IO Performance comparison

ioperf_test.py

import mmap,time
def test_io():
    f = open('test.dat','r+b',0)
    start = time.time()
    i = 0
    while i < 1000000:
        f.read()
        i += 1
    end = time.time()
    print("test_io: %s ms" % ((end - start)*1000))

def test_io_all():
    f = open('test.dat','r+b',0)
    start = time.time()
    f.read(1000000)
    end = time.time()
    print("test_io_all: %s ms" % ((end - start)*1000))

def test_mmap():
    f = open('test.dat','r+b')
    m = mmap.mmap(f.fileno(),0)
    start = time.time()
    i = 0
    while i < 1000000:
        m.read_byte()
        i += 1
    end = time.time()
    print("test_mmap: %s ms" % ((end - start)*1000))

def test_mmap_all():
    f = open('test.dat','r+b')
    m = mmap.mmap(f.fileno(),0)
    start = time.time()
    m.read(1000000)
    end = time.time()
    print("test_mmap_all: %s ms" % ((end - start)*1000))

if __name__ == '__main__':
    test_io()
    test_io_all()
    test_mmap()
    test_mmap_all()

Result

test_io: 1734.96699333 ms
test_io_all: 0.364065170288 ms
test_mmap: 186.017990112 ms
test_mmap_all: 0.677824020386 ms