with .py in fragment should not be readable."""
    url = "https://github.com/user/repo/blob/main/README#script.py"
    codeflash_output = reader.can_read(url) # 26.3μs -> 17.2μs (53.0% faster)

def test_github_url_with_multiple_dots(reader):
    """Edge: github.com URL with multiple dots before extension should be readable."""
    url = "https://github.com/user/repo/blob/main/a.b.c.d.script.py"
    codeflash_output = reader.can_read(url) # 18.1μs -> 16.4μs (10.1% faster)

def test_github_url_with_long_path(reader):
    """Edge: github.com URL with long path but valid extension should be readable."""
    url = "https://github.com/user/repo/blob/main/" + "a/"*10 + "script.py"
    codeflash_output = reader.can_read(url) # 17.8μs -> 16.5μs (8.02% faster)

def test_github_url_with_unicode_path(reader):
    """Edge: github.com URL with unicode in path and valid extension should be readable."""
    url = "https://github.com/user/repo/blob/main/файл.py"
    codeflash_output = reader.can_read(url) # 21.2μs -> 18.9μs (12.2% faster)

def test_github_url_with_invalid_url(reader):
    """Edge: Malformed URL should not be readable."""
    url = "https://github.com/user/repo/blob/main/script.py::"
    codeflash_output = reader.can_read(url) # 25.7μs -> 17.2μs (49.0% faster)

def test_github_url_with_private_ip(reader):
    """Edge: URL with private IP should not be readable."""
    url = "https://10.0.0.1/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 20.8μs -> 14.9μs (38.9% faster)

def test_github_url_with_localhost(reader):
    """Edge: URL with localhost should not be readable."""
    url = "http://localhost/user/repo/blob/main/script.py"
    codeflash_output = reader.can_read(url) # 18.9μs -> 14.4μs (30.5% faster)

# 3. Large Scale Test Cases

def test_large_number_of_valid_urls(reader):
    """Large scale: 1000 valid github.com .py URLs should all be readable."""
    base = "https://github.com/user/repo/blob/main/script{}.py"
    for i in range(1000):
        url = base.format(i)
        codeflash_output = reader.can_read(url) # 6.80ms -> 5.37ms (26.6% faster)

def test_large_number_of_invalid_urls(reader):
    """Large scale: 1000 invalid URLs (wrong domain) should not be readable."""
    base = "https://gitlab.com/user/repo/blob/main/script{}.py"
    for i in range(1000):
        url = base.format(i)
        codeflash_output = reader.can_read(url) # 9.17ms -> 5.31ms (72.5% faster)

def test_large_number_of_mixed_urls(reader):
    """Large scale: 500 valid and 500 invalid URLs, alternating."""
    valid_base = "https://github.com/user/repo/blob/main/script{}.py"
    invalid_base = "https://bitbucket.org/user/repo/blob/main/script{}.py"
    for i in range(500):
        codeflash_output = reader.can_read(valid_base.format(i)) # 3.43ms -> 2.73ms (25.6% faster)
        codeflash_output = reader.can_read(invalid_base.format(i))

def test_large_number_of_raw_github_urls(reader):
    """Large scale: 1000 valid raw.githubusercontent.com .md URLs should all be readable."""
    base = "https://raw.githubusercontent.com/user/repo/main/README{}.md"
    for i in range(1000):
        url = base.format(i)
        codeflash_output = reader.can_read(url) # 13.9ms -> 6.39ms (117% faster)

def test_large_number_of_urls_with_long_paths(reader):
    """Large scale: 1000 valid github.com URLs with long paths should be readable."""
    for i in range(1000):
        url = "https://github.com/user/repo/blob/main/" + "a/"*5 + f"script{i}.py"
        codeflash_output = reader.can_read(url) # 6.90ms -> 5.47ms (26.1% faster)

def test_large_number_of_urls_with_unicode(reader):
    """Large scale: 1000 valid github.com URLs with unicode in path should be readable."""
    for i in range(1000):
        url = f"https://github.com/user/repo/blob/main/файл{i}.py"
        codeflash_output = reader.can_read(url) # 7.16ms -> 5.66ms (26.7% faster)

def test_large_number_of_urls_with_invalid_extensions(reader):
    """Large scale: 1000 github.com URLs with .txt extension should not be readable."""
    base = "https://github.com/user/repo/blob/main/file{}.txt"
    for i in range(1000):
        url = base.format(i)
        codeflash_output = reader.can_read(url) # 11.9ms -> 5.40ms (120% faster)

def test_large_number_of_non_url_strings(reader):
    """Large scale: 1000 non-URL strings should not be readable."""
    for i in range(1000):
        name = f"script{i}.py"
        codeflash_output = reader.can_read(name) # 552μs -> 303μs (81.8% faster)
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
import re
import urllib.parse

# imports
import pytest  # used for our unit tests
from marimo._cli.file_path import GitHubSourceReader


# can_read function, as a standalone function for testing
def can_read(name: str) -> bool:
    return is_github_src(name, ext=".py") or is_github_src(name, ext=".md")

# --- Unit Tests ---

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










































#------------------------------------------------
from marimo._cli.file_path import GitHubSourceReader

def test_GitHubSourceReader_can_read():
    GitHubSourceReader.can_read(GitHubSourceReader(), '')

🔎 Concolic Coverage Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
codeflash_concolic_4al8aq2a/tmponnxtvd0/test_concolic_coverage.py::test_GitHubSourceReader_can_read	1.87μs	1.35μs	37.9%✅

To edit these changes git checkout codeflash/optimize-GitHubSourceReader.can_read-mh5tpjqv and push.