arista-eosext/PCAPDecoder decode benchmark

bench.py

#!/usr/bin/env python

import timeit
import locale
locale.setlocale(locale.LC_ALL, '') # Default user locale
#locale.setlocale(locale.LC_ALL, 'en_US') # ... or force it with this

runcnt=10000000

result = timeit.timeit(
    """(asicTime, utc, deviceId) = (
        int( '0x' + binascii.hexlify( v[ 0 : 8 ] ), 0 ),
        int( '0x' + binascii.hexlify( v[ 8 : 16 ] ), 0 ),
        int( '0x' + binascii.hexlify( v[ 40 : 42 ] ), 0 ),
    )""",
    setup="""import binascii; v='002863c2d9f3784e13cd081ccba1a7540000000000000000002863c2d9f60a8e000000000093fa0a006400340100'.decode('hex')""",
    number=runcnt
)
print locale.format_string("Using binascii, %d passes: %g seconds", (runcnt, result), grouping=True)

result = timeit.timeit(
    """(asicTime, utc, deviceId) = struct.unpack('>QQxxxxxxxxxxxxxxxxxxxxxxxxHxxxx', v)""",
    setup="""import struct; v='002863c2d9f3784e13cd081ccba1a7540000000000000000002863c2d9f60a8e000000000093fa0a006400340100'.decode('hex')""",
    number=runcnt
)
print locale.format_string("Using struct, %d passes: %g seconds", (runcnt, result), grouping=True)

bench.txt

$ ./bench.py 
Using binascii, 10,000,000 passes: 20.7187 seconds
Using struct, 10,000,000 passes: 2.18561 seconds

interactive example

>>> import binascii
>>> import struct
>>> v='002863c2d9f3784e13cd081ccba1a7540000000000000000002863c2d9f60a8e000000000093fa0a006400340100'.decode('hex')
>>> 
>>> (asicTime, utc, deviceId) = (
...         int( '0x' + binascii.hexlify( v[ 0 : 8 ] ), 0 ),
...         int( '0x' + binascii.hexlify( v[ 8 : 16 ] ), 0 ),
...         int( '0x' + binascii.hexlify( v[ 40 : 42 ] ), 0 ),
...     )
>>> (asicTime, utc, deviceId)
(11368687599843406, 1426805576714790740, 100)
>>> struct.unpack('>QQxxxxxxxxxxxxxxxxxxxxxxxxHxxxx', v)
(11368687599843406, 1426805576714790740, 100)