61 lines
1.4 KiB
Python
61 lines
1.4 KiB
Python
#!/usr/bin/env python3
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"""
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Scenario 1: The Optimized Version
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=================================
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This version calls the C implementation via ctypes.
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SETUP:
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gcc -O2 -fPIC -shared -o libprime.so prime.c
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EXERCISES:
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1. Compare: time python3 prime_fast.py
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2. Profile: py-spy record -o prime_fast.svg -- python3 prime_fast.py
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3. Compare the flamegraphs - what changed?
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"""
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import ctypes
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import sys
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import os
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# Load the shared library
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script_dir = os.path.dirname(os.path.abspath(__file__))
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lib_path = os.path.join(script_dir, "libprime.so")
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try:
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libprime = ctypes.CDLL(lib_path)
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except OSError as e:
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print(f"Error: Could not load {lib_path}")
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print("Please compile first: gcc -O2 -fPIC -shared -o libprime.so prime.c")
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sys.exit(1)
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# Define function signatures
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libprime.is_prime.argtypes = [ctypes.c_int64]
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libprime.is_prime.restype = ctypes.c_int
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libprime.count_primes.argtypes = [ctypes.c_int64]
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libprime.count_primes.restype = ctypes.c_int64
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def is_prime(n):
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"""Python wrapper for C is_prime."""
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return bool(libprime.is_prime(n))
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def count_primes(limit):
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"""Python wrapper for C count_primes."""
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return libprime.count_primes(limit)
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def main():
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limit = 1_000_000
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if len(sys.argv) > 1:
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limit = int(sys.argv[1])
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print(f"Counting primes up to {limit} (using C library)...")
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result = count_primes(limit)
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print(f"Found {result} primes")
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if __name__ == "__main__":
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main()
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